Title :
A Novel Non-blocking Extended OVSF Codes in WCDMA
Author :
Wang, Yih-Fuh ; Lin, Tun-Ying
Author_Institution :
Dept. of Inf. Manage., Leader Univ., Tainan
Abstract :
Orthogonal variable spreading factor (OVSF) codes are employed in the third generation (3G) wideband code division multiple access (WCDMA) wireless system as channelization codes. Any two codes OVSF of different levels are orthogonal if and only if one of two codes is not ancestor/descendant in each other. Therefore, when an OVSF code is assigned to a user, it blocks all of its ancestor and descendant codes. This results in a major drawback of OVSF codes, called blocking property: When an OVSF code is assigned, it blocks all of its ancestor and descendant codes from assignment because they are not orthogonal to each other. This paper presents a new extended orthogonal variable spreading factor (EOVSF) codes to support a quite large number code candidates for more people used in multi-rate next-generation wireless system. Thereby, no EOVSF code blocks the assignment of any other EOVSF code. It decreases more reject probability in WCDMA system
Keywords :
3G mobile communication; block codes; channel coding; code division multiple access; 3G wideband code division multiple access wireless system; EOVSF codes; WCDMA; blocking property; channelization codes; extended orthogonal variable spreading factor codes; multirate next-generation wireless system; nonblocking extended OVSF codes; 3G mobile communication; Communication networks; Frequency diversity; Interference; Multiaccess communication; Quality of service; Receiving antennas; Spread spectrum communication; Streaming media; Wideband;
Conference_Titel :
Information and Communication Technologies, 2006. ICTTA '06. 2nd
Conference_Location :
Damascus
Print_ISBN :
0-7803-9521-2
DOI :
10.1109/ICTTA.2006.1684772
