摘要
小波包分复用系统(WPDM)具有高数据传输率、高带宽利用率和强抗选择性衰落等特点,但其信号峰均功率比(PAPR)过高。针对这一问题,提出了一种基于小波包树形结构优选与峰值加窗限幅的降低PAPR的联合算法。通过对WPDM系统的分析可知,WPDM系统的峰均功率比与WPDM系统中小波包基函数的调制结构有关。首先,利用小波包调制独特的二叉树结构,改善小波包分复用系统性能,优选出具有最小干扰功率和误码率的调制树形结构,实现WPDM的优化。其次,利用改进的峰值加窗限幅法,抑制PAPR性能。仿真结果表明:改进后的算法提升了系统性能,且经小波包树形结构优选和峰值加窗限幅法改进的联合处理,在尽量不影响原系统误码性能的前提下,不仅减小了系统PAPR值,还降低了系统计算复杂度。
Wavelet packet division multiplexing （WPDM） features high data transmission rate, high bandwidth utilization and stronger anti - selective attenuation,but its signal peak to average power ratio （PAPR） is too high. To solve this problem,a joint algorithm for reducing PARP is proposed, the algorithm is based on wavelet packet tree structure optimization and peak windowing clipping. Through analyzing WPDM system, it is found that the PAPR of WPDM system is related to the modulation structure of wavelet packet basis function in WPDM system. Firstly, the binary tree structure of wavelet packet modulation is used to improve the performance of the wavelet packet division multiplexing system, and select the modulation tree structure with minimal interference power and bit error rate to realize the optimization of WPDM. Secondly, the improved peak windowing clipping method is adopted to inhibit of PAPR performance. The simulation results show that the improved algorithm improves system performance, and after the joint treatment of wavelet packet tree structure optimization and peak windowing clipping, the algorithm can not only better reduce the system PAPR value, but also decrease the computational complexity of the system, without affecting the error rate of original system.
出处
《自动化仪表》
CAS
2017年第9期32-35,共4页
Process Automation Instrumentation
