Enhanced Capacity Analysis in WCDMA System

The wide-band code division multiple access (WCDMA) based third generation wireless communication systems are designed to meet the increasing demands for high data rate applications and greater mobility. High data rate applications include voice, video telephony, Video streaming, File Transfer protocol (FTP), high quality image and wireless full internet access. WCDMA systems are expected to offer high data rate services upto 2Mbps, but there are many factors like loading of cell, intra and inter cell interference, co-channel interference etc. that limits to access these high data rate services or limits the capacity of WCDMA systems. There are various emerging technologies used to improve the capacity of WCDMA systems like sectorization, voice activity services, antenna array and interference cancellation. The later two techniques are particularly suitable for enhanced uplink performance since the additional complexity they require is concentrated at the base station. Both antenna array and interference cancellation (IC) receivers can be deployed to enhance the cell capacity i.e. number of users in a cell. This paper presents the effect of loading, interference, and voice activity on the capacity of a WCDMA system. The capacity can be enhanced by using antenna array structure of 2, 4 and 8 and by using Interference Cancellation (IC) receivers. The complete effect and capacity enhancement analysis is being done for different data rate applications like voice at 12.2 Kbps, video at 64Kbps, 144Kbps and high data rate multimedia services at 768Kbps with 3.84 Mcps spreading rate at 5MHz bandwidth. 70 Parveen Singla and Jyoti Saxena