Consideration of PHY design for 1.08GHz channel Sept 2012 doc.: IEEE 802.11-012/xxxxr1 September 2013 Consideration of PHY design for 1.08GHz channel Date: 2013-09-17 Presenter: Changming Zhang Xiaoming Peng / I2R

Author List September 2013 Month Year doc.: IEEE 802.11-13/xxxxr1 Changming Zhang John Doe, Some Company

Sept 2013 Abstract This document is to propose a PHY design to support low power 1.08GHz PHY It considers the PHY design with distortion compensation for I/Q imbalance for high order modulation and PA nonlinearity Xiaoming Peng

1.08GHz modulation and coding schemes Frame structure September 2013 Roadmap Background 1.08GHz modulation and coding schemes Frame structure IQ imbalance estimation and compensation PA nonlinearity treatment Conclusion Changming Zhang

Channelization Consideration for 802.11aj Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 Channelization Consideration for 802.11aj It is necessary to define 1.08GHz PHY Changming Zhang John Doe, Some Company

1.08GHz modulation and coding schemes Frame structure September 2013 Roadmap Background 1.08GHz modulation and coding schemes Frame structure IQ imbalance estimation and compensation PA nonlinearity treatment Conclusion Changming Zhang

CMCS Ctrl PHY September 2013 CMCS Index Modulation Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 CMCS Ctrl PHY CMCS Index Modulation Code Rate (Spreading Factor if not = 1) Payload Rate，11ad (Mbps) Payload Rate，1.08GHz (Mbps) Pi/2-DBPSK 1/2 (32, with pi/2-rotation) 27.5 13.75 Changming Zhang John Doe, Some Company

CMCS OFDM PHY September 2013 CMCS Index Modulation Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 CMCS OFDM PHY CMCS Index Modulation Code Rate (Spreading Factor if not = 1) Payload Rate，11ad (Mbps) Payload Rate，1.08GHz (Mbps) 18 SQPSK 1/2 693 346.5 19 5/8 866.25 433.125 20 QPSK 1386 21 1732.5 22 3/4 2079 1039.5 23 16QAM 2772 24 3465 25 4158 26 13/16 4504.5 2252.25 27 64QAM 5197.5 2598.75 28 6237 3118.5 29 6756.75 3378.375 Changming Zhang John Doe, Some Company

CMCS MR SC PHY September 2013 CMCS Index Modulation Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 CMCS MR SC PHY CMCS Index Modulation Code Rate (Spreading Factor if not = 1) Payload Rate，11ad (Mbps) Payload Rate，1.08GHz (Mbps) 1 pi/2-BPSK 1/2 (2) 385 192.5 2 1/2 770 3 5/8 962.5 481.25 4 3/4 1155 577.5 5 13/16 1251.25 625.625 6 pi/2-QPSK 1540 7 1925 8 2310 9 2502.5 Changming Zhang John Doe, Some Company

CMCS HR SC PHY September 2013 CMCS Index Modulation Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 CMCS HR SC PHY CMCS Index Modulation Code Rate (Spreading Factor if not = 1) Payload Rate，11ad (Mbps) Payload Rate，1.08GHz (Mbps) 10 pi/2-16QAM 1/2 3080 1540 11 5/8 3850 1925 12 3/4 4620 2310 13 13/16 \ 2502.5 14 pi/2-64QAM 15 2887.5 16 3465 17 3753.75 Changming Zhang John Doe, Some Company

CMCS Low power PHY September 2013 CMCS Index Modulation Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 CMCS Low power PHY CMCS Index Modulation Code Rate (Spreading Factor if not = 1) Payload Rate，11ad (Mbps) Payload Rate，1.08GHz (Mbps) 30 pi/2-BPSK 13/28 626 313 31 13/21 834 417 32 52/63 1112 656 33 pi/2-QPSK 1251 625.5 34 1668 35 2224 36 13/14 2503 1251.5 Changming Zhang John Doe, Some Company

1.08GHz modulation and coding schemes Frame structure September 2013 Roadmap Background 1.08GHz modulation and coding schemes Frame structure IQ imbalance estimation and compensation PA nonlinearity treatment Conclusion Changming Zhang

