The algorithm of channel estimation based on IEEE802.11ac

The conventional algorithm of channel estimation based on IEEE802.11ac is Least Square (LS) algorithm, which uses the Very High Throughput-Long Training Field (VHTLTF) of frame header as training sequence. While the conventional algorithm does not take into account the effects of noise and the varying characteristics of channel in time domain. In order to describe the slow change of channel in time domain, this paper considers that the VHT-LTF is linearly interpolated in the frames. To suppress the impact of noise, this paper proposes the Linear Minimum Mean Square Error (LMMSE) algorithm in frequency domain and utilizes a Wiener filter window function to approximate the correlation function in LMMSE. Simulation result shows that LMMSE provides 4dB SNR better than LS at 10
^-2
BER.