November 2000 doc IEEE 802 11 00392 OFDM

November 2000 doc. : IEEE 802. 11 -00/392 OFDM System Performance Karen Halford, Steve Halford and Mark Webster Submission 1 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 Outline of Proposal Presentations ² ² ² ² ² TGg Regulatory Approval Plan Speaker: Jim Zyren Overview of OFDM for High Rate Speaker: Steve Halford Reuse of 802. 11 b Preambles with OFDM Speaker: Mark Webster Ultra-short Preamble with HRb OFDM Speaker: Mark Webster OFDM System Performance Speaker: Steve Halford Power Am Effects for HRb OFDM Speaker: Mark Webster Channelization for HRb OFDM Speaker: Mark Webster Phase Noise Sensitivity for HRb OFDM Speaker: Jim Zyren Implementation and Complexity Issues for OFDM Speaker: Steve Halford Why OFDM for the High Rate 802. 11 b Extension? Speaker: Jim Zyren Submission 2 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 Outline of Presentation 5. 1 AWGN Performance 5. 2 Rayleigh Fading Performance 5. 3 Multipath Performance 5. 3. 1 Exponential Channel with Flat Fading 5. 3. 2 Exponential Channel without Flat Fading (Normalized) 5. 3. 3 PER sweeps from 1% to 10 % 5. 4 Throughput Performance 5. 5 Performance Against CW Jammer (FCC 15. 247 Test) Submission 3 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 1 AWGN Performance: 100 Byte Packets Submission 4 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 1 AWGN Performance: 1000 Byte Packets Submission 5 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 1 AWGN Performance: 2346 Byte Packets Submission 6 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 1 AWGN Performance: 1% and 10 % PER for 1000 Byte Packets Eb/No required for 1 % PER Eb/No required for 10 % PER Submission 7 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 2 Rayleigh Fading Performance: Block Diagram Generate Noise Calculate Noise Power (N 0) Measure energy per bit Measure Packet Error Rate Transmitter Model Packet Length Data Rate Submission x Receiver Model + Packet Error Rate Rayleigh Coefficient 8 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 2 Rayleigh Fading Performance: 1000 Byte Packets Submission 9 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 2 Rayleigh Fading Performance: 1% and 10 % PER for 1000 Byte Packets Eb/No required for 1 % PER Eb/No required for 10 % PER Submission 10 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 1 Multipath Performance with Flat Fading: Block Diagram Calculate Noise Power (N 0) Generate Noise Measure energy per bit Measure Packet Error Rate Transmitter Model Exponential Channel Model Packet Length Data Rate Sample Rate Delay Spread Submission Receiver Model 11 Packet Error Rate K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 1 Multipath Performance with Flat Fading: Matlab® Code Submission 12 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 1 Multipath Performance with Flat Fading: Eb/No Submission 13 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 1 Multipath Performance with Flat Fading: SNR Submission 14 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 2 Multipath Performance without Flat Fading: Block Diagram Generate Noise Calculate Noise Power (N 0) Measure energy per bit Measure Packet Error Rate Transmitter Model Packet Length Data Rate Submission Exponential Channel Model Receiver Model Packet Error Rate Sample Rate Delay Spread 15 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 2 Multipath Performance without Flat Fading: Eb/No Submission 16 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 2 Multipath Performance without Flat Fading: SNR Submission 17 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 3: Multipath Sweeps: 1% to 10% Comparison Item 24 For each modulation mode detemine and state the SNR (Es/No) at which in AWGN only, the waveform can achieve a PER of 0. 01 for packets lengths of 1000 B. Using the multipath model used in 23 b above, fix the amount of AWGN at the 0. 01 PER level for AWGN only. Increase the RMS delay spread until the PER for 1000 B packets reach 0. 1. State the RMS delay spread at this point. Answer: 0. 0 n. Seconds for all rates Why ? Submission 18 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 3 Multipath Sweeps: 1% to 10% PER Curves are very steep -about 2 d. B separates the 1% from the 10 % point Submission 19 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 3 Multipath Sweeps: 1% to 10% Rayleigh fading causes frequent swings to low SNR level Submission 20 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 3 Multipath Sweeps: 1% to 10% What we ran in place of Comparison Item 24 For each modulation mode detemine and state the SNR (Es/No) at which 25 n. Seconds RMS delay, the waveform can achieve a PER of 0. 