Research On Theory And Applications Of Integrating Optical Communication And Wireless Communication Base On Six-port Technology

With the development of the multimedia and internet of thing,it is essential to develop higher data rate,lager bandwidth and more access number communication technology in the next generation communication system.Researcher proposed smaller cell-site to increase access speed and access number and higher carrier frequency to achieve larger bandwidth.However,those solutions will challenge the conventional cell-site,because the smaller cell-site will increase the cell-site cost and overall power comsumption and higher carrier frequency will increase the complexity of cell-site.In this dissertation researches,the system integrating the digital baseband optical link and six-port transceiver is proposed,and the system features high performance,high stability,low cost and low power comsumption.The innovative achievements are as below:1.In this dissertation researches,a calibration algorithm based on time-delay radial basis function neural networks is proposed for modeling the six-port modulator and demodulator to mitigate the performance degradation.The proposed calibration algorithms,which consider impairments of both six-port structure,diodes and switches for modulation and demodulation,can improve the performance greatly.In addition,the time-delay inputs can greatly mitigate the memory effect of diodes or switches.The proposed calibration algorithm is evaluated and the parameters in the algorithm are analyzed.The EVM(Error Vector Magnitude)performances are found below 0.5%.2.In this dissertation researches,symmetrical six-port modulator and demodulator are proposed,and those modulator and demodulator share the same structure.The symmetrical structure of the six-port transceiver can reduce the cost when large-scale circuits are produced.A time division system based on proposed symmetrical six-port transceiver is set up and verified by using 800 Mbaud 16 QAM(Quadrature Amplitude Modulation)Signals.The EVM performances are found below 1.2%.3.In this dissertation researches,a six-port transceiver that consists of a single six-port correlator and four Schottky diodes is proposed,and the transciever can realize both modulation and demodulation simultaneously at different frequencies.Moreover,heterodyne demodulation for six-port transceiver is proposed to mitigate the interferences from baseband modulation signals.An experimental frequency-division duplex system that the six-port transmitter and receiver can operate concurrently is set up and verified.The EVM performances are found below 2%when heterodyne demodulation is utlized;the EVM performances are found below 3%when homodyne demodulation is utlized.4.In this dissertation researches,a scheme integrating baseband digital optical link and six-port transceiver is proposed.The digital optical link can provide a high reliability and low cost connection between the central office and base station.Moreover,combining the six-port transceiver with baseband digital optical links can reduce the data rate over optical link and complexity of the RF transceiver design.Moreover,the local oscillator power of the six-port transceiver is reletively low,which can reduce the power consumption of the base station.The experimental system is set up and verified by using 2 Gbaud 16 QAM Signals at 26 GHz.The EVM performances are found below 2%.