Study Of Weak Signal In Power Line Carrier Communication Detection Approaches

The study of weak signal under strong noise detection has always been the hot and difficulties for domestic and foreign scholars. It has long been the goal toward making unremitting exploration and hard work, and has made many significant progresses。However, the traditional weak signal detection method, input signal to noise ratio threshold are subject to certain restrictions, it is difficult to further reduce. In recent years, with the continuous development of nonlinear science, rapidly developed detection methods based on chaos to make up the deficiencies of traditional methods.Noise suppression range and signal to noise ratio limit has reach a new breakthrough. Signal detection based on chaotic oscillator is an important engineering application of research directions. This article focuses on research of chaos theory detect three-state pulse position modulation signals in low-voltage power line carrier communication.In this paper, two important thresholds of Duffing chaotic oscillator are discussed first by using the Melnikov method and Lyapunov exponents method, and verified the correctness of the threshold by simulation results Secondly, a simulation model are established ion experiments to verify measurement system based weak sinusoidal signal detection performance. Finally, base on the study of Duffing Oscillator weak signal detection method and the three-state pulse-position modulation signal characteristics, we using chaotic oscillator to realize three-state pulse-position modulation weak signal detection, this approach is fundamentally different from the traditional method. and described the principle of the method and implementation steps. Theoretical analysis and simulation results show that the method mentioned in the paper is very sensitive to signal submerged in noise and is strong suppress to noise. The three-state pulse-position modulation signal detection has reached the minimum SNR-23dB.At present, the studies of using chaos for weak signal detection theory are in the exploratory stage, but we have every reason to believe that chaos weak signal detection technology would attract people to carry out more and more in-depth study for its high-resolution and high sensitivity.