基于OFDM的认知无线电子载波功率分配算法

Subcarrier and Power Allocation in OFDM Based Cognitive Radio Systems

在基于正交频分复用(OFDM)的认知无线电系统中,由于系统发射功率预算和主用户与感知用户干扰受限,以最大化感知用户的容量为目标的最优功率分配算法复杂度太高,提出了两种基于线性注水机制的改进算法及简化算法,改进算法可以通过线性计算快速确定不需分配功率的子载波,进而不需多次迭代就可完成注水过程。仿真结果表明,改进算法下感知用户系统的容量非常接近最优算法,但是复杂度却远远低于最优算法。

With the target of maximizing the capacity of cognitive users in OFDM-based cognitive radio network,some optimal power allocation algorithms are proposed to keep both the total transmit power and interference introduced to the primary user blow the constraints.However,these algorithms are usually complex.Therefore,two improved power allocation algorithms and their simplified versions based on the linear waterfilling（LWF） are proposed,which can rapidly confirm the subcarriers without allocating power.both of which have a less complexity than the optimal does.Presented simulation results have shown that the performance of the two improved algorithms is close to the optimal one.