Efficient adaptive array receiver for OFDM based wireless local area networks (WLAN)

The paper considers low complexity and suboptimal frequency-domain process technology for orthogonal frequency division multiplexing (OFDM) adaptive array system. To reduce complexity, a novel receiver scheme is proposed which is a single beamformer in combination with channel equalization. The scheme computes a set of beamforming weight vector from the samples of a particular subcarrier, and applies the weight vector to all the subcarriers. In the frequency selective fading environment, in order to mitigate performance degradation arising from different channel fading across subcarriers, frequency domain channel estimation and equalization for the post-beamforming channel are employed at individual subcarrier. As an application case, the OFDM-based wireless local area networks (WLAN) standard IEEE 802.11a is considered. Simulation results show that the proposed method can achieve comparable performances with very low complexity.