Research On Interference Alignment Of MIMO System With Imperfect Channel

Interference as an important factor restricting the performance of wirelesscommunication systems, has been a hot issue in the field of communications technologyresearch. With the rapid development of wireless communication industry, the requirementfor communication quality is getting higher, but the conventional communicationtechnology, such as make the signal of each user orthogonal (in the time domain, frequencydomain and code domain), or increase the transmission power can’t meet therequirements, in this background, a new technology come to public sight——InterferenceAlignment.Interference alignment is not just a simple coding technique, it combines linearpre-coding at the source and interference suppression at the receiver that can effectivelysuppress interference between users and get the best multiplexing gain. This paper containstwo parts, the first part introduces the principle of interference alignment under the idealchannel and gives alignment interference model and pre-coding matrix constraints,proposed a pre-coding matrix optimization program, and make its performance simulationand analysis, and then derive the interference aligned channel capacity formula based onthe literature. The second part focuses on interference alignment technique under imperfectchannel. First, establishes a model of IA with channel estimation error, and thus gives theconstraints of pre-coding matrix under this channel, deduced the channel capacity and biterror rate formula; second, i do the study of interference alignment under feedback delaychannel, and give constraints of pre-coding matrix, deduce channel capacity and bit errorrate formula of interference alignment in this channel, and give the analysis of thesimulation results. Finally, according to the first two research above,this paper put forwardthe technical indicators of interference alignment under the channel that exist bothestimation error and feedback delay, and give the channel capacity and symbol error rateformula,provide analysis of simulation results.