一种改进微小卫星伪码测距信噪比的有效方法

微小卫星上的星载测控应答机最基本的功能是接收、解调并转发地面战发来的伪码测距信号,供地面站测距.微小卫星体积小、重量轻、功耗低的特点导致测控应答机工作功率较低和天线增益较小,测距伪码往往淹没在嘈杂的噪声中.严重影响后续信号同步信号提取、解调和检测,降低测距精度,甚至导致无法测距.传统基于功率谱带宽的滤波器只能起到一定程度提高信噪比的作用,本文提出基于最小二乘法问题的最小范数准则进行波形拟合的多项式滤波器方法,能够进一步显著提高信噪比,解决强干扰下伪码信号提取的问题.

An Effective SNR Promotion Method for Mini-satellite Pseudo-Code Range Measurement

The function of tracking, telemetry, and control transponder on mini-satellite is to receive, demodulate and transmit pseudo-code range measurement signal back to ground station. Small volume, light weight and low power of mini-satellite cause poor power for the transponder and small gain for the antenna. The pseudo-code range measurement signal usually is contaminated by strong noise and the poor SNR deteriorates the performance of immediate synchronous signal extraction, demodulation and detection. Conventional filter based on power spectrum bandwidth can only promote SNR to some extension. This paper provides a wave fitting polynomial filter which is based on least square solution criteria can increase significant SNR and extracts weak pseudo-code signal from strong noise and interference.