扩频接收机中带通滤波器最优相对带宽分析  

Analysis of the Band-pass Filter's Optimum Relative Bandwidth in Spread-Spectrum Receivers

作　　者：刘春霞[1] 李峥嵘[1] 王飞雪[1] 

机构地区：[1]国防科技大学电子科学与工程学院卫星导航定位研发中心,湖南长沙410073

出　　处：《电讯技术》2005年第6期38-41,共4页Telecommunication Engineering

基　　金：湖南省杰出青年科学基金资助项目(04JJY1011)

摘　　要：本文推导了扩频接收机检波前信噪比与接收端带通滤波器带宽等参数的关系,并进行了相应的数值分析。研究结果表明,接收端带通滤波器存在最优相对带宽使得检波前信噪比最大,并且最优带宽不等于信号带宽;最优相对带宽与输入载噪比、中心频率及相关积分时间无关,但受收发两端滤波器类型影响;当发射端滤波器相对带宽大于等于0.8时,接收端滤波器最优相对带宽与发射端滤波器相对带宽无关。This paper presents the expression of signal -to -noise ratio（SNR） before detection and the parameters such as the band- pass filter＇s bandwidth and so on in spread- spectrum receivers. Through numerical analysis, it is proved that there is an optimum relative bandwidth of this band - pass filter which maximizes the SNR before detection and which is not equal to the bandwidth of the signal. The optimum relative bandwidth is independent of the input carrier - to - noise ratio, center frequency and correlative integral time. But it is affected by the filter＇s type in both transmitters and receivers. When the filter relative bandwidth of the transmitters is not less than 0.8, the optimum relative bandwidth in the receivers is independent of the band - pass filter＇s bandwidth of transmitters.

关 键 词：扩频接收机 带通滤波器 最优相对带宽 数值分析 检波前信噪比 

分 类 号：TN914.42[电子电信—通信与信息系统]