An Adaptive Broadband Channelization Scheme Using Nonuniform Subband Decomposition

In modern broadband software defined radio systems, there usually exist several independent signals in the received intermediate frequency (IF) bandwidth. They have nonequal bandwidths and arbitrary band locations, which are unknown and time-variant. In order to efficiently channelize these signals, an adaptive channelization method is proposed based on complex-valued oversampled subband filterbanks. The IF signal is decomposed by uniform analysis filterbanks firstly. Then the signals' distribution is obtained according to the power estimations of every sub-signal. At last, the desired signals are extracted by merging the corresponding sub-signals using synthesis filterbanks. When the signals' distribution changes, the synthesis scheme is updated adaptively to channelize new signals without altering subband filterbanks. Polyphase decomposition are adopted to optimize the channelization method and reduce the computational complexity. Simulations are carried out to testify the reliability and efficiency of the proposed scheme.