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Doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 1 A PHY/MAC Proposal for IEEE 802.22 WRAN Systems.

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Presentation on theme: "Doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 1 A PHY/MAC Proposal for IEEE 802.22 WRAN Systems."— Presentation transcript:

1 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 1 A PHY/MAC Proposal for IEEE 802.22 WRAN Systems IEEE P802.22 Wireless RANs Date: 2006-03-07 Authors: Notice: This document has been prepared to assist IEEE 802.22. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.22. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chairhttp://standards.ieee.org/guides/bylaws/sb-bylaws.pdf Carl R. StevensonCarl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at patcom@iee.org.patcom@iee.org > NameCompanyAddressPhoneEmail John BenkoFrance Telecom (FT)USAJohn.Benko@francetelecom.com Yoon Chae CheongSAITKorea+82-31-280-9501Yc.cheong@samsung.com Carlos CordeiroPhilipsUSA+1-914-945-6091Carlos.Cordeiro@philips.com Wen GaoThomson Inc.USA+1-609-987-7308wen.gao@thomson.net Chang-Joo KimETRIKorea+82-42-860-1230cjkim@etri.re.kr Hak-Sun KimSamsung Electro-mechanicsKorea+82-31-210-3500hszic.kim@samsung.com Stephen KuffnerMotorolaUSA+1-847-538-4158stephen.kuffner@motorola.com Joy LaskarGeorgia Institute of TechnologyUSA+1-404-894-5268joy.laskar@ece.gatech.edu Ying-Chang LiangInstitute for Infocomm ResearchSingapore+65-68748225ycliang@i2r.a-star.edu.sg

2 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 2 Co-Authors NameCompanyAddressPhoneemail Myung-Sun SongETRIKorea+82-42-860-5046mssong@etri.re.kr Soon-Ik JeonETRIKorea+82-42-860-5947sijeon@etri.re.kr Gwang-Zeen KoETRIKorea+82-42-860-4862gogogo@etri.re.kr Sung-Hyun HwangETRIKorea+82-42-860-1133shwang@etri.re.kr Bub-Joo KangETRIKorea+82-42-860-5446kbj64370@etri.re.kr Chung Gu KangETRIKorea+82-2-3290-3236ccgkang@korea.ac.kr KyungHi ChangETRIKorea+82-32-860-8422khchang@inha.ac.kr Yun Hee KimETRIKorea+82-31-201-3793yheekim@khu.ac.kr Moon Ho LeeETRIKorea+82-63-270-2463moonho@chonbuk.ac.kr HyungRae ParkETRIKorea+82-2-300-0143hrpark@mail.hangkong.ac.kr@mail.hangkong.ac.kr Martial BellecFrance TelecomFrance+33 2 99 12 48 06Martial.Bellec@francetelecom.com Denis CallonnecFrance TelecomFrance+33-4-76-764412Denis.Callonnec@francetelecom.com Luis EscobarFrance TelecomFrance+33-2-45-294622Luis.Escobar@francetelecom.com Francois MarxFrance TelecomFrance+33-4-76-764109Francois.Marx@francetelecom.com Patrick PiratFrance TelecomFrance+33-2-99-124806Ppirat.ext@francetelecom.com Kyutae Lim Georgia Institute of Technology USA+1-404-385-6008ktlim @ece.gatech.edu Youngsik Hur Georgia Institute of Technology USA+1-404-385-6008yshur @ece.gatech.edu

3 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 3 Co-Authors NameCompanyAddressPhoneEmail Wing Seng LeonI2RSingapore+65-68748225wsleon@i2r.a-star.edu.sg Yonghong ZengI2RSingapore+65-68748225yhzeng@i2r.a-star.edu.sg Changlong XuI2RSingapore+65-68748225clxu@i2r.a-star.edu.sg Ashok Kumar MarathI2RSingapore+65-68748225ashok@i2r.a-star.edu.sg Anh Tuan HoangI2RSingapore+65-68748225athoang@i2r.a-star.edu.sg Francois ChinI2RSingapore+65-68748225chinfrancois@i2r.a-star.edu.sg Zhongding LeiI2RSingapore+65-68748225leizd@i2r.a-star.edu.sg Peng-Yong KongI2RSingapore+65-68748225kongpy@i2r.a-star.edu.sg Chee Wei AngI2RSingapore+65-68748225angcw@i2r.a-star.edu.sg Yufei BlankenshipMotorolaUSA+1-847-576-1902Yufei.Blankenship@motorola.com Brian ClassonMotorolaUSA+1-847-576-5675Brian.Classon@motorola.com Fred VookMotorolaUSA+1-847-576-7939Fred.Vook@motorola.com Jeff ZhuangMotorolaUSA+1-847-538-5924Jeff.Zhuang@motorola.com Kevin BaumMotorolaUSA+1-847-576-1619Kevin.Baum@motorola.com Tim ThomasMotorolaUSA+1-847-538-2586T.Thomas@motorola.com David GrandblaiseMotorolaFrance+33 1 69 35 25 82David.Grandblaise@motorola.com

4 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 4 Co-Authors NameCompanyAddressPhoneemail Dagnachew BirruPhilipsUSA+1-914-945-6401Dagnachew.Birru@philips.com Kiran ChallapaliPhilipsUSA+1-914-945-6357Kiran.Challapali@philips.com Vasanth GaddamPhilipsUSA+1-914-945-6424Vasanth.Gaddam@philips.com Monisha GhoshPhilipsUSA+1-914-945-6415Monisha.Ghosh@philips.com Gene TurkenichPhilipsUSA+1-914-945-6370Gene.Turkenich@philips.com Duckdong HwangSAITKorea+82 31 280 9513duckdong.hwang@samsung.com Chung JaehakSAITKorea+82-32-860-8421jchung@inha.ac.kr Kim JaemyeongSAITKorea+82-32-860-8420jaekim@inha.ac.kr Ashish PandharipandeSAITKorea+82 010-6335-7784pashish@ieee.org Yoo SangjoSAITKorea+82-32-860-8304sjyoo@inha.ac.kr Jeong Suk Lee Samsung Electro- Mechanics Korea+82-31-210-3217js0305.lee@samsung.com Chang Ho Lee Samsung Electro- Mechanics Korea+82-31-210-3217changholee@samsung.com Wangmyong Woo Samsung Electro- Mechanics Korea+82-31-210-3217wmwoo@samsung.com David Mazzarese Samsung Electronics Co. Ltd. Korea+82 10 3279 5210 d.mazzarese@samsung.com

5 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 5 NameCompanyAddressPhoneemail Baowei Ji Samsung Telecom America USA+1-972-761-7167Baowei.ji@samsung.com Max MuterspaughThomson Inc.USA+1-317-587-3711Max.muterspaugh@thomson.net Hang LiuThomson Inc.USA+1-609-987-7335hang.liu@thomson.net Paul KnutsonThomson Inc.USA+1-609-987-7314paul.knutson@thomson.net Josh KoslovThomson Inc.USA+1-609-987-7337josh.koslov@thomson.net Co-Authors

6 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 6 Presentation Outline PHY Proposal Updates to the MAC Proposal Conclusions

7 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 7 Presentation Outline PHY Proposal Updates to the MAC Proposal Conclusions

8 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 8 Disclaimer The following set of slides represent the joint ETRI- France Telecom-I2R-Motorola-Philips-Samsung- Thomson PHY proposal This is in contrast to the MAC presentation, which is confined to describe only the updates

9 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 9 PHY Outline Overview/ Channel bonding Fractional Bandwidth Sub-Channelization, pilot insertion Error Correction Coding Multiple antenna Sensing

10 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 10 PHY Overview OFDMA both in uplink and downlink QPSK, 16-QAM, and 64-QAM, transformed-QPSK More than 30 sub channels per TV channel Contiguous channel bonding upto 3 TV channels (and beyond in a stack manner) Data rate range from 5Mbps to 70Mbps TDD, FDD

