Research And Simulation Based On The SIR In TD-SCDMA Power Control Algorithm

With the development of mobile communications, the third generation mobile communication technology has been come into our life; Among them, td-scdma of the 3G technology is China's independent research and development. This paper mainly studies the td-scdma system's the key techniques: power control. As the code division multiple access (CDMA) system,"Near-far effect"and"Multi-access interference"is a difficult problem to solve of CDMA system. Power control is overcome the solution to the problem, accurate power control can assure communication effectiveness, at the same time, improve the system capacity.This paper firstly introduces td-scdma system power control technology norms and mechanism. Aiming at the existing uplink fixed step-length power control algorithm in depth fast fading channel when couldn't keep up with change, this paper proposes an improved power control algorithm. The new algorithm base on SIR measurement, and carry on the prediction to reflect different channel changes, and compared with target SIR provided outer race, then generate the power control command, by the Markov state corresponding to different power control step-length, choose the right step-length for power adjustment. Compared with the traditional power control algorithm, the improved algorithm better tracking channel changes. And aiming at the fixed step-length power control algorithm, the improved algorithm have more choices to reduce the possibility of misoperation adjustable. In order to verify performance of the algorithm, this paper use the MATLAB to built td-scdma system complete physical link. Finally, using the model on the improved algorithm, and simulation include: the improved algorithm and fixed step length performance of the algorithm to contrast and the improved algorithm on system performance improved analysis. Simulation results show that the improved algorithm is superior to the traditional algorithm on the system's performance improved.