Based On The Multi-point Cooperative Relay Wireless Transmission Technology Research

In recent years, with the development of wireless communications technologies, the requirement for higher transmission speed has been raised. Hence, in the densely populated areas, how to design a good multi-access scheme attracts more and more attention. FDMA (Frequency Division Multiple Access) and TDMA (Time Division Multiple Access) adopted in the1st and2nd generation of mobile networks tend not to be able to meet the increasing needs of people nowadays. Furthermore, CDMA (Code Division Multiple Access) in3rd mobile communication system always suffers from the MAI(Multi-Access Interference) and ISI(Inter-Symbol Interference). On the other hand, IDMA (Interleave Division Multiple-Access), which realizes multiple access by allocating different interleaver to each user, has gained more and more attention from researchers because of its efficient adoption of system resources and lower system complexity.Moreover, in the more and more mature field of optical communication, traditional fiber networks, enjoying very high transmission speed, has been widely applied in core networks by main operators. However, on account of the high cost of fiber and limited resources of electrical wireless connection, the "last-kilometer" access networks is constrained by these problems. In addition, the emerging of FSO (Free Space Optical) communication technology brings new heat to this researching field. FSO technology boasts strong security, open frequency resources and facilitation of equipment setup. So it is believed to be a good solution of access networks.Nevertheless, in the remote areas or the ones that have undesirable channel condition, traditional cell communication systems fail to provide good communication quality, high transmission speed and wide coverage. Therefore, more efficient wireless networks organizing schemes are expected to be proposed. It’s deemed to solve the problem of covering shadow areas through the cooperative communication mechanism which introduces relay nodes to networks and coordinates the source users, the relay ones and the base station. On the other hand, the spatial-diversity technology involving network coding also receives deeper and deeper research. This diversity mechanism can effectively reduce the channel fading influence with efficiently adopting frequency resources.Thus, firstly, this thesis proposes a wireless communication system based on IDMA and network-coding relay cooperative mechanism under the multi-path channel. The research of the BER (bit error rate) performance and multi-path contribution for anti-fading capability has been conducted with Turbo channel coding. Then another IDMA system has been put forward in FSO environment with the combination of photon counting technology. The multi-access decoding algorithm in the photon-counting receiver is delivered and the research of how the network-coding relay cooperative mechanism enhances the anti-fading performance of the system under Gamma-Gamma channel is conducted. At last, more accurate poisson-distribution quantum noise model is adopted to study the BER performance of MISO FSO IDMA system.