11 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 11 What We Have Proposed …. Adaptively scalable to spectrum availability Channel Bonding New frame structure for CR-enabled operation Enhanced PHY features - Adaptive sub-carrier allocation - Adaptive pilot insertion - Enhanced channel coding (LDPC, Turbo Code, SBTC) - Multiple antenna options Known and proven technology for broadband fixed/mobile wireless access (e.g., IEEE 802.16d/e – WiBro in Korea) Adaptive OFDMA

12 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 12 Advantages of Adaptive OFDMA Proposal Flexible Bandwidth Allocation –To use the partial bandwidth (1, 2, 3, 4, 5, 6, 7, 8 MHz) adaptively, depending on the channel state information (availability) –To fully utilize available bandwidth under a unified PHY framework Single Sampling Frequency –Sampling frequency is the same for all FFT modes. Constant Subcarrier Spacing –The subcarrier spacing is constant for all different channel bandwidths  Robust to the frequency offset

13 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 13 PHY (Baseband) Architecture

14 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 14 System Parameters: Proposed ParametersSpecificationRemark Frequency range54~862 MHz Service coverageTypical range 33 km, Bandwidth Mandatory: 6, 7, 8 MHz with channel bonding Optional: fraction BW Allows the fractional use of TV channel and channel bonding up to 3 TV channels Data rate Maximum: 70 Mbps Minimum: 4.5 Mbps Maximum of 23 Mbps for 6 MHz Spectral Efficiency Maximum: 3.94 bits/s/Hz Minimum: 0.75 bits/s/Hz Single TV channel BW of 6 MHz ModulationQPSK, 16QAM, 64QAM Transmit powerDefault 4W EIRP Multiple AccessAdaptive OFDMAPartial bandwidth allocation FFT Mode1024, 2048, 4096, 6144 Cyclic Prefix Mode1/4, 1/8, 1/16, 1/32 DuplexTDD or FDD Network topologyPoint-to-Multipoint Network

15 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 15 Channel Bonding: Motivation Spectrum occupancy measurements conducted by Shared Spectrum Company from January/2004 to August/2005 have shown that: “There is a significant amount of spectrum available in continuous blocks that are 1 MHz and wider ” “A dynamic spectrum sharing radio with a low agility, contiguous waveform will provide high utility” The November 18, 2005, study from Freepress and New America Foundation (entitled “Measuring the TV “White Space” Available for Unlicensed Use”) reveals that there exists a considerable amount of contiguous vacant TV channels (especially in the upper UHF band) More can be expected in other countries

16 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 16 Contiguous open spectrum available! Example: Jackson, Mississippi Source: “Measuring the TV ‘White Space’ Available for Unlicensed Wireless Broadband”, Nov 18, 2005, New America Foundation

17 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 17 Channel Bonding Make opportunistic and simultaneous use of multiple contiguous TV channels Benefits: –More data rate or range Initial link-budget analysis showed that single-TV channel can not support full data rate (e.g., 18Mbps) upto 30 Km range –Multi-path Diversity Small BW signal can have deep fade or flat fade Wider-bandwidth signal provides more frequency/multipath diversity –Interference Wider-band reduces the amount of interference

18 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 18 Channel Bonding: Capacity Aggregate TV channels to get more capacity – Shannon: C = B.log 2 (1+S/N) –capacity proportional to BW, but logarithmic with SNR or signal power If S/N is fixed, then capacity increases linearly with bandwidth If signal power is fixed, but bandwidth is increased –C = B.log 2 (1+S/(BNo)) –Capacity still increases as bandwidth is increased

19 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 19 Capacity of aggregated channels as a given signal power is spread over more channels

20 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 20 Preliminary Link Budget (LOS) Difficult to achieve 19Mbps over 30Km channel bonding needed to achieve long range

21 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 21 Channel Bonding Scheme 6, 12, 18 MHz channels Constant inter-carrier spacing Depends on availability Several receiver techniques to deal with flexible BW –Selectable analog filters –Up sampling digital filters

22 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 22 Channel bonding structure 6K FFT over 3 TV channels –2K per TV channel –Null out the outer carriers for 1 or 2 TV channels Fixed inter-carrier spacing –Several implementation possibilities 12 MHz 6 MHz 18 MHz

23 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 23 FFT Mode for WRAN Systems No. of Bonded Channel Basic FFT Mode 123 1K 2KNA 2K 4K6K 4K NA 6K NA

24 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 24 Superframe Structure

25 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 25 Preamble Superframe preamble –Over 1512 sub-carriers (every fourth or second non-zero), –5 MHz BW –Simply duplicate for additional TV channels –1 MHz gap between adjacent channels to relax filtering –2 symbol duration (1 more for data) Frame preamble: 1-3 TV channels –1728*N sub-carriers –Short preamble is optional (short) (long) Example structure

26 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 26 Preamble Preamble has the repetition pattern in the time domain: –Time synchronization –Frequency synchronization –Channel estimation –Cell ID detection Preamble is modulated using BPSK modulation.

27 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 27 Transformed QPSK/OFDMA Spread data over some sub- carriers (QPSK only) –Hadamard –Two-carrier –FFT based unitary pre-coding –Frequency offset DFT Depending on the receiver structure, this can –Increase capturing of multipath diversity –Increase resiliency to interferers Receiver structures –MMSE –Approximate ML

28 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 28 OFDMA Parameters/Single Channel (6MHz) Mode1K2K4K6K FFT Size1024204840966144 Bandwidth (k = 1, 2, …, 6) k MHz Sampling Factor8/7 No. of Used Subcarriers (including pilot, but not DC) 140 * k280 * k560 * k840 * k Sampling Frequency48/7 MHz Subcarrier Spacing6.696 kHz (***) 3.348 kHz1.674 kHz1.116 kHz Occupied Bandwidth6.696 kHz*140*k3.348 kHz*280*k1.674 kHz*560*k1.116 kHz*840*k Bandwidth Efficiency (*) 93~94 % FFT Time149.33 us298.66 us597.33 us896 us Cyclic Prefix Time (**) 37.33 us74.66 us149.33 us224 us OFDMA Symbol Time186.66 us373.33 us746.66 us1120 us (*) Bandwidth Efficiency = Subcarrier Spacing * (Number of Used Subcarriers + 1)/BW (**) It is assumed that cyclic prefix mode is 1/4. (***) Italics indicate an approximated value.

29 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 29 OFDMA Parameters/Single Channel (7MHz) Mode1K2K4K6K FFT Size1024204840966144 Bandwidth (k = 1, 2, …, 7) k MHz Sampling Factor8/7 No. of Used Subcarriers (including pilot, but not DC) 120 * k240 * k480 * k720 * k Sampling Frequency8 MHz Subcarrier Spacing7.812 kHz (***) 3.906 kHz1.953 kHz1.302 kHz Occupied Bandwidth7.812 kHz*120*k3.906 kHz*240*k1.953 kHz*480*k1.302 kHz*720*k Bandwidth Efficiency (*) 93~94 % FFT Time128 us256 us512 us768 us Cyclic Prefix Time (**) 32 us64 us128 us192 us OFDMA Symbol Time160 us320 us640 us960 us (*) Bandwidth Efficiency = Subcarrier Spacing * (Number of Used Subcarriers + 1)/BW (**) It is assumed that cyclic prefix mode is 1/4. (***) Italics indicate an approximated value.

30 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 30 OFDMA Parameters/Single Channel (8MHz) Mode1K2K4K6K FFT Size1024204840966144 Bandwidth (k = 1, 2, …, 8) k MHz Sampling Factor8/7 No. of Used Subcarriers (including pilot, but not DC) 105 * k210 * k420 * k630 * k Sampling Frequency64/7 MHz Subcarrier Spacing8.928 kHz (***) 4.464 kHz2.232 kHz1.488 kHz Occupied Bandwidth8.928 kHz*105*k4.464 kHz*210*k2.232 kHz*420*k1.488 kHz*630*k Bandwidth Efficiency (*) 93~94 % FFT Time112 us224 us448 us672 us Cyclic Prefix Time (**) 28 us56 us112 us168 us OFDMA Symbol Time140 us280 us560 us840 us (*) Bandwidth Efficiency = Subcarrier Spacing * (Number of Used Subcarriers + 1)/BW (**) It is assumed that cyclic prefix mode is 1/4. (***) Italics indicate an approximated value.

