Design And Implementation Of If Processing Based On Fpga In The Rf Streaming Disk System

RF streaming disk is an instrument for recording and playback of the changes about the signal, which has the function including the spectrum display, spectrum detection and large data storage and so on. It can be used for the common communication testing and recording and playback systems or instruments. It has an upgrade extended function of the real-time spectral analysis on the basis of the recorder, and plays an increasingly important role in the field of signal spectrum observation and surveillance. The IF processing is critical to the entire spectrum analysis which directly affects the overall quality performance of the spectrum analysis. The RF streaming disk puts forward higher requirement for IF processing system, such as higher transmission speed, faster real-time spectrum analysis and continuously variable fractional rate decimator.This paper studies the digital frequency about key technologies and related theory and proposes IF processing design, which is based on the use of background radio streaming project. The program mainly consists of three parts: 1, multi-switching automatic interception of digital down conversion. The design is proposed based on an efficient fractional extraction, and the efficient structure extraction is used extraction filter bank(CIC decimation interpolation filter) to complete. It not only saves a lot of resources in the FPGA, but also makes streaming real-time spectrum bandwidth analysis reach 42 to meet user demand for bandwidth about real-time analysis; the decimation achieves multi-levels, so that the clutter signal can be filtered out by multistage filters. About multi-stage filter output different stalls interception problems, in order to ensure the output data of the maximum dynamic range and DC maximal inhibition, this paper presents an automatic interception of algorithms and implemented the FPGA specific circuit to complete filter output automatically intercepted. 2, based on sliding DFT fast real-time spectrum analysis algorithms, relative to the Discrete Fourier Transform, sliding DFT has an advantage over the algorithm and implementation in terms of resources. Based on sliding DFT algorithm, Geortzel recursive algorithm is proposed to achieve a continuous analysis of discrete signals. 3, High-speed data transmission based on Aurora- protocol. The IF data after FPGA processing, needs to be transmitted to the next piece of FPGA by point to point. Xilinx designes a high-speed serial transmission interface to achieve a good high-speed transmission about IF data.The overall program design about IF signal processing of streaming radio systems is based on FPGA. It is proven that the whole IF processing module can achieve real-time analysis bandwidth of 40 MHz, single-channel interface transmission speed of 2Gbps. It meets the requirements of engineering applications and pre-technical indicators.