1. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 1 Advanced Coding Comparison Marie-Helene Hamon, John Benko France Telecom Apurva ModyIndependant With Contributions from : Claude Berrou ENST Bretagne Jacky TouschTurboConcept Brian EdmonstoniCoding

2. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 2 Outline Coding proposals in TGn Advanced FEC Code Requirements for TGn Comparing Codes –Complexity –Performance Facts & Recommendations

3. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 3 Coding Proposals in TGn (Historical) Partial (13): –NokiaLDPC –Infocomm ResearchLDPC –ST MicroLDPC –NortelLDPC –PanasonicLDPC –HughesLDPC –InprocommLDPC –Sharp7/8 CC –PhilipsConcatenated RS –TrelliswareHybrid LDPC/TurboCode –France TelecomTurbo Code –MotorolaTurbo Code –WwiseTurbo Code Full: –TGnSyncLDPCOptional –Wwise LDPCOptional –MitMotTurbo CodeOptional –QualcommNone

4. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 4 Advanced FEC Code Requirements Performance –Much better than 802.11a CC –Must have good performance for all possible blocksizes (small and large) Small blocksize example: VoIP packets (as small as 50 bytes) Large blocksize example: Streaming HD-Video Latency –Low, < 6 us –Good performance with a small number of iterations Implementation –Low Cost – small die size (memory and logic) –Mature, 802.11 – Chipsets require fast time to market Should not be held up due to a FEC without a well-defined implementation

5. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 5 Complexity Comparison Chip Area –Number of Gates –Technology used (ex. ASIC 0.13 mm, average density of 222 kgates/mm 2 ) –Degree of Parallelism (relates also to max decoded bit-rate) Latency < 6 ms –Number of Iterations –Degree of Parallelism –Clock Frequency used (typical F clk =200 MHz) Example Comparison Chart CodeMax Encoded Block Size F clk MHz PN it Total Memory Decoded Rate(Max) Max Latency Area (.13 mm) Wwise LDPC+ 1944 bits240?12?300 Mbps 6.0  s ? Sync LDPC 1728 bits??????? Turbo Code* duo-binary 2048 bits2008559 kbits320 Mbps 4.8  s 1.4 mm 2 20012568 kbits480 Mbps 3.2  s 2.0 mm 2 20012868 kbits200 Mbps 5.12  s 2.0 mm 2 *Estimates from [4] +Estimates from [1]

6. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 6 Performance Comparison

7. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 7 ST-Micro (Wwise)* LDPCC SISO AWGN BPSK + N=1744 bits Wwise LDPCC -972 bits (121.5 bytes) 12i => 600kGates, 6 us Duo-Binary TC -976 bits (122 bytes) 8i, P=12 => 2.0 mm 2, 5.12 us TGnSync LDPCC -Equivalent not found *Wwise Results from Berlin presentation [1] + BPSK, R=1/2 proposed as optional mode in Wwise

8. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 8 Wwise LDPCC* 2x2 SDM, AWGN 64-QAM, R=3/4 Gains over CC @ 10 -2 PER LDPCC: ~2.4 dB (12 iterations) TC : ~3.2 dB (8 iterations) *Wwise Results taken from [2] TC LDPCC CC

9. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 9 LDPCC from.16e* *LDPCC here [3] is slightly different from what is used in TGnSync SISO, AWGN, QPSK, R=1/2 LDPCC - 50 iterations (unrealistic) TC - 8 iterations (realistic) TC Gains over LDPCC@ 10 -2 PER N=2304: 0.2 dB N=576 : 0.3 dB (increase with smaller block size) TC LDPCC

10. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 10 Facts & Recommendations Modularity –Performance of the FEC code is independant of system –Codes proposed can be easily put into WWise and TGnSync Difficult to compare –From FRCC, code performance seen only in context of full system –Current two proposed specfications differ Wwise nor TGnSych provided simulation results for their code with other proposal –Codes compared in performance should be of similar complexity –Very little precise complexity results have been seen to this date Mature code –Enables pre and 1 st production devices to ship with advanced coding options. Action Item? –Re-thinking (creating) an advanced coding selection process will decrease the chances of selecting an advanced coding scheme that is not in the best interest of TGn –Suggestion: Investigate coding options in a separate coding sub-group

11. doc.: IEEE 802.11-05/0146r1 Submission March 2005 John Benko, Marie-Helene Hamon, France TelecomSlide 11 References [1] IEEE 802.11-04/400r4, " ST Microelectronics LDPCC Partial Proposal for 802.11n CFP”, ST Micro, September 2004. [2] IEEE 802.11/04-0877-09-000n, “WWiSE proposal response to functional requirements and comparison criteria.” [3] IEEE 802.16e-0/006, " LDPC Coding for OFDMA PHY", January 2005. [4] IEEE 802.11-04/1382r1, "Turbo Codes: Complexity Estimates", TurboConcept France Telecom R&D, November 2004. [5] http://www.uspto.gov [6] C. Berrou, A. Glavieux, P. Thitimajshima, "Near Shannon limit error- correcting coding and decoding: Turbo Codes", ICC93, vol. 2, pp. 1064-1070, May 93. [7] C. Berrou, "The ten-year-old turbo codes are entering into service", IEEE Communications Magazine, vol. 41, pp. 110-116, August 03. [8] C. Berrou, M. Jezequel, C. Douillard, S. Kerouedan, "The advantages of non-binary turbo codes", Proc IEEE ITW 2001, pp. 61-63, Sept. 01.