doc.: ieee 802.11-04/913r4 submission september 2004 slide 1 ieee 802.11n phy motorola ht partial...

September 2004 doc.: IEEE 802.11-04/913r4

Slide 1Submission

IEEE 802.11n PHY Motorola

HT Partial Proposal

Alexandre Ribeiro Dias, Stéphanie Rouquette-Léveil, Markus Muck, Marc de Courville, Jean-Noël Patillon,

Sébastien Simoens, Karine Gosse,

Keith Blankenship, Brian Classon

Motorola Labs


Slide 2Submission

Overview

• Overall goal and key features of proposal

• Turbo Codes

• Multiple-Antenna schemes

• OFDM modulator and data rates

• Preamble definitions

• Simulation results

• Hardware complexity estimation


Slide 3Submission

Overall goal of the proposed PHY design

Modification of IEEE 802.11a-1999 PHY in order to provide new OFDM PHY modes meeting the IEEE802.11n PAR with:

• High spectrum efficiency for achieving target performance with increased data rates

– Data streams transmitted in parallel using multi-antenna transceivers– Optimized multi-carrier modulation with lower overhead– Enhanced forward error correction schemes

• Improved link budget for lower to medium data rates– Providing the IEEE802.11a PHY data rates with increased range/link quality– Adapted to the support of services requiring small packet size such as VoIP– Exploit multi-antenna capabilities for robust transmission modes– Turn gains in spectral efficiency into link budget advantages

• Favored short term implementation and deployment with robust, low complexity techniques

– Open-loop multi-antenna solutions: simple, robust and without protocol overhead (feedback signalization)

– Improve operation in limited Outdoor environments with support of long channel impulse responses


Slide 4Submission

Key features (1/2)

• Multi-antenna extension:– MIMO with at least 2Tx/2Rx antennas scaling up to 4Tx– Support for asymmetric antenna configurations to accomodate

various classes of devices– Open-loop modulation technique

• Second OFDM modulator (optional):– 2 bandwidths supported: 20MHz and 40MHz– Optionally 128 carriers in 20/40MHz with 104 data carriers, and

guard interval of 32 samples• 8% PHY rate increase for 20MHz mode• 117% PHY rate increase for 40MHz mode vs 20MHz/64-carriers

• Turbo Codes: Increase roubustness


Slide 5Submission

Key features (2/2)

• New nPLCP preambles for MIMO support(same for 64- and 128-point IFFT/FFT)

• High order modulation (optional): 256-QAM

• Space/frequency interleaver

• Compatibility to legacy systems:– IEEE 802.11a convolutional code with code rates 1/2, 2/3, 3/4 and

5/6


Slide 6Submission

Turbo Codes: Motivation

• Stable, well-understood technology• Good performance• Block size and code rate flexibility

– Padding can be used to reduce number of interleavers– Puncturing patterns simple to describe and implement

• Incremental redundancy procedures easily defined• Highly parallelizable “parallel window” decoder architecture

– Easily scaled to meet latency requirements• Motorola 2048-bit information block implementation benchmark of 10s

per iteration on 2001-era FPGA scales to 1.25s per iteration on current technology ASIC with clock rate increase and window size decrease

– Interleavers can be parallelized to avoid memory contentions without performance penalty

• Known intellectual property landscape


Slide 7Submission

Coding Functional Description

scramb-ling

paddinginsertion

segment-ation

turboencoding

paddingremoval

puncturing

repeated for each segment

SE

RV

ICE

+ P

SD

U

. . .

code blocksto OFDM

modulator

• Scrambling before padding insertion– Before decoding, receiver may insert large LLRs at known locations

• Padding– Inserts minimum number of zeros to make block size multiple of 512 bits– Zeros are inserted uniformly across the SERVICE+PSDU at the ends of

