A low-complexity antenna diversity receiver suitable for TDMA handset implementation

Abstract

This paper introduces a low-complexity antenna diversity receiver suitable for TDMA handset implementation. The receiver employs two branches of diversity, and is capable of adaptively choosing among three different diversity techniques which are implemented in a single design which we refer to as a multi-diversity receiver. It consists of a single conventional wireless digital receiver chain augmented with a few additional low-cost passive RF components and minor control circuits. We present algorithms for efficient co-phasing and equal-gain combining, as well as a novel cochannel interference-reduction combining algorithm. These are implemented in a system design simulation which conforms to the PACS (Personal Access Communication System) standard. We then present simulation link performance for selection diversity (SD), equal-gain combining (EGC) and interference-reduction combining (IRC) under Raleigh fading, flat fading with cochannel interference and selective fading conditions. The results show that EGC and IRC yield a signal-to-noise ratio (SNR) improvement of 1 dB and a signal-to-interference ratio (SIR) improvement 4 dB-/spl sim/5.5 dB, respectively, compared with SD. The receiver also lowers the irreducible word error rate due to multipath delay spread when the Doppler shift is small. These results are compared with the results from other research.