Research On Rate Assignment Of The CDMA Forward Link And Its Implementation On Grid Environment

In this paper, we abstract a theoretical model according to the characteristics of data transmission, and study a hierarchical SIR and rate assignment algorithm. The algorithm can be used in the large scale of data transmission on the forward link. The Qos for data users is specified by delay and error rate constraints as well as utility functions which represent the throughput and fairness among data users. The algorithm is implemented using the hierarchical control structure of large scale systems. Mobiles independently adjust the SIR targets according to the users specific local information, and the base station adjust the data rates jointly for all the data users based on limited feedback information from the mobiles.The simulation results show the contrasts of the single-user system throughput and the multi-users system throughput. It proves that the time division dispatching can maximally increase the availability ratio of band width, but it will spent more time on establishing and destroying links, which may cause some more delay. On the opposite, the code division dispatching saves the time for establishing and destroying links, but has a lower availability ratio of band width.The algorithm has been applied to the rate assigning subsystem of NOPGrid (Grid of Mobile Telecommunications Network Optimizing). The tasks parallelization and hierarchical control are implemented using the parallel programming interface and the workflow engine, which are provided by the grid platform.