Realistic diversity systems in correlated fading

We present a framework for evaluating the bit error probability of N_d-branch diversity combining in the presence of non-ideal channel estimates. The estimator structure is based on the maximum likelihood (ML) estimate and arises naturally as the sample mean of N_p pilot symbols. The framework presented requires only the evaluation of a single integral involving the moment generating function of the norm square of the channel-gain vector, and is applicable to channels with arbitrary distribution, including correlated fading. Our results show that the diversity order of a system with practical channel estimation matches that of an ideal system operating in the same correlated fading environment, regardless of the number of pilot symbols used in the estimation process.