协作系统中基于比例公平的资源分配方法

针对多用户协作中继系统中的资源分配问题,提出了一种在满足用户速率比例公平约束条件下的新算法。该算法先将由2个时隙组成的中继用户传输链路转换为一个等效信道链路,将涉及子载波分配、中继选择和功率分配的组合优化问题转化为分步的次优化问题。该算法在等功率分配情况下,根据各用户速率比例公平系数进行初步子载波数目分配;以瞬时信道增益最佳原则,进行剩余子载波数目分配及具体子载波分配,同时完成中继选择;在速率比例公平约束条件下推导出次优化功率分配的闭式表达式,从而完成各子载波上的功率分配。仿真结果表明,该算法在有效提高系统容量的同时,保证了各用户速率之间的比例公平性。

Proportional Fairness Resource Allocation Algorithm in Cooperative Communications

Aiming at the resource allocation problem in muhi-user cooperative relay communications, a new algorithm with rate proportional fairness constraint is proposed. Above all, the transmission links of the relay users, consisting of two time slots, are converted into an equivalent channel link, then the joint optimization problem involving subcarrier assignment, relay selection and power allocation is decomposed into a step-by-step suboptimal problem. Firstly, assuming equal power distribution, the preliminary assignment of subcarrier numbers is addressed according to the rate proportional fairness constraint ; Then, with the principle of best channel conditions, the assignment of remaining subcarrier numbers and the specific subcarrier assignment are conducted to complete the relay selection; Finally, the closed form expressions for suboptimal power allocation are derived based on the rate proportional fairness constraint to accomplish the power allocation on each subcarrier.The simulation results show that the proposed algorithm effec- tively improves the total capacity while guaranteeing the rate proportional fairness.