一种正交调制协作系统的功率分配方法

Optimal Power Allocation for Cooperative Systems Utilizing Quadrature Modulation

针对正交调制协作系统中本地和中继信号采用等功率分配（EPA），导致系统资源利用率低的问题，提出了一种正交调制功率优化分配（QM—OPA）方法．QM—OPA方法以最小化系统误码率为目标，根据用户上行信道和用户间信道的平均信噪比来计算本地和中继信号的功率优化分配因子，并利用反馈信道将功率分配信息发送给协作用户，从而实现了功率的自适应分配，提高了系统的资源利用率．QM—OPA方法能降低系统误码率，且实现复杂度较低．仿真结果表明，在实际的非理想协作场景下，与EPA方法相比，QM—OPA方法在误码率为10^-2～10^-4时最大可提供约7dB的信噪比增益．

Since the equal power allocation （EPA） between the local and relayed signals in cooperative system utilizing quadrature modulation results in resource inefficiency, a quadrature modulation optimal power allocation （QM-OPA） algorithm is proposed. An optimal power allocation factor is obtained to minimize the end-to-end bit error rate （BER） of the system using the average signal-to-noise ratios （SNRs） between uplink and inter-user channels, and then the optimal power allocation data is transmitted to cooperative users through feedback channels so that the system resource utilization can be improved. The proposed algorithm is effective in reducing the BER performance and has low implementation complexity. Theoretical and simulation results show that in practical non-ideal cooperation scenarios, the QM-（）PA algorithm outperforms the EPA algorithm by a maximum SNR benefit of 7 dB when the BER is in the range [10 ^-1, 10^-2].