256-bit sub-blocks– Turbo interleaver maps padding to odd-numbered positions in second

encoder

• Segmentation– Breaks padded sequence into 2048-bit segments plus at most one segment

of length 512, 1024, or 1536 bits


Slide 8Submission

Turbo Encoder

• Rate-1/3 3G turbo code polynomials– Code rates 1/2, 2/3, 3/4, and 5/6 can be

achieved exactly through puncturing

• Contention-free turbo interleavers– Performance nearly identical to WCDMA

down to 104 frame error rates

• Constituent encoders left unterminated– Helps preserve exact code rate

– Negligible performance degradation

D D D

D D D

X

Y1

constituent encoder 1

constituent encoder 2

Y2


Slide 9Submission

Contention-Free Interleavers• Inter-window shuffle (IWS) interleaver

i = output position(i) = input position() = bit reversal intra-window permutation (same for all windows)(j) = {0(j),1(j),,M1(j)} = j-th permutation of {0,1,,M1} (periodic)

M = number of windows (2,4,6,8 for block size 512,1024,1536,2048, resp.)

window 0

W

(j) = {2,0,...,1}

j j+W

(j) (j)+W

(j)+2W

(j)+

(M 1)W

window 0

window 1

window 1

window 2

window 2

window M 1

window M 1

j+2W

j+(M

1)W

256mod256256modρ 256 iii i


Slide 10Submission

Non-Termination Performance• 8-th iteration static binary channel FER with IWS

interleavers (no tail compared with full 12-bit tail)

• Non-termination helps preserve exact code rate with negligible performance impact

512-bit block 2048-bit block


Slide 11Submission

Padding Removal• To preserve code rate, all padding bits and

associated parity bits (i.e., on same trellis step) are removed prior to puncturing

constituentencoder

1

constituentencoder

2

turbointerleaver

zero-padded information block

turbo encoder

known zero bit

unknown parity bit associated with known zero bit

KEY

removed padding


Slide 12Submission

Multi-antenna aspects of the proposal

• Transmission of 1, 2 or 3 parallel streams using: – Space-Time Block Coding (STBC), Spatial Division Multiplexing (SDM) or robust

hybrid solutions (STBC/SDM) optimize the rate vs link budget trade-off

• 2, 3 or 4 transmit antennas– The number of receive antennas determines the maximum number of spatial

streams that can be transmitted.– The capability of decoding 2 parallel data streams is mandatory – all the devices have to be able to decode all the modes where the number of spatial

streams is lower or equal than the number of receive antennas in the device. – It is required for a device to exploit all its antennas in transmission even for

optional modes.• 2 or more receive antennas

– With STBC or STBC/SDM, asymmetric antenna configurations can be supported• Importance of configurations in which NTx ≠ NRx

– NTx > NRx e.g. between AP and mobile handset (in DL)– NTx < NRx e.g. between MT and AP (UL), or if MT have upgraded multi-antenna

capabilities compared to AP (infrastructure upgrade cost)


Slide 13Submission

T r a n s m is s io n o f 3 s p a t ia l s t r e a m s( S D M )

T r a n s m is s io n o f 2 s p a t ia l s t r e a m s( S T B C )

*2s 1s

*1s 2s*4s 3s

*2s 1s

*1s 2s*4s 3s

s p a t ia l s t r e a m # 1


*2s 1s

*1s 2s*4s 3s

*2s 1s

*1s 2s*4s 3s




s p a tia l s t r e a m # 2

s p a tia l s t r e a m # 3

1s

3s

2sspatial stream #1

spatial stream #2

1sspatial stream #1

spatial stream #2 2s

Transmission of 2 spatial streams(SDM)

spatial stream #1

*2s 1s

*1s 2s

spatial stream #1

*2s 1s

*1s 2s

*2s 1s

*1s 2s

Transmission of 1 spatial stream(STBC)

Transmission of 3 spatial streams(STBC)

Transmission of 2 spatial streams(STBC)

spatial stream #1

spatial stream #2

spatial stream #3

*4s

*6s

*2s 1s

*1s 2s

3s

5s

spatial stream #1

spatial stream #2

spatial stream #3

*4s

*6s

*2s 1s

*1s 2s

3s

5s

spatial stream #1

spatial stream #2

*2s 1s

*1s 2s

*4s 3s

*3s 4s

*2s 1s

*1s 2s

*2s 1s

*1s 2s

*4s 3s

*3s 4s

2 transmit antenna schemes proposed 3 transmit antenna schemes proposed

4 transmit antenna schemes proposed

Asymmetric Modes for a robust hybrid solution


Slide 14Submission

OFDM modulation • 1st OFDM modulation based on IEEE802.11a parameters:

