Impact of Spatial Correlation on Adaptive Coded Modulation Performance in Rayleigh Fading

A performance analysis of an adaptive coded modulation (ACM) scheme operating on identically distributed and spatially correlated Rayleigh flat-fading channels is presented. In particular, we study a single-input multiple-output system where spatial diversity is exploited at the receiver by using a maximum ratio combining scheme. The ACM scheme consists of a set of multidimensional trellis codes originally designed for additive white Gaussian noise channels, with codes being based on quadrature amplitude modulation signal constellations of varying size. Rate adaptation is achieved by providing the transmitter with channel state information as predicted by the receiver. Approximate closed-form expressions for the average bit error rate and the average spectral efficiency are derived, and numerical examples are given for the case of Jakes correlation profile and maximum a posteriori optimal predictor coefficients