Receiving Performance Analysis Of Communication System Based On Mixed Carrier Signal

As a general form of Fourier Transform, the Fractional Fourier Transform (FRFR)can give both the time-domain information and the frequency domain information of thesignal at the same time, at present, because of this characteristic, the FRFT has beenwidely used especially in the processing of optical information. The research of FRFThas shown that the definition of FRFT contains both the Classical Fractional FourierTransform and the Weighted Fractional Fourier Transform. The paper is based on thehardware realization of4-Weighted Fractional Fourier Transform (4-WFRFT)communication system, and its real research continent is the effect of the signalcharacteristics caused by the synchronization mode of the receiving end.Firstly, starting from the basic theory, the paper analyzes the proposed definitionform of WFRFT and its evolution, gives its expression form of discrete4-WFRFT andanalyzes the signal expression form and realization characteristic of the communicationsystem which bases on the form of the discrete4-WFRFT; in the fundament of4-WFRFT signal, the paper designs the basic architecture of the4-WFRFTcommunication system.Secondly, the architecture of system which aims at the4-WFRFT communicationsystem is based on the FPGA hardware platform of ALTERA Company. The hardwareplatform is based on the FPGA core chips whose model is EPIC20F324I7and the otherassistant hardware resource, the platform design and set up the whole transceiverhardware platform of the4-WFRFT communication system and realizes the originatorof the signal encoding, the central4-WFRFT calculation, the channel transmission, theinverse transform of the4-WFRFT calculation in the receiving end and the signaldecoding as a whole process. In the process of the hardware realization, the platformachieves the multiplier module, FFT IP core calling module, the data scaling module,the divider module and the other modules, at the same time, in order to improve theutilization efficiency of the hardware resource the hardware designs and implements theoptimization of the existing methods.Finally, in order to get the pros and cons of the hardware based on the differentsynchronization model, the paper analyzes and compares the constellation property,implementation complexity and the coincident indicators of different model. The resultsof the hardware realization show the hardware platform which base on the basicsynchronization model in which the synchronization is following the weightingcalculation could get shorter synchronous establish time and lower complexity, while itcould not get the ideal constellation property of4-WFRFT communication system; onthe other hand, the hardware platform which bases on the synchronization in which the weighting is following the synchronization could get the ideal constellation property,however, this system sacrifices the complexity, synchronization set-up time andtransmission efficiency of the communication system; because of these flaws animproved synchronization is proposed in this article, the hardware realization of the newsynchronization model could get the ideal constellation property and improve thetransmission efficiency, while these improvements need higher complexity.