31 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 31 OFDMA parameters – channel bonding Parameter 3 TV bands2 TV bands1 TV bands 182124121416678 Inter-carrier spacing,  F (Hz) 334839064464334839064464334839064464 FFT period, T FFT (  s) 298.66256.00224.00298.66256.00224.00298.66256.00224.00 Total no. of sub-carriers, N FFT 614440962048 No. of guard sub-carriers, N G (L, DC, R) 1104 (552,1,551)736 (368,1,367)368 (184,1,183) No. of used sub-carriers, N T = N D + N P 504033601680 No. of data sub-carriers, N D 468031201560 No. of pilot sub-carriers, N P 360240120 Occupied bandwidth (MHz)16.88419.69822.51211.25613.13215.0085.6286.5667.504 Bandwidth Efficiency (%)93.8

32 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 32 Data Rate Bandwidth = 6 MHz FFT size = 2048 Cyclic prefix mode = 1/4 No pilot, no quiet periods assumed Code Rate Modulation 7/85/63/42/31/2 64QAM23.6322.5020.2518.0013.50 16QAM15.7515.0013.5012.009.00 QPSK7.887.506.756.004.50 Unit: Mbps Data Rate = No. of used subcarriers * code rate * no. of bits per modulation symbol/OFDM symbol time

33 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 33 Data Rate – Channel Bonding Bandwidth = 3*6 MHz FFT size = 2048 Cyclic prefix mode = 1/4 No pilot, no quiet periods assumed Code Rate Modulation 7/85/63/42/31/2 64QAM70.8967.5060.7554.0040.50 16QAM47.2545.0040.5036.0027.00 QPSK23.6422.5020.2518.0013.50 Unit: Mbps Data Rate = No. of used subcarriers * code rate * no. of bits per modulation symbol/OFDM symbol time * no. of channel bonded

34 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 34 Spectral Efficiency Code Rate Modulation 7/85/63/42/31/2 64QAM3.943.753.383.002.25 16QAM2.632.502.252.001.50 QPSK1.311.251.131.000.75 Unit : bps/Hz Spectral Efficiency = No. of used subcarrier*code rate*no. of bits per modulation symbol/OFDM symbol time/BW Single channel bandwidth = 6 MHz FFT size = 2048 Cyclic prefix mode = 1/4 No pilot, no quiet periods assumed The spectral efficiency is same for all fractional BW mode

35 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 35 Minimum Peak Throughput per CPE Code Rate Modulation 7/85/63/42/31/2 64QAM2.152.051.841.641.23 16QAM1.431.361.231.090.82 QPSK0.720.680.610.550.41 Unit : Mbps Min. Peak Throughput = No. of used subcarriers*code rate*no. of bits per modulation symbol/OFDM symbol time/no. of CPE’s Bandwidth = 6 MHz FFT size = 2048 Cyclic prefix mode = 1/4 No. of CPE’s = 512 CPE’s/oversubscription ratio 50 ~ 11 CPE’s No pilot, no quiet periods assumed

36 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 36 Fractional BW Usage

37 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 37 Fractional Bandwidth Usage If wireless microphones are in operation in TV channel, the WRAN systems may be clear the entire TV channel The number of used sub-carriers is proportional to the fractional bandwidth The fractional BW mode is identified by using a Preamble Example:

38 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 38 Fractional Bandwidth Mode Total Number of Fractional BW Mode To Detect : 36 12345678 1 2 3 4 5 6 7 8 Start position of fractional BW mode Fractional BW 1234567812345678 Fractional BW of 1 MHz Null Real BW of 8 MHz Start position of fractional BW mode Fractional BW mode zone Not applicable

39 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 39 Preamble Sequence for Fractional BW Usage (2K FFT) IndexFractional BWStart PositionPN Sequence (1680 bits) 010 0x251D994101EDA04D8BD0B8EA6FA20AE590C2CC199AB083C6AE61F091F2DD41D989EC164B1481D611BE9CE A0094AFE9DB56A4763F55B26E54EAB73ACD7D4BBA64C1421BC3EB9D67113A5FB9C529AADC9CAB1FB882905 601778659CDB69AFCBADDF8B42314A7985B5F87C20692309D350454FF9326481683FADAE4711DD0CC5DACEDF 7CD5DF1177D60EBA4DBE657F19F08189EFC6B5DE6C2CFDCD13195DE077586B8EE01E00B6468B10A53FAAC1D D846E2A01681980D444B6AD0D34C34EC9CFD9341507878EC9FBAE498F5A20614BDF3E4B22D 111 212 313 414 515 616 717 820 921 1022 1123 1224 1325 1426 ………… 3371 3472 3581 This sequence will be determined to minimize the PAPR

40 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 40 Flow Diagram of Fractional BW Mode Detection CPE Power On Fractional BW Mode Detection Using Preamble Decoding Superframe Control Header (SCH) Fractional BW Usage Mode Decoding Frame Synchronization & Channel Estimation Superframe Preamble Start Position Detection Signal Detection & Automatic Gain Control Channel Bonding Information

41 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 41 Simple Mode Detection Procedure (1) CPE Power On Search the Fractional BW Usage Mode (Correlation with All Preamble Sequence) Confirm the Fractional BW Usage Mode (Correlation with Previous Preamble Sequence) CorrelationOut>TH ? YES NO

42 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 42 Simple Mode Detection Procedure (2) Example: Transmitted SuperPreamble Index Correlated SuperPreamble Index Detected SuperPreamble Index 0 0 … 0 17 17 … 17 31 31 … 31 25 25 … All 0 … 0 0 17 … 17 17 31 … 31 31 25 … 0 0 … 0 17 17 … 17 31 31 … 31 25 25 … The Correlation Out is less than the Threshold Search all fractional mode again Fractional mode changed

43 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 43 Subchannelization

44 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 44 Symbol Structure For AMC/Diversity Subchannel The concept of AMC subchannel is same to that of 802.16-2004 The concept Diversity subchannel is same to the DL optional FUSC of 802.16-2004 Just the number of used subcarriers is different –802.16e: no. of subchanel=32, no. of subcarriers per subchannel=54 –802.22: no. of subchanel=30, no. of subcarriers per subchannel=56 So the basic permutation sequence will be slightly modified

45 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 45 Pilot Pattern Design (1) Pilot pattern is varied with channel condition Pilot pattern is controlled by adjusting the pilot symbol interval and pilot subcarrier interval A robust channel parameter estimation is required for reliable pilot design

46 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 46 Pilot Pattern Design (2) RMS delay spread of WRAN profile (Approximated) Pilot subcarrier interval can be determined as follows –Pilot subcarrier interval*subcarrier spacing < coherent bandwidth Multipath Profile Parameters ABCD Coherent Bandwidth (kHz) 90%28.9023.6118.633.38 50%289.02236.13186.3933.80 Pilot Subcarrier Interval 90%8.637.055.561.00 50%86.3270.5255.6710.09 1) We assume that the BW is 6 MHz and FFT mode is 2K. 2) 90% coherent BW=1/(50*rms delay spread), 50% coherent BW=1/(5*rms delay spread) Multipath ProfileABCD RMS Delay Spread692 ns847 ns1073 ns5917 ns (*) (*) We assume that the 6-th path has the excess delay of 60 ns and relative amplitude of -10 dB

47 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 47 Pilot Pattern Design (3) Coherent Time –1/f m, where, f m is the maximum doppler shift Pilot symbol interval can be determined as follows –Pilot symbol interval*OFDMA symbol time < coherent time Multipath Profile Parameters ABCD Maximum Doppler Shift (Hz)2.5 Coherent Time (sec)0.4 Pilot Symbol Interval1071.4 Here, we assume that the BW is 6 MHz, FFT mode is 2K, and GI mode is 1/4.

