Data Acquisition And Processing Of Correlation Ranging System With Chaotic Laser

Wideband chaotic signal is an ideal signal for communication and radar system, due to its noise-like behavior and good autocorrelation performance. Much attention has been focused on its generation,acquisition and processing. With the advance on new theories and techniques about chaotic laser, new research results also are emerging constantly.Our workgroup have successfully generated chaotic signal with several GHz bandwidth utilizing semiconductor lasers with feedback and find that it has much better autocorrelation curve than pseudo-random sequences. Following the correlation methods of random code, we propose a laser ranging system based on chaotic correlation method, which can be used for automotive collision avoidance, fiber or cable fault location, etc. The technique of fast data collection, storage and processing is the core in the system. In this thesis, we design and achieve the fast data acquisition and processing system for our ranging system, which promote the transformation from theoretical research into technology.Detailed works are summarized as below: 1. We propose a scheme of signal collection and processing for the chaotic laser correlation ranging system.2. We program to control the acquisition card by secondary developing technology of source code library based on VB programming platform.3. We raise an average discrete-component elimination algorithm, and program it to calculate real-time correlation. Results show that this kind of algorithm can improve the signal-to-noise ratio remarkably.4. According to Wiener-Khintchine Theorem, we determine a fast cross-correlation algorithm based on the frequency domain, which is accomplished on the VB programming platform by combining hybrid programming technology.5. We apply the data acquisition and processing system to chaotic radar, optical time domain reflectmeter and cables breakpoints or impedance mismatch detection. Study results show our system has good performance.