Optimal 100% Excess Bandwidth Signaling in Cochannel Interference

The problem of transmitter-receiver (T-R) filter design for detection of a binary phase-shift keying signal in asynchronous cochannel interference and Gaussian noise is considered. It is shown that maximum signal-to-interference-plus-noise ratio (SINR) can be achieved only if the T-R filters have a flat spectrum with 100% excess bandwidth. The bit error probability (BEP) performance of a system with the proposed filters is compared to that of a system with conventional root raised-cosine filters both for perfect and imperfect timing recovery cases. It is shown that the proposed filter design is superior to the conventional root raised-cosine filters both in having larger SINR and smaller BEP