48 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 48 Pilot Pattern For AMC Subchannel Typical BIN structure –Set of 14 contiguous subcarriers within an OFDMA symbol AMC subchannel consists of 4 contiguous bins 12 Data Subcarriers 2 Pilot Subcarriers

49 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 49 Pilot Pattern For Diversity Subchannel All the pilot subcarriers are allocated first And then the remaining subcarriers are used exclusively for data transmission Number of used subcarriers are divided into 14 contiguous subcarriers in which two pilot subcarriers are allocated The position of the pilot subcarriers in 14 contiguous subcarriers varies according to the index of OFDMA symbol which contains the subcarriers Pilot subcarrier index: –k : pilot subcarrier index, 0,…,239 for 2K mode –m : [symbol index] mod 3

50 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 50 Advanced Channel Coding

51 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 51 Channel Coding Coding Scheme –Mandatory: Convolutional Code -> similar to 802.16 –Optional: Duo Binary Turbo Code LDPC Code (IEEE 802.16e LDPC) New Shortened block turbo code New –Optional advanced codes currently undergoing cross-simulations Will compare results and select best optional code(s) Selected Code Rates –R = 1/2, 2/3, 3/4, 5/6

52 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 52 Duo-Binary Turbo-Code Summary Excellent performance for wide range of blocks –Have optimized parameters for blocks from 6 bytes to 240 bytes Highly flexible scheme –Same encoder/decoder for all blocksizes/coding rates Reasonable complexity –~35% decrease in complexity/decoded bit compared to Binary TC. Mature Technology Code Reuse/ Already in following standards –IEEE 802.16 / WiMAX; HomePlug, DVB-RCS, DVB-RCT, ETSI HIPERMAN

53 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 53 Low-Density Parity-Check Codes Motivation for LDPC –Near capacity performance –High-throughput low-complexity implementation –Code reuse between 802 specifications Features of IEEE 802.16e LDPC codes –Compact representation of code matrices –Simplified structured encoder/decoder architecture across all code rates –Low-complexity differential-style encoding –Enhanced Layered Decoding to reduce the number of iterations –Special design feature in rate 1/2, 2/3 code provides further throughput doubling in layered decoding

54 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 54 LDPC Code Reuse Within 802 LDPC codes adopted in DVB-S2, 802.16e, 802.11n IEEE 802.16 –Initial WiMax profile includes CC and CTC, Chase Combining HARQ for CTC –Future WiMAX profiles likely to include… CTC with incremental redundancy (IR) HARQ –IR may add little value for fixed access LDPC with Chase Combining –Missed first profile due to time-to-market considerations IEEE 802.11n –IEEE 802.16e-style LDPC codec adopted as the only advanced channel coding scheme in January 2006 joint proposal Selecting LDPC for 802.22 would lead to additional reuse to/from indoor antenna 802.22 radio 802.11n radio Common baseband elements to/from rooftop antenna ethernet

55 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 55 Shortened Block Turbo Code (SBTC) Turbo product code (TPC) is an advanced coding option in 802.16 STBC is an improved form of TPC –SBTC has lower decoding complexity than TPC without performance loss Component code –Extended Hamming code Native code: (16,11), (32,26) and (64,57) Other code rate through shortening –Parity check code (8,7) and (16,15)

56 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 56 Parity Check Matrices for Hamming Codes N’ = 15 K’ = 11 N’ = 31 K’ = 26 N’ = 63 K’ = 57 Special parity check matrix design simplifies the decoding complexity. The syndrome value gives the error position, thus, look-up table is not needed.

57 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 57 Multiple Antennae Options

58 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 58 Multiple Antenna Options –Equal Gain Transmit Beamforming Using Codebooks. –Downlink Closed Loop SDMA. –Adaptive Beam-Forming Techniques. –Space Time Block Coding (STBC). –Combined Diversity/Spatial multiplexing/Delay Management. –Uplink “Virtual” SDMA MIMO. Multiple antennae techniques offer various advantages in various scenarios, including inherent benefits for the protection of incumbents. We are studying the following options. Final decisions on which ones are included will be based on performance and complexity.

59 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 59 Equal Gain Transmit Beamforming When multiple antennae are used for transmission, it is very important to have equal gain transmissions from each antenna, especially when used with OFDM. Eigen-beamforming, when used in an asymmetrical situation (N T > N R ), DOES NOT guarantee equal power. Single-stream or multiple stream transmission is proposed

60 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 60 Quantized Equal Gain Beamformer For Single Stream N T transmit antennae and N R receive antennae (N R could be 1). Objective: find quantized beamformer Q (N T X 1). Method: –All entries of Q are restricted to be –First entry is fixed at 1+ j –Q is picked to maximize –No. of bits required to specify Q: 2*(N T -1) per frequency bin. –If p consecutive frequencies are grouped, Q is picked to maximize –e.g: 2x1 beamformer, grouping 4 tones over 64 tones bandwidth would require only 4 bytes of feedback, with ~ 1dB degradation. Multiple streams: find multiple beamformers of that form for the simultaneous transmission of multiple streams to 1 user

61 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 61 Quantized Equal Gain Beamformer Performance Summary Performance summary was presented in January 2006 [doc.: IEEE 802.22- 06/0005r1] Very simple and efficient codebook based beamforming, ensuring equal gain transmissions. About 6 –7dB downlink gain with 2 transmit antennae. About 11-12dB downlink gain with 4 transmit antennae. Similar gains on uplink, with receive-diversity at base-station. Gains can be realized with about 4 bytes of feedback per user for 2 transmit antennae and 12 bytes per user for 4 transmit antennae. CPE could have more receive antenna than transmit antennae, for added performance, without changing the feedback requirements.

62 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 62 Downlink Closed-Loop SDMA (CL-SDMA) Linear processing with downlink channel sounding Throughput performance was presented in January 2006 [doc.: IEEE 802.22- 06/0016r1] Very large throughput can be achieved by the use of reliable channel state information at the transmitter in slowly fading channels, to allow for coordinated beamforming between the transmitter and the receivers Practical implementation: – In FDD or TDD: CL-SDMA Mode 1 (2 base station antennas) No channel reciprocity requirement: finite-rate quantized feeedback – In TDD: CL-SDMA Mode 2 (2 or more base station antennas) Requires channel reciprocity: direct uplink sounding Use on adjacent permutation subcarriers with multiuser diversity

63 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 63 CL SDMA Overview The Base Station has N transmit antennas, and uses N beamforming vectors M 1 … M N CPEs have N or more receive antennas, and use beamforming vectors W 1, W 2 … W N CL SDMA Mode 1 is only applicable with N = 2 transmit antennas.

64 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 64 Base Station Transmitter and CPE Receiver Structures Receiver or user k

65 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 65 Adaptive Beam-Forming Adaptive beam-forming (ABF) for 802.22 systems: –Mitigate co-channel interference (CCI) inherent to OFDMA systems –Since all CPEs are fixed at known locations, their directions-of- arrival (DOAs) may easily be obtained at the BS. –Large cell in 802.22 networks also makes beam-forming problem simple from 2D to 1D problem: easy DOA estimation. –With the transmit and/or receive diversity, adaptive beam-forming may significantly increase the cell radius. More efficient than fixed-beam array

66 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 66 Adaptive Beam-Forming Algorithms DOA Based Sample Matrix Inversion (SMI) Algorithm where is the steering vector for incident angle  and is the estimated interference-plus-noise covariance matrix. Reference Signal Based SMI Algorithm where is the correlation vector and is the estimated covariance matrix. –Reference signal is required!

