Research Of OFDM Technology In The DRM System Based On FPGA

The traditional analog amplitude-modulation broadcasting is susceptible to interference, and its transmission quality is poor, business is single. In order to adapt to the radio and television information, network, digital direction, the analog amplitude-modulation broadcasting digital appears particularly important. It is important to strengthen the study of DRM technology and application for developing digital broadcasting and p romoting the construction of national economy by making full use of the latest digital broadcasting technology and enhancement of DRM technology and application Study. OFDM is one of the key techniques in DRM,for its high spectrum efficiency, large system capacity and well anty-interference ability,so the audio program, data and other large amounts of information transmit through the channel highly quality to better meet the requirements of the radio audience. The purpose of this paper is to study how to use FPGA technology to realize OFDM in the DRM system.The first chapter introduces the development and technical characteristics of the digital amplitude modulation broadcast. Then in the second chapter, it is introduced the basic principl’e of OFDM and its key technical links of FFT principle combined with OFDM transmission mode and system parameter designing in DRM. In the third chapter, FPGA technology is introduced from four respects--the FFT hardware features, Verilog HDL language, FPGA design flow and the programmable device.On this basis, the fourth chapter analyzes the working process of the FFT processor,then design a butterfly computation unit, an address generation unit and timing control unit module applicated of FPGA technology,each unit is designed and funcationaly simulated by Quartus Ⅱ8.0(32-Bit). A thought of a butterfly operation lines in the butterfly computation module designing is presented to make the data reading and writing operations are carried out at the same time. The program is designed by Verilog HDL language in data address selection unit designing from analyese of node data address generation law to promotion.Finally in the fifth chapter, it is emphasized from OFDM signal processing in the DRM transmitter and receiver to analysis the feasibility of digital transformation of amplitude modulation transmitter. The DRM transmission frame structure is introduced and parameters of the system is designed firstly, then OFDM signal generation function unit in the DRM system is module designed. Eventually the analog transmitter is reformed and DRM radio experiment is finished.