The Design Of Adaptive Lattice Filtering Algorithm And FPGA Realization

Adaptive filtering is always the focus in the field of academy, especially with a wide range of applications in the digital communication field.Adaptive lattice filtering is an important constituent of adaptive filtering,and lattice algorithm has an indispensable status in digital communication,but there are few researches about this field,and this paper mainly talks about theory and realization of lattice algorithm.This paper is based on a large number of relevant literature that we have studied and read.Firstly, we do a whole elaboration about adaptive filtering theory,educting it based on classical adaptive algorithm(LMS algorithm).The adaptive lattice filtering algorithm is summarized, analyzed and concluded and improvement,besides this paper introduces adaptive lattice recursion algorithm,lattice algorithm based on Berg,gradient statistical lattice algorithm,RLSL lattice algorithm,normalized lattice algorithm and QR decomposition lattice algorithm.Paper mainly improves gradient statistical algorithm,this algorithm not only remains the optimum reflection coeffient's convergence and stability of gradient algorithm,but also more suitable for saving the resource of hardware realization. At the same time,we compare the current digital communication chips,and select the modified gradient adaptive lattice filtering algorithm which is suitable to the FPGA hardware implementation,and we also analyzed the sessions and step length of the algorithm which is for the hardware realization. Using existing Simulink software, we draw lattice section module and make gradient adaptive lattice joint processor modules and have some relative simulation. According to DSP Builder software feature,we can transform matlab simulation module to VHDL language that is suitable to hardware realization,and we use the FPGA hardware features to complete the whole design.On the basis of existing design,we introduce the adaptive equalizer,and we design adaptive lattice least-square equalization algorithm. At last we improve lattice equalizer in the PLL embedded way to design adaptive equalizer for underwater acoustic transmission.The chip is EP2C5T144C6 inAltera company Cyclonell series in this research.