Ctrl PHY (The same as 11ad) Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 Frame structure Ctrl PHY (The same as 11ad) OFDM PHY Changming Zhang John Doe, Some Company

MR SC PHY (The same as 11ad) Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 Frame structure MR SC PHY (The same as 11ad) HR SC PHY Changming Zhang John Doe, Some Company

Low power PHY (The same as 11ad) Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 Frame structure Low power PHY (The same as 11ad) Changming Zhang John Doe, Some Company

1.08GHz modulation and coding schemes Frame structure September 2013 Roadmap Background 1.08GHz modulation and coding schemes Frame structure IQ imbalance estimation and compensation PA nonlinearity treatment Conclusion Changming Zhang

SFS-IQ imbalance estimation Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 SFS-IQ imbalance estimation SFS (Single-Frequency Sequence) Received baseband signal model: The phase difference between adjacent symbols is fixed at π/2, but it does not mean SFS is single-frequency signal, it is also constructed by symbols with the same time duration as the preamble and payload. The transmit MASK mainly depends on the time duration of symbols, so the MASK is maintained after SFS is added. SFS is in front of the original STF, thus synchronization and channel estimation are not impacted by IQ imbalance . The length of SFS is 512, but only 128 symbols is enough for IQ imbalance estimation, others are used for initial capture before IQ imbalance estimation. Changming Zhang John Doe, Some Company

SFS-IQ imbalance estimation Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 SFS-IQ imbalance estimation By calculating the second-order expectations of every two adjacent: symbols: Furthermore, let Then Thus, we can obtain: The reason for “≈’’ is due to the neglect of Δθ, which is reasonable as Δθ is quite small. Changming Zhang John Doe, Some Company

SFS-IQ imbalance compensation Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 SFS-IQ imbalance compensation With IQ imbalance, the received baseband signal can be expressed as: Without the presence of IQ imbalance, the baseband signals can be expressed as IQ compensation can be performed as: Changming Zhang John Doe, Some Company

Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 Explanations The proposed method for IQ imbalance treatment is almost independent of CFO. As IQ imbalance is compensated at the front of synchronization, then CFO estimation and compensation is not impacted by IQ imbalance. However, before IQ compensation, CFO estimation and compensation is quite hard. Consider the complexity, we only address RX frequency-independent IQ imbalance. However, as for frequency-dependent IQ imbalance, the proposed method can also achieve some effects, even though the compensation is not perfect in this case. Due to the limit of transmit EVM, TX IQ imbalance is not so significant as RX IQ imbalance, so the proposed method that only considers RX IQ imbalance is reasonable. Changming Zhang John Doe, Some Company

September 2013 L=128, r=0.05，∆r=5； t=0.005，∆t=0.5 Changming Zhang

September 2013 L=128, r=0.05，∆r=5； t=0.005，∆t=0.5 Changming Zhang

September 2013 L=128, r=0.05，∆r=5； t=0.005，∆t=0.5 Changming Zhang

September 2013 L=128, r=0.05，∆r=5； t=0.005，∆t=0.5 Changming Zhang

1.08GHz modulation and coding schemes Frame structure September 2013 Roadmap Background 1.08GHz modulation and coding schemes Frame structure IQ imbalance estimation and compensation PA nonlinearity treatment Conclusion Changming Zhang

Constellation diagram September 2013 Constellation diagram Standard constellation Distorted constellation PA nonlinearity distorts the constellation. We estimate the distorted constellation (DC) with TBLK in the Header for QAM signals, and demodulate signal according to DC. Changming Zhang

DC estimation analysis September 2013 DC estimation analysis Changming Zhang

Frame design September 2013 TBLK and payload BLK are with the same modulation; Every constellation point appears with the same probability in the TBLK. Changming Zhang

DC estimation September 2013 Parameters to be estimated: T distorted amplitudes , T additional phases: . (T＝3 for 16QAM) Likelihood function (LF) for the k-th symbol: Joint LF: Let , then By equaling the above first-order derivatives to zero, we can obtain the estimation results: Changming Zhang

