Abstract:
Wideband code division multiple access (W-CDMA) system is adopted as the 3rd
generation radio interface technology by 3rd generation partnership project (3GPP) [1].
In W-CDMA system, the orthogonal variable spreading factor (OVSF) code is the
channelization code used for multiple accesses in the same slot as well as in the same
cell. One of the most important characteristics of W-CDMA is the service flexibility,
which can be supported by using OVSF codes for the channelization codes of the
different users. In this paper, we propose hardware structure of W-CDMA frequency
division duplex (FDD) and time division duplex (TDD) dual mode OVSF code
generator using single code indexing method introduced in [2] with multi stage
spreading scheme. The proposed algorithm has the advantages on memory size (reduce
98 %) and processing time (max. 32 %) compare to existing method.