doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 1 A “High Throughput” Partial Proposal Patrik Eriksson, Anders Edman, Christian Kark Wavebreaker AB, Norrkoping, Sweden Scott Leyonhjelm (Editor), Mike Faulkner, Melvyn Pereira,Jason Gao,Aaron Reid,Tan Ying,Vasantha Crabb. Australian Telecommunication Co-operative Research Centre, Melbourne, Australia.

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 2 Presentation Outline Proposal Executive Summary Proposed PHY Design Proposed Frame Format Comparison Criteria Conclusion

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 3 Proposal Executive Summary Fully backward compatible with a/g –20MHz with a/g mask –All enhancements are simple extensions to 11a/g OFDM structure. –STS and LTS sequences are used in conjunction with progressive cyclic delay per antenna Higher Data Throughput due to combination of PHY technologies –MIMO-OFDM - Spatial Multiplexing, up to 3 transmit antennas (mandatory), 4 antennas (optional) –Fast Adaptive Loading - Rate adaptation on a per layer (mandatory) or per a subgroup (optional) level –Higher order modulation - 256QAM Higher Data Throughput due to combination of MAC enhancements –Shorter SIFS, down to 8 us. –Frames with NO short and long training sequences –Frame aggregation Minimising Hardware Complexity –Frame format designed to increase available time for inverting channel estimate.

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 4 Presentation Outline Proposal Executive Summary Proposed PHY Design Proposed Frame Format Comparison Criteria Conclusion

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 5 Proposed PHY Design Parallel Spatial Multiplexing Architecture Scalable architecture - supports up to 3 (mandatory) or 4 (optional) antennas The mapping function expanded to include 256QAM Cyclic Delay is implemented with a progressive 1 sample delay /per antenna Adaptive Loading (Rate Adaptation) DemuxDemux Data Bits Scramble Encode Punct Inter.Map Inter. FFTCP Cyclic Delay To DACs MapFFTCP Cyclic Delay MapFFTCP Cyclic Delay MapFFTCP Cyclic Delay Adaptive Loading Info from Sig3 Symbol ‘CSI’ field MuxMux STS and LTS Preambles MuxMux Pilots

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 6 Proposed PHY Design Adaptive Loading (Rate Adaptation) –The STA determines the maximum rate per layer (mandatory) or subgroup of carriers (optional) and this is communicated back to the AP, and vice-versa. –Adapts the Puncturing and Constellation Mapping on a layer basis. –Adaptive rate can vary from 0Mbit/s through to 72Mbits/s on a per layer basis. –Fast Adaptation handled at PHY layer Punct/ Map Data Bits Tx Channel Estimation Rx Data Bits Forward Link SNR (Link Margin/layer) Calculate Maximum Rate Possible on a per layer basis Decode Sig3 Symbol ‘Rev CSI’ field Reverse Link Encode Sig3 Symbol ‘Rev CSI’ field

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 7 Proposed Frame Format PHY Digital complexity – N layers vs 1 layer (11a) ~N times complexity for most baseband processing blocks (e.g. filter, FFT, frequency correction, mapping, demapping, decoding) –energy per bit for these parts remain constant compared to 11a. >N times complexity for Channel Estimation & Equalisation: –approx the same as for FFT b;lock for up to 3*3 MIMO system. –The increased length of payload, and transmission of frames without preambles keep the power cost for this operation at a reasonable level. –Sig3 symbol placement between last preamble and data increases available time for computation with one symbol period. This reduces the required complexity of the logic for this function. Analog Area and Power – N layers vs 1 layer (11a) <N times Area and Power consumption as some units are reused for all channels Summary for N=3; ~ 4 times 11a for Digital baseband computational complexity ~2.5 times 11a for Analog area and power consumption.

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 8 Presentation Outline Proposal Executive Summary Proposed PHY Design Proposed Frame Format Comparison Criteria Conclusion

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 9 Proposed Frame Format 3 new MIMO frame types are proposed: MIMO - Type 1 frames with Training. Note that the STS, LTS and Sig2 sequence can be received by legacy equipment. MIMO - Type 2 frames without Training. Note that time, frequency & channel tracking algorithms will be required. MIMO – Type 3 frames with Training used only in 5GHz band n MIMO - Type n MIMO - Type 2 STS1 LTS1Sig2LTS1aLTS1bLTS1c STS2 LTS2Sig2LTS2aLTS2bLTS2c STS3 LTS3Sig2LTS3aLTS3bLTS3c STS4 LTS4Sig2LTS4aLTS4bLTS4c Sig3 D1 D2 Dn Sig3 D1 D2 Dn n MIMO - Type 3 Sig2LTS1aLTS1bLTS1c Sig2LTS2aLTS2bLTS2c Sig2LTS3aLTS3bLTS3c Sig2LTS4aLTS4bLTS4c Sig3 D1 D2 STS1 LTS1Sig STS2 LTS2Sig STS3 LTS3Sig STS4 LTS4Sig D1 D2 Dn a OFDM Frame format g DSSS Frame format g OFDM Frame format STSLTSSigD1D2 PreambleHead STSLTSSigD1D2 D1D2 Ext Note: Sig3 and Data Symbols can be turned off.

