Nearest Neighbour Decoding in Block-Fading Channels with Imperfect CSIR

This paper studies the outage performance of block-fading channels with imperfect channel state information at the receiver (CSIR). Using mismatched decoding error exponents, we prove the achievability of the generalised outage probability, the probability that the generalised mutual information is less than the rate. Then, using nearest neighbour decoding, we study the generalised outage probability in the limit of large signal-to-noise ratio (SNR). In particular, we study the SNR exponents and we show that the SNR exponent is given by the SNR exponent of the perfect CSIR case times the minimum of one and the channel estimation error SNR exponent.