| The chaos that occurs in the definite system appears stochastic non-regular or the anomalous movement. It was developed in the 1970's, in the past dozens of years, the chaos theory has got the huge progress. But the chaos theory is just a brand-new science, and its theory is not mature, needs for further consummates. So, the chaos research will have the very important theory significance and the actual application value. Along with the chaos phenomenon research unceasingly, the chaos secure communications has become the front topic domain. I conduct the preliminary study to the chaos signal's production under such background, and design chaos signal communications platforms with the FPGA technology. The designs will lay the rationale as well as the test platform in the following study on secure communications.At first, we have introduced the background and the course of our research work in chapter one. In the second chapter we have explained the basic concept of chaos, and have done the preliminary study and the exploration to its essence; Finally we have introduced the method in the chaos circuit's modular design and the hardware realization, and given the chaos signal circuit's simulation result. The present paper that elaborates the chaos signal's transmission and processing are based on the FPGA platform, therefore, in third chapter we introduce the basic concept of FPGA and related software development tools briefly. Based on the in-depth investigation of relational datum, this paper presents the design of chaos signal serial communications platform with the FPGA technology. This chapter introduces the communications platform's hardware circuit design. And the design in software adopts the VHDL hardware description language to carry on the modular design to each part of functions.The fifth chapter, we use the new hardware platform (DE2 development board) to design the chaos signal parallel communications platform in the summary of serial communication platform design's foundation. The design's hardware circuit is completed with the aid of DE2 development board's FPGA chip and the speech chip. On the software, we adopt Verilog-HDL the hardware description language by the mean of modular design. Several modular is designed, and each modular carries on various part of function for communications system's transmitting end and receiving end separately. In the end of the chapter, we give speech signal and the chaos signal's experimental verification result of the parallel communications platform. The last chapter introduces the channel code/decoding recognition system's design, which could increase the correspondence reliability and consummate the chaos parallel communications platform.This article's characteristic is that the overall system uses FPGA technology to design and realize its function. And its function's realization depends on the software programming. The revision software can improve the system original design proposal or the original function with no change of the hardware platform. Thus, the communications system's design has enormous flexibility. |
