Space-time coding for the parametric fading channel

Error correction coding across multiple transmit and receive antennas has recently gained much attention, pioneered by the space-time coding techniques presented in [6]. Coding gains obtained therein rely on independence of fading on signals from different transmit antennas. In most cellular systems, fades from the closely spaced transmit antennas are highly correlated, thereby reducing coding gains. An alternative wireless channel model that takes fade correlations into account is the PARAMETRIC MODEL. Drawing upon this model we propose PATH CODING, which is error correction coding across multiple propagation paths. Since it is based on the physical channel, Path Coding is a more powerful method of exploiting naturally available diversity. We derive the exact average pairwise error probability (PEP) for maximum likelihood decoding. The PEP is a function of the norms of error sequences on different paths. We provide insight into minimization of the PEP subject to constraints on total norm.