The goal of Third Generation (3G) mobile communication systems is to provide users not only with the traditional circuit switched services, but also with high speed Internet access, video conferencing and multimedia applications. Universal Mobile Telecommunication System is the 3G mobile communication system specified by European Telecommunications Standards Institute. Wideband CDMA is the physical layer of UMTS Terrestrial Access Network. WCDMA employs direct-sequence code division multiple access Technology. The main limitation of this technology is multiple access interference. MAI is thus a major factor, which limits the capacity and the performance of a DSCDMA system. The conventional detector is a bank of correlators and it follows a single-user detection strategy The drawbacks of the single-user detector are that it is interference-limited and it also suffers from the near-far problem. A better detection strategy is Multi-User Detection. MUD reduces the MAI effect by jointly using information of multiple users to better detect each user. This increases the system performance as well as system capacity. Multi-user detection techniques are essential for achieving near optimal performance in communication systems. Therefore, the addition of multi-user detection capabilities to various network elements promises to be the key for enabling significant increase in capacity needed for 3G mobile systems.
I . OBJECTIVE :
The objective of the paper is to study the effects of subtractive interference cancellation detectors namely the SIC and PIC Detectors on the performance of WCDMA uplink transmi- ssion. We have implemented the WCDMA uplink end-to-end physical layer in MATLAB and compared the performance of multi-user detection with single-user detection. Factors such as the number of simultaneous users and channel estimation are taken into consideration, for three main UMTS channels namely: Indoor ChannelA, Pedestrian Channel A and Vehicular Outdoor Channel A.
II. HELPFUL HINTS :