CPN Modeling And Analysis Of Adaptive Radio Resource Management In OFDMA System

Wireless communication system appeared one hundred years ago. Now it has become an important part in people’s daily life and scientific research field. In the latest generation of wireless communication system of4G, OFDMA(Orthogonal Frequency Division Multiple Access) which received widespread attention is a very important technology. Researches show that, OFDMA technology can effectively improve the access rate of wireless communication system. OFDMA system can reduces narrowband interference and symbols interference caused by multipath spread effectively. RRM(Radio Resource Management) can improve capacity and control power in wireless communication network system. To achieve the higher data transfer rate and spectrum efficiency, RRM technology is the only way to make the use of radio resource effectively in OFDMA system.In recent years, to build the actual operation model and analysis the performance of a real system, simulation has become a kind of effective measures. CPN(Colored Petri Nets) modeling technology is widely used in modeling and performance analysis of different kinds of large complicated system. There are a lot of advantages of CPN modeling technology. It has high visuality and operation speed. The system model is convenient to modify too. At present, the study of CPN modeling on the RRM of the adaptive OFDMA system is mainly aimed at admission control part. The research has been verified that CPN model is isomorphic with the Markov model in state space. CPN have prominent advantages to overcome many existing problems (state space explosion, etc.) of SPN(Stochastic Petri Net). However, this model only considered the target to maximize’the capacity of the system. And it is lack of researching on the power control and distribution of the system.This paper firstly use CPN to build a adaptive RRM model of the OFDMA system, this model is based on the target of minimizing the total emission power of the whole system. It models the call admission control and resource distribution parts of the OFDMA system. In this system model, the target to minimize the total power of the system (MA optimization algorithm) is achieved by the ML programming language. This CPN model uses the hierarchical modeling method. Each part of the system is established of subnet.Then, a joint optimization adaptive RRM model of the OFDMA system is build in this paper. In this model, business sources are divided into two parts:FTP and voice business. Two parts business sources get their own different optimization criterion in this system This joint optimization model is based on both the targets of minimizing the total emission power of the whole system for the voice business and maximizing the capacity of the system for the FTP business. This model realizes the diversion of business process to optimize the performance of the OFDMA system.Finally, this paper use the simulation tools Monitor of CPN tools to simulate and analysis the performance of the model. A few of monitors are set to extract and keep data in the process of operation of the system in the simulation. By this way, the date can be get and prove the performance of the system, such as the average queue length, blocking probability, the total power and throughput of the system. The performances of the two system models build in this paper are compared with each other. Then they are compared with performances of the other system model build before.