DocumentCode :
1880170
Title :
Buffer control for variable complexity Fano decoders
Author :
Pan, Wendi ; Ortega, Antonio
Author_Institution :
Dept. of Electr. Eng. Syst., Univ. of Southern California, Los Angeles, CA, USA
Volume :
1
fYear :
2001
fDate :
2001
Firstpage :
176
Abstract :
Fano sequential decoders are variable complexity convolutional decoders, which have the desirable property of operating with very low computation at high SNR. In portable mobile communications, it is often desirable to trade BER with decoder complexity/power consumption. However, the variable complexity nature of the Fano algorithm means that buffers are required for the Fano decoder due to large variations in processing delays. In this paper, we formulate the buffer control problem as one that seeks to minimize the overall probability of block loss, subject to a finite buffer size constraint. The overall probability of block loss is comprised of two terms, corresponding to loss due to excessive bit errors and decoder buffer overflow, respectively. This leads to an interesting trade-off, as faster decoding often means higher bit error rate. Based on the joint distribution of decoding complexity and BER, at each decoding stage, we find an optimal Fano decoder parameter (Δ) to minimize block loss. In addition, we propose a simple real-time table lookup algorithm that implements the Δ control policy. Simulation results demonstrate the superior performance of the proposed algorithm
Keywords :
adaptive control; buffer storage; computational complexity; convolutional codes; error statistics; minimisation; mobile radio; probability; sequential decoding; table lookup; BER; Fano sequential decoders; SNR; bit error rate; block loss probability minimisation; buffer control; convolutional decoders; decoder buffer overflow; excessive bit errors; finite buffer size constraint; optimal parameter; performance; portable mobile communications; power consumption; real-time table lookup; variable complexity decoders; Bit error rate; Convolutional codes; Delay; Electric variables control; Energy consumption; Maximum likelihood decoding; Mobile communication; Power engineering and energy; Size control; Viterbi algorithm;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Global Telecommunications Conference, 2001. GLOBECOM '01. IEEE
Conference_Location :
San Antonio, TX
Print_ISBN :
0-7803-7206-9
Type :
conf
DOI :
10.1109/GLOCOM.2001.965102
Filename :
965102
Link To Document :
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