67 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 67 Adaptive Beam-Forming Performance Summary Performance summary was presented in January 2006 [doc.: IEEE 802.22-06/0005r1] Efficient CCI cancellation by simple adaptive beam-forming algorithms In uplink, the reference signal method seems more effective due to –Simplicity in implementation –Robustness to calibration errors due to self-healing nature –However, in case of a very large delay spread, the DOA based approach seems preferable. –Selective usage according to environments may be necessary. In downlink, the DOA based adaptive beam-forming seems more desirable. –Robustness to calibration errors in downlink

68 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 68 Figure. Block diagram of an STBC-OFDM system General STBC

69 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 69 STBC Performance Summary Performance summary was presented in January 2006 [doc.: IEEE 802.22-06/0005r1] 2K FFT OFDMA, 2 OFDM symbols preamble, and channel estimation –Partitioned MMSE estimation performed by using the preamble –SNR in MMSE: 20dB –RMS delay parameter in MMSE: 9  s About 3 –7dB downlink gain for  =0.7, when employing (2 x 1) STBC scheme. Additional ~2.5dB gain when employing (2 x 1) closed loop transmit diversity. Even in a highly correlated case, for example  =0.9, the performance improvement is rather significant.

70 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 70 Full Diversity Full Rate Scheme While Space-Time Coding (STC) aims for transmit diversity gain, Spatial Multiplexing (SM) increases the throughput in MIMO channels. Full Diversity Full Rate (FDFR) schemes strike both the diversity and multiplexing at the same time. In FDFR, complexity at the receiver is much higher than SM. We propose a scheme, which facilitates successive interference cancellation at the receiver with slight loss in rate. Thus, the proposed scheme is FD but almost FR.

71 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 71 Basic Transmit Beamforming (BTB) In DL, beamformer only directs transmission to the path/cluster with the strongest gain per user. Other directions are suppressed – reducing overall delay Frequency domain beamforming for each user (subchannel) – different directions

72 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 72 Transmit Beamforming with Diversity/Spatial Multiplexing In DL, beamformers direct transmission several pathss/cluster Uncorrelated eigen-channels may be used for diversity transmission (CDD) or spatial multiplexing.

73 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 73 Beamforming with Channel Delay Management By adjusting timings D1 and D2, the overall delay of the channel can be changed. Reflector 1 Or repeater Reflector 2 Or repeater CPE Rich local scatters Beam 1 Beam 2 Delay 1 T 1 = τ 1 + D 1 Delay 2 T 2 = τ 2 + D 2 Overall Delay |T1-T2| +δ Pre-alignment & beamforming Stream 1 Stream 2 When the overall channel delay exceeds the cyclic prefix period, spatial resolution of multipaths in the angular domain allows to alleviate the inter-block interference.

74 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 74 Uplink SDMA (formerly Virtual MIMO) Uplink Multiple Antennas at BS and single antenna at each CPE Multiple CPEs share the same physical channel Spectrum efficiency increase linearly with CPE number if the CPE number is less than the number of BS antennas CPE 1 CPE 2 Base

75 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 75 IEEE 802.16e Uplink Channel Sounding Presented in January 2006: 22-06-0013-00-0000_Uplink_Channel_Sounding.ppt ULCS is a means of providing channel response information to the BS on an as-needed basis –CPE transmits sounding waveform on the UL to enable the BS to measure the channel response –Intended for TDD systems where UL&DL RF reciprocity can be leveraged ULCS enables Closed-Loop Transmit Antenna Array Techniques on the DL in TDD: –Baseband digital transmit beamforming –Transmit Spatial Division Multiple Access (SDMA) –Closed-loop Multiple Input Multiple Output (MIMO) ULCS provides an easier and better-performing alternative to other 802.16e Closed-Loop techniques with minimal added complexity to the CPE –Lower channel measurement delay –Better frequency-response tracking Future-Proof: Transmit array algorithms can be upgraded at the BS with no impact on CPE –Technique is independent of the number of BS antennas Handles asymmetric bandwidth occupancy of UL&DL transmissions

76 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 76 Multiple antennas on-going work A spatial channel model for the WRAN is currently under development by the joint proposers. Supporting features, such as uplink channel sounding, specific preamble design, MAC messages. Performance evaluation and selection of the proposed schemes.

77 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 77 Spectrum Sensing

78 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 78 Spectrum Sensing : Fact Spectrum sensing should be accurate enough to protect incumbent users Spectrum sensing should be fast enough to support the sensing protocol in MAC Spectrum sensing block should be able to be implemented by reasonable cost/resources “Spectrum sensing technology” is implementation technology. There is no single sensing technology can meet all the sensing requirement.

79 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 79 Spectrum Sensing : What we proposed We proposed a “sensing system architecture”, not an individual sensing technology, which we believe is the most efficient way to support MAC while sustain accuracy. Within this system architecture, multiple sensing technologies can be chosen to meet the sensing requirements (time, sensitivity) by the manufacturer We’ve been trying to include various sensing technologies for primary user group to feel comfortable on WRAN

80 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 80 Sensing Receiver Architecture MAC Fine/Feature RFE Energy Detection Omni Antenna Control

81 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 81 Spectrum Sensing Strategy Energy Detection for wide band (Analog, RSSI, MRSS, FFT…) Begin Sensing Fine/Feature Detection for single channel End Sensing occupied? Y N MAC (Select single channel) FFTCSFD Field Sync Optimum Radiometer Multi-cycle Detector AAC Spectral Correlation Spectrum Usage Database (BS) ATSC Segment Sync

82 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 82 List of sensing techniques included in the proposal Energy detection –Analog integrator –MRSS (Samsung/GT) –RSSI (Philips) –FFT Fine/Feature Detection –Cyclo-Stationary Feature Detection (Samsung) –Field-sync detection (Philips) –ATSC Segment Sync (Thomson) –FFT based (Philips and Huawei) –Optimum radiometer (France Telecom) –Multi-cycle detector (France Telecom) –Analog Auto-Correlation (Samsung/GT) –Spectral correlation (Huawei)

83 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 83 Spectrum Sensing : What we will do Each of the sensing technology will be rigorously evaluated by the procedure to be defined. Individual sensing technologies that pass the evaluation process shall be included the draft as an optional. Our proposal is open to new innovative sensing technology.

84 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 84 Backup Slides

85 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 85 Equal Gain Beamformer For Multiple Streams Let received vector be: –N T : No. of transmit antennae. –N R : No. of receive antennae (assumed here to be = no of streams) –H is the channel matrix (N R X N T ), –Q is the beamforming matrix (N T X N R ). –x is the data vector (N R X 1), Transmitted vector: Equal-gain constraint implies that each row of Q has the same power. Let H = USV H be the SVD of H. Then, if N T = N R, and Q = V, we get equal gain beamforming because V is an orthonormal matrix. If N T > N R, and Q = V(:, 1:N R ), then each row of Q does not have the same power => unequal gains.

86 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 86 Quantized Equal-Gain Beamformer Simulation Scenario 2K FFT, 64 tones per user, all tones used for data transmission. ¼ cyclic prefix. Subchannelization: 16 groups of 4 tones, equally spaced over 6 MHz bandwidth. Each packet simulated had a randomly generated subcarrier set. Channel: 2  sec RMS delay spread (total impulse response spread = 20  sec), exponential Rayleigh fading, uncorrelated channels from each antenna. 1000 byte packets, each packet goes through a different channel realization, simulation run until 100 packet errors are accumulated.

