The Empty Block Codes Applied Research In Tropospheric Scatter Communications

Troposcatter phenomenon was found in the thirties of the twentieth century, it has beenused as a communication technique around the world for thirty years up to the present.Since the troposphere communication has special application value and plays an importantrole in today's wireless communication area, we choose the troposphere wireless channelas the research background in this thesis. By introducing space time block code, we intentto improve the communication performance of troposphere communication. Space-timeblock code was first proposed under flat fading channels, thus the application of STBC introposphere channels must take some practical problems into consideration since thetransmit condition in troposphere channels is much worse. This thesis is intents to dealwith those problems.The main research work of this thesis includes: Under the troposphere channelshaving serious ISI, some new space time coding schemes are studied by utilizing OFDMand SC-FDE. By comparing the four kinds of coding schemes proposed in this thesis, onekey conclusion is obtained that the ST-SC-FDE scheme has the best performance introposphere channels. The research work of other chapters is all base on this conclusion.Then we make some efforts on the decoding scheme when the receiver doesn't have thechannel information, whioh include the structure and the optimal selection of trainingsequence, and all of these are under the pre-combination and sub-equalization decodingframework based on channel estimation. At the same time, anew adaptive decodingscheme without channel information is proposed. Compared with the first decodingscheme, the adaptive decoding scheme has a much better performance at the expense oflarge computational complexity. Finally, the application of ST-SC-FDE in multi-usercircumstance is proposed, after discussed the implementation of uplink and downlinkrespectively, the entire multi-user application model has been constructed.