Research On Multi-channel Synchronization Search Based On 3G-ALE

As the means of communications that can connect any two point in the global range,HF communication occupies an irreplaceable position in the communication field.With the wide application of HF communication,the demand for HF communication is higher and higher,so the research on the real time and reliability of HF communication is continuously expanding.The U.S.military issued the third generation HF communication protocol MIL-STD-188-141B in 1999.People’s Liberation Army developed the third generation HF communication GJB 2077A-2007 based on MIL-STD-188-141B,which indicates that our research has stepped into 3G era.Although the link speed in the synchronous mode has been improved,the asynchronous mode is still the main channel of the polling call channel to capture the main call,which takes massive time delay.In order to improve the speed of the station building chain in the asynchronous mode,this dissertation focus on that and do a lot of research.The main innovation points of this dissertation are as follows:This dissertation improved the physical layer of the receiving scheme based on the asynchronous mode.Synchronization search module use multi-channel synchronous search to achieve rapid build chain between stations,which makes the receiver could scan multiplexed data in the unit time.Moreover,the probe header is divided into two sections,one for fine synchronization to determine the type of waveform.the other part is used as the frequency offset estimation and channel estimation to eliminate the Doppler frequency shift and obtain the initial channel parameter.The design of the program could ensure the accuracy of the demodulated information and improve the speed of construction of chain between stations.Furthermore,a multi-channel synchronization search strategy is proposed for the large delay caused by single path search in asynchronous mode.This strategy makes the call station in the same time to scan multiple call channels within the same time.The scheme has been completed on Parallella to demonstrate the feasibility.This scheme has been published in this area.