The Research On Subcarrier By Using Dpsk Modulation In Chaotic Communication

Chaos possesses the performance of natural random and anti-interference, which has made it wildly discussed in theory and experiment in the application of secure communication. The speed of chaotic communication is mainly limited by the relaxation oscillation frequency of the laser. Subcarrier modulation is more beneficial for the transmission of the signal. Furthermore, combining with WDM, it can use the subcarrier multiplexing to develop the optical fiber transmission capacity. When applied in chaotic secure communication, subcarrier modulation can effectively increase the transmission capacity of chaotic communication. Differential phase shift keying (DPSK) modulation possesses high tolerance to noise and nonlinear effects, and has a 3dB advantage. The performance of subcarrier chaotic communication can be improved by using DPSK modulation. This paper mainly focuses on the application of subcarrier by using DPSK modulation in chaotic communication. The work is as follows:1. In this paper, we review the research progress of chaotic secure communication, and describe the background of the subcarrier modulation and the application of the DPSK modulation technology. 2. The principle of chaotic secure communication is illustrated and the type and the implementations of chaotic synchronization are generalized. We analyze and summarize the main factors which influence chaotic filtering characteristics. We have analyzed main modulation project of chaotic communication and interpreted the systematic project and theory of subcarrier modulation which is applied to chaotic communication.3. We analyze the way of DPSK modulation and demodulation and put a simulation research on subcarrier by using DPSK modulation, which is applied to chaotic communication. We also study and analyze the application of subcarrier multiplexing in chaotic communication and compare it with the result of ASK demodulation.