WCDMA蜂窩系統(tǒng)的軟切換性能分析.pdf

1、Mobile cellular communication has enjoyed a tremendous growth of users and becomesmore and more important in today’s communication. Handoff is the functionality tomaintain a call progress when a Mobile Station across cel

2、l boundaries in mobilecommunication. Therefore，in order to provide a multitude of services in 3G，especially inmultimedia and high-bit-rate packet data，ETSI(European Telecommunications StandardsInstitute) adopted Wideband

3、 Code Division Multiple Access(WCDMA) as themainstream air interface solution for third-generation networks. In a cellular system usermobility results in handoff calls. Thus，to use limited radio resources to accommodate

4、anincreasing demand of services，one approach is to deploy smaller size cells for morefrequency reuse a consequence of which is more frequent handoffs. To be blocked at thebeginning of connection is better than to be drop

5、ped during the connection from a user’spoint of view. As a result，handoff calls should be given higher priority than new calls byreserving some resources exclusively for handoff calls. WCDMA is an asynchronousoperation c

6、oncept which means that the base stations should not be synchronized to eachother. In handoff area，to adjust the transmission timing for new Base Station(BS) iscomplex because in WCDMA the signals transmitted from differ

7、ent BSs need to arrive atthe device at the same time and some unnecessary handoff calls(pseudo handoff) occupymultiple channels with little contribution to the performance of handoffs. Some techniqueshave been introduced

8、 to cope with these problems.
　　 This thesis proposed a new scheme that can discriminate and eliminate those pseudohandoff calls from real handoff calls. The result shows that this scheme can significantlydecrease th