Reseach On Relay Network Optimization Algorithm For The Complex Environment And Structure

The wireless communication is undoubtedly one of the hottest research fields in the development process of present society,and the higher requirements for wireless communication requested by the whole society makes research of wireless communication technology obtain rapid development in recent years. Relay cooperative communication technology can not only obtain spatial diversity to improve the transmission rate of the system, but also expand the coverage of communication, even if it does not occupy additional spectrum resources. Therefore, the relay cooperative communication technology has become the focus of research in the area of wireless communications. However, the actual communication environment is complicated, and the nongaussianity of background noise makes the performance of relay cooperative network communication algorithm based on Gaussian impulsive noise significantly decreased. In addition, the spectrum resources become increasingly tense, but new media business demands higher data transmission rate and capacity, which need to seek new breakthroughs in wireless communication technology. Due to the use of airspace resources, two-way MIMO(Multiple Input Multiple Output) relay network not merely improve the spectrum efficiency and system throughput but also improve communication network transmission rate, which becomes one of the research hotspots in the academic and engineering at present.In this paper, impulsive noise and two-way MIMO relay network are chosen as the research object, the following research work has been done.The impulsive noise model based on the Laplace distribution is established, and the probability density function of a linear combination under this impulsive noise model is deduced. In addition, the relay network model containing single-source and single-destination and multi-relay is chosen as research model. Then the optimal beamforming matrix is formed by maximum likelihood estimation and the equalization coefficient is obtained from zero forcing equalizer. Simulation results show that the proposed algorithm performs better than the traditional algorithm upon Gaussian noise when deal with the impulsive noise, and the former algorithm can get smaller Bit-Error-Rate.This paper introduces an optimization algorithm which chooses SNR(Signal to Noise Ratio) and total relay transmission power as performance parameters for the two-way MIMO relay network containing a couple of transceivers and some relay nodes. In addition, expressions of the performance parameters are simplified through the mathematical deduction. The following three principles are using for joint optimization of the beamforming matrix and the equalization matrix: 1. the total relay transmission power is minimized with the constraint of minimal output SNR at two transceivers, 2. the minimal output SNR of the each transceiver is maximized with the constraint of total relay transmission power, 3. the minimal output SNR of the each transceiver is maximized with the constraint of individual relay transmission power. Then the optimization of two-way MIMO relay network can be solved by modeling as a second-order cone programming problem under the three optimization principles. Finally, the effectiveness of the proposed algorithm is verified via computer simulation.