Correlation number: a new design criterion in multi-antenna communication

This paper establishes a connection between antenna correlation and the Shannon capacity of multi-antenna channels. At low and moderate signal-to-noise ratios, which constitute the most relevant regime in contemporary mobile systems, a fundamental parameter emerges out of such connection. We illustrate how this parameter, for which we coin the term correlation number, can be used as a design criterion for diversity arrays. In addition, we present correlation numbers from experimental measurements conducted in New York City.