Design And Implementation Of Base-band Adaptive Predistortion Technology

With the rapid development of digital mobile communication technology, requirement of the capacity and transmission speed of wireless channel is much higher. Therefore, spectrum with higher utility rate is needed. Meanwhile, in communication system, large numbers of nonlinear devices, especially power amplifies, have the characteristic of nonlinearity, directly affecting the capability parameter and technology index of communication system. In this sense, the study of power amplify linearization technology is of great value in theory and its application.The dissertation discusses predistortion technology, one of linearization technologies. It could better overcome the nonlinearity and memory effect of power amplifier. Then the dissertation proposes two improved algorithm, which can achieve better linearization performances by using simpler operations and requiring less resource.One is LS/SVD simply algorithm. It bases on classical LS/SVD algorithm and subtracts the high order terms. So the algorithm requires less resource, needs simpler operations, but achieves little less linearization performances than classical LS/SVD algorithm. The other is LS iterative algorithm. It bases on Hammerstein DPD model, and combines the advantages of LS method and Hammerstein model. It can achieve better linearization performances by using simple iterative operations instead of one complex direct calculation. And then they are proved on Matlab software platform. The simulation results demonstrate that the proposed predistortion methods are effective.Then the dissertation analyzes the hardware implementation of memory polynomial predistorter algorithms. It shows the hardware design scheme and some key technologies. And the performance figure from FPGA hardware platform shows that the proposed predistortion method is effective. Finally, the dissertation makes suggestions for further research of power amplify linearization technology.