【作者】 邢玥；

【导师】 葛建华；

【作者基本信息】 西安电子科技大学 ， 通信与信息系统， 2008， 硕士

【摘要】 OFDM技术以其频谱利用率高和抗干扰能力强等优点得到了广泛的关注,已被成功应用到许多通信系统当中,并成为下一代移动通信系统的候选方案之一。但由于OFDM信号具有高的峰平比,使得它对功率放大器的非线性特别敏感。为了减小功放对OFDM信号产生的非线性失真,提高其功率效率,就必须对功放的非线性进行补偿。为此,人们研究了许多功放线性化方法,如功率回退法、前馈法、负反馈法、LINC法和预失真法。本文对基带预失真技术进行了深入研究,重点基于查询表预失真方法,对当前出现的各种预失真方案进行了分析总结,并分别提出了针对无记忆功放和有记忆功放的预失真方法。通过计算机仿真结果可以看出,本文提出的方案表现出优良的性能,且均适合工程实现。更多还原

【Abstract】 OFDM has been paid more attention to due to its high spectrum efficiency and robust capability in interference resistance. It has been successfully used in many communication systems and become one of the candidates for the next generation mobile communication system. But high PAR makes OFDM very sensitive to the nonlinearities of amplifier. To mitigate the nonlinear distortions to OFDM signals and improve HPA’s efficiency, it is necessary to compensate the nonlinearities introduced by the amplifier. So a lot of linearization methods have been investigated including back-off, feed-forward, feedback, LINC and predistortion method. In this paper we focus on the baseband predistortion technique in OFDM system. Based on the LUT predistortion method, we separately proposed new methods for both memoryless HPA and memory HPA, through analysising and summarizing many kinds of current predistortion methods. Computer simulation results show that these methods have perfect performances and are suitable for project implementation.更多还原