The Search Of Dynamic Channel Allocation Algorithm In The Smart Antenna System

With the rapid development of mobile communication technology, the third generation mobile communication system is fully used.TD-SCDMA mobile communication system as China's first international telecommunications standards of independent intellectual property rights attracted extensive attention at home and abroad.The system uses a series of advanced communications technology so that it has a distinct advantage in performance, capacity and manufacturing costs.This paper describes the development of mobile communication and give a detailed overview of the TD-SCDMA system with the use of smart antenna technology and radio resource management which lead to the discussion of the channel spatial reuse (SDMA). In the paper ,we presents the concept ,implementation scheme and working link of SDMA,especially focus on the inprovement of capacity and service blocking probability then achieved SDMA. For the system capacity, we discussed several ways to increase it and derived the SDMA system capacity with multi-angle-multi-path based on the Shannon formula. With both theoretical analysis and simulation ,we find that compared with omnidirectional antenna and cell sectorisation,the use of smart antenna can improve the system capacity obviously.For the service blocking probability, we give two simple channel spatial reuse scheme FD and DL scheme, analysis and simulates the blocking probability by analyzing the state transition process.As the DOA estimation of smart antenna is an important parameter to decide if the channel spatial reuse can be achieved,we also give a brief introduction of smart antenna and DOA estimation.We studied the common DOA algorithm like dely-add,CAPON,MUSIC and ESPRIT,compared them with the use of simulation software. In the final ,we studied the widely used channel allocation model based on the carrier to interference ratio.Compared with FD and DL scheme,we proposed a random scheme of our own.The system capacity and business blocking probability of the random scheme is carried out with a detailed theoretical analysis and simulation. The study and compare we did proved that the scheme we proposed is in reason and can assign the traffic more uniformly. At last, we gave a summary of the entire paper and show the short of it.Then,give an idea of making space dicvision multiplexing by coding the user information at the base station.