Source: [Yafei Tian, Chenyang Yang, Liang Li ] Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [The Difference on PHY layer between Chinese WPAN and IEEE802.15.4-2006 ] Date Submitted: [Dec. 19, 2006 ] Source: [Yafei Tian, Chenyang Yang, Liang Li ] Company: [Beihang University (BUAA), Vinno Technologies Inc. ] Address: [2 Xinxi St, Building D, Haidian District, Beijing, China 100085 ] Voice:[86-10-139-11895301], E-Mail:[yftian@vip.sina.com, cyyangbuaa@vip.sina.com , liangli@vinnotech..com] Re: [ Chinese Wireless PAN Group] Abstract: [Description the major difference on PHY Layer between IEEE802.15WG and Chinese WPAN WG] Purpose: [To encourage discussion.] Notice: This document has been prepared to assist the Chinese WPAN group. 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 acknowledges and accepts that this contribution becomes the property of C- WPAN and may be made publicly available by C-WPAN. Submission BUAA, Vinno

Outline Review of the proposed communication technique in C-WPAN PHY draft standard. Major difference with IEEE 802.15.4-2006 915MHz band PHY Spreading sequence SFD design Pulse shaping filter Synchronization and demodulation performance Submission BUAA, Vinno

Frequency bands and Data rate PHY (MHz) Frequency Bands Spreading Parameters Data Parameters Chip Rate (Mchip/s) Modulation Bit Rate (kb/s) Symbol Rate (ksymbol/s) 315 314-316 0.2 Chirp Sequence + MPSK 50 12.5 430 430-434 780 779-787 1 250 62.5 2400 2400-2482 2 Quasi-orthogonal Binary Sequence + O-QPSK Submission BUAA, Vinno

Reference Design of the Wireless Transceiver Submission BUAA, Vinno

Spreading Sequence and Mapping The Direct Sequence Spread Spectrum (DSSS) tech is applied 16 orthogonal spreading sequences are designed to map 4 information bits. The base sequence is a 16 length chirp sequence and the other 15 sequences are its cyclic shifts. Submission BUAA, Vinno

Pre-processing Conjugate the first sequence to obtain SFD The SFD sequence is the conjugate of the Preamble sequence, that means the phases of the SFD chips are adverse to the phases of the Preamble chips. DC component removal All chips of each symbol in the head and load of PPDU should be multiplied by –1 or 1 based on the follow PN code serials. Submission BUAA, Vinno

Pulse Shaping and Spectrum The Pulse Shaping Filter on I and Q path is designed as a raised cosine filter with roll-off factor 0.5: The Transmit waveform and Spectrum are : Submission BUAA, Vinno

Difference 1: Frequency Bands C-WPAN: Radio Management Office of P.R.China (Supervised by Ministry of Info Industry) approved the following frequency bands and TX power limitation for the operation of WPAN equipment 779 --- 787 MHz, Pt <=10mw (e.i.r.p) Channel separation is 2MHz, channel number is 4. 15.4-2006 915MHz band optional PHY: 902-928 MHz Channel separation is 2MHz, channel number is 10. Submission BUAA, Vinno

Difference 2: Spreading Sequence C-WPAN: Chirp code is orthogonal among its cyclic shifts Perfect auto-correlation property of the Preamble sequence, Perfect orthogonal property of the 16 spreading sequences, Reduce inter-chip interference in multipath environments. Chirp code is robust to frequency offset Low cost implementation of transmitter and receiver. 15.4-2006 915MHz band optional PHY: 16 sequences are quasi-orthogonal. The auto-correlation property of the Preamble sequence is not very well. The code is susceptible to frequency offset. Submission BUAA, Vinno

Sliding Correlation Values of the Preamble Sequence With Sequence in C-WPAN Draft Std With Sequence in 15.4-2006 Std Submission BUAA, Vinno

Difference 3: SFD Design C-WPAN: The 16 spreading sequences are cyclic shift of each other. The SFD sequence is the complex conjugate of the first spreading sequence. 15.4-2006 915MHz band optional PHY: The first 8 spreading sequences are cyclic shift of each other, and the last 8 spreading sequences are the complex conjugate of the first 8 spreading sequences. The SFD sequences are chosen from the spreading sequences. Submission BUAA, Vinno

Difference 4: Pulse Shaping Filter 15.4-2006: Half-sine filter To O-QPSK PHY, the zero-to-zero bandwidth is 1.5MHz. To C-WPAN PHY, the zero-to-zero bandwidth is 3MHz. C-WPAN: Raised cosine filter The chip duration is 1us. The zero-to-zero bandwidth is 1.5MHz. Submission BUAA, Vinno

Difference 5: Synchronization Performance In AWGN channel, basic sliding correlation algorithm is used. Submission BUAA, Vinno

Difference 5: System Packet Error Performance In AWGN channel, ideal synchronization, 32 data octets in each packet. Submission BUAA, Vinno

Thank you! Submission BUAA, Vinno

Backup Slides Submission BUAA, Vinno

C-WPAN System Performance in Multipath Channel Tapped-Delay-Line Channel Model IEEE P802.15 Working Group for WPANs, Multipath Simulation Models for Sub-GHz PHY Evaluation, 15-04-0585-00-004b, Oct. 2004. Power delay profile is exponentially declined. Each path is independently Rayleigh fading. The average power of the channel response over many packets is 1, but in each packet the power is varied. Short Delay Environments Without rake receiver Long Delay Environments With 3-tap rake receiver Submission BUAA, Vinno

C-WPAN System Performance in Multipath Channel Test Conditions RMS delay spread 0~600ns Tx nonlinear amplifier, Rapp’s model, p=3, backoff=1.5dB Tx and Rx frequency offset ±80ppm, phase noise -110dBc/Hz @±1MHz Tx and Rx IQ imbalance 2dB, 10o 3bit AD sampling, 8bit baseband processing Rx will implement time and frequency synchronization and data detection 5000 packets are tested for each SNR, each packet comprises 20 octets The packet error rate is counted for 90% coverage Submission BUAA, Vinno

PER in Short Delay Environments without Rake Receiver Submission BUAA, Vinno

PER in Long Delay Environments with 3-tap Rake Receiver Submission BUAA, Vinno