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Signaltointerferencebased Power CONTROL FOR WIRELESS NETWORKS: A SURVEY, 1992–2005
"... This paper summarizes and explains the main results on signaltointerference (SIR) based power control algorithms, which are used to increase network capacity, extend battery life, and improve quality of service in cellular wireless radio systems. The classic works of Aein, Meyerhoff, and Nettlet ..."
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This paper summarizes and explains the main results on signaltointerference (SIR) based power control algorithms, which are used to increase network capacity, extend battery life, and improve quality of service in cellular wireless radio systems. The classic works of Aein, Meyerhoff, and Nettleton and Alavi attracted considerable attention in the nineties. The modern approach to the power balancing control problem in wireless networks, formulated by Zander in 1992, matured in the papers of Foschini and Yates and their coworkers in the latter part of the nineties. However, the field is still wide open for research as is indicated by the increasing number of papers published in the area each year. The most recent approaches to solving the mobile power distribution problem in wireless networks use Kalman filters, dynamic estimators, and noncooperative Nash game theory.
Probability of false power control command in CDMA systems subject to measurement errors
 IEEE Communications Letters
"... Abstract — In this letter we introduce a new performance measurement, the probability of false power control command (PFC), to evaluate the impact of measurement errors on the closedloop power control in code division multiple access systems. We derive a closedform expression for PFC. As compared ..."
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Abstract — In this letter we introduce a new performance measurement, the probability of false power control command (PFC), to evaluate the impact of measurement errors on the closedloop power control in code division multiple access systems. We derive a closedform expression for PFC. As compared to the variablestepsized power control, we find that the fixedstepsized CLPC scheme, thanks to its nonlinear operation in the up/down control scheme, is less sensitive to the measurement error. Index Terms — CDMA, power control, false power control command. I.
Power control for cellular communications with channel uncertainties,” in
 Proc. Am. Control Conf., St.
, 2009
"... ABSTRACT Power control in a codedivision multiple access (CDMA) based cellular network is a challenging problem because the communication channels change rapidly because of multipath fading. These rapid fluctuations cause detrimental effects on the control efforts required to regulate the signalt ..."
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ABSTRACT Power control in a codedivision multiple access (CDMA) based cellular network is a challenging problem because the communication channels change rapidly because of multipath fading. These rapid fluctuations cause detrimental effects on the control efforts required to regulate the signaltointerference plus noise ratios (SINRs) to the desired level. Thus, there is a need for powercontrol algorithms that can adapt to rapid changes in the channel gain caused by multipath fading. Much of the previous work has either neglected the effects of fast fading, assumed that the fading is known, or assumed that all the link gains are known. In this paper, we model the effects of fast fading and develop practical strategies for robust power control based on SINR measurements in the presence of the fading. We develop a controller for the reverse link of a CDMA cellular system, and use a Lyapunovbased analysis to prove that the SINR error is globally uniformly ultimately bounded. We also utilize a linear prediction filter that utilizes local SINR measurements and estimates of the Doppler frequency that can be derived from local SINR measurements to improve the estimate of the channel fading used in the controller. The powercontrol algorithm is simulated for a cellular network with multiple cells, and the results indicate that the controller regulates the SINRs of all the mobile terminals (MTs) with low outage probability. In addition, a pulsecodemodulation technique is applied to allow the control command to be quantized for feedback to the transmitter. Simulation results indicate that the outage probabilities of all the MTs are still within the acceptable range if at least 3bit quantization is employed. Comparisons to a standard algorithm illustrate the improved performance of the predictive controller.
DSCDMA Cellular Systems Performance with Base Station Assignment, Power Control Error, and Beamforming over Multipath Fading
"... The interference reduction capability of antenna arrays, base station assignment and the power control algorithms have been considered separately as means to increase the capacity in wireless communication networks. In this paper, we propose base station assignment method based on minimizing the tra ..."
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The interference reduction capability of antenna arrays, base station assignment and the power control algorithms have been considered separately as means to increase the capacity in wireless communication networks. In this paper, we propose base station assignment method based on minimizing the transmitter power (BSAMTP) technique in a direct sequencecode division multiple access (DSCDMA) receiver in the presence of frequencyselective Rayleigh fading and power control error (PCE). This receiver consists of constrained least mean squared (CLMS) algorithm, matched filter (MF), and maximal ratio combining (MRC) in three stages. Also, we present switchedbeam (SB) technique in the first stage of the RAKE receiver for enhancing signal to interference plus noise ratio (SINR) in DSCDMA cellular systems. The simulation results indicate that BSAMTP technique can significantly improve the network bit error rate (BER) in comparison with the conventional case. Finally, we discuss on three parameters of the PCE, number of resolvable paths, and channel propagation conditions (pathloss exponent and shadowing) and their effects on capacity of the system via some computer simulations.
