数模同播音频广播系统中OFDM调制解调器的设计

摘要

A high-efficient OFDM module based on IFFT/FFT algorithm is designed for digital-analogue simulcast audio broadcasting system. The OFDM modulation and demodulation device is composed by time-frequency domain interleave module, OFDM modulation, OFDM de-modulation module and time-frequency domain de-interleave module in digital OFDM transmitter or receiver. Using the improved IFFT/FFT algorithm, the data is transferred into and out of the OFDM module in the same order. Therefore reverse the order of the input and output and radix-2 FFT can be extended to any point, which IFFT/ FFT algorithm can be used to achieve time-frequency transformation for any point. The resource of IFFT/FFT module and interleave/de-interleave module are reduced.%设计了一种基于IFFT/FFT的高效OFDM调制解调器，实现数模同播音频广播系统中数字音频信号的OFDM调制解调，包括发射机中用于形成OFDM符号的时域与频域交织模块、OFDM调制模块和接收机中OFDM解调模块、时域与频域解交织模块。通过对IFFT/FFT算法的改进，该OFDM调制解调器中数据的输入顺序和输出顺序相同，不需要进行顺序输人逆序输出，并且可以把现有基2的幂次方的FFT变换扩展到任意点，实现适用于任意点的IFT/FFT,简化了IFFT/FFT模块本身和交织／解交织的资源消耗，巧妙地节省了系统所需的资源。