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 结合导航信号的具体物理模型,从信息量和信噪比两个角度入手,对ADC前后导航信号所含有效信息量及信噪比变化规律进行推导计算。从理论上证明2~3 bit量化已能满足一般接收机正常工作的需要,在此基础上归纳不同的量化门限选择对信号信噪比的不同影响,发现在特定的干扰下,合理地选取量化门限反而会增加信号的信噪比这一反常规现象。最后提出一种合理选取量化门限的方法,以获得最优的信噪比增益,并进行了试验仿真的验证,对接收机前端设计具有一定的启发意义。 更多还原

【Abstract】 A precise deducing about the changes of effective information of the navigation signal and signal-to-noise ratio is given,theoretically confirming that an ADC in 2 or 3 bits would meet most of the requirements in general receivers.Furthermore,the different influences,determined by the chosen AD threshold,are elaborated too.One result shows that in some very kind of interference,the signal-to-noise ratio increased after the ADC,which is profitable for the ensuing processes thought not agreeing wi... 更多还原