Research And Application Of NOMA And SSK Modulation Technology

Cooperative relay system has many advantages,such as increased spectral efficiency,reduce network cost,high-speed transmission and so on.However,due to the development of mobile communications,the transmission rate of existing systems cannot meet the needs of future mobile communication applications.In order to solve this problem,Non-orthogonal multiple access(NOMA)technology and Space Shift Keying(SSK)technology have emerged.Considering the Nakagami-m fading environment,this paper mainly considers NOMA-based cooperative relay system and SSK modulation system with hardware impairnents conditions,and has achieved some research results.Firstly,considering the two-hop decoding and forward cooperative relay system based on NOMA,this paper studies its effective capacity performance.Obtain a closed expression of the effective capacity of the system in the Nakagami-m fading environment with the channel fading parameter m>0.5 taking any real and positive integer values.Furthermore,using the Mixed Gamma model to model the received SNR,this paper obtain a closed expression of the effective capacity of the system in the generalized composite fading channel environment(ie,considering small-scale fading and shadow fading).The results can be covered,such as Rice and other fading scenarios.Numerical calculations and Monte Carlo simulations verify the correctness of the theoretical results obtained.The research results can be used to guide the structural design and performance optimization of NOMA-based cooperative relay networks in fading environments.Then,on the basis of the previous research,considering the cooperative multi-relay system based on NOMA to maximize the effective capacity selection criterion,this paper propose a relay selection scheme transmission scheme.The simulation results show that the proposed transmission performance is significantly better than the existing relay transmission scheme.For example,when SNR=20 dB,the EC of the proposed scheme can reach 4.975 bits/s/Hz,while the EC of the existing random relay selection scheme is 4.713 bits/s/Hz.The research results provide an effective transmission scheme for data transmission of NOMA-based cooperative multi-relay networks.In the actual communication system,phase noise,I/Q branch imbalance and high power amplification cause damage to the system hardware,distortion of the signal,and degradation of the performance of the communication system.Finally,considering the hardware damage,this paper studies the bit error rate performance of the SSK modulation system.For the system with two antennas at the transmitting end and one antenna at the receiving end,the expression of the average bit error rate of the system in Rayleigh fading environment is obtained by mathematical transformation.Numerical calculations and Monte Carlo simulations show that hardware damage can reduce the performance of SSK modulation system,and the larger the design parameters,the greater the degree of hardware damage,the greater the system error rate and the worse the performance.The research results have important guiding significance for the practical application of SSK modulation technology.