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: [Proposal on Preamble Structure for IEEE 802.15.4b PHY] Date Submitted: [Jan. 2005 ] Source: [Liang Li, Liang Zhang, Yafei Tian, Chenyang Yang, Zhijian Hu, Hongyu Gu] Company: [WXZJ] Address: [2 Xinxi St, Building D, Haidian District, Beijing, China 100085 ] Voice:[86-10-139-11895301], E-Mail:[liang_1@yahoo.com] Re: [ IEEE 802.15.4b ] Abstract: [Analysis of E16 orthogonal spreading code for 868/915MHz band PHY.] Purpose: [To encourage discussion.] 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, WXZJ Inc.

2. Overview This document proposals the Transceiver Structure for IEEE802.15.4b working group: OQPK + Pulse Shape + (TX filter). It also suggests one E16 orthogonal code Sequence for the DSSS Spreading At same time, the document offers the simulated (TX/RX) performances of this Transceiver system at 915MHz and 868MHz bands: Liang Li, WXZJ Inc.

3. Transceiver at 868 MHz Band •Key design parameters –Summary of design requirements for the TG4b PHY •PSD of TX signal •Auto-correlation performance of E16 code sequence – Auto-correlation ofO-QPSK with half sine pulse shaping / I/Q modulation at 2x sampling rate – sync in condition of frequency offset • The Receiver Performance with propsoal – simulation condition or system construction – AWGN and Rayleigh channel in ideal condition – Frame detection, synchronization, phase noise, frequency offset, sampling error, respectively (to be continued) •Summary Liang Li, WXZJ Inc.

4. Key Features of Transceiver at 868MHz • Bit rate 100 kBit/s • Better orthogonal characteristic • 16 sequences for 4 bits mappin • 400k chip rate per second • Bandwidth, Pulse shape , PAPR, frequency offset • The 1st null-null bandwidth 600kHz; • <1dB PAPR, • With r=0.6 raise cosine filter, constant module and continuous phase,lower out-of-band emission; • Nearly 50dB lower over 600kHz wide bandwidth, which satisfies the state of ETSI; • Tolerated frequency offset at least 40ppm; • Multipath fading robustness • Achieve PER<10^-2 at channels with 250ns delay spread (Multipath channel model offer by Paul with high sampling rate); • Support of current RF • Support current 600kHz band available at 1% duty cycle in Europe today • Allow use of extended European bands and bands in other countries once they become available • Allow addition of additional 600 kHz channels as per current ETSI / ECC report (4/6 channels?) • Do not expect US-like wide, unrestricted bands or all egulatorydomains • Support of more flexible channel selection method to flexibly add support for more countries • Low cost and low power consumption Liang Li, WXZJ Inc.

5. OPSK variants reviewed in this presentation Liang Li, WXZJ Inc.

6. OQPSK + half sine pulse with Tx filter Tx / Rx Performance at 868MHz, 600KHz bandwidth Assumption: • E16 orthogonal code + OQPSK + half-sine pulse shaping • Tx: Tx digital raised cosine filter with r=0.6; • Rx: Synchronization performance • Receiver (Non-Rake) performance comparison based on our simulation results In the following slides, two Tx filters will be analyzed at 2x sampling rate and 4x sampling rate, respectively. Liang Li, WXZJ Inc.

7. PSD(dB) 0 raised cosine filter r=0.6 SUPPOSE: 1, 0.8MHz (2x)sampling rate; 2, 200kHz pass band; 3, Tx digital FIR filter; Liang Li, WXZJ Inc.

8. Impulse response of Tx filter –raised cosine filter r=0.6 SUPPOSE: 1, 0.8MHz (2x)sampling rate; 2, 200kHz pass band; 3, Tx digital FIR filter; Liang Li, WXZJ Inc.

9. 100kbps Data rate PSD with Tx filter • 100kbps; • 400k chip rate; • 600k bandwidth; • half sine pulse shape; • Raised cosine filter with r=0.6; • 2x over sampling rate; (0.8M sampling rate) Liang Li, WXZJ Inc.

10. PAPR of 100kbps with Tx filter PAPR is less than 1dB (about 0.95dB) The amplitudes of samples after Tx filter Liang Li, WXZJ Inc.

11. PSD(dB) 0 raised cosine filter r=0.6 SUPPOSE: 1, 1.6MHz (4x)sampling rate; 2, 200kHz pass band; 3, Tx digital FIR filter; Liang Li, WXZJ Inc.

12. Impulse response of Tx filter –raised cosine filter r=0.6 SUPPOSE: 1, 1.6MHz (4x)sampling rate; 2, 200kHz pass band; 3, Tx digital FIR filter; Liang Li, WXZJ Inc.

13. 100kbps Data rate PSD with Tx filter • 100kbps; • 400k chip rate; • 600k bandwidth; • half sine pulse shape; • Raised cosine filter with r=0.6; • 4x over sampling rate; (1.6M sampling rate) Liang Li, WXZJ Inc.

14. PAPR of 100kbps with Tx filter PAPR is less than 1dB (about 0.65dB) The amplitudes of samples after Tx filter Liang Li, WXZJ Inc.

15. Nonlinear PA Characteristics Liang Li, WXZJ Inc.

16. Impact of PA Nonlinearity: 2x sampling rate (2) (1) (1) Tx PSD without Tx filter or PA (2) Tx PSD with Tx filter, no PA (3) Tx PSD with Tx filter and PA Because of aliasing at relatively low sampling rate, the signal side-lobe is susceptible to PA nonlinearity. (3) Liang Li, WXZJ Inc.

17. Impact of PA Nonlinearity: 4x sampling rate (2) (1) (1) Tx PSD without Tx filter or PA (2) Tx PSD with Tx filter, no PA (3) Tx PSD with Tx filter and PA At 4x sampling rate, the impact of PA nonlinearity is neglectable. (3) Liang Li, WXZJ Inc.

18. 100kbps Data rate performance Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Frame Detection: No SFD: No Ideal sync With Tx filter Liang Li, WXZJ Inc.