Universal Decoding for Noisy Channels
نویسنده
چکیده
A universal decoder for a parametric family of channels is a decoder that for any channel in the family attains the same random coding error exponent as the best decoder for that particular channel. The existence and structure of such decoders is demonstrated under relatively mild conditions of continuity of the channel law with respect to the parameter indexing the family. It is further shown that under somewhat stronger conditions on the family of channels the convergence of the performance of the universal decoder to that of the optimal decoder is uniform over the set of channels. Examples of families for which universal decoding is possible include the family of finite state channels and the family of Gaussian intersymbol interference channels.
منابع مشابه
IRWIN AND JOAN JACOBS CENTER FOR COMMUNICATION AND INFORMATION TECHNOLOGIES Universal Decoding Using a Noisy Codebook
We consider the topic of universal decoding with a decoder that does not have direct access to the codebook, but only to noisy versions of the various randomly generated codewords, a problem motivated by biometrical identification systems. Both the source that generates the original (clean) codewords, and the channel that corrupts them in generating the noisy codewords, as well as the main chan...
متن کاملCapacity and decoding rules for classes of arbitrarily varying channels
Ahstrucf -We consider the capacity of an arbitrarily varying channel (AVC) for deterministic codes with the average probability of error critenon and, typically, subject to a state constraint. First, sufficient conditions are provided that enable (relatively) simple decoding rules such as typicality, maximum mutual information, and minimum distance, to attain capacity. Then the (possibly noisy)...
متن کاملIRWIN AND JOAN JACOBS CENTER FOR COMMUNICATION AND INFORMATION TECHNOLOGIES Universal Decoding for Arbitrary Channels Relative to a Given Class of Decoding Metrics
We consider the problem of universal decoding for arbitrary unknown channels in the random coding regime. For a given random coding distribution and a given class of metric decoders, we propose a generic universal decoder whose average error probability is, within a sub–exponential multiplicative factor, no larger than that of the best decoder within this class of decoders. Since the optimum, m...
متن کاملIterative Decoding of Multiple Descriptions
This paper considers the transmission of multiple descriptions over noisy channels rather than the on-oo channels that are traditionally considered. We introduce the use of iterative decoding techniques similar to those used in \turbo" decoding to decode multiple correlated descriptions transmitted over a noisy channel. For a given transmission rate per channel and a given channel state, the ee...
متن کاملSoft Decoding for Vector Quantization Over Noisy Channels with Memory
We provide a general treatment of optimal soft decoding for vector quantization over noisy channels with nite memory. The main result is a recursive implementation of optimal decoding. We also consider an approach to sub-optimal decoding, of lower complexity, being based on a generalization of the Viterbi algorithm. Finally we treat the problem of combined encoder{decoder design. Simulations co...
متن کامل