Abstract:

To improve the error performance and the resource
utilization of cooperative systems, the optimum resource allocation,
i.e., power allocation and partner choice, for an adaptive
decode-and-forward (DF) cooperative diversity system based on
quadrature modulation is investigated. The closed-form expression
of the bit error rate (BER) system performance is derived and an
optimal power allocation (OPA) algorithm is proposed to optimize
the power allocation between the local and relayed signals under
the minimum BER criterion. Based on the OPA algorithm, a partner
choice strategy is proposed to determine the partner locations
specified by various cooperation gains. Simulation results show
that the proposed resource optimization algorithms are superior
to the unoptimized algorithms by significantly reducing the BER
and improving the cooperative gain, which is useful to simplify the
practical partner choice process.