The Detection of Weak Light Signal Based on Pseudo-Random Sequences
YU Rong-jin · Dianzi xuebao · 2009
A new method for the detection of weak light signal using pseudo-random sequences(PNs) was introduced.A beam of light modulated by PNs was injected into the measurement system;the output light signal was detected by a photoelectric diode then dealt with the correlate detection technology using PNs.Because the characteristic of PNs is similar to that of the white noise,the disturbance and noise in the process of measurement had been a little influence on the peak value of the correlation function,so the weak light signal could be detected clearly.The results from the simulation and experiment proved that this method was an effective way for detection of weak light signals.The prime signal can be detected when the signal noise ratio(SNR) is as low as-15dB;the gain of SNR is about 30dB.