Digital Audio Broadcasting System Design

OFDM ( Orthogonal Frequency Division Multiplexing ) , a high-speed transmission technique under wireless environment , promises to be a key technique for wireless communication systems in the future . In 1995 , ETSI (European Telecommunication Standard Insititute) has firstly brought up DAB standard , the first standard introducing OFDM.This paper mostly studies the system architecture of digital audio broadcast. Firstly it describes the development ,basic principle and application and propagation characteristic of mobile channel, then investigates the system structure of DAB transmitter and receiver separately and the key technology of realization of the digital audio broadcast system.And then discusses the system component of FFT —the demodulation module of OFDM .The 409- points FFT module employs a radix-4 decimation-in-frequency algorithm, includes arithmetic element , read and write address element ,twiddle factor element and control element, is realized by FPGA. In the end , the result is verified in the matlab .The verification indicates that the error of the result data meet the demand , it show that the design of the whole FFT module is feasible, coule be used in the OFDM system.