87 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 87 Quantized Equal-Gain Beamformer Performance

88 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 88 CL SDMA Flowchart CSI = channel state information CQI = channel quality indicator

89 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 89 Performance of downlink closed-loop SDMA with correlated fading at the transmitter 3GPP LTE suburban-macro small-scale fading channel model (mean CINR = 7.5 dB)

90 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 90 Adaptive Beam-Forming (2) Adaptive array vs. Fixed-beam array –More Efficient CCI Suppression: Adaptive array system steers the main beam to the direction of a desired signal, while steering nulls to the directions of undesired signals. Figure. Adaptive array vs. fixed-beam array

91 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 91 ABF Performance Evaluation Antenna Array –Array type: Linear equi-spaced array with half wavelength spacing consisting of 8 antenna elements. –Root-MUSIC is used to estimate the DOAs of incident signals. –All incident signals are assumed to have zero elevation angle. Angular Spread –Laplacian model –All clusters are assumed to have the angular spread of 0.3 o. Others –No. of OFDM symbols for reverse link preamble is 1. –No. of sub-carriers assigned to users is 256. –No. of sub-carriers per sub-band is 16 for reference signal method. –No channel coding employed

92 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 92 Channel Parameters for ABF Simulation (1)

93 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 93 Channel Parameters for ABF Simulation (2)

94 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 94 Figure. Comparison of BER performance for reverse link (INR = 25dB, interference DOAs =(20 o, 30 o ), relative amplitude = (0dB, -3dB) ) Performance Evaluation : ABF Algorithms (1)

95 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 95 Figure. Average output SINR vs. azimuth difference for reverse link ( Profile A, SNR = 15dB, INR = 25dB, relative amplitude = (0dB, -3dB) ) Performance Evaluation : ABF Algorithms (2) Perfect interference cancellation : Output SINR = 24dB

96 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 96 Figure. Channel mismatch effect for reverse link ( Profile A, INR = 25dB, interference DOAs = (20 o, 30 o ), relative amplitude = (0dB, -3dB) ) Performance Evaluation : ABF Algorithms (3) Error distribution: truncated Gaussian Ref. signal method: insensitive due to self-healing nature DOA based method: relatively insensitive

97 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 97 Figure. Effect of channel mismatch for forward link ( Profile A, INR = 25dB, interference DOAs = (20 o, 30 o ), relative amplitude = (0dB, -3dB) ) Performance Evaluation : ABF Algorithms (4) Error distribution: truncated Gaussian Ref. signal method: extremely sensitive DOA based method: relatively insensitive

98 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 98 Figure. BER performance of Alamouti’s scheme in 802.22 environments (QPSK, degree of correlation  = 0.7) Performance gain: 3.7dB ~ 7.5dB at 10 -2 ~ 10 -3 BER Performance Evaluation : STBC (1)

99 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 99 Figure. BER performance of Alamouti’s scheme in 802.22 environments (16QAM, degree of correlation  = 0.7) Performance Evaluation : STBC (2) Performance gain: 3.4dB ~ 7.0dB at 10 -2 ~ 10 -3 BER

100 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 100 Figure. BER performance of Alamouti’s scheme in 802.22 environments (64QAM, degree of correlation  = 0.7) Performance Evaluation : STBC (3) Performance gain: 3.1dB ~ 6.0dB at 10 -2 ~ 10 -3 BER

101 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 101 Figure. BER performance vs. degree of correlation in 802.22 environments (Profile A, QPSK) Performance Evaluation : STBC (4)

102 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 102 Degree of Correlation vs. Antenna Separation Figure. Degree of correlation vs. antenna separation for various angular spreads (Laplacian model, zero nominal azimuth angle)

103 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 103 FDFR The combination of pre-coder and the delay elements makes the error matrices full rank.  FD. The loss by the tail edges becomes negligible as the block size increases. The interference from the previous vectors are subtracted while that from the later vectors are suppressed. The symbols within a vector are jointly decoded via ML, sphere decoder or any types of linear decoder.

104 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 104 Presentation Outline PHY Proposal Updates to the MAC Proposal Conclusions

105 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 105 Disclaimer The following set of slides are restricted to describe only the updates to the MAC proposal described in documents 22-06-0003-01-0000 and 22-06-0005-01-0000 (presented in January/2006) The following updates together with documents 22-06- 0003-02-0000 and 22-06-0005-02-0000 represent the joint ETRI-France Telecom-I2R-Motorola-Philips- Samsung-Thomson MAC proposal

106 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 106 MAC Presentation Outline MAC Protocol –MAC layer data communication Support for Adaptive Antenna System (AAS) Explicit outband signalling for hidden incumbent detection Channel switch procedure –Coexistence Opportunistic in-band sensing Credit tokens based rental protocol for inter-BS dynamic resource sharing Enhanced measurement and channel management capabilities –Clarifications Frequency hopping Support for Single Channel CPEs Quiet period management for sensing Performance Evaluation –Synchronization of overlapping BSs –CBP

107 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 107 MAC Presentation Outline MAC Protocol –MAC layer data communication Support for Adaptive Antenna System (AAS) Explicit outband signalling for hidden incumbent detection Channel switch procedure –Coexistence Opportunistic in-band sensing Credit tokens based rental protocol for inter-BS dynamic resource sharing Enhanced measurement and channel management capabilities –Clarifications Frequency hopping Support for Single Channel CPEs Quiet period management for sensing Performance Evaluation –Synchronization of overlapping BSs –CBP

108 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 108 Support for Adaptive Antenna System (AAS) Optional mode MAC takes advantage of the increased capacity and range offered by AAS –Similar to 802.16e Frame structure simultaneously support AAS and non-AAS traffic

109 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 109 Support for Adaptive Antenna System (AAS) For AAS downlink synchronization, a CPE utilizes the broadcast preamble For network entry and initialization, two options are possible: –CPE receives enough energy from the broadcast channel that allows it to decode control information (e.g., UCD/DCD and maps) Hence, proceeds with network entry and initialization –Otherwise, BS shall dedicate a fixed and pre-defined portion of the superframe structure as initial ranging contention slots Sufficient slots are used by the CPE as to allow the BS enough time to beamform towards the CPE CPE shall wait for transmission from BS before retry Network entry and initialization proceeds after that

110 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 110 Support for Adaptive Antenna System (AAS) Alert-Window (AW) Contention slots for initial ranging Used by AAS CPEs and by single channel CPEs

111 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 111 Support for Adaptive Antenna System (AAS) Channel state information can be done in two ways: –Reciprocity: Assumes the upstream channel state estimation as the downstream channel state –Feedback: CPE explicitly transmits the estimated channel to the BS Two channel feedback options are available: –New MAC control messages (namely, AAS-CFB-REQ and AAS- CFB-RSP) have been defined –Piggybacked together with the existing measurement reports used for incumbents and other 802.22 systems Bandwidth request can be done using either the broadcast allocations or by polling

112 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 112 Hidden Incumbent Systems A WRAN System is on service in channel x. –CR BS sensed some channels and it recognized channel x was available, or BS just started the service based on its database information. Some CPEs inside the incumbent system radio area may not be able to decode the CR BS signal because of strong interference. –So, the CPEs cannot report the existence of the incumbent system and current status to the BS. –BS cannot recognize this situation because of no information. –Also, some incumbent users have experienced interference from the WRAN system. Ch x CPE Ch x Incumbent System CR System Not overlapped CR CPE Overlapped CR CPE (cannot decode CR Signal and cannot report anything) Incumbent user

113 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 113 Hidden incumbent case occurs –When a BS starts the service, –The BS changes the service channel Candidate channel broadcasting by BS and sensing reports for the candidate bands by CPEs can reduce the possibility of hidden incumbent system. But, BS may change its service channel without notification. Problem –CPEs inside the overlapped area are aware of the strong interference by incumbent system. –How to report it to BS? Implicit hidden incumbent case detection –A BS periodically sends sensing request and all CPEs respond. –If a BS did not receive sensing responses from some CPEs, then sends again. –After some trials, if still some CPEs don’t respond, BS notices hidden incumbent system appearance and changes the channel. –Still there remains some problems  some CPEs power off ( Confuses BS as if hidden incumbent case occurs)  CPEs inside the overlapped area just turn on, hence the BS doesn’t know the existence of CPEs.

114 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 114 Explicit OutBand Signaling for Hidden Incumbent Case Detection Hidden Incumbent System Case Method –BS periodically broadcasts the information on current channel in some of other unoccupied channels (e.g. candidate channels). Out-band signal: control signal on the band other than current band. This broadcasting signal follows the same PHY and MAC frame architecture (not to necessitate additional protocol or PHY module). –CPEs that are not able to decode the BS’s current service channel try to sense other channels to locate the BS signal. –If CPEs receive the explicit out-band broadcast signal, It recognizes the current service channel id. If the current channel is already sensed and is found to be not decodable, then the CPE sends a report to the BS using the upstream in out-band. –After noticing the existence of the hidden incumbent, BS changes its service channel to other available band.

