压缩感知在分段式双反馈预失真器的模型简化研究

针对预失真器中模型参数过多的问题，从压缩感知(compressed sensing, CS)的理论出发，提出了一种用于宽带射频功率放大器(power amplifier, PA)的预失真器模型简化方法。在稀疏度自适应匹配追踪(sparsity adaptive matching pursuit, SAMP)算法的基础上进行改进，提出了基于频域陷波的相关支集选择SAMP算法(RSS-FNSAMP)。该算法能够对PA行为模型进行简化，而后将其运用在提出的分段式双反馈DPD系统中，以补偿被带内残差所掩盖的带外失真，在增强了系统稳定性的同时降低了其复杂度，提升了DPD线性化效果。为了验证该方法，使用20 MHz LTE信号驱动一个35 dBm的F类功率放大器。实验结果表明，归一化均方误差(normalized mean squared error, NMSE)与ILA-SAMP、ILA-DOMP和分段式双反馈-DOMP相比提升了3～5 dB,相邻信道功率比(adjacent channel power radio, ACPR)改善了25 dBc,表明该方法能够在降低模型参数数目的同时，提升功放...

Research on model simplification of compressed sensing insegmented dual feedback predistorter

To address the problem of too many model parameters in predistorters, this paper proposes a predistorter model simplificationmethod for broadband power amplifier (PA) based on the theory of compressed sensing (CS). On the basis of the sparsity adaptivematching pursuit (SAMP) algorithm, the relevant support selection SAMP algorithm based on frequency domain notch (RSS-FNSAMP)is proposed. The PA behavior model can be simplified and used in the proposed segmented dual-feedback DPD system, and the out-ofband distortion masked by the in-band residual can be compensated, which not only enhanced the stability of the system, but alsoreduced its complexity and improved the linearization effect of DPD. To verify the method, a 35 dBm class F power amplifier is driven by20 MHz LTE signal. The experimental results show that the normalized mean squared error (NMSE) is improved by 3~ 5 dB comparedwith ILA-SAMP, ILA-DOMP and segmented dual feedback-DOMP, and the adjacent channel power ratio ( ACPR) is improved by25 dBc, which shows that the proposed method can improve the linearity of power amplifier while reducing the number of modelparameters.