DESIGN OF EMBEDDED FILTERS FOR INNERLOOP POWER CONTROL IN WIRELESS CDMA COMMUNICATION SYSTEMS
"... ABSTRACT We study innerloop power control for mobile wireless communication systems using code division multiple access transmission. We focus on the uplink, i.e., on communication from the mobileto the basestation, and show how to minimise the variance of the signaltointerference ratio (SIR) ..."
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ABSTRACT We study innerloop power control for mobile wireless communication systems using code division multiple access transmission. We focus on the uplink, i.e., on communication from the mobileto the basestation, and show how to minimise the variance of the signaltointerference ratio (SIR) tracking error through incorporation of recursive filters. These filters complement existing power controllers and are designed by using a linear model which takes into account quantisation of the power control signal, dynamics of channel gains, interference from other users, target SIR, and SIR estimation errors. Simulation results indicate that significant performance gains can be obtained, even in situations where the models used for design are only an approximation.
SINR Prediction in Mobile CDMA Systems by Linear and Nonlinear Artificial NeuralNetworkBased Predictors
"... This article describes linear and nonlinear Artificial Neural Network(ANN)based predictors as Autoregressive Moving Average models with Auxiliary input (ARMAX) process for Signal to Interference plus Noise Ratio (SINR) prediction in ..."
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This article describes linear and nonlinear Artificial Neural Network(ANN)based predictors as Autoregressive Moving Average models with Auxiliary input (ARMAX) process for Signal to Interference plus Noise Ratio (SINR) prediction in
Steffensen iterations for power updates in CDMA wireless networks ∗
"... Abstract — In this paper we present a new algorithm for mobile power updates in wireless CDMA systems. The algorithm in fact represents accelerated Jacobi iterations for mobile power updates of the algorithm popularly known as the DPC (distributed power control) algorithm. The new algorithm, with mo ..."
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Abstract — In this paper we present a new algorithm for mobile power updates in wireless CDMA systems. The algorithm in fact represents accelerated Jacobi iterations for mobile power updates of the algorithm popularly known as the DPC (distributed power control) algorithm. The new algorithm, with more rapid convergence, is obtained using Steffensen fixedpoint iterations initialized by two Jacobi iterations. With minor extensions the Steffensen iteration algorithms presented can be used to accelerate the constrained version of the DPC algorithm. We present simulation results using realistic data to illustrate the improved convergence of the new algorithm as compared with the DPC and the secondorder power control (SOPC). I.
Reverse Link Performance of DSCDMA Cellular Systems through ClosedLoop Power Control and Beamforming in 2D Urban Environment
"... The interference reduction capability of antenna arrays and the power control algorithms have been considered separately as means to decrease the interference in wireless communication networks. In this paper, we propose smart step closedloop power control (SSPC) algorithm in direct sequencecode d ..."
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The interference reduction capability of antenna arrays and the power control algorithms have been considered separately as means to decrease the interference in wireless communication networks. In this paper, we propose smart step closedloop power control (SSPC) algorithm in direct sequencecode division multiple access (DSCDMA) receivers in a 2D urban environment. This RAKE receiver consists of conjugate gradient adaptive beamforming (CGBF) and matched filter (MF) in two stages and finally, the output signals from the MFs are combined and then are fed into the decision circuit for the desired user. Also, we present switchedbeam (SB) technique for enhancing signal to interference plus noise ratio (SINR) in network. Also, we study an analytical approach for the evaluation of the impact of power control error (PCE) on DSCDMA systems in a 2D urban environment. The simulation results indicate that the convergence speed of the SSPC algorithm is faster than other algorithms. Also, we observe that significant saving in total transmit power (TTP) are possible with our proposed algorithm. Finally, we discuss two parameters of the PCE and pathloss exponent and their effects on capacity of the system via some computer. KEYWORDS Closedloop power control, conjugate gradient adaptive beamforming, DSCDMA, power control error, matched filter 1.