115 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 115 Ch A Time channel Ch C Ch B Explicit outband signaling period CPE that cannot decode the current service channel will try to sense other channels The CPE finally receives at least one of the periodic outband broadcast signals Frequency Ch A Ch BCh CCh DCh ECh FCh X Ch Y Not available Current Service Channel BS Outband Signal broadcast Outband Signal broadcast Outband Signal broadcast Outband Signal broadcast Outband Signal broadcast Frequency Ch A Ch BCh CCh DCh ECh FCh X Not available CPE Not available Ch Y Outband Signal broadcast Report service signal Outband Signal broadcast It can be decided by incumbent system detection time requirement.

116 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 116 Explicit out-band broadcast signal –Follow the usual PHY and MAC frame architecture like in the service channel –In SCH: need a flag to differentiate Regular service MAC frame (in service channel) Out-band broadcast signal MAC frame (for broadcasting channel) –In DS-Bust: include service channel information Service channel numbers, candidate channel numbers, … Hidden incumbent case report –When a CPE receives a out-band signal and if the current service channel is not decodable by the CPE, then –Sends “Hidden incumbent report” to BS using the broadcasting US-Burst FCH US- MAP DS - Burst DS- MAP US- Burst SCHSCH

117 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 117 Hidden Incumbent System Report –CPE report can be either of “the current service channel x is not decodable” “the current service channel x is used by a incumbent system” –If the CPE can recognize incumbent signal. –CPE report can also include sensing result for some other channels. US resource (data-burst) allocation for “hidden incumbent report” report. –BS may allocate explicit resource to each CPE after CPE initialization procedure – overhead –BS may list up slotted US busts for unknown CPEs, which possibly reply their reports using one of the slotted busts. Slotted US burst size can be determined in accordance with the maximum hidden incumbent report size. CPEs that need to send “hidden incumbent report” contend each other Random back-off to send a message. Some overheads necessary in BS to broadcast out-band signals in different channels. CPEs do not need any change on their implementation. Implicit method can supplement the explicit method.

118 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 118 Channel Switch Procedure WRAN system build a candidate channel list using distributed sensing. When incumbent users and other WRAN system are detected in the current operating channel, –The BS selects a channel CHselect from the candidate channel list, either randomly or based on some algorithms. –Randomly selects a wait time twait from a time window [ Tmin, Tmax ] –Start a wait timer with Twait as the expiration time –Advertises the channel selection using backhaul channel or WRAN air interface before jumping to CHselect. Meanwhile the WRAN system sense CHselect for incumbent signals and other WRAN systems –If the channel CHselect is still idle/available, it jumps to CHselect when the wait timer expires. –If incumbent signals or other WRAN systems exist in CHselect, it goes back to the beginning to select another channel from the candidate channel list or its previously operated channel if occupied by incumbent users If collision occurs after channel switch, it increase tmax and goes back to the beginning to select another channel from the candidate channel list or its previously operated channel if not occupied by incumbent users –Otherwise, it decrease Tmax and remove CHselect from the candidate channel list.

119 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 119 Selects a channel CH select from the candidate channel list Start a wait timer with T wait as the expire time Randomly selects a wait time T wait from a time window [ T min, T max ] Advertise the channel selection CH select Sense channel CH select Channel CHselect idle? Wait timer expire? Switch to channel CH select Stop the wait timer Add previously operating channel not occupied by incumbents to the candidate channel list Detect incumbent users and other WRAN system on the current operating channel Stop Increase T max no yes Incumbent users and other WRAN system on Channel CH select ? yes no Remove CH select from the candidate channel list and reduce Tmax no Remove CHselect from the candidate channel list

120 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 120 MAC Presentation Outline MAC Protocol –MAC layer data communication Support for Adaptive Antenna System (AAS) Explicit outband signalling for hidden incumbent detection Channel switch procedure –Coexistence Opportunistic in-band sensing Credit tokens based rental protocol for inter-BS dynamic resource sharing Enhanced measurement and channel management capabilities –Clarifications Frequency hopping Support for Single Channel CPEs Quiet period management for sensing Performance Evaluation –Synchronization of overlapping BSs –CBP

121 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 121 The Opportunistic In-band Sensing Scheme Applicable for those cases where the traffic is low, and so sensing can take place within a frame –For these cases, the opportunistic in-band sensing can have performance benefits such as reducing detection time and improving detection accuracy This scheme may be able to run in parallel with the out-of-band sensing algorithm: –However, whenever there is contention between the opportunistic in-band sensing and out-of-band sensing, out-of-band sensing shall take precedence

122 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 122 The Opportunistic In-band Sensing Scheme (cont.) The main idea is to use common “sensing-eligible” frames to do in-band sensing A “sensing-eligible” frame is: –A frame with no traffic, i.e. no US or DS traffic –A frame at which the backlogged traffic (both US and DS) is less than the remaining capacity in the current superframe and no sensing frame has been allocated in the superframe –The last frame of the superframe and no sensing frame has been allocated in the superframe A “sensing-eligible” frame is designated as a sensing frame if it is not marked for use for out-of-band sensing

123 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 123 The opportunistic in-band sensing scheme The Opportunistic In-band Sensing Scheme (cont.)

124 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 124 Credit Tokens based Rental Protocol for Inter-BS Dynamic Resource Sharing Rental Protocol –Offeror –Renter Problem: –How to deal access/usage contention issues when several renters compete to access to the same offer at the same time ? –How to schedule the competing renters in a fair fashion while maximizing the spectrum efficiency ? The proposed mechanism complements the existing proposal –It introduces a cooperative sharing negotiation protocol: credit tokens based rental protocol between one offeror and several renters

125 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 125 Credit Tokens based Rental Protocol for Inter-BS Dynamic Resource Sharing (cont.) Definition –Radio channel: time*frequency. –BIN = time unit*frequency unit. –A radio channel = a number of BINs. –Credit Tokens (CT): « money like » unit. What can be shared/negotiated? –Number of BINs for a given time duration. –The starting time of the sharing. –The ending time of the sharing. Principles –Each offeror and renter BS is prior allocated with a given credit tokens budget. –A BIN is charged as a number of CT per time*frequency unit. –A radio channel can be shared by exchanging CT between offeror and renter. –The exchange is dynamic and supported through the CT transactions.

126 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 126 Credit Tokens based Rental Protocol for Inter-BS Dynamic Resource Sharing (cont.) Principles –Transactions rely on the real time and dynamic usage of reserve price auctionning and bidding mechanisms (e.g. ascending bid auction) to solve contention issues between renters BSs: Offeror = auctionner Renter = bidder –BSs do not manipulate money. CT is used for self coordination in a distributed fashion between BS (self gouvernance). –Incentive for sharing and fairness support is achieved through CT awarding. The credit tokens usage at each BS is ruled by the radio etiquette.

127 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 127 Credit Tokens based Scheduling Cycle Resource Usage phase (10) BW Granting (9) Transaction (8) Final Bidding results/Pricing (5) (n-1) th Bidding results (6) Express new bidding (n th ) (7) n th Bidding results Offeror BSRenter BS n th iteration (n > 1) of the dynamic credit tokens based auctioning/bidding phase Final pricing and Transaction phase Credit tokens based BW Granting phase First iteration (n = 1) of the dynamic credit tokens based auctioning/bidding phase Interest expressing phase (1) Awareness/Advertising (3) Inform bidding phasing (2) Express interest (5) 1 st Bidding results (4) Express initial bidding Offeror BSRenter BS Advertising phase

128 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 128 Credit Tokens based Rental Protocol for Inter-BS Dynamic Resource Sharing (cont.) This credit tokens based rental protocol can be implemented: –either over the air (MAC level) –or the backhaul (wired) For the over air implementation, the credit tokens based rental protocol rules the MAC frame structure sharing between renters and offerors Scalable for different resoure renting timescales –Different auctioning strategies can be applied depending on the time constraints for the negotiation Credit token charging mechanisms (different auctioning strategies) can be dynamically tuned to the context through the radio etiquette –Space time traffic intensity variations in each cell –Number of bidders –...

