组合结构设计的双频带数字预失真方法

Designed digital pre-distortion with hybrid architecture for concurrent dual-band transmitters

双频带射频功放的数字预失真技术(DPD)要求支持更宽的带宽。为了保证功放输出的线性指标并降低预失真系统的实现开销,设计一种组合结构的双频带宽带数字预失真方法。该方法采用一维整频带数字预失真模型与四个一维分频带数字预失真模型的组合结构来综合处理双频带的发射信号。仿真实验结果表明,采用90 MHz的双频带LTE信号,临道泄露比(ACLR)指标较改进的二维记忆多项式DPD有1 d B提升,与二维DPD有0.5 d B差别,满足系统指标要求。

igital pre-distortion （DPD） of the concurrent dual-band radio frequency power amplifiers （PA） need to support wider bandwidth of the signals. In order to achieve linear target of PA output and reduce the realization cost of the DPD system, this paper designed a hybrid DPD architecture which contained one dimensional whole band DPD structure and four of one dimensional band-division DPD structures. Simulation experiment shows that there is 1 dB better than 2D modified memory polynomials DPD structure in ACLR and 0.5 dB worse than 2D DPD when using 90MHz dual-band LTE signal. Result validates that it can meet system requirement.