连线干涉测量宽带信号处理方法改进与验证

Improvement and validation of broadband signal processing method in connecting-line interferometry

为了提高连线干涉测量中两测站接收同一信号的时延差估计精度,提出一种利用宽带数传信号进行处理的新思路。用FX型相关处理算法求两路宽带数传信号互功率谱得到的群时延,解载波相位延迟的整周相位模糊,通过载波的相位延迟求出更精确的时延。针对BPSK调制的宽带数传信号,对信号进行平方变换后分别估计两路信号的载波的频率和相位并求出载波相位延迟。蒙特卡洛仿真验证,该方法在一定信噪比条件下可以提高信号到达两测站时延差估计精度。

To improve the estimated accuracy of time-delay difference when two measurement stationsin connecting-line in-terferometry receives a same signal, a new processing idea to utilize broadband transmission signal is proposed. FX correlation processing algorithm is used to derive the group delay recieved by cross power spectrum of two channel broadband transmission signals to solve the phase period ambiguity of carrier＇s phase delay, and then calculate the more accurate time-delay by carrier phase delay. For broadband transmission signal modulated by BPSK, two channel signals＇ carrier frequency and phase are esti-mated respectively after a square transformation of the signal, then carrier phase delay is obtained. Monte Carlo simulation result proves validity and effectiveness of the method. Under the condition of certain signal to noise ratio, the method can improve the estimation accuracy of time delay difference which signal reaches to two stations.