Channel capacity of MIMO OSTBC systems in Nakagami fading environments

In recent literature, performance analyses of multiple-input multiple-output (MIMO) multiuser systems using orthogonal space-time block coding (OSTBC) over Nakagami-m fading via bit error rate (BER) estimation have been obtained. In addition, analyses of the average channel capacity of these systems were carried out. From these findings, it was reported that closed-form expressions of the average channel capacity are difficult to obtain because of the presence of a finite product of an incomplete Gamma function. This paper shows that a new closed-form upper bound expression on the average channel capacity for non-integer values of m can be derived which gives insights into performance of OSTBC MIMO systems. The new bound is shown to be tight and valid with sensible numerical results.