Multiple Relay Orthogonal Frequency Division Multiplexing for Total throughput Maximization

Abstract

Efficient utilization of radio resources in wireless networks is crucial and has
been investigated extensively. This letter considers a wireless relay network where
multiple user pairs conduct bidirectional communications via multiple relays based on
orthogonal frequency-division multiplexing (OFDM) transmission. The joint optimization
of channel and relay assignment, including subcarrier pairing, subcarrier allocation as well
as relay selection, for total throughput maximization is formulated as a combinatorial
optimization problem. Using a graph theoretical approach, we solve the problem optimally
in polynomial time by transforming it into a maximum weighted bipartite matching
(MWBM) problem. Simulation studies are carried out to evaluate the network total
throughput versus transmit power per node and the number of relay nodes