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 10 Proposed Frame Format Type 3 only – Single MIMO frame transmission –MIMO frames appended to a 11a/g frame => backward compatible with 11a/g frames –contains MIMO training and Data –Sig2 symbol – Indicates MIMO setup –Sig3 symbol – indicates MIMO rates being used and length of MIMO transmission. Type 3,2 & 1 –RTS/CTS frame transfer –Type 3 Training required for initially establishing Adaptive Loading Sig3 symbol – indicates Adaptive Loading rates & Data Length - increases available time for inverting channel estimate. –Type 2 - Data carrying with no Training Sequence –Type 1 - backward compatible with 11a/g frames, used for Used on a retransmission Re-synchronising during a RTS/CTS transmission, and Extending the duration of the transmission (CTS to self) SIFS an take a value between 8 to 16us –receiver must be ready to receive after 8us but a transmitter is allowed to wait up to 16us before starting

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 11 Proposed Frame Format To Achieve Goodput of >100Mbps for PER 10%, PHY average rate =144Mbps Single Frame Transmission Mode –Packet Size = 5.5kbyte packet RTS/CTS Transmission Mode –Packet Size > 2kbyte –Tranmission Length = 10kbyte Frame Aggregation –Increases MAC efficiency –Proposed max. 16kbyte packet

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 12 Proposed Frame Format Implementation Details of the Frame Format proposal Channel Models in n are slowly moving (low Doppler) –Channel sufficiently stable for at least 50 symbols (MSE <-35dB) –Channel F with 40kph Doppler Component Type 2 packets have NO training sequences –Initial ST/LTS sets up Timing grid –Transmissions start at 4us intervals –Receiver uses fast power detection algorithms to determine if packet (sig3 symbol) is present or not –Frequency offset and sampling time offsets must flywheel over non- transmission periods Implementation Requirements –Time, frequency offsets tracked via 4 pilots –Channel Tracking

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 13 Presentation Outline Proposal Executive Summary Proposed PHY Design Proposed Frame Format Comparison Criteria Conclusion

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 14 Comparison Criteria CC51- mandatory –BPSK thru to 256QAM –Rates 0 thru to 72Mbps per layer –1,2 or 3 transmit antennas CC42- The short and long training sequences are the same as the a/g defined training sequences with the following modifications: –Both the STS and LTS sequences have a progressive cyclic delay of 1 sample per antenna applied, see also Appendix A, Section 7.1 –The LTS sequences are also phase loaded on a per antenna basis

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 15 Comparison Criteria CC58 –RTS/CTS frame transmission mode achieves a goodput of more than 100Mbps, –The single frame transmission mode achieves a maximum goodput of 80Mbps when the average PHY data rate is 288Mbps !. To get >100Mbps With frame aggregation a 5.5kbyte packet size transmitted at a average PHY data rate of 144Mbps With channel bonding (optional) the average PHY data rate is increased by a factor 1.8

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 16 Comparison Criteria CC59 –AWGN Channel –Observation : the capacity is a linear function of the number of transmit antennas. –Each layer had the same rate, even if the adaptive loading algorithm was switched on.

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 17 Comparison criteria CC80- The modifications required for a legacy PHY are; –The scalable architecture supports up to 3 (mandatory) or 4 (optional) antennas –The adaptive loading modifies the puncturing and Constellation Mapping on a layer basis, –Include 256 QAM –Cyclic Delay implemented with a progressive 1 sample delay /per antenna –The LTS preambles are modified versions of the a/g defined sequences

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 18 Presentation Outline Proposal Executive Summary Proposed PHY Design Proposed Frame Format Comparison Criteria Conclusion

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 19 Conclusion – Key Features Higher Data Throughput due to combination of PHY technologies –MIMO-OFDM – 1 to 3 antennas using Spatial Multiplexing –Rate Adaptation –Higher order modulation – 256QAM Higher Data Throughput due to combination of MAC enhancements –Shorter SIFS - down to 8 us. –Frames with NO short and long training sequences –Frame aggregation – up to 16kbytes/packet

doc.: IEEE /0929r0 Submission August 2004 Patrik Eriksson et. al., WaveBreaker ABSlide 20 Conclusion Backward Compatibility is ensured by –Operation within a 20MHz bandwidth with the same a/g spectral mask. –Single and RTS/CTS frame transmission modes are fully compatible with legacy a/g devices. All Functional Requirements are met Low Overhead Frame formats 100Mbps Goodput Achieved when –20MHz and 2 transmit antennas –> 144Mbps Average PHY data rate –Rate Adaptation