| With the development of digital electronic technology, Digital Signal Processing is widely used in many fields, such as sonar, radar, telecommunication, speech and image processing and so on. The Fast Fourier Transform (FFT) algorithm plays an important role in the implementation of digital processing algorithms and systems, which improves the efficiency of the computation of the Discrete Fourier Transform (DFT) dramatically.The processor is required to have the capability of high-speed, high-precision, large-capacity and real-time processing. Field Programmable Gate Array (FPGA), which has developed rapidly in recent years, has great advantage in processing large-scale data. So, a scheme which implements the FFT algorithm on FPGA is adopted in the paper.The hardware design of the digital signal processing board is one of the important parts in the paper. At first the principle and the method of the beam forming and FFT algorithm are introduced briefly, then according to real-time processing requirement, the hardware circuit is designed and the realization of the hardware is analyzed.According to the design method of digital system, 1024-point FFT is implemented in VHSIC Hardware Description Language (VHDL) using three methods, radix-2 Decimation-in-Time (DIT) FFT, radix-4 DIT FFT and FFT Mega Core function. Then the comparison of the three methods is given. We can conclude that FPGA meet the real-time processing requirement of beam former, then According to the protocol of the Universial Serial Bus (USB),the firmware of the ISP1581 is programmed in VHDL, and the enumerative process of the device is implemented. |
