Weight tracking method for OFDM adaptive array in time variant fading channel

In Orthogonal Frequency Division Multiplexing (OFDM) system, in order to reduce the influence of Co-Channel Interference (CCI), Minimum Mean Square Error-Adaptive Array Antenna (MMSE-AAA) is attractive. To get the space diversity gain, the distance between adjacent elements should be set to be more than several wavelengths. However, it is difficult to derive the optimal weights with a few training symbols because fading status is independent in each element. As a result, Bit Error Rate (BER) performance is deteriorated. In this paper, we propose a novel weight tracking method to achieve space diversity gain and fast convergence with a few pilot symbols. In the proposed method, before updating the weights, channel estimation is applied to track the multipath fading of the desired signals. By computer simulation, we show that the proposed system can improve BER performance compared to the conventional system without channel estimation, even if the Doppler frequency is high.