A multirate equalizer for inter-symbol interference channels based on successive interference cancellation

Abstract

A multirate transmission scheme to mitigate intersymbol interference (ISI) is proposed in this paper. The proposed method first decomposes the channel into two half-rate subchannels by employing successive interference cancellation (SIC). Then the channel is further decomposed into 2M parallel channels by applying the method recursively. We demonstrate that these sub-channels tend to become memoryless as M increases. The proposed reception algorithm can be implemented in frequency domain and thus, it has a complexity in the order of linear equalizers. The proposed transmission scheme does not employ any sort of linear pre-coding at the transmitter. Therefore, it does not increase the peak-to-average power ratio at all. Furthermore, the proposed transmission method can surpass even the genie aided decision feedback equalizer in terms of reliable throughput and it can get quite close to independent identically distributed (i.i.d.) capacity of the channel which is a quite important achievement for a practical equalizer.