Optimizing Zero-Forcing Based Gain Allocation for Wireless Multiuser Networks

We consider a wireless multiuser network where a number of source/destination pairs communicate concurrently over the same physical channel. A set of amplify-and-forward relay nodes assist the communication by multiplying their received signal with a complex gain factor before retransmission. We propose and compare different strategies for finding the gain factor for every relay terminal, motivated by the chosen figures of merit: average sum rate, diversity, and fairness. A new and practical definition of diversity is provided in the context of our system model. For each strategy we investigate the provided gains in terms of the figures of merit, and the trade-off between them. The existing schemes in the literature act as references to the proposed schemes.