– 48 data subcarriers, 64-point IFFT/FFT, 20MHz Bandwidth 180Mbps maximum PHY rate (120Mbps mandatory)

• 2nd OFDM modulation (optional extension):– 104 data subcarriers, 128-point IFFT/FFT, 8 pilots, 20MHz Bandwidth 195Mbps maximum PHY rate

• 3rd OFDM modulation (optional extension):– 128-point IFFT/FFT, 40MHz Bandwidth– 104 data subcarriers, 8 pilots – Guard interval duration: 0.8s – 234Mbps maximum PHY rate


Slide 15Submission

28838483/4256QAM2144Mbps

24028865/664QAM2120Mbps

21628863/464QAM2108Mbps

19228862/364QAM296Mbps

14419243/416QAM272Mbps

24028865/664QAM160Mbps

19228862/364QAM148Mbps

14419243/416QAM136Mbps

9619241/216QAM124Mbps

729623/4QPSK118Mbps

489621/2QPSK112Mbps

244811/2BPSK16Mbps

Data bits/ symbol (NDBPS)

Coded bits/ symbol (NCBPS)

Coded bits per subcarrier per stream (NBPSC)

Coding rate (R)

ModulationNumber of

spatial streams (NS)

Data rate (Mbits/s)

Mode: 2-TX

48 carriers20MHz

62483283/4256QAM2156Mbps

52062465/664QAM2130Mbps

46862463/464QAM2117Mbps

41662462/364QAM2104Mbps

31241643/416QAM278Mbps

52062465/664QAM165Mbps

41662462/364QAM152Mbps

31241643/416QAM139Mbps

20841641/216QAM126Mbps

15620823/4QPSK119.5Mbps

10420821/2QPSK113Mbps

5210411/2BPSK16.5Mbps

Data bits/ symbol (NDBPS)

Coded bits/ symbol (NCBPS)

Coded bits per subcarrier per stream (NBPSC)

Coding rate (R)

ModulationNumber of

spatial streams (NS)

Data rate (Mbits/s)

Mode: 2-TX

104 carriers20MHz


Slide 16Submission

Mode: 2-TX

104 carriers40MHz

Mode: 3/4-TX

48 carriers20MHz

Data rate (Mbits/s)

Number of spatial streams

(NS)

Modulation Coding

rate (R)

Coded bits per

subcarrier per

stream (NBPSC)

Coded bits per OFDM symbol (NCBPS)

Data bits per OFDM symbol (NDBPS)

Number of data

subcarriers (NSD)

13Mbps 1 BPSK 1/2 1 104 52 104 26Mbps 1 QPSK 1/2 2 208 104 104 39Mbps 1 QPSK 3/4 2 208 156 104 52Mbps 1 16QAM 1/2 4 416 208 104 78Mbps 1 16QAM 3/4 4 416 312 104

104Mbps 1 64QAM 2/3 6 624 416 104 130Mbps 1 64QAM 5/6 6 624 520 104 156Mbps 2 16QAM 3/4 4 416 312 104 208Mbps 2 64QAM 2/3 6 624 416 104 234Mbps 2 64QAM 3/4 6 624 468 104 260Mbps 2 64QAM 5/6 6 624 520 104 312Mbps 2 256QAM 3/4 8 832 624 104

Data rate (Mbits/s)


(NS)

Modulation Coding

rate (R)

Coded bits per

subcarrier per

stream (NBPSC)


Data bits per OFDM symbol (NDBPS)

Number of data

subcarriers (NSD)

12Mbps 2 BPSK 1/2 1 48 24 48 24Mbps 2 QPSK 1/2 2 96 48 48 36Mbps 2 QPSK 3/4 2 96 72 48 48Mbps 2 16QAM 1/2 4 192 96 48 72Mbps 2 16QAM 3/4 4 192 144 48 96Mbps 2 64QAM 2/3 6 288 192 48

