Implementation Methodology Of Adaptive Clutter Cancellation Based On Fpga In Passive Radar

The implementation on FPGA of the clutter cancellation method in passive radar isstudied in this paper. The performance of LMS and RLS algorithm is analyzed andcompared, of which the result shows that LMS is sensitive to the environment and theRLS entails high computation complexity. Thus, an improved version of the LMSalgorithm, constituted by NLMS and FBLMS, is adopted to cancel clutter. NLMSconverges fast with adaptive step size; FBLMS, implemented with block division infrequency domain, reduces its computation complexity using FFT to calculate theconvolution and increases the convergence performance using the orthogonaltransformation. For the implementation of NLMS and FBLMS based on FPGA, thepaper presents the structure and characteristics of FPGA and provides detailedintroduction and simulation of common IP Cores like PLL, FIFO, FFT and RAM inFPGA. The paper divides the two algorithms into several functional divisions forhardware implementation and uses IP Cores to demonstrate their hardware structures.The reliability of these two adaptive algorithms is verified by the joint functionsimulation in ModelSim and MATLAB.