The Key Technology Of Single Carrier Frequency Domain Equalization In HF Channel

The HF(High Frequency) communication system, famous for its long-distance communication, fast and flexible convenient network reconfiguration, has been used widely in military communication. Since HF communication relies on the reflection of the unstable atmosphere, which will lead to multipath effect, time-varying dispersive, serious fading, complex interference and the limited channel of frequency spectrum, this thesis will choose the single carrier frequency domain equalization to make the research for its good anti-multipath capability and lower equalization complexity.Firstly, this thesis expounds the basic characteristic of the wireless channel, and then analyzes the characteristics of HF channel, single carrier frequency domain equalization technology and basic principle in the comparison of Signal Carrier-Frequency Domain with the Orthogonal Frequency Division Multiplexing system. This thesis mainly takes the Unique Wordas a pilot to improve frame structure to suit the HF channel. In order to save spectrum of HF communication system, I decide to adopt overlap algorithm to increase the transfer efficiency of the system and use Inter Block Interference factor to make its transmission performance approach which used protection interval system. Then the thesis will research the channel estimation of HF channel and put forward a plan about the channel estimation algorithm, which could not only restrain the Gaussian noise, but also use interpolation algorithm to track channel fading. Secondly, analysis frequency domain equalization algorithm, Compare Zero Forcingequalizationwith Minimum Mean Square Error equalization commonly, useddecision feedback algorithm and multipath merge algorithmto improveperformance of system. The proposedplan could increase the transmission efficiency of the system, suit the conditionof HF Channel and achieve the purpose of saving spectrum of HF Channel.