Message passing-based OFDMA uplink resource allocation to users with different date rate needs

摘要

Different needs on Qos usually result in different date rates for the subscribers in a wireless network. To address the problem of distributed resource allocation in orthogonal frequency division multiplexing access (OFDMA) uplink, an optimization model is utilized to minimize the transmitted power constrained on exclusive occupation of each subchannel for avoidance of multiuser access interference (MAI) and minimum rate of each user for fairness, to reach a suboptimal solution. Two schemes are compared. The 1st scheme is a traditional one that all subchannels are equally assigned to all users based on message passing (MP) algorithm, afterward dynamic programming (DP)-based bits-loadings are performed. The 2nd scheme is an improved one as follows: each user is given a subchannel-quota firstly, which is configured to be proportional to its individual date rate needed, and based on all these quotas MP algorithm is executed, and the final course is the same. Theoretical analysis and simulation verification indicate that the 2nd scheme outperforms the 1st one significantly on the transmitted power consumption, and their iteration times are very close.