认知无线电中考虑公平性的OFDMA资源分配策略

Study on the Fairness of OFDMA Resource Allocation Strategy in Cognitive Radio

针对认知无线电资源分配过程中出现的多认知用户资源分配不公平的问题,提出了在保证各认知用户速率公平分配前提下实现吞吐量最大的资源分配算法.该算法分为各认知用户子载波分配和子载波功率分配两步,在第一步中提出了两种子载波分配方案,两种方案根据各认知用户所要求的速率比进行子载波分配,不同的是方案二把所有的子载波进行了分类,从而使子载波分配更加公平;在第二步中采用了子载波功率注水方案以实现认知用户吞吐量的最大化.仿真结果表明了所提算法的有效性.

Based on the assumption that the distance between the source transmitter and the final receiver is not infinite in distributed network, the effective transmission distance is redefined, the upper and lower bounds of the expectation of effective transmission distance and the density of progress are derived, and how the network parameters affect the density of progress is studied. Numerical and simulation results show that： the simulation value for the expectation of effective transmission distance is between its upper and lower bounds, and decreases with the angle of the region for the selection of relay; the simulation value for the density of progress, which is between its upper and lower bounds, is closer to its upper bound, and the density of progress is determined by the expectation of effective transmission distance and the maximum probability of outage.