Optimal Detection of Discrete Markov Sources Over Discrete Memoryless Channels - Applications to Combined Sources-Channel Coding

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dc.contributor.authorPhamdo, N.en_US
dc.contributor.authorFarvardin, Narimanen_US
dc.contributor.departmentISRen_US
dc.date.accessioned2007-05-23T09:50:16Z
dc.date.available2007-05-23T09:50:16Z
dc.date.issued1992en_US
dc.description.abstractWe consider the problem of detecting a discrete Markov source which is transmitted across a discrete memoryless channel. The detection is based upon the maximum a posteriori (MAP) criterion which yields the minimum probability of error for a given observation. Two formulations of this problem are considered: (i) a sequence MAP detection in which the objective is to determine the most probable transmitted sequence given the observed sequence and (ii) an instantaneous MAP detection which is to determine the most probable transmitted symbol at time n given all the observations prior to and including time n. The solution to the first problem results in a "Viterbi-like" implementation of the MAP detector (with large delay) while the later problem results in a recursive (with no delay). For the special case of the binary symmetric Markov source and binary symmetric channel, simulation results are presented and an analysis of these two systems yields explicit critical channel bit error rates above which the MAP detectors become useful.<P>Applications of the MAP detection problem in a combined source-channel coding system are considered. Here it is assumed that the source is highly correlated and that the source encoder (in our case, a vector quantizer (VQ) fails to remove all of the source redundancy. The remaining redundancy at the output of the source encoder is referred to as the "residual" redundancy. It is shown, through simulation, that the residual redundancy can be used by the MAP detectors to combat channel errors. For small block sizes, the proposed system beats Farvardin and Vaishampayan's channel- optimized VQ by wide margins. Finally, it is shown that the instantaneous MAP detector can be combined with the VQ decoder to form a minimum mean-squared error decoder. Simulation results are also given for this case.en_US
dc.format.extent1027903 bytes
dc.format.mimetypeapplication/pdf
dc.identifier.urihttp://hdl.handle.net/1903/5208
dc.language.isoen_USen_US
dc.relation.ispartofseriesISR; TR 1992-25en_US
dc.subjectdata compressionen_US
dc.subjectdetectionen_US
dc.subjectdigital communicationsen_US
dc.subjecterror- detection codesen_US
dc.subjectinformation theoryen_US
dc.subjectCommunication en_US
dc.subjectSignal Processing Systemsen_US
dc.titleOptimal Detection of Discrete Markov Sources Over Discrete Memoryless Channels - Applications to Combined Sources-Channel Codingen_US
dc.typeTechnical Reporten_US

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