A diversity co-channel interference canceller for AMPS cellular systems

Abstract

In cellular communication systems co-channel interference (CCI) is a major capacity limiting factor. A number of system characteristics (e.g. voice quality and dropped call rate) can be improved individually or in combination by providing co-channel interference cancellation, at either the base station or mobile. This paper describes the development and performance evaluation of separate speech and data, two antenna co-channel interference canceller (CCIC) algorithms for the Advanced Mobile Phone Service (AMPS). In the presence of a single dominant AMPS interferer, the speech CCIC algorithm provides carrier to interference (CIR) gains of between 3 and 14 dB, dependant on the fading rate, as compared to a switched diversity scheme for the same average output signal to noise plus distortion ratio (SINAD). For similar channel conditions the data CCIC algorithm provides CIR gains in excess of 10 dB for a target bit error rate (BER) of 1%.