Design And Research Of Short-time Burst Communication System

The signal in the information confrontation will be disturbed by one’s own equipment and the various artificial interference of the enemy,which makes the communication environment on the military battlefield become very bad,which leads to the decline of the communication efficiency.Therefore,a reliable and efficient communication system is the key to gaining the initiative in information confrontation.The ultra-short burst communication can transmit data at high rate in short time,and has good anti-interception ability,which will become the most promising solution for future mobile communications.Based on the background of "**** system" project,this paper mainly studies the signal system design of the burst communication system,design and realization of the key technology scheme and system synchronization algorithm.and also verifies the performance of the design scheme.The simulation results show that the system designed in this paper can transmit and receive the signals reliably under the bad communication condition.The main contents of this paper are as follows:1、According to design indicators of the system,this paper completes development signal system of the short-term burst communication system,designs the distributed protocol frame of the system,and determines the system block diagram and work flow.Combining with the frame structure,a burst communication system of LDPC code and GMSK modulation techniques is determined,and proposes a distributed synchronization scheme based on matched filters.2、In order to make use of the signal power as much as possible,an improved GMSK quadrature modulation method based on look-up table method is used in this paper.The phase integral operation is divided into two parts: real-time phase and accumulative phase,which simplifies the integral operation and reduces the computational complexity.It also gives the theoretical derivation of this method and program performance verification.3、The system adopts LDPC code as the channel error correction code.two LDPC codes is proposed in paper.One is the algebraic construction method based on complete residue system,which can generate the regular LDPC codes whose minimum girth is 8 under the condition of column weight 3.The other is structure construction method based on different circulant permutation matrix(CPM),that can structures irregular LDPC code with excellent performance.Through analysis and verifies of the program performance,this paper selects the irregular code.4、According to the distributed frame structure,the synchronous code group adopts the Maori code of length 30 that is inserted into the data frame according to the polarity of the Barker code,and it uses the synchronous code to multiplex and realizes the symbol synchronization and frame synchronization.