中文摘要：

在TD-SCDMA系统中采用接力切换方式，越区切换频繁发生，如果切换算法不合理或者不完善，很有可能导致用户掉话，影响通话的过程。为此提出一项改进的切换算法，除了信号强度外，还充分考虑了UE的移动情况，根据UE的运动方向和移动速度选择目标小区，从而避免了不必要的切换；在小区内根据切换当前的信号强度，给用户分配优先级，按照优先级的高低分配信道的使用权，从而降低切换的阻塞率，总体上更高效地完成了整个切换过程。通过用建立MATLAB仿真模型对语音业务进行算法仿真，验证了改进后算法的优越性。

英文摘要：

Handoff occurs frequently in the TD-SCDMA system because of using the relay switching mode. If the switching algorithm is unreasonable or not perfect, the system may probably cause to dropping calls, and to affecting the process of communications. In this paper, an improved handover algo- rithm is proposed. Unnecessary switching can be avoided by the novel algorithm, which gives not only full consideration to the moving of User Equipment （ UE）, but also the choice of target cell for UE＇ s moving direction and speed, besides the signal strength. In the area of signal strength of current switching, the novel algorithm assigns a priority for the user, and distributes channel based on priority level in order to reduce the handoff blocking rate and complete the switching process efficiently. The improved algorithm is verified to be more superior by the MATLAB simulation of voice services.