扩频原理在聚合物光纤性能测量中的应用

提出了一种将扩频通信原理用于聚合物光纤性能测量的新方法,使用伪随机序列对注入测量系统的光信号进行调制,实现输入光信号的扩展频带,输出光信号经光电转换后,用伪随机序列对信号进行解扩处理,根据扩频原理,解扩后的信号的信噪比会有较大提高.对测量系统的性能进行了仿真分析并与实验结果进行了比较,结果表明该方法可以精确地测量信噪比低于-20 dB的有用信号波形.

An Application of the Principle of Spread Spectrum Communication to the Measurement of Polymer Optical Fiber Properties

A new method for the measurement of polymer optical fiber (POF) properties based on the principle of spread spectrum communication is introduced.The spectrum of optical signal is spread by modulation using pseudo-random sequences (PNs) and injected into the POF,and the output optical signal is detected by a photoelectric diode then dispread with the original PNs.According to the principle of spread spectrum communication,the interference and noise after the process of dispreading are bated effectually,the signal-noise ratio (SNR) of the signals after dispreading improves evidently,and the measurement accuracy of signal waveform increases.The results from simulations and experiments show that this method can be used to detect week signal waveform under a background of strong noise and interference where the SNR is -20 dB or under.