MIMO-OFDM Technology Research In Waters Near Wireless Communication

The total length of the coastline is 1.8 km and coastal waters cover 470 million square kilometers in our country and the number of islands which are over 500 square meters is about 6500. The settlement of maritime disputes, protection of sea lanes security, marine disaster forecasting are main tasks of "Marine Silk Road" with the strategy of "O ne belt and one road". O n one hand wireless communications provide important technical support in the coastal waters and satellite communication is the main way o f coastal waters’ communica--tion because of its wide frequency bandwidth and extensive coverage.On the other hand satellite life span is short, the satellite communication price is expensive; the communication process is delayed, sharing detection data is difficult and the communica--tion quality is easy infected by bad weather. The poor data security can cause trouble during marine disputes. The paper will try to surmount the deficiencies of satellite communications in coastal waters using the method of MIMO-OFDM technology.Firstly the paper analyzes the radio channel fading characteristics and common fading model, including Rayleigh model and Royce model, Secondly to analyze MIMO system channel and capacity characteristics. To simulate coastal waters environment with multi--antenna channel model based on kronecker product. To analyze the OFDM technology which overcome sea multipath effects and the Space diversity techniques which take advantage of multipath effects. Mainly to analyze not only the OFDM technology principle of transferring fast and overcoming multipath and the pace-time block coding(STBC) and maximal ratio combining detection(M RC) principle.,but also the MIMO-OFDM system the data transmission in the coastal waters.In the study of MIMO system channel capacity, simulation conditions: Rayleigh channel. The simulation demonstrates the system capacity correlated with the number of antennas and has little impact with channel state information. In the study of MIMO-OFDM system performance effect, simulation conditions: 2 transmitting antenna and 2 receiving antennas MIMO system. To generate channel coefficients by the kronecker product channel model. Mapping method is 16 QAM, Code methods is STBC coding and MRC merging, concluding that channel model has serious implications to system BER. In the study of system performance, under the same channel model and 2 transmitting antenna and 2 receiving antennas system, single antenna’s error rate is more than 1-2 orders to a single antenna.