Title :
A novel joint strength and SIR based CDMA reverse link power control with variable target SIR
Author :
Zhang, D. ; Zhang, Q.T. ; Ko, C.C.
Author_Institution :
Dept. of Electr. Eng., Nat. Univ. of Singapore, Singapore
Abstract :
The use of power control to achieve the desired signal-to-interference ratio (SIR) is a crucial issue to ensure the quality of service of a code division multiple access (CDMA) cellular system. Power control based on SIR alone, however, often leads to the problem of vicious circle such that all mobile stations reach their power limits and yet, fail to achieve the desired SIR. In this paper, we present a novel power control scheme, which can significantly reduce the possibility of a vicious circle. The new scheme Is based on two observations. First, control of the target function SIR must take the signal power into account so as to avoid the problem of trivial optimization. Second, for a given channel operational environment, it is unnecessary and also impossible to pursue an unreasonably high SIR using brute force. The basic philosophy behind the new technique is therefore to define an acceptable SIR region over the entire SIR axis instead and use an adaptive technique for two purposes. Namely, adaptively adjust both the target SIR and the step size to approach it according to the changing channel characteristics. The new scheme is essentially a Markov system with adaptive control
Keywords :
Markov processes; adaptive control; cellular radio; code division multiple access; power control; quality of service; radiofrequency interference; telecommunication control; CDMA reverse link power control; Markov system; SIR; adaptive control; adaptive technique; cellular system; channel operational environment; code division multiple access; mobile stations; power limits; quality of service; signal power; signal-to-interference ratio; step size; variable target SIR; Adaptive control; Base stations; Electric variables control; Fading; Interference; Land mobile radio; Multiaccess communication; Power control; Quality of service; Time division multiple access;
Conference_Titel :
Communications, 2000. ICC 2000. 2000 IEEE International Conference on
Conference_Location :
New Orleans, LA
Print_ISBN :
0-7803-6283-7
DOI :
10.1109/ICC.2000.853747