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

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [FEC coding for TG4a] Date Submitted: [19 October 2005] Source: [Kenichi Takizawa, Huan-Bang Li, and Ryuji Kohno] Company [NICT] Voice: [+81 46 847 5085], E-Mail: [lee@nict.go.jp]

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

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  1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [FEC coding for TG4a] Date Submitted: [19 October 2005] Source: [Kenichi Takizawa, Huan-Bang Li, and Ryuji Kohno] Company [NICT] Voice:[+81 46 847 5085], E-Mail: [lee@nict.go.jp] Abstract: [FEC coding proposal] Purpose: [Assist the group in the selection of a modulation scheme] 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. Takizawa, Li, and Kohno (NICT)

  2. FEC Option 1 Takizawa, Li, and Kohno (NICT)

  3. 64 TB (PRF=494MHz) 32 TB (PRF=247MHz) Ts = Duration of one symbol = Modulation : bursts and peak PRF • PRF = 494MHz: 1 pulse = 1 chip ~ 2ns; 1TB ~ 16ns • PRF = 247MHz 1 Pulse = 2 chips ~4ns; 1TB ~ 32ns TB = burst duration = One code = 8pulses ~ 1us Takizawa, Li, and Kohno (NICT)

  4. S S S S 47 47 47 47 48 48 48 48 0 0 0 0 1 1 1 1 31 31 31 31 32 32 32 32 33 33 33 33 63 63 63 63 15 15 15 15 16 16 16 16 -S -S -S -S Modulation : 2PPM+BPSK Guard time for channel delay spread (260ns) Code scrambling interval coherent non-coherent One codeburst with PRF = 494 MHz One code bust with PRF = 247 MHz Takizawa, Li, and Kohno (NICT)

  5. S S S S S S S S -S -S -S -S -S -S -S -S 23 23 23 23 23 23 23 23 24 24 24 24 24 24 24 24 39 39 39 39 39 39 39 39 40 40 40 40 40 40 40 40 47 47 47 47 47 47 47 47 48 48 48 48 48 48 48 48 56 56 56 56 56 56 56 56 57 57 57 57 57 57 57 57 0 0 0 0 0 0 0 0 31 31 31 31 31 31 31 31 32 32 32 32 32 32 32 32 63 63 63 63 63 63 63 63 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 15 15 15 15 15 15 15 15 16 16 16 16 16 16 16 16 Guard time for channel delay spread (130ns) Modulation : 4PPM+BPSK One codeburst with PRF = 494 MHz One code bust with PRF = 247 MHz Takizawa, Li, and Kohno (NICT)

  6. K=3 Convolutional coding with 2PPM+BPSK ~1000ns 0 code 0..0 0..0 0..0 0..0 0..0 0..0 0..0 1 0..0 0..0 0..0 0..0 code 0..0 0..0 0..0 D D 0 -> +1 1 -> -1 Coherent receiver K=3 Viterbi decoder (coding rate = 1/2) Non-Coherent receiver ~1000ns Uncoded 0 code 0..0 0..0 0..0 0..0 0..0 0..0 0..0 1 0..0 0..0 0..0 0..0 code 0..0 0..0 0..0 D D Takizawa, Li, and Kohno (NICT)

  7. K=3 Convolutional coding with 4PPM+BPSK ~1000ns 00 code 0..0 0..0 0..0 0..0 0..0 0..0 0..0 01 0..0 0..0 code 0..0 0..0 0..0 0..0 0..0 10 0..0 0..0 0..0 0..0 code 0..0 0..0 0..0 11 0..0 0..0 0..0 0..0 0..0 0..0 code 0..0 D D 0 -> +1 1 -> -1 Coherent receiver K=3 Viterbi decoder (coding rate = 1/3) Non-Coherent receiver K=3 Viterbi decoder (coding rate = 1/2) This FEC code is suitable for non-coherent receiver. D D Takizawa, Li, and Kohno (NICT)

  8. K=4 Convolutional coding with 4PPM+BPSK ~1000ns 00 code 0..0 0..0 0..0 0..0 0..0 0..0 0..0 01 0..0 0..0 code 0..0 0..0 0..0 0..0 0..0 10 0..0 0..0 0..0 0..0 code 0..0 0..0 0..0 11 0..0 0..0 0..0 0..0 0..0 0..0 code 0..0 D D D 0 -> +1 1 -> -1 Coherent receiver K=4 Viterbi decoder Non-Coherent receiver 00 code 0..0 0..0 0..0 0..0 0..0 0..0 0..0 Punctured K=2 Viterbi decoder 01 0..0 0..0 code 0..0 0..0 0..0 0..0 0..0 10 0..0 0..0 0..0 0..0 code 0..0 0..0 0..0 11 0..0 0..0 0..0 0..0 0..0 0..0 code 0..0 D D D Takizawa, Li, and Kohno (NICT)

