March 2005 doc IEEE 802 15 05 0103

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Project: IEEE P 802. 15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Enhanced E 16 Code with Offset QPSK for 802. 15. 4 b High Rate Alt-PHY] Date Submitted: [13 Jan, 2004] Source: [Liang Zhang, Hongyu Gu, Liang Li, Yafei Tian, Chenyang Yang, Zhijian Hu, Yong Guan] Company: [WXZJ Inc. ] Address: [2 Xinxi St, Building D, Haidian District, Beijing, China 100085 ] Voice: [86 -10 -139 -11895301], E-Mail: [liang_1@yahoo. com] Re: [Response to the call for proposal of IEEE 802. 15. 4 b] Abstract: [This presentation compares all proposals for the IEEE 802. 15. 4 b PHY standard. ] Purpose: [Proposal to IEEE 802. 15. 4 b Task Group] Notice: This document has been prepared to assist the IEEE P 802. 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 P 802. 15. Submission 1 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Motivation Choose DSSS code sequences that will lead to efficient transmission and low implementation complexity. Submission 2 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Six desirable properties of DSSS code sequences 1. All sequences contain equal number of ones and zeros 2. All sequences contain equal number of ones and zeros in the even numbered chips (I phase) 3. All sequences contain equal number of ones and zeros in the odd numbered chips (Q phase) 4. Total phase rotation in I / Q plane accumulates to 0 degree over a complete symbol period 5. The first 8 symbols are shifted versions of each other 6. The last 8 symbols have inverted odd numbered chips (Q phase); when compared to the 8 first symbols, have the exact inverted baseband phase Submission 3 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Issue: Non-zero DC value of E 16 DSSS Sequence Decimal Symbol Binary Symbol Chip Values 0 0000 001101000100 1 1000 011000010001 2 0100 000001110111 3 1100 010100100010 4 0010 0011101101001011 5 1010 0110111000011110 6 1110 00001111000 7 0111 0101110100101101 8 0001 001101001011 9 1001 011000011110 10 0101 000001111000 11 1101 010100101101 12 001110110100 13 1011 011011100001 14 0111 000010000111 15 1111 010111010010 Source doc. : IEEE 802. 15 -04 -0314 -02 -004 b Submission 4 DC values Total DC values = -16 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Attachment I: generation of E 16 Walsh matrix W is Decimay Walsh matrix 0 1 1 1 1 1 -1 1 -1 1 -1 2 1 1 -1 -1 3 1 -1 -1 1 4 1 1 1 1 -1 -1 5 1 -1 -1 1 6 1 1 -1 -1 1 1 7 1 -1 -1 1 1 -1 8 1 1 1 1 -1 -1 9 1 -1 -1 1 10 1 1 -1 -1 1 1 11 1 -1 -1 1 1 -1 12 1 1 -1 -1 1 1 13 1 -1 -1 1 1 -1 14 1 1 -1 -1 1 1 -1 -1 15 1 -1 -1 1 -1 -1 1 Submission 5 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Attachment I: generation of E 16 • Local sequence is 0 0 1 1 0 0 0 1 0 0 ; • E 16 is generated by correlating local sequence with Walsh Matrix W; Submission 6 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Proposed Symbol-to-Chip Mapping (Enhanced 16 -chip Code Set W 16) Submission Decimal Value Binary Symbol Chip Value DC Value 0 0000 0011111000100101 0 1 1000 10010001111 0 2 0100 0000110100010110 -4 3 1100 01011000011 -4 4 0010 1100111011010101 4 i 5 1010 1001101110000000 – 4 i 6 0110 00000011001 -4 – 4 i 7 1110 1010100010110011 4 -4 i 8 0001 1100000100100101 -4 9 1001 0110101110001111 4 10 0101 1111001000010110 0 11 1101 0101100010111100 0 12 0011 1100111000101010 4 -4 i 13 1011 1001101101111111 4+4 i 14 0111 1111110100011001 4 i 15 1111 0101011110110011 4 i Total DC Value 0 +0 i 7 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Attachment II: generation of W 16 Modified Walsh matrix W’ is Decimay Modified Walsh matrix for W 16 0 1 1 1 1 1 -1 1 -1 1 2 1 1 -1 -1 3 1 -1 -1 1 4 -1 -1 1 1 1 1 5 -1 1 1 -1 6 1 1 -1 -1 1 1 7 -1 1 1 -1 -1 1 8 -1 -1 1 1 1 1 9 1 -1 -1 1 10 -1 -1 1 1 1 1 -1 -1 11 1 -1 -1 1 1 -1 12 -1 -1 1 1 1 1 -1 -1 13 -1 1 1 -1 -1 1 14 -1 -1 1 1 -1 -1 1 1 15 1 -1 -1 1 -1 -1 1 Submission 8 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Attachment II: generation of W 16 • Local sequence is 0 0 1 1 1 0 0 0 1 0 1 ; • W 16 is generated by correlating local sequence with modified Walsh Matrix W’; Submission 9 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b The Features of W 16 Sequences l Having same features of DSSS sequences of 802. 15. 4 std: – – 1. 2. 3. 