DocumentCode :
1758554
Title :
Two-dimensional spreading scheme employing 2D orthogonal variable spreading factor codes for orthogonal frequency and code division multiplexing systems
Author :
Puri, P. ; Singh, Navab
Author_Institution :
Dept. of Electron. & Commun. Eng., Jaypee Inst. of Inf. Technol., Noida, India
Volume :
7
Issue :
5
fYear :
2013
fDate :
March 26 2013
Firstpage :
463
Lastpage :
470
Abstract :
Future 4G systems require transmission of richer multimedia services which inevitably implies an increase in data rate. Orthogonal frequency and code division multiplexing (OFCDM) technique has shown promising results in achieving a high data rate while simultaneously combating multipath fading. OFCDM is an amalgamation of orthogonal frequency division multiplexing and two-dimensional (2D) spreading. 2D spreading helps to achieve diversity gains in both time and frequency domains. The present OFCDM systems employ 1D orthogonal variable spreading factor (OVSF) codes to achieve the required 2D spreading in code multiplexed channels. However, 2D OVSF codes have better correlation properties in comparison to 1D OVSF codes. Motivated by this principle, the authors propose a spreading scheme for OFCDM systems using 2D OVSF codes. The spreading scheme is designed to increase the system throughput and reduce multi-code interference. Here, the authors study the OFCDM system performance using the proposed spreading scheme in a multipath fast fading channel with varying spreading factors in both time and frequency domains. The results are compared with the existing OFCDM systems using 1D OVSF codes.
Keywords :
4G mobile communication; OFDM modulation; channel coding; fading channels; interference suppression; multipath channels; orthogonal codes; time-frequency analysis; 1D OVSF codes; 1D orthogonal variable spreading factor codes; 2D OVSF codes; 4G systems; OFCDM technique; code multiplexed channels; frequency domains; multicode interference reduction; multimedia services; multipath fast fading channel; orthogonal frequency and code division multiplexing systems; time domains; two-dimensional orthogonal variable spreading factor codes; two-dimensional spreading scheme;
fLanguage :
English
Journal_Title :
Communications, IET
Publisher :
iet
ISSN :
1751-8628
Type :
jour
DOI :
10.1049/iet-com.2012.0197
Filename :
6526695
Link To Document :
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