Hard decision demodulation: September 2013 DC demodulation Hard decision demodulation: For every received symbol, the demodulation output is the DC point with the least distance to it. Soft decision demodulation: The DC soft demodulation style is similar to the SC soft demodulation, where the SC points should be replaced by the DC points. For example, if we require the LLR output demodulation, it can be depicted as: Changming Zhang

September 2013 11ad’s PA model OBO=6 dB Changming Zhang

September 2013 11ad’s PA model OBO=6 dB Changming Zhang

September 2013 11ad’s PA model OBO=6 dB Changming Zhang

September 2013 11ad’s PA model OBO=6 dB Changming Zhang

September 2013 Changming Zhang Code Rate EVM (dB) 1/2 -19 5/8 -20 3/4 -21 13/16 -23 Changming Zhang

September 2013 Changming Zhang Code Rate EVM (dB) 1/2 -19 5/8 -20 3/4 -21 13/16 -23 Changming Zhang

September 2013 Changming Zhang Code Rate EVM(dB) 1/2 -24 5/8 -25 3/4 -26 13/16 -28 Changming Zhang

September 2013 Changming Zhang Code Rate EVM(dB) 1/2 -24 5/8 -25 3/4 -26 13/16 -28 Changming Zhang

Month Year doc.: IEEE 802.11-13/xxxxr1 September 2013 Explanations The preamble, CES and original Header are BPSK signals, and the impact of PA nonlinearity is neglectable. Distorted constellation estimation is performed after equalization, thus the proposed method is decoupled of ISI. If the transmit EVM is not controlled well, the impact of PA nonlinearity is serious especially for 64-QAM, and the proposed method can overcome the impact well at receiver. If the transmit EVM meets the requirements, PA nonlinearity is relatively weak, and impact is weaker, but the proposed method still achieves some performance improvement. Changming Zhang John Doe, Some Company

September 2013 r=0.05，∆r=5； t=0.005，∆t=0.5 Changming Zhang Code Rate EVM(dB) 1/2 -19 5/8 -20 3/4 -21 13/16 -23 Changming Zhang

September 2013 r=0.05，∆r=5； t=0.005，∆t=0.5 Changming Zhang Code Rate EVM(dB) 1/2 -19 5/8 -20 3/4 -21 13/16 -23 Changming Zhang

September 2013 r=0.05，∆r=5； t=0.005，∆t=0.5 Changming Zhang Code Rate EVM(dB) 1/2 -24 5/8 -25 3/4 -26 13/16 -28 Changming Zhang

September 2013 r=0.05，∆r=5； t=0.005，∆t=0.5 Changming Zhang Code Rate EVM(dB) 1/2 -24 5/8 -25 3/4 -26 13/16 -28 Changming Zhang

1.08GHz modulation and coding schemes Frame structure September 2013 Roadmap Background 1.08GHz modulation and coding schemes Frame structure IQ imbalance estimation and compensation PA nonlinearity treatment Conclusion Changming Zhang

Frame structure of 1.08 GHz PHY September 2013 Conclusion CMCSs of 1.08 GHz PHY For Ctrl PHY, OFDM PHY, and Low power PHY, the CMCSs are the same as that of 11ad. SC PHY is divided into MR SC PHY and HR SC PHY, MR SC PHY corresponds to PSK modulation, and HR SC PHY corresponds to QAM modulation. Here 13/16-16QAM, and 64QAM are new compared with 11ad. Frame structure of 1.08 GHz PHY Including Ctrl PHY, OFDM PHY, MR SC PHY, HR SC PHY, and Low power PHY. The frame structure of Ctrl PHY, MR SC PHY, and Low power PHY are consistent with that of Ctrl PHY, SC PHY, and Low power PHY of IEEE 802.11ad, respectively. Compared with 11ad, SFS is added at the beginning for OFDM PHY, which is used to estimate and compensate IQ imbalance. Compared with the SC PHY of 11ad, also SFS is added at the beginning for HR SC PHY that used to estimate and compensate IQ imbalance. In addition, TBLK is added before payloads, which is used to estimate distorted constellation to react PA nonlinearity. The proposed methods that compensate IQ imbalance and PA nonlinearity work well, which can be observed from the performance evaluation. Changming Zhang

September 2013 Thanks！ Changming Zhang