Turbo coding in ADSL DMT systems

Author

Zhang, L. ; Yongacoglu, A.

Author_Institution

Sch. of Inf. Technol. & Eng., Ottawa Univ., Ont., Canada

Volume

1

fYear

2001

fDate

11-14 Jun 2001

Firstpage

151

Abstract

Increasing the transmission speed and/or the loop length in asymmetric digital subscriber lines (ADSL) is highly desirable. This can be achieved by employing sophisticated channel coding techniques. We investigate the potential usage of turbo codes in ADSL discrete multitone (DMT) systems to improve the system performance. Using turbo coding in ADSL DMT systems is shown to give a 6 dB coding gain at a bit error rate (BER) as low as 10^-6. To lower the decoding complexity, Gray mapping of turbo coded QAM symbols is proposed and a standard binary decoder is employed at the receiver. To counter impulse noise, another major impairment in subscriber loop transmissions, using turbo codes together with proper interleaving and erasure decoding results in very good performance

Keywords

binary codes; channel coding; convolutional codes; decoding; digital subscriber lines; error statistics; impulse noise; interleaved codes; modulation coding; quadrature amplitude modulation; turbo codes; ADSL DMT systems; BER; Gray mapping; asymmetric digital subscriber lines; binary decoder; bit error rate; channel coding; coding gain; decoding complexity; discrete multitone systems; erasure decoding; impulse noise; interleaving; loop length; receiver; recursive systematic convolutional codes; subscriber loop transmission; system performance; transmission speed; turbo coded QAM symbols; turbo codes; turbo coding; Bit error rate; Channel coding; Code standards; DSL; Decoding; Gain; OFDM modulation; Quadrature amplitude modulation; System performance; Turbo codes;

fLanguage

English

Publisher

ieee

Conference_Titel

Communications, 2001. ICC 2001. IEEE International Conference on

Conference_Location

Helsinki

Print_ISBN

0-7803-7097-1

Type

conf

DOI

10.1109/ICC.2001.936292

Filename

936292