Fpga-based Finite Impulse Response Digital Filter Realization

The digital filters is an important part of digital signal processing and used widely in variety of application such as signal separation, restoration or shaping. FIR filter discussed in this paper is widely used because of its strict phase distortion and sharp cut-off characteristic.In the engineering practice, there is often a request for the real-time and flexible signal processing. However, software and hardware technique available for implementation are difficult to meet the demand for both of the two aspects at the same time.The programmable logic device is an IC that could be structure function by user himself. This task's main contents are:(1) Reserch a design method of digital filter that meets the engineering parctice based the baisc theory of FIR filter;(2) Study the Distributed Arithmetic thorough. Analyse the means of complete the arithmetic through the look up table of FPGA after explain the arithmetic theroy;(3) Illuminate a FIR filter's design technique of a low pass filter. Adopt a thinking of hiberarchy, modulizing, parameterizing, complete the partition of the whole FIR filter and the idiographic design;(4) Designed a hardware circuit of FIR low pass filter that could adjust the parameters: the main IC is EPF1K50TC144-1, including A/D convert circuit, D/A convert circuit and the in system config circuit. Use the voice as the input signal, check the actual effect.The experiment prove that this system is real-time, veracity, agile and paracticability comparing with the traditional filter.