The Study On The Multi-Antenna Based Wireless Network MAC Protocol

With the rapid development of broadband wireless communication, WLAN (Wireless Local Area Network) is a broadband wireless access mode.It is flexible for networking and convenient for moving.It also has advantages of well scalability and low maintenance cost. With the MIMO technology growing maturity, the use of multi antenna technology(distributed antenna and large-scale MIMO) to achieve higher data transmission rate is an inevitable trend.Firstly the paper studies the working principle of IEEE802.11DCF and performs the theoretical derivation of the saturation throughput and delay.Then the paper studies the C-MMAC protocol(Cognitive-Multichannel MAC protocol) and points out its advantages and disadvantages.The survey of the multi-user MIMO MAC protocol is also presented.Then the paper introduces distributed antennas into a cognitive radio network and presents a heterogeneous network consisting of an ad-hoc mode and infrastructure mode and proposes a synchronous cognitive MAC protocol(DAHCWNS-MAC protocol).The paper describes in detail every part of the protocol and carries out the mathematical modeling and performance simulation. The simulation results proves that utilizing distributed antennas to sense spectrum and transmit data can improve the sensing performance and increase network throughput by broadening the communication range of the original single-hop network. The paper compares the DAHCWNS-MAC protocol with the C-MMAC protocol to demonstrate that increasing antenna hardware costs can broaden the communication range so as to increase the network throughput. At last the paper introduces the Large-scale MIMO into WLAN and proposes a Large-scale MIMO Based Wireless Network MAC(LSMWN-MAC) protocol and the wireless resource allocation method which are suitable for large-scale MIMO environment.The proposed protocol reduces the interaction time via TDMA/FDMA hybrid method and increases throughput via SDMA/FDMA hybrid method to transmit data.The paper carries out the mathematical modeling and performance simulation.Then the drawbacks of the LSMWN-MAC protocol are pointed out and a modified MLSMWN-MAC(Modified Large-scale MIMO Based Wireless Network MAC) protocol and modified resource allocation method are proposed.The modified method adopts dynamic allocation method to adapt the realtime channel.Meanwhile the paper performs the simulation and compares to the LSMWN-MAC protocol to demonstrate the MLSMWN-MAC can reach higher throughput.In the future work,the paper will use the distributed antennas to locate and adopt hybrid access method to obtain higher spectrum efficiency and throughput of cognitive network.In addition,the uplink MAC protocol of large-scale MIMO will be studied to complete the wireless access policy for large-scale MIMO scenarios.