Fpga Hardware Implementation Of The Chen-mobius Communication System And Application

In the 1990s, Professor Chen Nanxian, academician of Chinese Academy of Science, applied the Mobius inversion formula in infinite series form to solve a series important inverse problems in applied physics; and created the wonderful methods of applying,extending the Mobius transform in Number theory (i.e. The Chen-Mobius transform) to solve various inverse problems in physics. His works were highly evaluated by the top scientific magazine <> in 1990.Professor Su Wuxun et al, applied the methods of Mobius transform to the calculations of the inverse transforms of the Fourier series of eight common used waveforms (including rectangular pulse, even and odd symmetrical square wave and triangle wave, sawtooth wave, half-wave cosine and full-wave cosin waveforms), and derived the expanded formula of the sine, cosine and general periodic functions on these waveforms. They also derived the very important functions which are orthogonal with the corresponding common-used waveforms respectively and can be used to calculate the expanded coefficients and in information modulation-demodulation. Then they applied the methods of Mobius transform in the coherent modulation-demodulation system and put forward a new communication system, named the Chen-Mobius communication system. The paper presented here has mainly completed two aspects of work,realizing the Chen-Mobius multiple-carriers communication system on FPGA and speech encryption diplex operation system based on Chen-Mobius transformation. First, the Chen-Mobius multiple-carriers communication system (four-channel and eight-channel) is simulated by DSPBuilder software inserted in MATLAB\SIMULINK. The error rates are computed according to different ratios of average signal power to average noise power (S/N )and based these results, the figures of the error rates to S/N are given; Secondly ,Main modules in the Chen-Mobius multiple-carriers communication system, including some functions and integrators, are transformed into the HDL hardware language by Signalcompiler in DSPBuilder. On the QuartusⅡsoftware platform, hardware modules (frequency division, time delay, control module and so on) are programmed by VHDL. The integrity Chen-Mobius communication system is built and simulated by them, including design synthesis,pin assignments,simulation analysis and timing analysis etc; At last, the Chen-Mobius multiple-carriers communication system is realized on the Altera's Stratix FPGA development board.On otherhand, the speech signal is encrypted and deciphered respectively by the modulation system and demodulation system in Chen-Mobius single-channel communication system. The speech encryption diplex operation system based on Chen-Mobius transformation is successfully realized on two DE2 FPGA development boards. It has vital significance to finish this design, and it starts to forward one solid step to apply the Chen-Mobius communication system into each aspect in communication domain.