Study On MAC Protocol In Ad Hoc Network Based On MIMO Interference Alignment

Ad Hoc network is a distributed control and rapid self-organization wirelesscommunication technology. It is to solve the problems of environment without infrastructurecoordination such as military operation, field investigation, disaster site and so on. MIMOmulti-antenna system can not only increase the maximum transmission rate by transmittingmultiple different data streams modulated into multiple independent parallel spatial channels,but also reduce the bit error rate by using multiple the same data streams in multiple spatialsubchannels. Interference alignment has been proposed in recently years, which is a newtechnology of MIMO area. With interference alignment, MIMO systems can increase paralleltransmitting useful data streams by breaking the spatial-multiplexing gain constraints ofreceiver antenna number in traditional theory. By the achievement of interference alignmentin the MIMO-based Ad Hoc network MAC protocol, with the precoding of the transmitter andthe aligning interference of the receiver, the system can achieve better enhancement ofmulti-packet reception (MPR) effect and transmit more useful data packets in the same time.This paper begins with an overview of Ad Hoc networks research progress and MIMOtechnique principle at the present stage, and discusses the existing Ad Hoc networks MACprotocols combined with MIMO designs. By depth analysis of the PRP-MAC protocol andthe MIMO alignment basic principle, this paper presents a new Ad Hoc physical layer modeland makes a simple simulation on it. After that, this paper designs a new MAC protocol calledIAPRP-MAC based on MIMO interference alignment. This paper not only studies thetransmitter buffer detection mechanism, the control frame structure, the node operationprocess, the possible scenarios and the hidden terminal problem of the IAPRP-MAC, but alsoproposes the CTS parameter algorithm of receiver and the transmitting ways determinedalgorithm according to CTS of transmitter. At last the simulation shows that IAPRP-MAC cannot only reduce the transmission delay of PRP-MAC, but also enhance the networkthroughput of PRP-MAC.