A Novel Power Allocation Scheme for Distributed Space-Time Coding

This paper derives an optimal power allocation (PA) to maximize the effective average signal-to-noise ratio (SNR) of distributed space-time coding (DSTC) in wireless relay networks, where the locations of the relays can be anywhere between the source and destination. It is first shown that in maximizing the average SNR, not all the relays might be active, and hence the code performance might be compromised. The amount of fading is then introduced for the relay networks and used as a constraint to derive a novel PA scheme. This new PA is shown to obtain the maximum diversity order of both noncoherent and coherent DSTC systems at high SNR.