Performance analysis of Viterbi decoding for 64-DAPSK and 64-QAM modulated OFDM signals

Author

May, Thomas ; Rohling, Hermann ; Engels, Volker

Author_Institution

Inst. of Telecommun., Tech. Univ. Braunschweig, Germany

Volume

46

Issue

2

fYear

1998

fDate

2/1/1998 12:00:00 AM

Firstpage

182

Lastpage

190

Abstract

The multilevel modulation techniques of 64-quadrature amplitude modulation (QAM) and 64-differential amplitude and phase-shift keying (DAPSK) have been proposed in combination with the orthogonal frequency-division multiplexing (OFDM) scheme for digital terrestrial video broadcasting (DTVB). With this system a data rate of 34 Mb/s can be transmitted over an 8-MHz radio channel. A comparison of these modulation methods in the uncoded case has been presented by Engels and Rohling (see European Trans. Telecommun., vol.6, p.633-40, 1995). The channel coding scheme proposed for DTVB by Schafer (see Proc. Int. Broadcasting Convention, Amsterdam, The Netherlands, p.79-84, 1995) consists of an inner convolutional code concatenated with an outer Reed-Solomon (RS) code. In this paper the performance of the convolutional codes is analyzed for the two modulation techniques. This analysis includes soft decision Viterbi (1971) decoding of the convolutional code. For soft decision decoding of DAPSK modulated signals a new metric is developed

Keywords

Reed-Solomon codes; Viterbi decoding; amplitude shift keying; channel coding; concatenated codes; convolutional codes; differential phase shift keying; digital television; frequency division multiplexing; quadrature amplitude modulation; television broadcasting; 34 Mbit/s; 64-DAPSK; 64-QAM; 8 MHz; OFDM signals; channel coding; data rate; differential amplitude and phase-shift keying; digital terrestrial video broadcasting; inner convolutional code; multilevel modulation; orthogonal frequency-division multiplexing; outer Reed-Solomon RS code; performance analysis; quadrature amplitude modulation; radio channel; soft decision Viterbi decoding; Amplitude modulation; Convolutional codes; Decoding; Digital TV; Digital modulation; OFDM modulation; Performance analysis; Phase modulation; Radio broadcasting; Viterbi algorithm;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.659477

Filename

659477