Research The Key Point Technology In Physical Layer Of TD-SCDMA System

With the development of communication,The enormous impact of 3G technology as the core of modern technology have penetrated into all fields of living. Design of physical layer in TD-SCDMA system, has become a basic direction of development in the New Period. Stimulation technology and information research environment will bring opportunities to reform of the TD-SCDMA;they also put new demands on designing of TD-SCDMA.This paper introduce smart antenna pattern function firstly,and to study how to apply this method in antenna array pattern synthesis,combined with smart antenna Beam Forming, DOA(Directions Of Arrival) application example,and for the TD-SCDMA smart antenna system specific mode of application, ant colony algorithm was first proposed on the beam pattern formation function parameters and variables generated by the array direction of arrival direction of vector solution optimized, MATLAB simulation results show that the ant colony algorithm for antenna arrays integrated on a wide range of applications.Secondly, proposed a spatial filtering model in TD-SCDMA,filter model to simulate the antenna mode TD-SCDMA, in the simulation design algorithm using the least mean square (LMS) point to recursive least squares algorithm (RLS) mutual Diego generation of adaptive computing principles,given spatial filtering results.MATLAB simulation results show that this combined algorithm has good stability and robustness.Though using the theory design in fact engineering have advantages to improve the TD-SCDMA system and find a new way to realize commerce in TD-SCDMA system, and have more contributions to the development of TD-SCDMA industry.Again, according to the standard ITU-U2000 using MATLAB simulated TD-SCDMA physical layer, MATLAB running results verify the integrity of the system. Finally, it summarize the purpose and method of power control,proposed based on combination of strength SIR power control algorithm, using MATLAB to simulation of the power control method. Experimental results show that the algorithm has overcome the traditional algorithm to generate positive feedback, on the fast-moving production to control the fast fading effect are not ideal,and other shortcomings.Adaptive power control algorithm which can fast fading channel characteristics,the dynamic adjustment step, to achieve better control performance.