Simulation And FPGA Implementation Of Adaptive Noise Canceling Filters

Adaptive filter’s coefficients can be automatically adjusted with changes of theexternal parameters, and always maintaining the optimal filtering, it has been widelyused in system identification, communication channel equalization, signal prediction,signal enhancement and other fields. Adaptive noise cancellation filter is one of themain applications in the form of the adaptive filter. With the development of signaland information processing technology, the applications of adaptive signal processingbecame more and more widely, and its hardware implementation of the adaptive filterhas become one of the hot and difficult problems in the field of signal processingresearch recent years.Taking the most representative sine wave signal and Gaussian white noise signalfor example in the signal processing field in this pape. Firstly, the basic principle ofadaptive noise cancellation filter was introduced, and a detailed theoretical analysiswas put forward about the LMS and RLS recursive adaptive algorithms. On theMatlab platform, through the writing program of adaptive noise cancellation filter, aseries of simulation and comparative analysis on the convergence rate of the LMSalgorithm and RLS algorithm performance was performed with changing the adaptiveparameters. Some valuable conclusions were acquired, and it provided a reference forthe hardware implementation of adaptive filters.On this basis, the eight-order serial LMS algorithm adaptive noise cancellationfilter model was constructed and simulated using the Altera Corporation’s DSPBuilder tool package. Then the model was eventually converted to the VHDLhardware description language, and the RTL register transfer level simulation wasexecuted with Modelsim-altera software. After that, logic synthesis and fiter wascompleted with QuartusII software. Finally, a high-speed adaptive filter with thehighest response frequency of44.64MHz was achieved on EP2C35F484C8FPGA.