120Mbps 2 64QAM 5/6 6 288 240 48 144Mbps 3 64QAM 2/3 6 288 192 48 162Mbps 3 64QAM 3/4 6 288 216 48 180Mbps 3 64QAM 5/6 6 288 240 48 216Mbps 3 256QAM 3/4 8 384 288 48


Slide 17Submission

Mode: 3/4-TX

104 carriers20MHz

Mode: 3/4-TX

104 carriers40MHz

Data rate (Mbits/s)


(NS)

Modulation Coding

rate (R)

Coded bits per

subcarrier per

stream (NBPSC)


Data bits per

OFDM symbol (NDBPS)

Number of data

subcarriers (NSD)

13Mbps 2 BPSK 1/2 1 104 52 104 26Mbps 2 QPSK 1/2 2 208 104 104 39Mbps 2 QPSK 3/4 2 208 156 104 52Mbps 2 16QAM 1/2 4 416 208 104 78Mbps 2 16QAM 3/4 4 416 312 104

104Mbps 2 64QAM 2/3 6 624 416 104 130Mbps 2 64QAM 5/6 6 624 520 104 156Mbps 3 64QAM 2/3 6 624 416 104

175.5Mbps 3 64QAM 3/4 6 624 468 104 195Mbps 3 64QAM 5/6 6 624 520 104 234Mbps 3 256QAM 3/4 8 832 624 104

Data rate (Mbits/s)


(NS)

Modulation Coding

rate (R)

Coded bits per

subcarrier per

stream (NBPSC)


Data bits per

OFDM symbol (NDBPS)

Number of data

subcarriers (NSD)

26Mbps 2 BPSK 1/2 1 104 52 104 52Mbps 2 QPSK 1/2 2 208 104 104 78Mbps 2 QPSK 3/4 2 208 156 104

104Mbps 2 16QAM 1/2 4 416 208 104 156Mbps 2 16QAM 3/4 4 416 312 104 208Mbps 2 64QAM 2/3 6 624 416 104 260Mbps 2 64QAM 5/6 6 624 520 104 312Mbps 3 64QAM 2/3 6 624 416 104 351Mbps 3 64QAM 3/4 6 624 468 104 390Mbps 3 64QAM 5/6 6 624 520 104 468Mbps 3 256QAM 3/4 8 832 624 104


Slide 18Submission

OFDM Parameters Overview (I/2) Parameter Value

NSD: Number of data subcarriers 48 NSP: Number of pilot subcarriers 4 NST: Number of subcarriers, total 52 (NSD+NSP) F: Subcarrier frequency spacing 0.3125MHz (=20MHz/64)

TFFT: IFFT/FFT period 3.2s (1/F) TGI: GI duration 0.8s

TSYM: Symbol interval 4s (TGI +TFFT)

Parameter Value NSD: Number of data subcarriers 104 NSP: Number of pilot subcarriers 8 NST: Number of subcarriers, total 112 (NSD+NSP) F: Subcarrier frequency spacing 0.15625MHz (=20MHz/128)

TFFT: IFFT/FFT period 6.4s (1/F) TGI: GI duration 1.6s

TSYM: Symbol interval 8.0s (TGI +TFFT)

• 20MHz• 48 Carriers



Slide 19Submission

OFDM Parameters Overview (II/2)

Parameter Value NSD: Number of data subcarriers 104 NSP: Number of pilot subcarriers 8 NST: Number of subcarriers, total 112 (NSD+NSP)

F: Subcarrier frequency spacing 0.3125MHz (=40MHz/128) TFFT: IFFT/FFT period 3.2s (1/F)

TGI: GI duration 0.8s TSYM: Symbol interval 4.0s (TGI +TFFT)



Slide 20Submission

Frequency and space interleaver

• IEEE802.11a based frequency interleaver defined for both 48 and 104 data subcarriers