129 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 129 Enhanced Measurement Capability Besides the detailed and on-channel report, a CPE can now send a Consolidated Spectrum Occupancy Report –A Consolidated Spectrum Occupancy Report conveys a summary of the overall spectrum occupancy from the point of view of a CPE For a particular channel, the CPE reports its state as a 3 bit field: –Unmeasured –Vacant –Occupied (i.e., energy detected) –Occupied by an Incumbent –Occupied by 802.22

130 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 130 Enhanced Channel Management Capability Based on the measurement reports from CPEs, a BS can transmit a Channel Occupancy Update message to CPEs –Allows quicker recovery, more efficient measurements, etc. Similar to a CPE, for a particular channel the BS reports its state as a 3 bit field: –Unmeasured –Vacant –Occupied (i.e., energy detected) –Occupied by an Incumbent –Occupied by 802.22

131 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 131 MAC Presentation Outline MAC Protocol –MAC layer data communication Support for Adaptive Antenna System (AAS) Explicit outband signalling for hidden incumbent detection Channel switch procedure –Coexistence Opportunistic in-band sensing Credit tokens based rental protocol for inter-BS dynamic resource sharing Enhanced measurement and channel management capabilities –Clarifications Frequency hopping Support for Single Channel CPEs Quiet period management for sensing Performance Evaluation –Synchronization of overlapping BSs –CBP

132 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 132 Frequency Hopping Purpose –To dismiss any presumption that the proposed MAC does not allow frequency hopping Treated as an optional implementation issue In order to avoid an in-band quiet period, a WRAN may hop to a Channel A provided: –The Channel A evaluation meets the Channel Availability Check Time as specified in the FRD –The Channel A is not occupied by any incumbent –The Channel A is not occupied by any 802.22 network Otherwise, it may be worse than sticking to your current channel –Adjacent channels have also been checked for the presence of incumbents, as to adhere to the EIRP profile

133 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 133 Support for Single Channel CPE From the BS point of view, bonding of 3 contiguous TV channels is a mandatory feature –Guarantees interoperability –Enables multiple business cases However, channel bonding in CPEs is optional –CPEs can support either one, two, or three bonded TV channels To support this feature, an Alert Window (AW) is added to the superframe structure –Used to notify the BS about incoming CPEs who cannot operate in the same mode as the BS

134 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 134 Support for Single Channel CPE (cont.) Alert-Window (AW) Contention slots for initial ranging Used by AAS CPEs and by single channel CPEs

135 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 135 Quiet Period Management for Sensing Background –A potentially very large number of channels (up to N±15) have to be periodically sensed for the presence of incumbents –At the same time, support to QoS traffic requires delays as low as 20ms (see FRD) Question –How is sensing done as to meet these requirements? Answer –Sensing is a two-stage process Stage 1: Fast sensing (e.g., energy detection) Stage 2: Only if needed, perform fine sensing (feature detection)

136 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 136 Quiet Period Management for Sensing (cont.) Quiet period structure The fast sensing is performed in-band only –May or may not be scheduled by the BS (e.g., between two consecutive MAC frames) –Upon BS request, a consolidated report on the fast sensing outcome is sent by CPEs –BS then determines the need for the next fine sensing and how much time is required

137 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 137 Quiet Period Management for Sensing (cont.)

138 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 138 Quiet Period Management for Sensing (cont.) Since quiet periods from overlapping 802.22 cells are synchronized, sensing is highly effective

139 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 139 Quiet Period Management for Sensing (cont.) Given that the nature of incumbent appearance on a channel is sparse (e.g., new TV stations do not come on the air every hour): –The fast sensing stage will be enough most of the time –Hence, the fine sensing stage will not need to be performed –Even if the fine sensing stage is required to be performed, its duration will exactly fit how much is required to be measured Outperforms frequency hopping in many respects –Does not require an abundance of vacant channels –The time taken for fast sensing is likely much less than the switching time required in frequency hopping –Does not assume an independent sensing receiver Therefore, with this mechanism: –Not only will incumbents have their protection guaranteed –The stringent QoS requirements specified in the FRD will be met

140 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 140 MAC Presentation Outline MAC Protocol –MAC layer data communication Support for Adaptive Antenna System (AAS) Explicit outband signalling for hidden incumbent detection Channel switch procedure –Coexistence Opportunistic in-band sensing Credit tokens based rental protocol for inter-BS dynamic resource sharing Enhanced measurement and channel management capabilities –Clarifications Frequency hopping Support for Single Channel CPEs Quiet period management for sensing Performance Evaluation –Synchronization of overlapping BSs –CBP

141 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 141 Performance Evaluation Two aspects of the proposal are further evaluated –Distributed synchronization of overlapping 802.22 cells Four (4) step-by-step scenarios Overall convergence time for tens of thousands of scenarios –Additional CBP protocol evaluation, which assesses Self-coexistence Distributed quiet period synchronization of overlapping 802.22 cells

142 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 142 Synchronization of Overlapping WRANs For all simulations –Number besides a node is the superframe transmission time (STT) –Red line between nodes means nodes in range and STT NOT aligned –Blue line between nodes means nodes in range and STT aligned –Units Time is milliseconds Space is kilometers

143 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 143 Synchronization of Overlapping WRANs: Scenario 1 A total of 24 WRANs are considered BSs and CPEs have a radio range of 25 Km

144 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 144

145 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 145 Synchronization of Overlapping WRANs: Scenario 2 A total of 30 WRANs are considered All WRANs power up at the same time (worst case analysis) BSs and CPEs have a radio range of 20 Km

146 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 146

147 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 147 Synchronization of Overlapping WRANs: Scenario 3 A total of 10 WRANs are considered All WRANs power up at the same time (worst case analysis) –Random STT at startup BSs and CPEs have a radio range of 20 Km

148 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 148

149 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 149 Synchronization of Overlapping WRANs: Scenario 4 A total of 10 WRANs are considered All WRANs power up at the same time (worst case analysis) –Random STT at startup BSs and CPEs have a radio range of 20 Km

150 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 150

151 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 151

152 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 152

153 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 153

154 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 154

155 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 155

156 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 156

157 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 157

158 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 158 Synchronization of Overlapping WRANs: Overall Convergence Time Comprehensive evaluation of the synchronization mechanism –Used for self- coexistence (e.g., CBP) as well as for quiet periods Results show the quick convergence and efficiency of the algorithm –A similar scheme is used in the WiMedia UWB MAC

159 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 159 CBP/Synchronization Evaluate the self-coexistence mechanisms of the proposed MAC –Synchronization –CBP in every frame The number of overlapping 802.22 cells are progressively increased –Up to 4 cells are simulated –BSs and CPEs start at random Network is fully loaded and traffic is uniform 1 cell: 2 cells:

160 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 160 CBP/Synchronization (cont.) 3 cells: 4 cells:

161 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 161 CBP/Synchronization (cont.) Simple scheduler CBP together with Synchronization can provide significant performance improvements –Since CBP is under control of the BS, it can be made adaptive

162 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 162 Presentation Outline PHY Proposal Updates to the MAC Proposal Conclusions

163 doc.: IEEE 802.22-06/0005r4 Submission March 2006 ETRI, FT, I2R, Motorola, Philips, Samsung, ThomsonSlide 163 Conclusions Presented the updates to the PHY and MAC proposal –The proposal effectively protects incumbents while efficiently meeting the requirements set forth by the 802.22 WG PHY –Based on OFDMA –Flexible channel configurations –TV and Part 74 service detection and protection MAC –Coexistence is a key feature Incumbent protection Self-coexistence –CBP, dynamic resource sharing, channel bonding, etc.


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