Cdma System Reverse Link Power Control Technology

As the core technology of the third generation mobile communication system, CDMA has good privacy performance and anti-interference ability. Power control is one of the important key technologies of CDMA system and has become the focus of theoretical research in mobile communication. In order to increase the quality of communication system, the reverse link power control of CDMA system is deeply investigated in this paper.For the randomness and variability of mobile communication system, a power control algorithm based on improved MMSE prediction is proposed. With the combination of MMSE channel prediction algorithm and variable step power control algorithm, the adaptive MMSE-ASPC power control algorithm is achieved and the computational complexity of this algorithm is effectively decreased by the introduction of steepest descent method. The OPNET simulation results show that the algorithm has good performances in the SINR error rate,channel gain and mean square errors and so on, and can dynamically adjust power control step size according to real-time prediction in order to compensate the channel fading in time.For the rationality and fairness of the allocation of system resources, a power control algorithm based on game theory under imperfect interference cancellation is proposed. The algorithm transforms power control strategy into the problem of finding the user's largest profit in the game theory. Based on the traditional revenue function, a new dynamic cost function with a cost factor defined by channel gain and signal interference ratio is designed to adjust the user's transmitting power adaptively, and the existence and unique of Nash Equilibrium is also proved in this paper. Simulation results show that compared with other classical power control algorithms, our algorithm can significantly improve system performance, which can meet the needs of the user's high profit with lower transmitting power.