Study Of Rate Variable High-Frequency Communication Based On RCPC Code

Awful channels for wireless communication forced us to make use of various kinds oftechnique measures in order to obtain well effective and reliable communication. As we know,rate-variable technique, which has been used to achieve well effective and reliablecommunication, can take advantage of channel very well through actively adapting changesof channel state.Rate variable technique has been widely applied in cellular mobile communication andWireless Local Area Network now. But in contrast, similar application in High-Frequencysystems is not common as it is in WLAN. For cellular mobile system and WLAN, thedistance between basestation and mobile terminal is at the level of some kilometers, and thetransmission delay, which correspond to handshaking and agreement is neglectable. However,the transmission delay related to the similar process in HF system is considerable, since thedistance between transmitter and receiver is hundreds kilometers and even thousandskilometers. So, similar process to accomplish rate changing will bring large delay.Then a method of rate variable that putting rate-changing process into HARQ isadvanced. And the method, that avoiding process of handshakeing and acknowledgement, canadapting to changing of channel state quickly. And this method is carried out by changingcode rate directly, in other word, we take Rate Compatible Punctured Convolutional code intoconsideration. This paper analyzed encoding and decoding principles of Rate CompatiblePunctured Convolutional(RCPC) code, and presented a kind of decoding algorithm for rate1/1punctured codes. Then, a group of waveform is designed and discussed.Finally, this paper designed and studied IR-HARQ Rate Variable CommunicationBased on RCPC Code. The result of analysis and simulation indicated that rate variablecommunication can greatly improved efficiency of data transmission.