【作者】 牛利民；

【导师】 田坦；

【作者基本信息】 哈尔滨工程大学 ， 水声工程， 2008， 硕士

【摘要】 随着数字电子技术的发展,数字信号处理广泛应用于声纳、雷达、通讯语音处理和图像处理等领域。快速傅立叶变换(Fast Fourier Transform,FFT)在数字信号处理系统中起着很重要的作用,FFT有效地提高了离散傅立叶变换(Discret Fourier Transform,DFT)的运算效率。处理器一般要求具有高速度、高精度、大容量和实时处理的性能,而现场可编程门阵列(Field Programmable Gate Array,FPGA)是近年来迅速发展起来的新型可编程器件,在处理大规模数据方面,有极大的优势。论文采用了在FPGA中实现FFT算法的方案。数字信号处理板的硬件电路设计是本论文的重要部分之一。在介绍了FFT以及波束形成的基本原理和基本方法的基础上,根据实时处理的要求,给出了数字信号处理板的硬件设计方案并对硬件电路的实现进行了分析和说明。依据数字系统的设计方法,分别采用基二按时间抽取FFT算法、基四按时间抽取FFT算法以及FFT兆核函数三种方法利用硬件描述语言(VHSICHardware Description Language,VHDL)实现了1024点的FFT,接着对三种方法进行了评估,得出了FPGA完全能满足处理器的实时处理的要求的结论。然后根据通用串行总线(Universial Serial Bus,USB)协议,利用VHDL语言编写了USB接口芯片ISP1581的固件程序,实现了设备的枚举过程。更多还原

【Abstract】 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.更多还原