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单边带技术具有频带窄(带宽为2.8kHz),在弱信号条件下可靠性高的特性。数十年来,它一直是高频频段的主要通信方式。然而,当研究固定信道业务的操作时,单边带技术有待改进之处甚多。首先,它所允许的频率漂移能力很有限,频率漂移会在失谐时产生有名的“唐老鸭”(Donald DUCK)效应,这样用户就要频繁的使用“抑扰”旋钮。其次,与调频技术相比,它的话音质量差。由于不发射载波,所以就没有用来控制接收机增益的控制标准,故在环境噪声很高时其性能欠佳,而且在通话的间隙和信号快衰落时往往会突然发生这种环境噪声。一般来说,单边带电台的
Single-sideband technology has a narrow bandwidth (bandwidth of 2.8kHz), in the weak signal conditions, high reliability features. For decades, it has been the main communication method in the high-frequency band. However, when studying the operation of fixed-channel services, single-sideband technology needs to be improved a lot. First, it allows limited frequency drift and the frequency drift produces the famous “Donald DUCK” effect when detuning, so users have frequent use of “dampening” knobs. Second, its voice quality is poor compared to FM technology. Since there is no carrier to transmit, there is no control standard to control the receiver gain, so its performance is poor at high ambient noise and this kind of environmental noise often happens suddenly when talk gaps and signal fading. In general, single sideband radio