Research And Implement Of Power Domain Non-Orthogonal Multiple Access Technology

The key technologies of None-Orthogonal Multiple Access(NOMA)in power domain are studied in this thesis.The NOMA system is a technology that uses the power domain at the transmitting end to assign different power to different users to realize the user differentiation,and then separate multiple reuse users on the receiving end based on the power size.This thesis focuses on the following four aspects.First,the basic principle of the Power Domain Non-orthogonal Multiple Access technology is briefly introduced,and a two user downlink model is constructed.Then,the receiver technology of NOMA system is introduced in detail,including three kinds of serial interference elimination algorithms,including Symbol-level SIC algorithm,Codeword-level SIC algorithm and two user iterative SIC algorithm,and the joint constellation detection algorithm.Then,the simulation analysis is carried out for the receiver algorithm introduced,and the performance comparison of the four kinds of receiver detection algorithms is carried out in the aspects of bit error rate,complexity and receiving delay.Finally,the Codeword-level SIC receiving algorithm is selected as the receiver algorithm used in this system.Then,the phase rotation of transmitter side of NOMA system is studied theoretically and simulated.First,the NOMA constellation rotation superposition model under various modulation combinations is introduced.In view of the rotation superposition constellation,the optimal phase rotation angle of different modulation combinations is derived theoretically.Finally,the correctness of the theoretical derivation is verified by the MATLAB simulation.Afterwards,adaptive simulation is carried out for the current two user downlink model.First,adaptive parameters are simulated,that is,when the total power of the base station is different,the optimal power allocation mode,the optimal modulation and demodulation mode and the optimal encoding and decoding mode are chosen.Then the signal to noise ratio estimation algorithm is introduced,and the two order four order moment signal noise ratio estimation algorithm is simulated.Then,based on the above simulation results,the overall adaptive simulation of the NOMA downlink system is carried out.Finally,the model construction of NOMA uplink and the related simulation are carried out.Finally,the FPGA implementation of the NOMA downlink system is implemented,and the implementation of the system is divided into modules in the VIVADO environment.Finally,the error rate performance is verified on the zc706 hardware platform,which conforms to the MATLAB simulation results,thus proving the correctness of the system implementation.