Enhancement of a dual-signal receiver using pre-detection microdiversity for narrowband and wideband signals

The dual-signal receiver (DSR) for simultaneous reception of two co-channel signals, shows large performance degradation for SIR/spl cong/0 dB. In this paper, antenna diversity techniques are investigated to overcome this problem. Computational results for BPSK modulated signals in narrowband and wideband fading multipath channels, show that antenna combining results in a significant performance enhancement for the DSR; the largest improvement is achieved by minimum mean square error combining (MMSEC). For the narrowband Rayleigh fading channel and a four element array, MMSEC performance with two signals is nearly equal to the one signal case for SIR=0 dB. In the wideband channel, the SIR required to achieve good performance, increases with increasing symbol rate due to intersymbol-interference.