• Spatial division: – NSD : number of data subcarriers

NSD-symbol-cyclingAcross NS streams stream #0

stream #1

stream # NS-1

Spatialfrequencysymbol

interleaving

interleaved stream #1


interleaved stream # NS-1

Spacetime

encoding

NSD-symbol-cyclingAcross NS streams stream #0

stream #1

stream # NS-1


interleaving


interleaving



interleaved stream # NS-1

Spacetime

encoding

Spacetime

encoding


Slide 21Submission

nPLCP preamble (I/2)• n S T S

– E a c h S T S 1 , … , S T S 1 0 c o r r e s p o n d s t o t h e l e g a c y s h o r t t r a i n i n g d e f i n e d o v e r i n d e x e s - 2 8 , 2 8

S - 2 8 , 2 8 = { 0 , 0 , 0 , 0 , - 1 - 1 j , 0 , 0 , 0 , - 1 - 1 j , 0 , 0 , 0 , 1 + 1 j , 0 , 0 , 0 , 1 + 1 j , 0 , 0 , 0 , 1 + 1 j , 0 , 0 , 0 , 1 + 1 j , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 + 1 j , 0 , 0 , 0 , - 1 - 1 j , 0 , 0 , 0 , 1 + 1 j , 0 , 0 , 0 , - 1 - 1 j , 0 , 0 , 0 , - 1 - 1 j , 0 , 0 , 0 , 1 + 1 j , 0 , 0 , 0 , 0 }

– D u r a t i o n o f t h e n S T S s h o r t t r a i n i n g s e q u e n c e : 1 0 × 0 . 8 = 8 µ s .

S T S 1 S T S 2 S T S 3 S T S 4 S T S 5 S T S 6 S T S 7 S T S 8 S T S 9 S T S 1 0

n S T S

S T S 1 S T S 2 S T S 3 S T S 4 S T S 5 S T S 6 S T S 7 S T S 8 S T S 9 S T S 1 0S T S 1 S T S 2 S T S 3 S T S 4 S T S 5 S T S 6 S T S 7 S T S 8 S T S 9 S T S 1 0

n S T S

• n L T S

• E a c h L T S 1 , L T S 2 i s b a s e d o n t h e l e g a c y l o n g t r a i n i n g , b u t d e f i n e d o v e r i n d e x e s - 2 8 , 2 8 :L - 2 8 , 2 8 = { 1 , 1 , 1 , 1 , - 1 , - 1 , 1 , 1 , - 1 , 1 , - 1 , 1 , 1 , 1 , 1 , 1 , 1 , - 1 , - 1 , 1 , 1 , - 1 , 1 , - 1 , 1 , 1 , 1 , 1 , 0 , 1 , - 1 , - 1 , 1 , 1 , -1 , 1 , - 1 , 1 , - 1 , - 1 , - 1 , - 1 , - 1 , 1 , 1 , - 1 , - 1 , 1 , - 1 , 1 , - 1 , 1 , 1 , 1 , 1 , - 1 , - 1 }

• D u r a t i o n o f t h e n L T S l o n g t r a i n i n g : 1 . 6 + 2 × 3 . 2 = 8 µ s

G I 2 L T S 1 L T S 2

n L T S

G I 2 L T S 1 L T S 2

n L T S


Slide 22Submission

nPLCP preamble (II/2)• Overview on different frame structures:

IEEE802.11a OFDM Frame STS LTS SIG D1 D2

IEEE802.11g OFDM Frame STS LTS SIG D1 D2 EXT

IEEE802.11n OFDM Frame, NTX = 2

nSTS nLTS nLTS

nSTS + CS nLTS + CS nLTS + CS

A1:

A2:nSIG nD1 nD2


nSTS nLTS nLTS


A1:

A2: nSIG nD1 nD2

nSTS nLTS (-1) x nLTSA3:


nSTS nLTS nLTS


A1:

A2:nSIG nD1 nD2

nSTS nLTS (-1) x nLTSA3:

nSTS + CS nLTS + CS (-1) x nLTS + CSA4:


Slide 23Submission

Simulation results

• AWGN, TGnB, TGnD, TGnE channel comparisons for 20MHz Bandwidth

• Essential points– Throughput increase with optional modes (FFT-128) at

constant SNR requirements in AWGN channels

– Robust modes based on STBC for good coverage and support of asymetric configurations

