无线再生中继网络的功率优化分配

Optimal power allocation for wireless regenerative relaying networks

针对中继传输中系统性能与发送端和中继器发射功率均有关的问题,提出了一种在总功率一定的条件下,以误码率最小为准则,优化分配发送端和中继器发射功率的方法.对于两跳中继(无分集)和合作分集两种再生中继网络,以大信噪比时的误码率上界表达式为目标函数,通过Lagrange乘数法求得发送端和中继器功率优化分配的数值解.仿真结果表明,与发送端和中继器均匀分配功率相比,经功率优化分配后的中继网络,在误码率下降的同时,中断概率和信道容量的性能也得到提升.

The system performance of relaying transmission depended on the transmit power of both the source and the relay. On the assumption of constant total transmit power, an optimal power allocation scheme between the source and the relay was proposed to minimize the bit error rate （BER）. Two types of regenerative relaying networks were considered, i.e. two-hop relaying networks （without diversity） and cooperative diversity networks. With the upper bound of BER in high SNR as the objective function, numerical solutions of the total power allocated to the source and the relay were obtained, based on Lagrange multiplier method. Simulation results showed that the new scheme promised to reduce BER and enhance the performance of outage probability and channel capacity as well, compared to the uniform power allocation scheme between the source and the relay.