Resource Allocation for Multiuser Improved AF Cooperative Communication Scheme

Joint power and bandwidth allocation of an improved amplify and forward (AF) cooperative communication scheme is proposed to utilize the spectrum efficiently. Each user adapts to a mixed strategy transmission using frequency division multiplexing (FDM), where part of the data is transmitted using AF relaying with diversity, and the other part is transmitted using direct transmission without diversity. The resource allocation problem aimed at maximizing the sum rate of a multi-user up-link scenario using the improved scheme is formulated. Both flat and frequency-selective fading channels are addressed. The resource allocation problem of the power and bandwidth profiles is non-convex and difficult to solve. In this sense, a two-step iterative algorithm is proposed, which alternates between solving either power allocation sub-problem for a given bandwidth profile or a bandwidth allocation sub-problem for a given power profile. The convergence and optimality of the proposed algorithm are discussed using game theory framework. Numerical simulations show the merits of the proposed improved AF cooperative communication scheme and the proposed iterative algorithm.