Deterministic Combining for Fading Channels

For a communication system employing receive diversity in flat Rician fading, we consider linear combining receivers with deterministic weights. Two receiver structures are proposed: (1) a modified maximum likelihood receiver in which detection is performed by maximizing the likelihood function of the combined received signal, (2) a deterministic maximal-ratio combining (MRC) receiver which uses the same structure as that of an MRC receiver with deterministic weights. The deterministic weight vector is chosen such that it minimizes the union bound on the symbol error probability. The error performance of the receivers is compared with that of the square-law combining and the equal-gain combining receivers.