  9. Simulation results on AWGN Takizawa, Li, and Kohno (NICT)

  10. Simulation results on CM1 and CM8 peak PRF = 494MHz Takizawa, Li, and Kohno (NICT)

  11. Eb/N0 required for PER of 1% (AWGN) Takizawa, Li, and Kohno (NICT)

  12. Eb/N0 required for PER of 1% (Multipath) upper: 4-finger Rake bottom:8-finger Rake Takizawa, Li, and Kohno (NICT)

  13. Complexity comparison *: 4PPM+BPSK c1 c2 4PPM DEC c0 c1 c2 b FEC DEC c0 3M 1Mbps BPSK DEC 1/3-rate code Takizawa, Li, and Kohno (NICT)

  14. Additional information(if we allow iterative processing) Takizawa, Li, and Kohno (NICT)

  15. K=3 code with 2PPM + BPSK using iteration 4BOK mapping ~1000ns 0 code 0..0 0..0 0..0 0..0 0..0 0..0 0..0 Systematic 0..0 0..0 0..0 0..0 code 0..0 0..0 0..0 1 Systematic Convolutional Encoder K=3 R=1/2 interleaver Parity 0 -> +1 1 -> -1 interleaver Convolutional interleaver Coherent Receiver: Convolutionalcode Rate = ½ Non Coherent Receiver: Uncoded 2 4 6 The memory requirement is 12. Coherent receiver Iterative demapping and decoding (IDD) between 4BOK demapper and K=3 half-rate Viterbi decoder ADC code correlator 4BOK decoder FEC decoder deinterleaver interleaver code correlator outputs for each time slot Takizawa, Li, and Kohno (NICT)

  16. Improved performance with iteration Generation polynomial G=[1,5/7] 2dB gain by 3 iterations Takizawa, Li, and Kohno (NICT)

  17. Improved performance with iteration Generation polynomial G=[1,5/7] Takizawa, Li, and Kohno (NICT)

  18. K=3 code with 4PPM + BPSK using iteration ~1000ns 00 code 0..0 0..0 0..0 0..0 0..0 0..0 0..0 systematic 01 Systematic Convolutional Encoder 1 K=3 R=1/2 0..0 0..0 code 0..0 0..0 0..0 0..0 0..0 parity 0..0 0..0 0..0 0..0 code 0..0 0..0 0..0 10 11 interleaver systematic 0..0 0..0 0..0 0..0 0..0 0..0 code 0..0 Systematic Convolutional Encoder 2 K=3 R=1/2 Not use parity 0 -> +1 1 -> -1 Convolutional interleaver Coherent Receiver: Convolutionalcode Rate = 1/3 Non Coherent Receiver: Convolutional code Rate = 1/2 2 4 6 The memory requirement is 12. Coherent receiver Iterative decoding between the two K=3 half-rate decoders 4BOK decoder FEC decoder 2 ADC code correlator FEC decoder 1 deinterleaver interleaver Takizawa, Li, and Kohno (NICT)

  19. Improved performance with iteration Generation polynomial G=[1,5/7] 2.4dB gain by 4 iterations Takizawa, Li, and Kohno (NICT)

  20. Improved performance with iteration Generation polynomial G=[1,5/7] Takizawa, Li, and Kohno (NICT)

  21. Complexity comparison with FEC 1 Coherent detection 2.5dB 4.1dB Takizawa, Li, and Kohno (NICT)

  22. Conclusion FEC Option 1 • Three combinations of convolutional codes with MBOK were shown. • (a) K=3 convolutional code (rate=1/2) with 2PPM+BPSK • (b) K=3 convolutional code (rate=1/3) with 4PPM+BPSK • (c) K=4 convolutional code (rate=1/3) with 4PPM+BPSK • (a) reasonable performance with lowest complexity. • (b) best performance for non-coherent by trading off that for coherent. • (c) best performance for coherent receiver with increased complexity. Iterative processing • If we approve the use of a bit-wise interleaver, we can use iterative processing at coherent receivers. • Trade-off between coding gain and decoding complexity Takizawa, Li, and Kohno (NICT)

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