01 for packets lengths of 1000 B. Using the multipath model used in 23 c above, fix the amount of AWGN at the 0. 01 PER level for 25 n. Seconds RMS delay. Increase the RMS delay spread until the PER for 1000 B packets reach 0. 1. State the RMS delay spread at this point. Submission 21 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 3. 3 Multipath Performance: PER sweeps from 1% to 10% Submission 22 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4 Throughput Performance 5. 4. 1 Preamble Structures 5. 4. 2 ACK Assumptions 5. 4. 3 Throughput Analysis 5. 4. 3. 1 Tables of 100, 1000, 2346 Byte Packets 5. 4. 3. 2 Plots for full range of packet sizes 5. 4. 4 Throughput analysis for varying durations of overhead Submission 23 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 1 Preamble Structures: Long and Short Preambles 802. 11 HRb LONG PREAMBLE/HEADER 192 usecs OFDM SYNC Signal Extension PSDU SELECTABLE OFDM Symbols @ 6. 6, 9. 6, 13. 2, 19. 8, 26. 4, 39. 3, 52. 8 or 59. 4 Mbps 10. 9 usecs ~6 usecs Data Payload 802. 11 HRb SHORT PREAMBLE PREAM/HDR 72 BITS @ 1 Mbps 96 usecs Submission OFDM SYNC Signal Extension PSDU SELECTABLE OFDM Symbols @ 6. 6, 9. 6, 13. 2, 19. 8, 26. 4, 39. 3, 52. 8 or 59. 4 Mbps ~6 usecs 10. 9 usecs 24 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 1 Preamble Structures: Ultra-Short Preamble • Proposed Ultra-Short Preamble • Data Rate • # bytes of data 12 Short Syncs Rep’s Long SYNC 16 usecs Submission SIGNAL SYMBOL Data Payload Signal Extension PSDU SELECTABLE @ 6. 6, 9. 9, 13. 2, 19. 8, 26. 4, 39. 6, 52. 8 or 59. 4 Mbps ~6 usecs 3. 6 usecs 25 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 2 ACK Assumptions 1) No RTS/CTS OR MPDU < RTS_Threshold: source DIFS Many different scenarios, but the constant is: {MPDU, SIFS, ACK} Data SIFS ACK destination 2) RTS/CTS and/or MPDU > RTS_Threshold: source DIFS RTS destination SIFS Data SIFS ACK SIFS CTS 3) Middle of Fragmented Transmission: source SIFS Fragment 1 destination Submission SIFS ACK 1 26 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 2 ACK Assumptions (continued) SIFS Packet Header PSDU SELECTABLE OFDM Symbols 112 Bits @ 6. 6 Mbps = 20 usec Packet Header ACK @ 6. 6, 9. 6, 13. 2, 19. 8, 26. 4, 39. 3, 52. 8 or 59. 4 Mbps OFDM PAD ~6 usecs Submission 27 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 3. 1 Throughput for 100 Byte Packets Submission 28 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 3. 1 Throughput for 1000 Byte Packets Submission 29 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 3. 1 Throughput for 2346 Byte Packets Submission 30 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 3. 2 Throughput with ACK Submission 31 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 3. 2 Throughput without ACK Submission 32 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 4 Comparison of Throughput for Variable Overhead for 100 Byte MPDU Submission 33 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 4 Comparison of Throughput for Variable Overhead for 1000 Byte MPDU Submission 34 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 4 Comparison of Throughput for Variable Overhead for 2346 Byte MPDU Submission 35 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 4. 5 Aggregate Throughputs for 2. 4 GHz • Our proposal allows for 3 channels in US 2. 4 GHz band • Each channel can coexist in the same area • Aggregate throughput is 3 times single channel throughput Submission 36 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 5 CW Jammer Test Description CW jammer test steps a CW tone across the signal band in 50 k. Hz steps. At each step, the jamming level required to to produce the recommended BER is determined. The worst 20% of the J/S levels are discarded and the smallest of the remaining J/S is used as the jamming margin. Processing gain is then calculated according to the following: Submission 37 K. Halford, S. Halford and M. Webster, Intersil

November 2000 doc. : IEEE 802. 11 -00/392 5. 5 Performance Against CW Jammer Gp = (S/N)0 + Mj + Lsys Submission 38 K. Halford, S. Halford and M. Webster, Intersil