Research On Technologies Of Carrier Mode Keying Based On The Weighted Type Fractional Fourier Transform

Traditional wireless communication transmit message on the radio signal with amplitude modulation,phase modulation and frequency modulation.In the detector,we usually get information with noncoherent detection methods or coherent demodulation.In this thesis,we proposed an original modulation technique called“Carrier Mode Keying”.In this method,information is carried by the difference of carrier modes.Generally,carrier keying system includes both single-carrier system and multi-carrier system,and attaches a new channel transmitting additional keying information on the existing ones.In this thesis,the SC-FDE and OFDM coexisting system was studied,based on the fundamental system we proposed the single-carrier mode or multi-carrier mode keying structure.We researched the theory of WFRFT,and a technology of carrier mode keying based on the WFRFT was proposed which could be more commonly used.After that,we further improved the identification accuracy of carrier mode and put forward the M-ary carrier mode keying technology.In order to adapt the system to more situations,we proposed multi band M-ary carrier mode keying technology.In addition,this thesis proposed three demodulation algorithms for designed system,which are binary-tree classification algorithm based on higher-order cumulant,parameter identification algorithm based on HOC of back propagation neural network and parameter estimation based on maximum likelihood.And we compared the designed system with index modulation,the simulation results show that the carrier mode keying system has higher spectral efficiency and better performance of bit error rate generally.Researches show the LTE system will suffer a decrease in spectral efficiency when transmitting low data rate information.But the system we proposed support simultaneous transmission of high-rate and low-rate information,and it will have practical value in the future.