A Study Of Cpc Technology In Wcdma System

In recent years, with the rapid development of WCDMA technology, especially the high-speed downlink packet access (HSDPA) and the High Speed Uplink Packet Access (HSUPA) technology, wireless IP-based IMS business network development has become maturity. Increasingly popular IM communication services to communication services has been simplified into a "client-server" structure, will simplify the communication services to the extreme.HSDPA and HSUPA light the expectations of the user's packet switching (PS) persistent connections, under this situation the user needs to maintain the connection state, occasionally sending and receiving packets of data, but it demands a high requirement on the delay. There has also been the base station and terminal battery power capacity issues. In order to solve this problem, 3GPP proposed continuous packet connectivity (CPC) technology in Release 7. CPC technology allows users to maintain always online, to avoid the frequent wireless link connecting, disconnecting, re-establishing and inherent the cost and delay of the system.The first chapter, it introduces the research background and significance, which understands the WCDMA system through internal and external business development and the development needs of IMS, and explains the importance of CPC technology. In the second chapter, it describes WCDMA physical layer technology associated with the CPC: channel, synchronization and power control. The third and fourth chapters analyze and describe the characteristics of each sub-CPC algorithm theory and implementation, and analyze the physical layer synchronization, power control and compressed mode's changes because of the impact of the introduction of CPC technology. Finally, I analysis the CPC and technology for system-level performance and simulation, and verify the uplink discontinuous transmission (UL DTX) function in a real environment.Studies show that the CPC technology increases the use of cell capacity through reducing the uplink interference and saving channelization code, and increases talk time through the lower terminal power consumption.