Impact of diversity reception on fading channelswith coded modulation . Part I : Coherent detection

We address the problem of designing and analyzing the performance of a coded modulation scheme for the fading channel when space diversity is used. Under fairly general conditions a channel aaected by fading can be turned into an additive white Gaussian noise (AWGN) channel by increasing the number of diversity branches. Consequently , it can be expected (and is indeed veriied by our analyses and simulations) that a coded modulation scheme designed to be optimal for the AWGN channel will perform asymptotically well also on a fading channel with diversity. Thus, we can argue that \fading codes" are not essential when diversity is introduced. This paper contains the following results: Bounds on the bit error probability of a system with coded modulation and diversity , for space-and time-correlated Rician at fading. Speciically, we derive a new method which allows evaluation of the pairwise error probability extremely easy, as well as accurate and computationally fast. The accuracy achieved improves considerably on the widely used, but rather loose, Chernoo bound. Asymptotic behavior of the fading channel with diversity as the number of diversity branches increases. EEects of diversity on coded-modulation performance and design criteria, including the eeect on interleaver depth (which aaects the total delay of the system).