Frequency domain equalization of linear polyphase channels

In this paper, we consider the problem of linear equalization of polyphase channels and its implementation in the frequency domain. These channels may result from oversampling the single output of a transmission channel or/and by receiving multiple outputs of an antenna array. From the polyphase representation of the fractionally spaced channels/equalizers we derive a novel low complexity frequency domain implementation structure for optimum infinite-length equalizers. As an example we apply the concept to a high speed wireless indoor communication system. The digital baseband processing requirements are considered and simulation results for typical multipath channel conditions are presented.