Abstract:

In order to improve the sumcapacity of amplifyandforward scheme for twoway relaying over orthogonal frequency division multiple (OFDM), a subcarrier pairing method based on sorting the channel coefficients (SPSCC) with low complexity is proposed. And for jointing subcarrier pairing and its optimal power allocation, a resource allocation strategy is presented. The subcarrier pairing by applying SPSCC with equal power allocation among each subcarrier pair is firstly considered; and a dual decomposition for power allocation among each subcarrier pair with total power constraint is employed. Finally, the power of each subcarrier pair is allocated to each node，i.e. the optimal power allocation of each node is obtained. Numerical analysis shows that the proposed resource allocation strategy can improve the sumcapacity.

Key words: twoway relaying, subcarrier pairing, power allocation, dual decomposition