– Unilateral modification of number of antennas in TX and RX can be exploited Useful for independent evolution of AP/MT


Slide 24Submission

Simulation results - AWGN

• 2TX/2RX to 4TX/4RX configuration and SNR ~21dB:120Mbps 180Mbps (130Mbps 195Mbps)


Slide 25Submission

Simulation results - TGnB

• Diversity gain for all streams• 120 Mbps lowers SNR ~ 36dB 28dB 24.5dB

XXX 42dB 34dB180

10dB 7dB 6dB12

20dB 16dB 14dB48

32dB 24dB 21dB96

36dB 28dB 24.5dB120

SNR for PER=10-1Mode/

Mbps


Slide 26Submission


• For new schemes: Same behaviour is observed for diversity modes as for classical schemes

• Clear improvements for 2 streams from 2x2 3x3 mode• Clear improvements for 3 streams from 2x2/3x3 4x4

mode


Slide 27Submission


• # TX antennas < # RX antennas e.g. Update of MT

26.5dB120

5dB12

16dB48

24dB96

SNR for PER=10-1Mode/Mbps

31.5dB120

11dB12

20dB48

28dB96


• # TX antennas > # RX antennas e.g. Update of AP


Slide 28Submission

PHY Throughput Analysis – TGnB

• Link adaptation is based on long term average SNR sub-optimum inferior bound

• Finer grid possible with more modes


Slide 29Submission

Simulation results - TGnD

• Diversity gain for all streams• 120 Mbps lowers SNR ~ 35dB 25.5dB 23dB

XXX 36dB 29dB180 (effect)

XXX 36dB 29dB180

5dB 4.5dB 3.5dB12

18dB 14dB 11dB48

27.5dB 21dB 19dB96

35dB 25.5dB 23dB120


Mbps


Slide 30Submission

Simulation results - TGnD


24dB120

2dB12

14.5dB48

20dB96


30dB120

7dB12

17dB48

25.5dB96




Slide 31Submission

PHY Throughput Analysis – TGnD




Slide 32Submission

Simulation results - TGnE

• Diversity gain for all streams• 120 Mbps lowers SNR ~ 37dB 26.5dB 24dB

XXX 43dB 31dB180

7dB 5dB 4dB12

19dB 15dB 12dB48

30dB 22.5dB 20dB96

37dB 26.5dB 24dB120


Mbps


Slide 33Submission

Simulation results - TGnE


25dB120

4dB12

15dB48

21.5dB96


31.5dB120

9dB12

18dB48

26.5dB96




Slide 34Submission

PHY Throughput Analysis – TGnE




Slide 35Submission

Simulation results – TGnD/TGnE• Similar to TGnB:

– 2Tx:• Diversity gain for 1 stream, but not for 2 streams• 120 Mbps requires SNR ~ 35dB (TGnD) 37dB (TGnE)

– 3Tx:• Diversity gain for 2 streams, but not for 3 streams• 120 Mbps lowers SNR:

– ~ 36dB 26dB (TGnD)– ~ 37dB 26.5dB (TGnE)

– 4Tx:• Diversity gain for all streams• 120 Mbps lowers SNR

– ~ 36dB 26dB 23dB (TGnD)– ~ 37dB 26.5dB 24dB (TGnD)


Slide 36Submission

Simulation results – Offset compensation

• No significant impact at 10% PER in channel E (NLOS)


Slide 37Submission


• Impact of carrier frequency offset and symbol clock offset at SNR=50dB in channel E (LOS):– Small degradation of the PER performance– High data rate modes are more impacted:

• PER (+40ppm) = 112/100xPER (0ppm) at 48Mbps• PER (+40ppm) = 163/100xPER (0ppm) at 120Mbps

Antenna configuration

Data rate (Mbits/s)

PER whencarrier offset

= -40ppm

PER when carrier offset

= 0ppm

PER whencarrier offset =+40ppm

2x2 12Mbps 0.0003 0.0003 0.0002

2x2 48Mbps 0.0016 0.0016 0.0018

2x2 96Mbps 0.0039 0.0037 0.0042

2x2 120Mbps 0.0297 0.0183 0.0298


Slide 38Submission


Antenna configura

tion

Data rate (Mbits/s)

