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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [New C(8,4) chip sequence for Multi-rate OQPSK Modulation ] Date Submitted: [12, May, 2010] Source: [Francois Chin, Yuen-Sam Kwok, Liang Zhang, Liang Li, Tao Xin, Haitao Liu] Company: [Institute for Infocomm Research, Singapore, Vinno, Huawei, SIMIT] Address: [1 Fusionopolis Way #21-01 Connexis South Tower, Singapore ] Voice: [ ] FAX: [] Re: [Response to the call for proposal of IEEE G] Abstract:[This presentation compares all proposals for the IEEE G standard.] Purpose:[Proposal to IEEE G Task Group] Notice:This document has been prepared to assist the IEEE P 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

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 2 Current (8,4)-DSSS code sequence for high rate mode does not support non-coherent receiver. It is desirable choose a code sequences that supports low- complexity non-coherent receiver. Motivation

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 3 Current C(8,4) in Std draft Decimal ValueBinary SymbolChip Value

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 4 Cross-correlation Characteristics for Current C(8,4) in Std draft No modulation; no over-sampling (all in real numbers) (a) cross-correlations of all 16 COBI-C8 codes(b) cross-correlation of one COBI-C8 code

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 5 (a) cross-correlations of all 16 COBI-C8 codes(b) cross-correlation of one COBI-C8 code With O-QPSK modulation; 2x over-sampling (complex domain) Cross-correlation Characteristics for Current C (8,4) in Std draft

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 6 The sequences are related to each other through cyclic shifts and odd-bit inversion. The first 8 and last symbols are both shifted versions of each other. Proposed New Symbol-to-Chip Mapping (8-chip Code Set C 8 ) Decimal ValueBinary SymbolChip Value (Root – 5C)

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 7 Search Based: Other Root Sequences (8-chip C 8 for Coherent Despreading only) The following Root Sequences are found through exhaustive search with identical low cross correlation and autocorrelation, in base 10:

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 8 No modulation; no over-sampling (all in real numbers) (a) cross-correlations of all 16 COBI-C8 codes(b) cross-correlation of one COBI-C8 code Cross-correlation Characteristics for Proposed C8

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 9 (a) cross-correlations of all 16 COBI-C8 codes(b) cross-correlation of one COBI-C8 code With O-QPSK modulation; 2x over-sampling (complex domain) Cross-correlation Characteristics for Proposed C8

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 10 Comparison cross-correlation of one Current C(8,4) code cross-correlation of one Proposed C8 code Several Peaks of the cross-correlation of the Current C(8,4) will introduce more demodulation error with coherent or non-coherent receiver. Hence, the Proposed C8 with only one Peak of the cross-correlation has better demodulation performance.

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 11 Cross-correlation Characteristics The cross-correlation of current C(8, 4) (slide 4) indicates that decoding of the correct symbol based on maximum magnitude of correlation value is not possible

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 12 Autocorrelation Characteristics of C 8 Autocorrelation of all 16 COBI-C8 sequences No modulation; no over-sampling (all in real numbers)

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 13 Autocorrelation Characteristics of C 8 Autocorrelation of all 16 COBI-C8 sequences O-QPSK modulation; 2x over-sampling (complex domain)

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 14 The Benefits of Proposed C8 code The Correlation Calculation is still the basic processing for Decoding. The stronger auto-correlation and improved cross correlation may decrease the PER The Proposed code sequences are a round-shift of two essential codes.

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 15 Simulation parameters & assumptions: –O-QPSK + Raised cosine pulse shape with roll-off factor = 0.8 –20 octets in each packet –20,000 packets for Monte-Carlo simulation –No Sync error –No SFD detection –Both Coherent and Non-coherent demodulation System Performance

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 16 The Definition for Coherent and Non- Coherent Receivers Coherent receiver –phase of received signal is synchronized –symbol detection based on maximum correlation value Non-coherent receiver –phase of received signal is not synchronized –symbol detection based on magnitude of correlation value

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 17 Performance Comparison (BER)

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 18 Performance Comparison (PER)

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Doc.: IEEE g Submission July 2010 I 2 R, Vinno Slide 19 New proposed COBI-C s has the better cross-correlation Characteristics The Proposed code sequences are a round-shift of two essential codes. For low-complexity non-coherent receiver, New proposed COBI- C 8 performance is much better. Suggestion: Adopt New Cobi-C8 chip sequence and instead of the current C(8,4) sequence in draft. Summary and Suggestion

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