在短距离无线通信中,无线节点或移动终端通常有低成本、小体积、低功耗的要求,因此无法使用复杂的预失真或补偿电路克服功放的非线性影响,这是无线节点或移动终端在上行链路中难以使用高阶QAM调制的重要原因之一.基于QAM矩形星座的特点,提出了一种K-means聚类的改进算法作为中央基站节点的高阶QAM解调算法.在发送信号受到较严重的功放非线性失真时,所提改进算法解调性能更优,算法复杂度更低.
Wireless network nodes and mobile devices are always constrained by power,dimension and price in the shortrange wireless communication system.Thus,it's impossible for them to use some complex methods such as pre-distortion and compensation to restrain the nonlinear effects caused by power amplifier,which is one of the important reasons why the high order QAM could not be used in uplink.Based on the characteristics of QAM rectangular constellation,an improved K-means clustering algorithm is presented to be the demodulation algorithm of high order QAM.It has better demodulation performance and lower computational complexity.