The Research on Admission Control Algorithms in TD-SCDMA Trunking Communications System

The paper puts forward an improved admission control algorithm for the TD-SCDMA trunking communications system. According to the technical features of TDD (Time Division Duplex) and one downlink channel shared by multi-users in this system, the improved algorithm predicts the power increment of interference through the group's target SIR (Signal to Interference Ratio) and bandwidth requirement. Then, the system decides that whether the new group be admitted by the increment. The simulation results of dropping rate and admission rate show that the improved algorithm can predict interference increment more accurately, reduces the influence of new call on system, and ensures the coverage of cell.