4. Equal number of “ 0”s and “ 1”s in preamble sequence; The first chip is not always 0 or 1; Total DC value is 0, even though not always 0 in every sequence; The phase comes back to 0 after one symbol period. l Maintaining good characteristics of E 16 sequences: – 1. Orthogonality characteristics introduced by Walsh conversion; – 2. Performance similar to that of E 16 orthogonal sequences; – 3. Low complexity of correlation decoder implementation. Submission 10 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Key Parameters of W 16 (1) • Bit rate of 250 k. Bit/s – – – Better orthogonal characteristic 16 sequences for 4 bits mapping Each consisting of 16 chips Chip rate = 1 Mchips per second Center frequency = 915 MHz; • Bandwidth, pulse shape, PAPR, frequency offset – The 1 st null-null bandwidth 1. 5 MHz; – Half-sine pulse shape; – 0 d. B PAPR, same MSK scheme as 15. 4, constant modulus and continuous phase, lower out-of-band emission; – PSD: 30 d. B lower over 2 MHz-wide bandwidth, conforming to 802. 15. 4 std; – Frequency offset tolerance over 40 ppm; Submission 11 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Key Parameters of W 16 (2) • Multipath fading robustness – Achieving PER<10 -2 in multipath channels of 250 ns rms delay spread (channel model suggested by Paul) • Support of current RF – Support 2 MHz-wide channels as allocated in the USA and other countries • Low cost and low power consumption Submission 12 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b PSD of W 16 Bandwidth, Pulse shape: The 1 st null-null bandwidth 1. 5 MHz; Half-sine pulse shape: MSK modulation offers constant modulus and continuous phase; PSD 30 d. B lower at 1. 5 MHz from center frequency. Submission 13 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b W 16 PSD characteristic • PSD of W 16 is not affected by sampling error. • Low out-of-band emission: no need for Tx filter • Satisfies the IEEE 802. 15. 4 PSD requirements Source: IEEE 802. 15. 4 Standard Submission 14 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Auto-correlation performance Synchronization performance of W 16 based on simulations: • Auto-correlation characteristics with MSK modulation in 2 x sampling rate • Synchronization performance in the presence of frequency offset Submission 15 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b The Auto-Correlation of W 16 and En- Cobi 16 En-Cobi 16 W 16 In this test, the correlations are calculated after spreading sequences are OQPSK modulated with half-sine pulse shaping. Submission 16 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Cross-correlation of received Signals of W 16 and En-Cobi 16 W 16 En-Cobi 16 (2 x over sampling rate) Submission 17 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Frequency offset performance Simulation parameters & assumptions: – – – Rayleigh Channel model as suggested at TG 4 discussions O-QPSK + half-sine pulse shaping 2 M sampling rate (1 M chips/sec) Frequency offset from 0 ppm to 40 ppm Center frequency = 915 MHz Average over 1 million Monte-Carlo simulations Notes: 1. Synchronization is achieved by correlating local PN with received preamble impaired by frequency offset. 2. Throughout this document, the perfect synchronization (no error) in a multipath environment is defined as the receiver being synchronized to the strongest path. Submission 18 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Frequency offset performance: simulations Sync performance BER performance Frequency offset affects the sync and decoding performance significantly. So, frequency offset should be considered in 154 b system. Submission 19 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Proposal for preamble Preamble of 15. 4 standard: Preamble here proposed for 15. 4 b: The preamble field proposed here consists of at least 4 octets (prefer 6 octets). Submission 20 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b System performance comparison between W 16 and COBI 16 Simulation parameters & assumptions: – 250 ns rms delay spread Rayleigh Channel model – O-QPSK modulation + half sine pulse – without frequency offset – without synchronization error – 20 octets in each packet – 10, 000 packets for Monte-Carlo simulation – Non-coherent demodulation – No SFD detection – No fading • The solid curve indicates the performance of W 16 and the dash one indicates the performance of COBI 16 Submission 21 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b System Simulation Models Discrete exponential channel model: – Sampled version of diffuse channel model offer by Paul with 4 MHz sampling rate; –At least 10000 random channel realizations; –PER calculated on 20 bytes PPDUs with preamble. Submission 22 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b AWGN: Ideal Sync. vs. Correlation Sync. Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Submission Frame Detection: No SFD: No 23 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel: no fading + correlation sync (1) Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission Frame Detection: No Phase noise : No SFD: No Sync. : Correlation Down sampling error: No 24 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel: no fading + correlation sync (2) Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission Frame Detection: No Phase noise : No SFD: No Sync. : Correlation Down sampling error: Yes 25 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel: no fading + correlation sync (3) Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: Yes Submission Frame Detection: No Phase noise : No SFD: No Sync. : Correlation Down sampling error: No 26 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel: no fading + correlation sync (4) Frame Detection: No Phase noise : YES SFD: No Sync. : Correlation Down sampling error: No Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission 27 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel: no fading + correlation sync (5) Frame Detection: No Phase noise : YES SFD: YES Sync. : Correlation Down sampling error: No Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission 28 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel: no fading + correlation sync (6) Frame Detection: YES Phase noise : YES SFD: Yes Sync. : Correlation Down sampling error: No Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission 29 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel: no fading + correlation sync (7) Frame Detection: YES Phase noise : YES SFD: Yes Sync. : Correlation Down sampling error: Yes Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission 30 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel: no fading + correlation sync (8) Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: Yes Submission Frame Detection: YES Phase noise : YES SFD: Yes Sync. : Correlation Down sampling error: Yes 31 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel without Fading + Correlation Sync. (frequency offset estimation) Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: Yes Submission Frame Detection: YES Phase noise : YES SFD: Yes Sync. : Correlation Down sampling error: Yes 32 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel with fading + correlation Sync (1) Frame Detection: No Phase noise: No SFD: No Sync. : Correlation Down sampling error: No Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission 33 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel with fading + correlation Sync (2) Frame Detection: Yes Phase noise : Yes SFD: Yes Sync. : Correlation Down sampling error: No Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission 34 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Nonlinear PA Characteristics Submission 35 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Impact of PA Nonlinearity: 2 x sampling rate (1) Tx PSD without PA (2) Tx PSD with PA For the constant module and continuous phase in our proposal, the Tx PSD is not affected by nonlinear PA. Submission 36 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b AWGN: Ideal Sync. Among E 16, W 16 and COBI 16 Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Submission Frame Detection: No SFD: No 37 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Multipath channel with fading Among E 16, W 16 and COBI 16 Frame Detection: No Phase noise: No SFD: No Sync. : Ideal Down sampling error: No Packet Number: 10000 PSDU Length: 20 Byte Tx/Rx Over Sample Rate: 2 Channel Over Sample Rate: 4 Time offset: No Submission 38 Liang Li, WXZJ

March 2005 doc. : IEEE 802. 15 -05 -0103 -01 -004 b Summary • Enhanced W 16 can satisfy the some criteria – – 1. 2. 3. 4. Equal number of “ 0”s and “ 1”s in preamble sequence; The first chip is not always 0 or 1; Total DC value is 0, even though not always 0 in I or Q route of every sequence; The phase comes back to 0 after one symbol period. • No spikes in frequency spectrum • The sync performance using correlation method is the same as the En-COBI 16 , and the performance of demodulation is about 0. 5 db better than that of En-COBI 16(d 1) • The system PER performance of W 16 is about 0. 5 d. B better than that of En-COBI 16(d 1), especially in condition of large delay spread Submission 39 Liang Li, WXZJ