Research On Channel Estimation And Signal Detection Of MIMO-OFDM Wireless Communication Over The Sea

In recent years,the information level of communication system has been improved.Especially,the wireless communication system is developed from narrowband,low speed to wideband and high speed wireless communication.MIMO technology can transmit different information simultaneously through multiple antennas in wireless channel.And it can increase the system capacity and throughput by expanding the coding technology to obtain diversity gain.The OFDM system divides the transmit information bits into many different sub blocks and sends them to different channels via the orthogonal subcarrier.It can not only overcome the problem of relatively serious frequency selective fading,but also help to mitigate the effect of multipath fading.The merged MIMO-OFDM Systems inherited their common advantage,eliminating each other's flaws.Therefore,it will be higher data rate and more reliable transmission.In the special working environment of maritime wireless communication with signal fading and multipath effect,when frequency selective fading appear in the channel because of using MIMO multipath technique,only the information of individual undesirable subcarrier is affected by all kinds of interference,but the performance of the whole system is still quite outstanding.OFDM technology utilizes orthogonal subcarrier to effectively counteract the interference between each signal waveform,and it is suitable for high speed data transmission in ocean multipath transmission environment and deep fading channel.Therefore,MIMO-OFDM technology will be used in marine wireless communications,and vigorously realize the maritime wireless communications business needs between the"ship-ship" or/and "Ship-shore".Compared with maritime communications such as INMARSAT,shortwave and ultra-short wave,MIMO-OFDM technology can enhance the integration of future maritime communication technologies by means of higher system capacity,faster transmission rate,shorter communication delay and lower business cost.In this paper,the transmission performance and advantages of land MIMO,OFDM and MIMO-OFDM technology are studied theoretically,and they are expanded and applied to the maritime wireless communication with the application of space-time encoding,space frequency encoding and space-time frequency encoding for the corresponding description and comparative analysis.And the detection method of the channel estimation and signal simulation are researched not only to provide a theoretical basis for the maritime 4G and future 5G communication,but also provide basis for the construction of maritime information communication system.