Exploiting multipath and Doppler array gains in fast-fading wireless channel

Abstract

This study deals with signal transmission and reception over a fast-fading wireless environment. Conventional methods usually consider the rapid change of channel to be harmful, which may decrease the performance of existing systems. There are also methods proposed to make use of the cause of degradation in existing systems – Doppler spread – to provide additional diversity, at the cost of folds increased complexity. In this study, the authors focus on exploiting the array gains provided by the fast-fading wireless channel multipath array gain (MAG) and Doppler array gain (DAG). The conceptions of MAG and DAG are straightforward extensions of the conception of array gain in multi-antenna systems. For methods which exploit multipath and Doppler diversities, complex signal processing is required at the receiver side, leading to a great increase in complexity. The MAG and DAG can be easily obtained using simple transmit waveform design. Therefore, no extra computational load is required. Both analytical and simulation results show that, with the same computational complexity, the proposed methods can significantly outperform the conventional ones.