Subband method for wideband adaptive beamforming with conjugate quadrature mirror filter bank

An efficient subband adaptive beamforming method for wideband array antenna is proposed in this paper, which is used to enhance performance of suppressing the interference and accelerate convergence speed of weights. A conjugate quadrature mirror filter bank is adopted to split the signal into subbands and avoid aliasing between them. As subbands run at a lower sampling rate due to the narrower band and in manner of parallel, loads of computational processing costs, compared with traditional fullband methods, can be alleviated. Convergence speed of weights is also improved. In addition, the narrower subband signal is, the less taps are needed, the addition of uncorrelated noise resulted from taps is much less, improved signal gain and deep suppression of the interference. The proposed subband method exhibits better performance than fullband counterparts through simulations, except for the same output square errors pretty nearly.