Shortwave Minimum Communication System

The technology of very low bit rate for HF(high frequency) communication means that,one technology of ECM(Electronic Counter Measures) resistant communication is developed for low bit data message exchange in the time of battle which data communication is destroyedby electronic disturber.It is regarded by armies in the battle ofinformation,because that it can overcome the very low SNR(Signal Noise Ratio) ,very high Narrow-Band Interference and Multipath with maxium delay of fifty millisecond. This task is funded by navy equipment pre-reseach project,"HF network access and integrated service access technology study". This task uses the DS-SS technology,and researchs the important technologies ,such as synchronization of DS-SS,RAKE Receive, Narrow-Band Interference suppression,etc.These technology are useful for the voice-band channel of HF.I designed one system of very low bit rate for HF data communication,and completed the softwave module design of the system .I get the result of system's simulator,it's useful for the system realization.