A New Generic Maximum-Likelihood Metric Expression for Space–Time Block Codes With Applications to Decoding

The metric expression for a generic linear space-time block code (STBC) is studied using a different approach to vectorization and a new representation of the metric. The new representation lends itself to a simple measure of reliability based on the sum of inner products, and provides a quantifiable definition for minimum distance of a STBC. This provides the framework for a new family of near-maximum-likelihood (ML) and ML decoding algorithms. It also has applications in the development of optimality test criteria for STBCs, as well as in the design of STBCs with low decoding complexity.