Impact of a Line of Sight Component on the Performance of a MIMO System Designed under Statistical Channel Knowledge

This paper deals with the problem of the design of a multi-antenna system assuming that only a statistical channel knowledge is available at the transmitter. More precisely, in the proposed design it is considered that an optimum maximum likelihood detector is employed at the receiver side and that the channel has a line of sight component. The design is obtained to minimize the worst pairwise error probability, which is averaged over the channel statistics. The benefits of exploiting this statistical channel knowledge are compared with a system requiring no channel state information at the transmitter. Finally, the asymptotic gain at high transmit power thanks to the line of sight component is found in closed-form.