【摘要】 提出了一种自适应预失真器及其迭代算法,可同时解决宽带OFDM发射机中功率放大器的非线性和记忆效应问题。该预失真器由均衡器和基于查询表(LUT)的无记忆预失真器串联组成,首先通过窄带训练序列,获得无记忆预失真器的参数,抵消功率放大器的非线性,然后通过迭代算法修改均衡器的参数,补偿功率放大器的记忆效应。与以往解决OFDM功率放大器记忆效应的预失真器相比,迭代算法简单,便于实现。仿真结果表明该预失真器可有效校正和抵消宽带OFDM系统中功率放大器的非线性和记忆效应。更多还原

【Abstract】 An adaptive predistorter and its iteration algorithm are presented,which can solve the nonlinearity and memory effects of power amplifier in wideband OFDM transmitter.The predistorer consists of equalizer and memoryless predistorter based on look-up table.The parameters of the memoryless predistorter can be estimated by using narrowband training sequence and then the parameters of equalizer are updated by iteration algorithm,which is to compensate the memory effects of power amplifier.Compared with other predistorter in OFDM transmitter,the iteration algorithm in the new predistorter is simple.Simulation results show that the new predistorter can correct and compensate the nonlinearity and memory effects of power amplifier in wideband OFDM system.更多还原