Implementation issues for high rate turbo codes on BPSK/QPSK channels

Author

Afikel, I.F.

Author_Institution

Klipsch Dept. of Electr. & Comput. Eng., New Mexico State Univ., Las Cruces, NM

fYear

1999

fDate

1999

Firstpage

148

Abstract

We consider a practical method of decoding punctured high rate turbo codes with the BCJR a posteriori probability (APP) decoder. The full BCJR algorithm is computationally complex and has a large decoding delay for long interleaver sizes. By using the suboptimal sliding window log-BCJR (SW-log-BCJR) algorithm, it is possible to design an APP decoder that is less complex with short decoding delays. We consider decoding of rate 3/4, 7/8, 15/16 punctured turbo codes with optimum sliding window sizes and uniform quantization of decoding parameters in order to minimize the BER. Simulation results show that implementation loss of these turbo codes decoded by SW-log-BCJR algorithm is within 0.2 dB

Keywords

channel coding; computational complexity; decoding; delays; error statistics; minimisation; modulation coding; probability; quadrature phase shift keying; turbo codes; APP decoder; BCJR a posteriori probability decoder; BER; BPSK/QPSK channels; SW-log-BCJR algorithm; decoding; decoding delay; high rate turbo codes; implementation; long interleaver sizes; punctured high rate turbo codes; quantization; rate 15/16 punctured turbo codes; rate 3/4 punctured turbo codes; rate 7/8 punctured turbo codes; suboptimal sliding window log-BCJR algorithm; AWGN; Algorithm design and analysis; Binary phase shift keying; Bit error rate; Convolutional codes; Delay; Iterative decoding; Quadrature phase shift keying; Quantization; Turbo codes;

fLanguage

English

Publisher

ieee

Conference_Titel

Global Telecommunications Conference, 1999. GLOBECOM '99

Conference_Location

Rio de Janeireo

Print_ISBN

0-7803-5796-5

Type

conf

DOI

10.1109/GLOCOM.1999.831625

Filename

831625