Concatenated coded spreading with coherent demodulation for DS-CDMA

Author

Frey, Thomas ; Schramm, Peter

Author_Institution

Dept. of Inf. Technol., Ulm Univ., Germany

Volume

3

fYear

1998

fDate

18-21 May 1998

Firstpage

1910

Abstract

In DS-CDMA systems, spreading may be viewed as inner coding and user-specific scrambling. In practice, spreading is combined with an outer convolutional code, which leads to so-called concatenated coded spreading (CCS). The standard approach is to use repetition codes. In the IS-95 uplink, a (64,6,32) orthogonal code is defined, which can be interpreted as 64-ary orthogonal modulation. In this paper, a CCS scheme with power efficiency superior to the IS-95 uplink is proposed. The use of decision-directed coherent demodulation for both schemes is discussed, and it will be shown that the coding gain of the improved CCS requires a modified channel estimation scheme

Keywords

cellular radio; code division multiple access; concatenated codes; convolutional codes; demodulation; pseudonoise codes; spread spectrum communication; (64,6,32) orthogonal code; 64-ary orthogonal modulation; DS-CDMA; IS-95; channel estimation scheme; coding gain; coherent demodulation; concatenated coded spreading; decision-directed coherent demodulation; inner coding; repetition codes; user-specific scrambling; AWGN channels; Binary phase shift keying; Carbon capture and storage; Channel estimation; Concatenated codes; Convolutional codes; Demodulation; Information technology; Modulation coding; Multiaccess communication;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 1998. VTC 98. 48th IEEE

Conference_Location

Ottawa, Ont.

ISSN

1090-3038

Print_ISBN

0-7803-4320-4

Type

conf

DOI

10.1109/VETEC.1998.686088

Filename

686088