Design of channel-optimized vector quantizers in the presence of channel mismatch

Author

Jafarkhani, Hamid ; Farvardin, Nariman

Author_Institution

Dept. of Electr. Eng., Maryland Univ., College Park, MD, USA

Volume

48

Issue

1

fYear

2000

fDate

1/1/2000 12:00:00 AM

Firstpage

118

Lastpage

124

Abstract

We study the design of channel-optimized vector quantizers in the presence of channel mismatch. We show that when the statistics of the channel bit-error rate (BER) are not known, a minimax solution is the one obtained by designing for the worst possible channel. Then, we consider the case when the probability density function of channel BER is known and propose an algorithm that provides a minimum average distortion. Also, by using an estimate of the channel BER at the decoder, we develop a decoder-adaptive scheme that further improves the performance. In all cases, we have limited ourselves to table-lookup decoders, which amount to very small computational complexities. Finally, the utilization of lookup tables at the encoder and the effects of imperfect estimation of channel BERs are considered

Keywords

AWGN channels; adaptive decoding; combined source-channel coding; error statistics; table lookup; vector quantisation; BER; bit-error rate; channel imperfect estimation; channel mismatch; channel-optimized vector quantizers; computational complexities; decoder-adaptive scheme; minimax solution; minimum average distortion; probability density function; table-lookup decoders; worst possible channel; Bit error rate; Decoding; Fading; Minimax techniques; Power capacitors; Probability density function; Speech processing; Statistics; Switches; Table lookup;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.818879

Filename

818879