Easily Invertible Tight Bounds for Diversity Reception

Diversity techniques will play a key role in next generation wireless communication systems, thus system design will benefit from a clear understanding of how these techniques affect system performance. To this aim we propose simple bounds, optimized within a given class, on the symbol error probability (SEP) in the presence of non-ideal channel estimation for arbitrary two-dimensional signaling constellations. Unlike known bounds, the optimized simple bounds are tight for all signal-to-noise ratios (SNRs). In addition, these bounds are easily invertible, which enables us to obtain bounds on the symbol error outage (SEO) and SNR penalty. As an example application for digital mobile radio, we consider the SEO in log-normal shadowing for both maximal ratio combining with unequal branch power profile and subset microdiversity. The reported lower and upper bounds are extremely tight, that is, within a fraction of a dB from each other.