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Author Frenger, P.K. ♦ Orten, P. ♦ Ottosson, T. ♦ Svensson, A.B.
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©1972
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics ♦ Electricity & electronics
Subject Keyword Convolutional codes ♦ Multiaccess communication ♦ Communication systems ♦ Quality of service ♦ Delay ♦ Speech ♦ Fading ♦ Oral communication ♦ Image communication ♦ Videoconference
Abstract New rate-compatible convolutional (RCC) codes with high constraint lengths and a wide range of code rates are presented. These new codes originate from rate 1/4 optimum distance spectrum (ODS) convolutional parent encoders with constraint lengths 7-10. Low rate encoders (rates 115 down to 1/10) are found by a nested search, and high rate encoders (rates above 1/4) are found by rate-compatible puncturing. The new codes form rate-compatible code families more powerful and flexible than those previously presented. It is shown that these codes are almost as good as the existing optimum convolutional codes of the same fates. The effects of varying the design parameters of the rate-compatible punctured convolutional (RCPC) codes, i.e., the parent encoder rate, the puncturing period, and the constraint length, are also examined. The new codes are then applied to a multicode direct-sequence code-division multiple-access (DS-CDMA) system and are shown to provide good performance and rate-matching capabilities. The results, which are evaluated in terms of the efficiency for Gaussian and Rayleigh fading channels, show that the system efficiency increases with decreasing code rate.
Description Author affiliation :: Ericsson Radio Syst. AB, Stockholm, Sweden
ISSN 00906778
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1999-06-01
Publisher Place U.S.A.
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Volume Number 47
Issue Number 6
Size (in Bytes) 425.78 kB
Page Count 9
Starting Page 828
Ending Page 836


Source: IEEE Xplore Digital Library