Research On Coding Technology For Short-burst MIMO-OFDM Communication System

Short burst communication systems are often used in military,satellite,deep space and other communications fields.In order to ensure the confidentiality of transmitted information,short burst communication systems usually adopt a short frame structure.However,the short frame structure brings some problems to the short burst system.The short frame structure limits the length of the training sequence,leading to the decrease of the channel estimation accuracy at the receiving end and the performance of the system,which is an important issue.Differential coding is a non-coherent detection and coding technique.When the channel information is unknown,the transmission data can also be decoded.Therefore,this paper mainly studies the short burst communication system based on differential coding to avoid explicit channel estimation.The specific work is as follows:1.A short burst MIMO-OFDM communication system based on differential space-timefrequency coding is constructed.A differential space-time-frequency coding scheme is adopted in the system,and channel status information is not required at both the transmitting end and the receiving end.Differential encoding of different subcarriers in the same OFDM symbol is suitable for the frame structure of the constructed system,which can reduce the redundancy of reference symbols,improve the proportion of data symbols in the system,and obtain the maximum diversity of the system.The simulation of the system is compared with the short burst MIMO-OFDM system based on channel estimation,which proves the superiority of the constructed system.In order to further improve the reliability of the system,channel coding is introduced in the constructed system,and the RS code is selected as the most suitable channel coding pattern by simulation.2.A short burst massive MIMO communication system based on differential coding is constructed.The receiving end of the system is equipped with a large number of receiving antennas,thereby improving the data transmission rate and spectrum efficiency of the system.Using block-by-block differential coding,this paper completes the theoretical derivation of the whole process from the transmitter to the receiver decoding and simulates it.The multi-symbol differential detection scheme is to extend the observation interval of the traditional two symbols to the observation interval of multiple symbols,which can compensate for the performance difference with the coherent detection.Therefore,the multi-symbol differential decoding scheme is introduced into the constructed system,and a massive MIMO multi-symbol differential communication system for short bursts is constructed.Through simulation analysis,it is proved that the proposed scheme further improves the performance of the system.