UBC Theses and Dissertations
Efficient coding/decoding strategies for channels with memory Lai, Cuong H.
Many digital communication channels are affected by errors that tend to occur in bursts. A great deal of work has been devoted to finding good burst-error-correcting codes and developing burst-error-correcting schemes. However, burst-error-correcting codes are generally useless for long bursts. Some burst-error-correcting schemes suffer long delay in decoding. Others are very sensitive to random errors in the guard space. Most of these schemes are not adaptive to channel conditions. In this thesis, two new schemes are proposed to overcome these drawbacks. The proposed schemes are analyzed over a two state Markovchain channel model. Both schemes employ a combination of two codes. In the first scheme, one of the codes is used for random error correction and for burst detection while the other one is used only for burst recovery. In the second scheme, one of the codes is used for burst detection and for channel state estimation, and both codes are used for error correction. Unlike existing burst-error-correcting schemes, it is shown that the proposed schemes are adaptive to channel conditions and less sensitive to errors in the guard space. For the same delay, the proposed schemes offer better performance than the interleaving schemes. When the channel is heavily corrupted by bursts, the improvement is even more pronounced.
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