Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [DSSS Modulation for PHY Layer Proposal at MBAN bands] Date Submitted: [1-May−2011] Source: [Liang Li, Zhang Liang, Zhongliang Deng.Ning Li, Pingping Xu,Hao Liu ] Company: [Vinno Technologies Inc,. Beijing University of Posts and Telecommunications. Southeast University] Address: [Suite 202, Building D, No.2 Shangdi Xinxi Lu, Beijing 100085, China] Voice:[8610-82782373], FAX: [8610-82893004] E−Mail: [liangli@vinnotech.com] Re: [802.15.4J] Abstract: [ ] Purpose: [To encourage discussion in 802.15.4J] Notice: This document has been prepared to assist the IEEE P802.15. 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 IEEE and may be made publicly available by P802.15. Liang Li (Vinno)

2. Proposal • A new PHY Proposal for low-rate WPAN that employs the OQPSK modulation scheme in MBAN band • The OQPSK tech is adopted as the basic modulation of communication in LR-WPAN at 2360Mhz band. • Data rate = 250Kbps. • Channel separation = 2MHz. The 1st null-null bandwidth = 0.5Mhz • Pt < 10mw. Liang Li (Vinno)

3. The Important Operation Coefficients Fc=2361 + (k-1)*2 MHz, k=1, … ,20 The Transmit Path (I or Q Paths) Liang Li (Vinno)

4. DSSS Mapping (Symbol to Chips) • 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. Liang Li (Vinno)

5. 0 1 0.8 -10 0.6 -20 Pluse Shape 0.4 PSD (dB) -30 0.2 -40 0 -50 -0.2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -60 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 t [Tc] f [MHz] Pulse Shaping Filter The Pulse Shaping Filter on I and Q paths is Raised-Cosine (α=0.5 ): Liang Li (Vinno)

6. PPDY Packet • The Preamble sequence is defined as: The Preamble is used by the transceiver to obtain chip and symbol synchronization with an incoming message , and the bits in the Preamble field shall be binary zeros. • The SFD sequence is defined as: The SFD is a field indicating the end of the SHR and the start of the packet data, and the SFDis an 8-bit field. Liang Li (Vinno)

7. PSD in the Band • PSD Requirements in Band • Minimum Receiver Jamming Resistance Requirement Liang Li (Vinno)

8. 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. • Flat Fading Channel Power delay profile is exponentially declined. Each path is independently Rayleigh fading. Liang Li (Vinno)

9. Summary • Regulatory rules for MBAN may require reduced side lobes: -36dBm outside of the 2.36-2.4 GHz Band and -34dBm between Channels • The non-coherent demodulation of OQPSK can achieve same performance with the OQPSK mode @ 915, 779 MHz bands (which are 802.15.4-2006 and 4C) • RC shaping is recommended w.r.t. EVM < 35% • The OQPSK modulation with 16- orthogonal spreading sequences are recommended as one of proposals to implement the PHY layer operation in LR-WPAN in MBAN Liang Li (Vinno)