Research On Distributed Multi-antenna Bidirectional Cooperative Relay Transmission Scheme

In a distributed wireless communication systems, distributed space-time-frequency coding scheme can achieve both systems with spatial diversity, time diversity and frequency diversity to improve anti-jamming capability of the network, reducing the system bit error rate, has become in recent years research focus and difficulty. However, existing distributed space-time-frequency coding schemes are often based on a single antenna diversity gain space systems, low error rate performance, and distributed space-based multi-antenna frequency coding scheme, because of its access to the same time a similar multiple-input multiple-output (MIMO:Multiple-Input Multiple-Output) antenna system, the diversity gain, but also to obtain cooperative communication system cooperative diversity gain, expanded system coverage. Joint coding technology to send data stream by treating joint coding done to improve the system diversity gain, cyclic delay each antenna technology to transmit data on the cyclic shift, equivalent exacerbated the frequency selective channel excavated frequency diversity system. Combining the advantages of both technologies, a kind of distributed multi-antenna bidirectional cooperative relay transmission scheme. The specific content of the paper is as follows:(1) Study the MIMO system based on joint coding technology to analyze how the system is to achieve high diversity gain and transmission rate of the internal mechanism and gives a high detection complexity arising after the use of joint coding solutions.(2) The joint coding techniques and cyclic delay diversity technology into full-rate communication model, the effects of unidirectional and bidirectional full-speed model agreement cyclic delay diversity techniques and coding schemes based on joint coding techniques. Cyclic delay diversity techniques introduced not only improves the diversity gain of the system, but also reduces the complexity of detecting the receiving end. (3) On the basis of in-depth study on these two programs, a kind of distributed multi-antenna bidirectional cooperative relay transmission scheme. The transmission scheme comprises two slots, all the nodes are equipped with multiple antennas, the data source node while the first two slots to be jointly encoded and transmitted through the orthogonal frequency division simultaneously broadcast to all nodes in the relay multiplexing modulation; the second relay node will receive all the slots to amplify signals transmitted to the source node after the two cycle latency. Use joint coding technology reduces the error rate of the system, the use of technology to make cyclic delay detection model and testing complexity increases with the receiving end are not relaying nodes and change, reduce hardware design complexity and by theoretical analysis and simulation shows implementation costs. In this paper, the design of distributed bidirectional transmission scheme, compared with traditional distributed scalable coding scheme, the coding process is simple and easy to design, to achieve full rate transmission and detection of low complexity, with high practical value.