The QC-LDPC code, with its excellent error correction performance and hardware friendliness, has been identified as one of the channel encoding schemes by Wi-Fi 6. Shorting, puncturing, or repeating operations are needed to ensure that user data can be sent with integer symbols and complete rate matching. Due to the uncertainty of the user data size, the modulation’s selectivity, and the difference in the number of spatial streams, the receiver must deal with more than 10⁶ situations. At the same time, other computationally intensive tasks occupy the time slot budget of the receiver. Typical are demodulation and decoding. Hence, the receiver needs to quickly reverse the demodulated data process. This paper first proposes a co-processing method and VLSI architecture compatible with all code lengths, code rates, and processing parameters. The co-processor separates field and block splicing, simplifying the control logic. There is no throughput rate bottleneck, and the maximum delay is less than 1 us.

A successive interference cancellation (SIC)-based weighted least-squares (WLS) estimation for the carrier frequency offset (CFO) and the sampling frequency offset (SFO) is presented for wireless local area networks (WLANs) based on orthogonal frequency division multiplexing (OFDM). The proposed SIC-based WLS performs the estimation by exploiting the phase rotation in the frequency domain caused by the CFO and the SFO. SIC-based WLS estimates the CFO and the SFO successively instead of by traditional simultaneous estimation. The estimation of CFO based on the Taylor series is performed first, and then the WLS estimation of SFO based on successive cancellation of the CFO is carried out. The simulation results show that the SIC-based WLS can estimate the CFO and the SFO effectively. Compared to the WLS scheme, a performance improvement of more than 0.6 dB is achieved by SIC-based WLS, and nearly 10 percent of the complexity is reduced.

In this letter, an angle adjustment method is proposed to improve the accuracy of the sampling frequency offset (SFO) estimation for the very high throughput wireless local area networks (WLANs). This angle adjustment can work together with existing least square (LS) and weighted least square (WLS) to achieve better system performance. Simulation results show that, the angle adjustment can help LS and WLS to get better pocket error rate (PER).

In this paper, we propose a simplified weighted least square (SWLS) to estimate phase variations utilizing pilots, for Orthogonal Frequency Division Multiplexing (OFDM) based very high throughput wireless local area networks (WLANs). For SWLS, the common phase error (CPE) maximum likelihood (ML) estimation and the angle boundary treatment are improved to enhance the performance of phase estimation, while the combined scheme of pair pilots is used to reduce the complexity. Simulation results show that, compared to weighted least square (WLS) scheme, a similar pocket error rate (PER) is achieved by using the SWLS method, but more than 40 percent of complexity is reduced.