PER when

carrier offset = -40ppm

PER when carrier offset = 0ppm


3x3 12Mbps 0.0002 0.0001 ~0

3x3 48Mbps 0.0006 0.0006 0.0005

3x3 96Mbps 0.0041 0.0041 0.0043

3x3 120Mbps 0.0043 0.0045 0.0050

3x3 180Mbps 0.0963 0.0617 0.0974

Antenna configura

tion

Data rate (Mbits/s)

PER when

carrier offset = -40ppm

PER when carrier offset = 0ppm


4x4 12Mbps ~0 ~0 ~0

4x4 48Mbps 0.0001 0.0001 0.0001

4x4 96Mbps 0.0016 0.0016 0.0019

4x4 120Mbps 0.0021 0.0021 0.0022

4x4 180Mbps 0.0023 0.0024 0.0029

• High data rate modes are less impacted if spatial diversity:– 3x3: PER (+40ppm) = 158/100xPER (0ppm) at 180Mbps– 4x4: PER (+40ppm) = 121/100xPER (0ppm) at 180Mbps


Slide 39Submission

Implementation complexity8 0 2 . 1 1 n 8 0 2 . 1 1 a / gC 1 . 2 5 CT X G a t e s T X G a t e s

T G n T X i m p l e m e n t a t i o n r e q u i r e s s o m e c o m p l e x i t y f o r S T i n t e r l e a v i n g .

8 0 2 . 1 1 n 8 0 2 . 1 1 a / gC 2 . 0 CR X G a t e s R X G a t e s + T u r b o D e c o d e r

T G n R X i m p l e m e n t a t i o n w i l l t y p i c a l l y l e a d t o a p a r a l l e l i z e d M a x i m u m -L i k e l i h o o d d e c o d e r a n d M M S E b a s e d s e p a r a t i o n a u f p a r a l l e l s t r e a m s ( h i g h e r c o m p l e x i t y r e q u i r e m e n t s f o r i t e r a t i v e i n t e r f e r e n c e c a n c e l l a t i o n a l g o r i t h m s ) .

8 0 2 . 1 1 n 8 0 2 . 1 1 a / g/ /C 3 . 3 . . . . 4 . 3 CT X R X M I P S T X R X M I P S

T G n c a l c u l a t i o n p o w e r r e q u i r e m e n t s a p p r o x i m a t e l y s c a l e w i t h t h e o u t p u t d a t a r a t e s ( i . e . u p t o 4 . 3 x f o r f a s t e s t o p t i o n a l m o d e ) .

8 0 2 . 1 1 n 8 0 2 . 1 1 a / g/ /C CT X R X f i l t e r i n g T X R X f i l t e r i n g N o a d d i t i o n a l f i l t e r i n g c o n s t r a i n t s a r e

e x p e c t e d f o r T G n i m p l e m e n t a t i o n s .

8 0 2 . 1 1 n 8 0 2 . 1 1 a / g/ /C 2 . 5 CT X R X c l o c k r a t e T X R X c l o c k r a t e

D e p e n d i n g o n t h e l e v e l o f a r c h i t e c t u r a l p a r a l l e l i z a t i o n , t h e c l o c k r a t e i s e x p e c t e d t o b e a p p r o x . 2 . 5 x h i g h e r .


Slide 40Submission

Conclusion

• Proposal: MIMO extension of IEEE802.11a addressing– Short term implementation needs through mandatory

modes relying on a mix of STBC and SDM

– Take into account device size constraints allowing asymmetric TX/RX antenna configuration independent upgrade of APs / MTs possible

– Enable PHY throughput covering 54Mbits/s 180 (468) Mbps


Slide 41Submission

doc.: ieee 802.11-04/913r4 submission september 2004 slide 1 ieee 802.11n phy motorola ht partial...

Documents

ofdm symbol ncbpsdata

stream nbpsccoded bits

spatial streams stbcdoc

bandwidth104 data subcarriers

number of subcarriers

tx104 carriers20mhzmode

tx104 carriers20mhzdoc

tx104 carriers40mhzmode