As the power amplifier( PA) is inherently nonlinear in Wireless Communication System, the spectral growth out of the signal bandwidth limits the data rate and spectal efficiency. This paper, based on analyzing the principle of digital pre-distortion, used different methods, Look-Up Table(LUT) algorithm and Recursive Least Squares ( RLS) -Least Mean Square ( LMS) algorithm, to implement the linearization for memory-less and memory behavioral model of PA respectively. Create the circuit model in the Mallab environment, the simulation results show that, the digital predistorter can improve power spectrum density of the two models up to 39dB and 15dB respectively, enhance PA's efficiency and reduce the adjacent channels interference( ACI). This paper, after the comparison of different PA models, gives the suitble optimized algorithm ,and it will be helpful in designing pratical circuit of PA linearization.%无线通信系统中,由于功放本身的非线性失真,导致信号带外产生频谱,限制了数据速率和频谱利用率.通过分析功放非线性原理,针对无记忆和记忆两种功放行为模型,提出分别采用查找表算法和最小二乘与最小均方误差相结合的算法进行线性优化.在Matlab环境下创建数字基带预失真链路模型.仿真结果表明,预失真器对两种模型中功率谱密度的改善分别达到39dB和15dB,提高了功放效率,降低了邻道干扰.针对不同功放类型的线性化进行对比研究讨论,并选择出适合不同功放的最优算法,具有较好的预失真效果,为设计实际功放线性化电路具有指导意义.
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