On the Performance of Aperiodic Inverse Filter Approximations

Abstract

In 1989, the author proposed the aperiodic inverse filter rather than the matched filter for multipath channel estimation. Thereafter, Massey specified a CDMA-like multiuser communication scheme called Code Time Division Multiple Access (CTDMA), which applies inverse filtering in the despreader for complete separation of the users. This paper evaluates the performance of implement able inverse filter approximations such as the truncated inverse filter, its improved replica by a modified gradient alogorithm and its digital realization when its taps are quantized. These results are needed in order to implement a CTDMA-receiver in digital hardware.