TD-CDMA Uplink And Downlink TFCS Selection Algorithm Research

With the fast development of wireless media service, the characteristic of anisomerous traffic between uplink and downlink becomes more and more obvious. TD-CDMA system can allocate flexible uplink and downlink timeslot with the need of uplink and downlink traffic, so it is suitable for the multimedial service, and is widely used in microcell which has larger anisomerous uplink and downlink traffic, but in low speed environment, so this system can used to solve the"hot spot"problem in telecom. In order to achieve the biggest capacity of one cell, it is very important to adjust user's transmitting power and data rate with the change of user's wireless environment, and the above problem is the research content of this paper.TD-CDMA Controls UE transferring data rate via selecting different TFCS, then achieves different QoS, but 3GPP don't describe anything about TFCS selection algorithm, only specify the interface and parameter of TFCS. This paper introduces an uplink and downlink TFCS selection algorithm in TD-CDMA system, gives the relative test data, validate the algorithm's feasibility and analyzes the algorithm's performance.In TD-CDMA system, different transferring rate service requires different SIR. The uplink TFCS selection algorithm is based on UE's measure information, calculates the UE's achieved SIR via monitoring UE's wireless environment, system configuration, interference and so on, then select relevant TFCS according with the system TFCS selection threshold. The downlink TFCS selection algorithm has close relationship with downlink power control, the algorithm designs 8 different TFCS according with different SIR requirement's of different data rate traffic, firstly monitors UE's pathless, interference and SIR, then calculates one connection's remnant transmitting power, compares whether the remnant transmitting power is in the presented range and considers the real time BLER, then the TFCS selection can be made. The uplink and downlink TFCS selection algorithm has lots of parameters which can be configured with different wireless environment. In order to make the transferring data rate change more smoothly, this paper begins the elementary research and exploration about the uplink and downlink TFCS design and parameters configuration.This paper also designs one lab uplink and downlink TFCS selection algorithm validated test system, the system considers the simulation of the real environment commendably, and uses the relevant equipment and method to simulate the UE's different location, different pathless and different interference, so make the test system close to the real test wireless environment. The system finishes the task very well, and completes the data collection, analyze and management. The test result proves the uplink and downlink TFCS selection algorithm has good feasibility, validity and performance. So the algorithms described in the paper have good referenced value for the TD-CDMA system RRM module design.