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一、引言采用数字编码方法传送优质模拟声频信号早在70年代初就已在地面无线电广播中实际应用了。主要是用于广播台演播室和发射台之间的节目传输和城市之间广播节目的交换。与传统的通过市话音频电缆或微波中继、超短波无线电台传输模拟音频的方法比较,采用数字编码方式后提高了抗干扰性,扩大了动态范围,降低了非线性失真,增加了信噪比。对立体声节目来说,具有左右声道串音小,振幅和相位可做到非常一致,同时在一条信道中可实现多
I. INTRODUCTION The use of digital encoding to deliver high-quality analog audio signals was used in terrestrial radio broadcasting as early as the early 1970s. It is mainly used for the transmission of programs between broadcasting stations and transmitting stations and the broadcasting programs between cities. Compared with the traditional method of transmitting analog audio through the local telephone audio cable or the microwave relay and the ultrashort wireless radio, the digital coding method is adopted to improve the anti-interference capability, expand the dynamic range, reduce the nonlinear distortion and increase the signal-to-noise ratio. For stereo programs, with a small crosstalk between the left and right channels, the amplitude and phase can be very consistent, and more can be achieved in one channel