Title :
Code Tree Extension and Performance Improvement in OVSF-CDMA Systems
Author :
Saini, Davinder S. ; Bhooshan, Sunil V.
Author_Institution :
Dept. of Electron. & Commun. Eng., Jaypee Univ. of Inf. Technol., Waknaghat
Abstract :
UTRA-FDD systems use orthogonal variable spreading factor (OVSF) codes for channel separation in uplink and downlink. The OVSF codes are the limited resources in the downlink. The limited codes as well as code blocking property of OVSF codes gives lower system throughput. In this paper the OVSF code tree is extended such that the capacity of the tree becomes four times. Also the modified system uses single rake combiner providing no additional complexity increase in the user equipments (UEs). Simulation results are demonstrated to show the reduction in new call blocking probability using the OVSF code tree extension
Keywords :
channel coding; code division multiple access; diversity reception; orthogonal codes; probability; radio links; radio receivers; tree data structures; OVSF-CDMA systems; UTRA-FDD systems; call blocking probability; channel separation; code blocking property; code division multiple access; code tree extension; orthogonal variable spreading factor codes; rake combiner; receiver; Artificial intelligence; Bandwidth; Binary trees; Downlink; Information technology; Multiaccess communication; Proposals; Scattering; Telecommunication standards; Throughput; OVSF codes; WCDMA; code (channel) placement and replacement; code blocking; spreading factor (SF);
Conference_Titel :
Signal Processing, Communications and Networking, 2007. ICSCN '07. International Conference on
Conference_Location :
Chennai
Print_ISBN :
1-4244-0997-7
Electronic_ISBN :
1-4244-0997-7
DOI :
10.1109/ICSCN.2007.350755
