1. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 1 A 3-Dimensional Joint Interleaver for 802.11n MIMO Systems Jeng-Hong Chen (jhchen2@winbond.com) Pansop Kim (pkim@winbond.com) Winbond Wireless Design Center Torrance, CA, USA September 2004

2. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 2 Simulation Parameters (based on 11a) 2X2, 2X3, 2X4, 3X2, 3X3, 3X4, 4X2, 4X3, 4X4 antennas 11n Channel B, D, E and 11g uncorrelated exponential channel OFDM based on 11a: 64-pt FFT (only 48 data sub-carriers) 10% PER over 1000 simulated packets 1000 un-coded bytes per packet Perfect CSI, Perfect AFC, AGC, ACQ No pulse shaping filter, no ADC/DAC CC rates=1/3,1/2, 2/3,3/4,7/8 from ½ CC code (K=7) with puncturing/repetition BPSK, QPSK, 16QAM, 64QAM Interleaver defined in 11a and joint interleaver 6, 8, 12, 18, 24, 36, 48, 63 Mbps per transmit antenna MMSE Receiver

3. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 3 System Models PART-I: Joint 3D Space-Frequency-Time Interleaver PART-II: Circulation Transmittion (1) OFDM Symbol Based Circulation (2) Sub-carrier Based Circulation PART-III: Coding Rates & MIMO Tables

4. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 4 Challenges of MIMO Interleaver Design L=Number of OFDM symbols from FEC outputs N I =Number of OFDM symbols per 3D Joint Interleaver N OFDM = Number of OFDM symbols are transmitting at the same time M=Number of transmitter antennas (M  N OFDM ) N CBPS =Number of coded bits per OFDM symbol N sub =Number of data sub-carriers per OFDM symbol N BPSC =Number of coded bits per sub-carrier Example: L=18, N I =6, N OFDM =2, M=3, and N sub =48 (see next page) How to choose an appropriate interleaver size, N I, for a MIMO system? How to transmit N OFDM (  M) OFDM symbols at the same time from M TX Ant.? How to interleave total N I *N CBPS coded bits from FEC outputs and map into –N I *N sub sub-carriers (frequency domain) and various N BPSC for different QAM –M TX antennas (spatial domain) and –N I total OFDM symbols and N OFDM at the same time?

5. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 5 Example: L=18, N I =6, N OFDM =2, M=3, and N sub =48 Uncoded bits 18 OFDM 6 OFDM ? Time=t9 t8 t7 t6 t5 t4 t3 t2 t1 1 OFDM ?

6. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 6 PART-I: 3D Joint Interleaver

7. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 7 Transmitting Total L OFDM Symbols from M TX Antennas Properties of a MIMO OFDM System: –Diversities include space (antennas),frequency (sub-carrier),and transmission in times –Adjacent coded bits from FEC are highly correlated within d free bits –Same sub-carrier (frequency domain) from different antennas are correlated –The correlation between adjacent sub-carriers are strongly correlated especially if rms of delay spreading is small. Purpose of 3D Joint interleaver (Part-II) and Circulation Transmission (Part-III) –Adjacent FEC coded bits are transmitted from nonadjacent sub-carriers and different TX antennas Coded bits has L OFDM symbols N I OFDM symbols N I OFDM symbols MIMO Circulation To M TX Antennas A(k) B(j) 1D input bit stream 1D output bit stream 1-to-1 mapping

8. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 8 11a Interleaver Two-step permutation –First permutation To ensure that adjacent coded bits are mapped onto nonadjacent subcarriers Three subcarrier separations between consecutive coded bits Example: N BPSC =1, N CBPSC =48 036…45 147…46 258…47 012…15 161718…31 323334…47 –Second permutation (Only applied to 16QAM and 64QAM) To ensure that adjacent coded bits are mapped alternately onto less and more significant subcarriers 11a Interleaver A(K)B(j) Writing order (index of k) Reading order (index of j)

9. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 9 Parallel 11a Interleavers (A1) Adjacent bits (ex, A(0), A(1), A(2) and A(3)) are assigned to the same TX antenna. Performance is worse if low correlations between Tx antennas and small delay spread. 01234567 … 47 OFDM 0A(0)A(16)A(32)A(1)A(17)A(33)A(2)A(18) … A(47) OFDM 1A(48)A(64)A(80)A(49)A(65)A(81)A(50)A(66) … A(95) OFDM 2A(96)A(112)A(128)A(97)A(113)A(129)A(98)A(114) … A(143) OFDM 3A(144)A(160)A(176)A(145)A(161)A(177)A(146)A(162) … A(191) Example: N I =4,N BPSC =1, N CBPS =48 Coded bits from FEC outputs

10. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 10 Parallel 11a Interleavers (A2) Adjacent bits (ex, A(0), A(1), A(2) and A(3)) are assigned to the same subcarrier. Performance is worse if high correlations between Tx antennas and large delay spread. 01234567 … 47 OFDM 0A(0)A(64)A(128)A(4)A(68)A(132)A(8)A(72) … A(188) OFDM 1A(1)A(65)A(129)A(5)A(69)A(133)A(9)A(73) … A(189) OFDM 2A(2)A(66)A(130)A(6)A(70)A(134)A(10)A(74) … A(190) OFDM 3A(3)A(67)A(131)A(7)A(71)A(135)A(11)A(75) … A(191) Example: N I =4,N BPSC =1, N CBPS =48 Coded bits from FEC outputs

11. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 11 2D Joint 11a interleaver Example: N I =4,N BPSC =1, N CBPS =48 –First Permutation (the number of rows is N I times.) Writing order (index of k) Reading Order (index of j) 01224…180 11325…181 21426…182 …………… 112335…191 012…15 161718…31 323334…47 …………… 176177178…191 –Second Permutation The same as the 11 a interleaver Only apply to 16QAM and 64QAM

12. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 12 2D Joint 11a Interleaver (B1) Adjacent bits (ex, A(0), A(4),A(8), and A(12).) are assigned to the same subcarrier, Performance is worse if high correlations between Tx antennas and large delay spread. 0123 … 12 … 24 … 47 OFDM 0A(0)A(16)A(32)A(48) … A(1) … A(2) … A(179) OFDM 1A(4)A(20)A(36)A(52) … A(5) … A(6) … A(183) OFDM 2A(8)A(24)A(40)A(56) … A(9) … A(10) … A(187) OFDM 3A(12)A(28)A(44)A(60) … A(13) … A(14) … A(191) Example: N I =4,N BPSC =1, N CBPS =48

13. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 13 2D Joint 11a Interleaver (B2) Adjacent bits (ex, A(0), A(1), A(2),.. and A(15)) are assigned to the same TX ant. Performance is worse if low correlations between Tx antennas and small delay spread. 01234567 … 47 OFDM 0A(0)A(64)A(128)A(1)A(65)A(129)A(2)A(66) … A(143) OFDM 1A(16)A(80)A(144)A(17)A(81)A(145)A(18)A(82) … A(159) OFDM 2A(32)A(96)A(160)A(33)A(97)A(161)A(34)A(98) … A(175) OFDM 3A(48)A(112)A(176)A(49)A(113)A(177)A(50)A(114) … A(191) Example: N I =4, N BPSC =1, N CBPS =48

14. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 14 Proposed 3D Joint Interleaver Purposes –Backward compatible with 11a interleaver and preserve all good properties –To separate consecutive bits by 3*N BPSC or 3 sub-carriers. –To assign consecutive bits to different OFDM symbols Example: N I =4, N BPSC =1, N CBPS =48 0123456789101112 … 47 OFDM 0A(0)A(64)A(128)A(17)A(81)A(145)A(34)A(98)A(162)A(51)A(115)A(179)A(4) … A(191) OFDM 1A(16)A(80)A(144)A(33)A(97)A(161)A(50)A(114)A(178)A(3)A(67)A(131)A(20) … A(143) OFDM 2A(32)A(96)A(160)A(49)A(113)A(117)A(2)A(66)A(130)A(19)A(83)A(147)A(36) … A(159) OFDM 3A(48)A(112)A(176)A(1)A(65)A(129)A(18)A(82)A(146)A(35)A(99)A(163)A(52) … A(175) Rotating the output bits of 2D 11a Joint Interleaver (B2) to different OFDM symbol

15. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 15 Indexing of Proposed 3D Joint Interleaver k: the index of coded bit before the first permutation i: the index after the first and before the second permutation j: the index after the second permutation, just prior to modulation mapping  First permutation rule where  Second permutation rule where  This interleaver can be easily implemented with 3D block memory

16. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 16 Input/Output Indexing (BPSK, N I =4, N CBPS =48) Input Index A(k) Output Index B(j) adjacent 3 sub-carrriers adjacent FEC coded bits different OFDM symbols

17. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 17 Generalized 3D Joint Interleaver N I =width of 3D interleaver=number of OFDM symbols N column =length of 3D interleaver=number of columns N row =N CBPS /N column =height of 3D interleaver=number of rows N SCPC =N CBPS /N row =number of subcarriers in one column N CBPS = N row  N column =number of bits per OFDM symbol N SC = N SCPR  N column =number of subcarriers per OFDM symbol Guaranteed separation of consecutive coded bits is N SCPC subcarriers. Guaranteed separation of coded bits in consecutive subcarriers is (N I  N column ) bits  First permutation rule where  Second permutation rule where

18. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 18 Generalized 3D Joint Interleaver Input Index A(k) Output Index B(j) N I bits N column bits N row bits N SCPC =N row /N BPSC Sub-carriers  Applicable to all numbers of TX antennas, e.g., N I =1,2,3,4,5,…  Applicable to all QAM modulations, e.g., N BPSC =1(BPSK),2(QPSK),4(16QAM), 6(64QAM),8,…  Applicable to both 20MHz and 40 MHz bandwidth  EX: N SC =48 (11a),54,96,108,114, or other numbers of subcarriers  EX: N column =6, 16 (11a),18 or other numbers of bits per column Choose N column  consecutive coded bits has N SCPR =N SC /N oolumn subcarriers separation  EX: BW=40MHz, N SC =108, N column =18, N SCPR =6 subcarriers separation N SC (subcarriers)= N SCPR  N column N CBPS (bits)= N row  N column

19. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 19 3D Joint Interleaver vs. Parallel 11a Interleaver (A2) Channel D, half lambda, 2X2 SMX 3D Joint interleaver performs better as expected.

20. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 20 3D Joint interleaver vs. 2D Joint 11a Interleaver (B1) Channel B, half lambda, 2(4)X2 CSMX 3D Joint Interleaver performs better.

21. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 21 Input/Output Indexing (QPSK, N I =4, N CBPS =96) Input Index A(k) Output Index B(j)

22. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 22 Input/Output Indexing (16QAM, N I =4, N CBPS =192) Input Index A(k) Output Index B(j) 2 nd Permutation

23. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 23 Input/Output Indexing (64 QAM, N I =4, N CBPS =288) Input Index A(k) Output Index B(j) 2 nd Permutation

24. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 24 TGn Sync Interleaver (IEEE 802.11-04/889r0) Ex. 20 MHz, N BPSC =1, N I =4, N CBPS =48, N column =16 Note: N SS =4 in the definition of above document. j 0123456789101112131415…47 k, OFDM 00641284681328721361276140168014420…188 k, OFDM 161125189165129569133973137137714117…185 k, OFDM 25812218662126190266130670134107413814…182 k, OFDM 355119183591231876312719136713177113511…179 Adjacent bits (ex. A(0), A(1), …, A(11)) are not evenly distributed over all subcarriers Adjacent bits (ex. A(3),A(6),A(9),A(12)) are assigned to the same subcarrier. Winbond proposed 3D Joint Interleaver, N BPSC =1, N I =4, N CBPS =48, N column =16 j 0123456789101112131415… k, OFDM 0064128178114534981625111517946813221… k, OFDM 11680144339716150114178367131208414837… k, OFDM 232961604911311726613019831473610016453… k, OFDM 34811217616512918821463599163521161805…

25. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 25 WWiSE Interleaver (IEEE 11-04-0886-00-000n) Ex. 20 MHz, N BPSC =1, N I =4, N CBPS =54 Note: N CBPS =216, N SS =N I, I DEPTH =N column in the definition of above document. j0123456789101112131415161718… k, OFDM 002448729612014416819242852761001241481721968… k, OFDM 112114516919352953771011251491731979335781105129… k, OFDM 2305478102126150174198103458821061301541782021438… k, OFDM 31511751991135598310713115517920315396387111135159… j…38394041424344454647484950515253 k, OFDM 0…648811213616018420820446892116140164188212 k, OFDM 1…18520921456993117141165189213125497397 k, OFDM 2…941181421661902142265074981221461701946 k, OFDM 3…2153275175991231471711957315579103127 Adjacent bits (ex. A(0), A(1), …, A(11)) are not evenly distributed over subcarriers. Some adjacent bits (ex. A(21), A(27)) are on the same subcarrier.

26. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 26 WWiSE Interleaver (IEEE 11-04-0886-00-000n) Note: Equation (14) in the above doc. has been changed from to to shift D n subcarriers for N BPSC =1,2,4 and 6. Winbond proposed 3D Joint Interleaver, N BPSC =1, N I =4, N CBPS =54, N column =18 j0123456789101112131415161718… k, OFDM 00721441991163381101825712920147614823951676… k, OFDM 11890162371091815612820037514722941664111318524… k, OFDM 236108180551271992741462193165401121845913120341… k, OFDM 3541261981731452092164391111835813020257514959…

27. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 27 PART-II: Circulation Transmission Transmission Options: (A)Circular Spatial Multiplexing (CSMX) (B)Circular Space-Time Alamouti (CALA) Circulation Options: (C) OFDM Symbol Based Circulation (S_BC) (D) Sub-carrier Based Circulation (Sub_BC) NOTE: The same proposed 3D Joint Interleaver is applied for all above options.

28. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 28 Why Circulation?  Circulation is one simple way to achieve all available diversities including space, frequency, and time. When Circulation?  Always. Especially when transmitting N OFDM (  M) at the same time from M TX antennas. How Circulation? Together with proposed 3D Joint Interleaver to explore all available diversities

29. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 29 (A) Circular Spatial Multiplexing (CSMX) Transmitting N OFDM (  M) OFDM Symbols from M TX Antennas High throughputs if high SNR (B) Circular of Space-Time Alamouti Code (CALA) Simple to encode and decode Can be easily modified to be compatible with 11a/g Circular Alamouti is applied if more than two transmit antennas Circulation bases on two OFDM symbols to preserve orthogonality Definition: N OFDM (M) denotes a MIMO system transmits N OFDM OFDM symbols at the same time from M TX antennas Transmission Options

30. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 30 Circulation Options for CSMX Systems  (C) OFDM symbol-based circulation (S_BC)  Only N OFDM IFFTs are required  Only N OFDM TX Ant. are transmitting at the same time  (D) Subcarrier-based circulation (Sub_BC)  M IFFTs are required  All M TX Ant. are transmitting at the same time  Smaller size of interleaver than S_BC  Smaller processing delay than S_BC

31. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 31 Circulation Options for CALA Systems (N OFDM=2 )  (C) OFDM symbol-based circulation (S_BC)  Only 2 IFFTs are required  Only 2 TX Ant. are transmitting at the same time  (D) Subcarrier-based circulation (Sub_BC)  M IFFTs are required  All M TX Ant. are transmitting at the same time  Smaller size of interleaver than S_BC  Smaller processing delay than S_BC

32. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 32 Example of a 2 (3) CSMX System

33. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 33 Example of a 2 (3) CALA System

34. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 34 Interleaver Outputs Before Circulation Transmission S-BC (Ex. N I =6, N OFDM =2, M=3) Sub-BC (Ex. N I =2, N OFDM =2, M=3) (D) Sub_BC (C) S_BC

35. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 35 Circulation Patterns for CSMX Pattern # Systems 012345 1(1)0N/A 1(2)01N/A 1(3)012N/A 1(4)0123N/A 2(2)(0,1)N/A 2(3)(0,1)(2,1)(2,0)N/A 2(4)(0,1)(3,2)(0,2)(1,3)(1,2)(0,3) 3(3)(0,1,2)N/A 3(4)(0,1,2)(3,1,2)(3,0,2)(3,0,1)N/A 4(4)(0,1,2,3)N/A Systems NINI S_BCSub_BC 1(1)11 1(2)21 1(3)31 1(4)41 2(2)22 2(3)62 2(4)122 3(3)33 3(4)123 4(4)44 N Pattern = =Number of circulation patterns for both S_BC and Sub_BC N I =N OFDM X N Pattern for CSMX systems with S_BC N I =N OFDM for CSMX systems with Sub_BC NOTE: Bigger N I implies bigger HW size and longer decoding delay

36. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 36 Circulation Patterns for CALA Pattern # Systems 012345 2(2)(0,1)N/A 2(3)(0,1)(2,1)(2,0)N/A 2(4)(0,1)(3,2)(0,2)(1,3)(1,2)(0,3) Systems NINI S_BCSub_BC 2(2)22 2(3)62 2(4)122 N Pattern = = Number of circulation patterns for both S_BC and Sub_BC N I =N OFDM x N Pattern for CALA systems with S_BC N I =N OFDM for CALA systems with Sub_BC NOTE: Bigger N I implies bigger HW size and longer decoding delay

37. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 37 Sub-carrier mapping for Sub-BC Coded bits from FEC outputs Example: 2(3) MIMO System CSMX with Sub_BC 11a/g sub-carrier intrerleaving with 3-sub-carrier separation Circulation subcarriers Into all TX antennas

38. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 38 Example: 2(3) MIMO System CSMX with Sub_BC s012345678910…454647 Pattern(s) 0 12 1 20 2 01 0 1…012 D 0 (s) A(0) 0A(80)0A(33)A(81)A(18)A(34)0A(19)0…A(31)0A(79) D 1 (s)A(16)A(48)0 A(1) 0A(65)0A(50)A(82) A(3) A(35)… A(15) A(47)0 D 2 (s)0A(32)A(64)A(17)A(49)X A(2) 0A(66)0A(51)…0A(63)A(95) s012345678910…454647 Pattern(s)01212020101…012 D 0 (s)C 0 (0)XC 1 (2)XC 1 (4)C 0 (5)C 1 (6)C 0 (7)XC 0 (9)X…C 0 (45)XC 1 (47) D 1 (s)C 1 (0)C 1 (1)XC 1 (3)XC 1 (5)XC 1 (7)C 1 (8)C 1 (9)C 1 (10)…C 1 (45)C 1 (46)X D 2 (s)XC 0 (1)C 0 (2)C 0 (3)C 0 (4)XC 0 (6)XC 0 (8)XC 0 (10)…XC 0 (46)C 0 (47) Subcarrier012345678910…454647 OFDM 0,C 0 (s)A(0)A(32)A(64)A(17)A(49)A(81)A(2)A(34)A(66)A(19)A(51)…A(31)A(63)A(95) OFDM 1, C 1 (s)A(16)A(48)A(80)A(1)A(33)A(65)A(18)A(50)A(82)A(3)A(35)…A(15)A(47)A(79) Coded bits from FEC outputs Adjacent bits have 3-subcarrier separations and circulate into M TX antennas.

39. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 39 Example: 2(3) MIMO CSMX System with S_BC pattern012 TX #0OFDM 0XOFDM 5 1OFDM 3OFDM 4X 2XOFDM 1ODFM 2

40. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 40 Sub-BC and S-BC in 11n Channel B  Two schemes have similar performances. Systems NINI S_BCSub_BC 1(4)41 2(4)122 3(4)123 The interleaver size and decoding delay for Sub_BC is much smaller than S_BC.

41. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 41 Sub-BC and S-BC in 11n Channel D  Two schemes have similar performances. Systems NINI S_BCSub_BC 1(4)41 2(4)122 3(4)123 The interleaver size and decoding delay for Sub_BC is much smaller than S_BC.

42. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 42 RF and BB Related Issues  RF Total TX Power for 2(3) MIMO Systems  Assuming max power of each subcarrier is p,  Total power of OFDM symbol based circulation = 48 * p * 2 = P  Total power of modulated symbol based circulation= 32 * p * 3 = P  Power per antenna is P/2 for S_BC and P/3 for (Sub_BC)  Baseband (BB) hardware requires  Two IFFT/FFT for S_BC and Three for Sub_BC  NOTE: Bigger N I implies bigger HW size and longer decoding delay  Example: 2(4) CSMX requires N I =12 for S_BC and N I =2 for Sub_BC  If the power consumption of more active TX antennas at RF and more active IFFT/FFT at BB are acceptable, Sub_BC is recommended with minimal decoding delay and interleaver size.

43. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 43 Backward Compatibility with 11a/g The proposed 3D Joint Intereleaver is backward compatible to the standardized 11g/11a 2D interleaver –If N I =1, the 3D joint interleaver becomes a 2D 11a/g interleaver –The 3D joint based on 3-subcarrier separation is backward compatible to 11a/g interleaver for all 8 11a data rates –Same 2 nd permutation as 11a Both proposed circulation options (C) S_BC and (D) Sub_BC are backward compatible with 11a interleaver –No circulation (N pattern =1) for option (C) S_B Circulation –The 3-subcarrier separation of consecutive mapped data of option (D) Sub_BC is the same as the 11a interleaver

44. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 44 High Throughput Requirement for 11n The proposed 3D Joint Intereleaver can be implemented into a general MIMO systems with M TX antenna The proposed 3D Joint interleaver supports all 8 data rates in 11a Tables up to 4x4 MIMO systems are shown in this proposal. For a N OFDM (M) MIMO system with M  N OFDM =1,2,…,6,… Size of proposed 3D Joint Interleaver=N I = N OFDM x Example: M=4, data rate of a 4(4) CSMX system is Mx54=216 Mbps The proposed interleaver is a 4x16x18 3D interleaver (N I =4) For a general N OFDM (M) MIMO system, the proposed 3D Joint interleaver can support data rates up to Mx54 Mbps in 20MHz bandwidth, M is any integer

45. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 45 Conclusions Proposed 3D Joint Interleaver which intereleaves adjacent FEC coded bits into all available diversities in space, frequency, and time is recommended. Proposed 3D Joint Interleaver is backward compatible with 11a/g standard interleaver. Proposed OFDM symbol based circulation and sub-carrier based circulation can be applied in all MIMO mode with arbitrary TX antennas, and transmission schemes (CSMX,CALA). Proposed S_BC and Sub_BC is backward compatible to 11a/g. Proposed Sub_BC with minimal decoding delay is recommended

46. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 46 PART-III: Coding Rates Selection and MIMO Tables

47. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 47 Code rate selection 11a selection –6, 9, 12, 18, 24, 36, 48, 54 Mbps –Two problems 9 Mbps (BPSK, 3/4) performs bad. 48 and 54 Mbps is only 6 Mbps difference. Suggestion –Introducing new low code rate Rate 1/3 is generated by repetition of the rate 1/2 coded bits (next page) 9 Mbps (BPSK, 3/4)  8Mbps (QPSK, 1/3) –Introducing new puncturing to increase the max. rate. 7/8 by puncturing pattern (1111010, 1000101) 54 Mbps  63 Mbps

48. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 48 Generate Rate 1/3 from Rate 1/2 To decrease the coding rate from 1/2 to 1/3 Two possible ways –New optimal code: (133, 145, 175) d free =15 New Viterbi decoder is required  Not recommended –By repetition every other coded bit: d free =15 Same Viterbi decoder (mother code rate=½) can be used Repetition method is used for simulations Rate=1/3 Rate=1/2 64 coded bits

49. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 49 Code rate selection Consistent decrease the rates (24% - 33%) by introducing 7/8 rate 9 Mbps is replaced by 8 Mbps. 15 12 6 6 2 4 Rate (Mbps)64QAM16QAMQPSKBPSK 63 7/8 54 3/4 48 2/3 42 7/8 36 1/2 3/4 32 2/3 24 1/3 1/2 21 7/8 18 3/4 16 1/3 2/3 12 1/2 10.5 7/8 9 3/4 8 1/3 2/3 6 1/2

50. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 50 Code rate selection Channel D, half lambda New selection of rates provides more smooth curves, higher data rate

51. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 51 2(M) CALA vs. 1(M) CSMX Channel D, half lambda CALA performs slightly better than 1(M)CSMX. CALA CSMX

52. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 52 Conclusions Proposed new rate, 63 Mbps with new puncturing –Shown to be good for increasing max. rate and consistent rate decreases. –Easily implemented with small hardware addition for new puncturing Proposed new rate, 8 Mbps with repetition –Shown to be better performance than 9 Mbps –Compatible to 11a/g Viterbi decoder 2(M) CALA vs. 1(M) CSMX –2(M) CALA always performs better than 1(M) CSMX –Average performance improvement is less than 0.5 dB –1(M) CSMX is still a candidate since Simpler at both TX and RX Less decoding delay at RX –For 2(M) CALA, at least two OFDM symbol decoding delay is required –For 1(M) CSMX, only one OFDM symbol decoding delay is required

53. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 53 MIMO Mode Table MIMO mode table has been developed in DCN 802.11-04/553r0 based on –Uncorrelated exponential MIMO channels with rms delay spread 50 nsec –CALA and CSMX only –ZFE We develop our MIMO mode table based on –Uncorrelated exp. and channel models given in IEEE P802.11-03/940r3 Channel B, D and E with half lamda antenna separation Exponential Channels with 15, 50 and 100 nsec –CALA, CSMX –MMSE decoding at receiver Some results –Alamouti vs. Circular Alamouti: only small gain for all cases –SMX vs. Circular SMX: large gain especially for small delay spread and non- zero correlation

54. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 54 MIMO Mode Table (M=2,3 or 4, N=2) Rate (Mbps) MIMO Scheme Modulati on Coding Rate Rate decreaseCondition 126(63X2)CSMX64QAM7/8 (new)N/A 96(48X2)CSMX64QAM2/324% 63CSMX or CALA64QAM7/8 (new)34% 48CSMX or CALA64QAM2/324% 36CSMX or CALA16QAM3/425% 24CSMX or CALA16QAM1/233% 18CSMX or CALAQPSK3/425% 12CSMX or CALAQPSK1/233% 8CSMX or CALAQPSK1/3 (new)33% 6CSMX or CALABPSK1/225%

55. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 55 MIMO Mode Table (M=2,3 or 4, N=3) Rate (Mbps)MIMO Scheme Modula tion Coding Rate Rate Decrease Condition 189(63X3)CSMX64QAM7/8 (new)N/AM=3 only 126(63X2)CSMX64QAM7/8 (new)33% 96(48X2)CSMX64QAM2/324% 72(36X2) or 63 CSMX CSMX or CALA 16QAM 64QAM 3/4 7/8 25% 34% 48(24X2) or 48 CSMX CSMX or CALA 64QAM2/3 33% (24%) 36CSMX or CALA16QAM3/425% 24CSMX or CALA16QAM1/233% 18CSMX or CALAQPSK3/425% 12CSMX or CALAQPSK1/233% 8CSMX or CALAQPSK1/3 (new)33% 6CSMX or CALABPSK1/225%

56. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 56 MIMO Mode Table (M=2, N=4) Rate (Mbps) MIMO Scheme Modulat ion Coding Rate Rate Increase Condition 126(63X2)CSMX64QAM7/8 (new)N/A 96(48X2)CSMX64QAM2/324% 72(36X2)CSMX16QMA3/425% 48(24X2) or 48 CSMX CSMX or CALA 16QAM 64QAM 1/2 2/3 33% 36(18X2) or 36 CSMX CSMX or CALA QPSK 16QAM 3/4 25% 24(12X2) or 24 CSMX CSMX or CALA QPSK 16QAM 1/2 33% 18CSMX or CALAQPSK3/425% 12CSMX or CALAQPSK1/233% 8CSMX or CALAQPSK1/3 (new)33% 6CSMX or CALABPSK1/225%

57. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 57 MIMO Mode Table (M=3 or 4, N=4) Rate (Mbps) MIMO Scheme Modulati on Coding Rate Rate Decrease Condition 252(63X4)CSMX64QAM7/8 (new)N/AM=4 only 189(63X3)CSMX64QAM7/8 (new)25% 144(48X3)CSMX64QAM2/324% 108(36X3)CSMX16QAM3/425% 72(24X3) or 72(36X2) CSMX QPSK 16QMA 1/2 3/4 33% 48(24X2) or 48 CSMX CSMX or CALA 16QAM 64QAM 1/233% 36(18X2) or 36 CSMX CSMX or CALA QPSK 16QAM 3/4 25% 24(12X2) or 24 CSMX CSMX or CALA QPSK 16QAM 1/2 33% 18CSMX or CALAQPSK3/425% 12CSMX or CALAQPSK1/233% 8CSMX or CALAQPSK1/3 (new)33% 6CSMX or CALABPSK1/225%

58. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 58 PART-IV: Simulation Results

59. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 59 Simulation Results 11n Channel B (rms delay spread=15ns), D (50ns), and E (100ns) 11a/g uncorrelated exponential channels with rms delay spread=15ns, 50ns, and 100ns Number of receiver antennas, N=2,3,4 are simulated CSMX and CALA are simulated TX/RX antennas from 2x2 up to 4x4 are simulated Proposed Joint Interelaver is applied to all cases Antenna spacing is ½ MMSE decoding at receiver Details of simulation parameters are listed on page 1.

60. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 60 11n Channel B (rms=15ns), N=2 SMX v.s. CSMX Improvements found when compared CSMX v.s. SMX and CALA v.s. ALA 2x63Mbps 2x48 Mbps 2x36 Mbps 2x24 Mbps 2x18 Mbps 2x12 Mbps 2x8 Mbps 2x6 Mbps

61. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 61 11n Channel B (rms=15ns), N=3 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA 2(M) 1(M) 2(M) CSMX v.s. CSMX vs CALA

62. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 62 11n Channel B (rms=15ns), N=4 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA 2(M) 1(M) 2(M) CSMX v.s. CSMX vs CALA

63. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 63 11n Channel D (rms=50ns), N=2 SMX v.s. CSMX v.s. CALA

64. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 64 11n Channel D (rms=50ns), N=3 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA

65. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 65 11n Channel D (rms=50ns), N=4 SMX v.s. CSMX SMX v.s. CSMX

66. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 66 11n Channel E (rms=100ns), N=2 SMX v.s. CSMX v.s. CALA

67. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 67 11n Channel E (rms=100ns), N=3 SMX v.s. CSMX SMX v.s. CSMX

68. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 68 11n Channel E (rms=100ns), N=4 SMX v.s. CSMX SMX v.s. CSMX

69. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 69 Exponential Channel, rms=15ns, N=2 SMX v.s. CSMX v.s. CALA

70. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 70 Exponential Channel, rms=15ns, N=3 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA

71. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 71 Exponential Channel, rms=15ns, N=4 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA

72. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 72 Exponential Channel, rms=50ns, N=2 SMX v.s. CSMX v.s. CALA

73. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 73 Exponential Channel, rms=50ns, N=3 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA

74. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 74 Exponential Channel, rms=50ns, N=4 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA

75. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 75 Exponential Channel, rms=100ns, N=2 SMX v.s. CSMX v.s. CALA

76. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 76 Exponential Channel, rms=100ns, N=3 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA 2(M) 1(M) 2(M) CSMX v.s. CSMX vs CALA

77. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 77 Exponential Channel, rms=100ns, N=4 SMX v.s. CSMX SMX v.s. CSMX v.s. CALA 2(M) 1(M) 2(M) CSMX v.s. CSMX vs CALA

78. doc.: IEEE 802.11-04/934r1 Submission September 2004 Jeng-Hong Chen, Pansop Kim, Winbond ElectronicsSlide 78 Conclusions Proposed 3D interleaver distributes FEC coded bits to all available diversities in space, time, and frequency Proposed 3D interleaver is backward compatible to 802.11a systems Proposed 3D interleaver is applicable to both 20MHz and 40MHz bandwidths with total 64 or 128 I/FFT subcarriers Proposed TX circulations outperform TX schemes without TX circulations (CSMX v.s. SMX, CALA v.s. ALA) Proposed sub-carrier based TX circulations which has smaller interelaver size and decoding delay is highly recommended.