1. A Paging Indication Channel for 802.16m IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE S802.16m-08/1161 Date Submitted: 2008-09-16 Source: Havish Koorapaty, Per ErnstromVoice:+1 919 4727524 Ericsson, Inc.E-mail:havish.koorapaty@ericsson.com 8001 Development Drive, RTP, NC 27709 Venue: Session #57 in Kobe, Japan Base Contribution: C802.16m-08/1161 Purpose: Review and discuss in support for adoption of C802.16m-08/1161 Notice: This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who 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 802.16. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and.http://standards.ieee.org/guides/bylaws/sect6-7.html#6http://standards.ieee.org/guides/opman/sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat

2. Introduction to Quick Paging/Paging Indication Quick paging signal –Mechanism to extend standby time of MS –Used in CDMA2000 and WCDMA Provides an indication to selected mobiles to read the full paging message that occurs in a subsequent frame. –If you don’t receive the paging indication, you don’t read the full paging message Significantly shorter duration of the quick paging message –Lowers the wake-up time of the MS –Lowers the time the RF part of receiver is on

3. Standby time –The timeaveraged powerconsumption for reading the paging indication (pi) is proportional to the number N of OFDMA symbols the terminal need to wake up: P pi = c*N –The standby time is: T standby = E battery /(P other +P pi ) = E battery /(P other +c*N) –or in the case that P other << P pi T standby = E battery /(c*N) –For detailed study – see main contribution.

4. Optimal solution –The quick paging signal should be as short as possible, i.e. one OFDMA symbol long N=1? –But the terminal needs to listen to the SCH to sync too N=2? –Send synchronisation channel and paging indication in the same OFDMA symbol! N=1! –But how?

5. Optimal solution Reference system –Preamble mapped on every third subcarrier SCH in the SDD (802.16m-08/003r4) –Hierarchical case P-SCH is mapped on every other sub-carrier S-SCH (hierarchical case) is mapped on every TBD sub-carrier –Non hierarchical case SCH is mapped on every other sub-carrier Transmit Paging Indication over the unused subcarriers of the SDD At much lower power than the SCH not to violate SCH funtionality Strongly coded to allow paging indication detection

6. Detailed evaluation based on legacy preamble To show the viability of the concept we perform a detailed analysis based on the legacy preamble (since 16m SCH details are lacking). The legacy preamble is a tough case since it is based on reuse. Therefore the conclusions should be generally applicable.

7. For 10 MHz, preamble has 568 empty spaces –Use Walsh-Hadamard code of length 512: 512 codewords –Orthogonal codes work well at low SNR –Low complexity decoding method using the FWT –Use a PN mask to avoid spectral peaks For 5MHz, length 256 Walsh-Hadamard code can be used Good channel estimates are available from the known preamble –Use bio-orthogonal code based on WH – codewords and their inverses Number of addressable paging groups: 1024 for 10 MHz, 512 for 5 MHz –Paging group can be assigned the WH codeword –If received, then full paging message will be read Quick Paging Signal Design

8. System Performance Evaluation Performance evaluation using combination of System and Link Simulations Using System Simulation, get long-term path gain values for MS from different base stations Feed to link simulation –Generate preamble and paging indication signal from each base station and scale according to path loss –Apply radio channel (Ped B) –Generate additive noise –Receive paging indication signal on own BS – practical channel estimation, error covariance estimation –Log error events 600 uniformly distributed MS used –100 channel realizations per MS –100 codeword and noise realizations per channel realization

9. Performance Evaluation Parameters AspectValue Number of Cells/Sites57/19 Reuse1/1 (1/3 for preamble) Path Loss ModelITU Vehicular Site-to-Site Distance2.8km Penetration LossNone Shadowing Standard Deviation8dB Shadowing Correlation Distance100m Bandwidth10 MHz FFT Size1024 Transmit Power (for Preamble)20 W Noise Figure9 dB Channel ModelPedestrian B Relative Power of Paging Signal-20dB Codeword Size512

10. Performance Metrics Probability of Missed Detection (Pmiss) –Codeword is sent, but MS misses receiving codeword –Full Paging message is missed Probability of False Alarm (Pfalse) –Different codeword is sent, but MS receiver mistakenly identifies codeword as own –MS will read full paging message –System behavior is unaffected, but impact on MS battery life Using appropriate thresholds, can trade off between Pmiss and Pfalse

11. Performance Results

12. Effect on Legacy MS of Low Power Signal

13. Conclusions Design for paging indication transmitted over the unused subcarriers of the SCH Negligible impact on SCH functions Performance evaluation shows reliable reception of paging indication signal Significant energy savings with use of paging indication

14. TEXT PROPOSAL for the SDD 11.7.2.X Paging Indication Channel (PICH) The Paging Indication Channel (PICH) carries the paging indication information. The PICH is transmitted over the unused subcarriers in the frequency domain of the S-SCH and P-SCH (hierarchical) or SCH (non-hierarchical). The PICH is transmitted on a much lower power than the SCH. A Walsh-Hadamard code is used to code the paging indication information. 11.7.2.1.3 Synchronization channel Sequence Design Properties The SCH enables timing synchronization by autocorrelation. The power of synchronization channel can be boosted The SCH (non-hierarchical) or P-SCH (hierarchical) is mapping with every other subcarrier on the frequency domain. The S-SCH (hierarchical) is mapping with every [FFS] subcarriers on the frequency domain The unused subcarriers in the frequency domain of the S-SCH and P-SCH (hierarchical) or SCH (non- hierarchical) may be used for a low power paging indication signal. New section 11.7.2.X: Modified section 11.7.2.1.3: