J. Blom and F. Gunnarsson, Power Control in Cellular Radio Systems, Ph.D. thesis, Linkoepings Universitet, EE, Linkoeping, Sweden, 1998.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....hence improving the overall performance. Although there exists a large body of work for voice traffic where SIR requirements for satisfactory service are fixed and well established, power control for wireless data networks has only recently been a topic of interest [1] 2] 3] 4] 5] 6] [7]. Since the SIR requirements for a desired level of service vary from one individual user to another in wireless networks, the power control problem becomes also one of resource allocation. Recent studies [1] 4] 5] make use of concepts and tools from the field of economics, such as pricing and ....

....BS determines the total received power level through measurements, and sends it to the mobile. Measurement, processing (both at BS and mobile) and signaling of this information takes time, which results in non negligible delays in the network, which can go up to 0. 5 seconds in GSM systems (see [7], p.28) Here we model such delays as a single fixed feedback delay. Since propagation delays are negligible for cellular wireless networks, all mobiles in a cell experience almost the same amount of feedback delay. In other words, delays are symmetric within a cell. Hence, the power update ....

J. Blom and F. Gunnarsson, Power Control in Cellular Radio Systems, Ph.D. thesis, Linkoepings Universitet, EE, Linkoeping, Sweden, 1998.

....schemes are also considered in [9 11] however the treatment there does not take into account the coupling between users. This paper analyzes the reverse link of a CDMA system with this up down power control algorithm in the presence of fading. Power control with nonlinearity was study in [12] using root locus techniques and describing functions. Stability and convergence properties of a similar up down power control loop was studied in [13] and [14] Both works consider nonfading environments. In this paper, we will consider a fading environment. We focus primarily on shadow fading ....

J. Blom and F. Gunnarsson, Power Control in Cellular Radio Systems, Thesis No. 706, Department of Electrical Engineering, Linkopings Universitet, Linkopin, Sweden, 1998.

....schemes are also considered in [9 11] however the treatment there does not take into account the coupling between users. This paper analyzes the reverse link of a CDMA system with this up down power control algorithm in the presence of fading. Power control with nonlinearity was study in [12] using root locus techniques and describing functions. Stability and convergence properties of a similar up down power control loop was studied in [13] and [14] Both works consider nonfading environments. In this paper, we will consider a fading environment. We focus primarily on shadow fading ....

J. Blom and F. Gunnarsson, Power Control in Cellular Radio Systems, Thesis No. 706, Department of Electrical Engineering, Linkopings Universitet, Linkopin, Sweden, 1998.

....The main issue in this work is methods to assign appropriate transmission powers to the users in cellular radio systems with the intention of maximizing the capacity, while providing su#cient transmission quality to the users. Distributed power control algorithms have previously been studied in [1, 2, 3, 4], and the references therein. These algorithms perform well in rather ideal cases, but in real systems there are a number of e#ects that hamper the performance. Measuring and control signaling takes time, which result in time delays in the system. # This work was supported by the graduate ....

....on specific channels a#ect the output power. The signals needed for control may not be available and have to be estimated. Quality is a subjective measure, and relevant objective measures have to be employed. The first two items are addressed here, while the latter two are discussed in [1, 5] and the references therein. Thorough analysis of the overall systems is only plausible in very simple cases. Considering the stated aspects we discuss the applicability of analysis and design in the distributed local loops. As a generic case, this is applicable to various related control ....

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J. Blom and F. Gunnarsson. Power Control in Cellular Radio Systems. Licenciate Thesis, Linkopings universitet, Sweden, June 1998. Available at http://www.control.isy.liu.se.

....is desirable to use distributed algorithms, where the transmitter powers are locally controlled based on local mea # This work was supported by the graduate school ECSEL and the Swedish National Board for Industrial and Technical Development (NUTEK) surements or estimates. For an overview, see [2, 3] and the references therein. Most algorithms are relying on accurate C I estimates, and popular methods for estimation with good performance are described in [4, 5] In those approaches, however, it is assumed that analog signal strength measurements are available, which is not the case in a real ....

....X( x t ;#) f min . Finally, the parameters may be changing at di#erent rates. The carrier and the mean interference are typically fast varying, while, the standard deviation of the interference is varying more slowly. This is solved by post filtering the estimates using exponential filtering [2, 12]. with di#erent forgetting factors k # k (t 1) 1 k) # ML k (t 1) k # k( t) Thus, we propose the following estimation algorithm: Algorithm: ML Estimation Let the measurements at time t, be given by the vector x t , with the corresponding probability function fX (x t ; #) M # ....

J. Blom and F. Gunnarsson. Power Control in Cellular Radio Systems. Licenciate Thesis, Linkopings universitet, Sweden, June 1998. Available at http://www.control.isy.liu.se.

....and multi path fading with spatial correlation. For details on how these factors are modeled, we refer PSfrag replacements Power Gain [dB] Traveled Distance g p g s g m Fig. 5. The model for radio wave propagation comprises path loss (g p ) shadow fading (g s ) and multi path fading (g m ) to [11 13] 4.2 Interference The interference can be modeled as a stochastic variable depending on a number of parameters I = I(m I ; oe 1 ; oe n ) where m I is the mean of the interference As an example, we take frequency hopping GSM, where the characteristics of the interference distribution ....

....as in Figure 2, the objective of the PCA is to track the reference signal obtained from the outer loop. Therefore, a PI controller may be sufficient. With this structure, most of previous work regarding power control can be adopted and thereby applied to realistic cases. However, it was shown in [11] that most of the work to date are special cases of or related to p i (t 1) p i (t) fi(fl ref (t) Gamma fl i (t) 3) which is a integrating controller. For instance, the Distributed Power Control (DPC) 4,3] algorithm is obtained when fi = 1 and fl tgt (t) is constant. In addition, it ....

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J. Blom and F. Gunnarsson. Power Control in Cellular Radio Systems. Licenciate Thesis, Linkopings universitet, June 1998. Available at http://www.control.isy.liu.se.

....slightly shifted towards issues related to power control in such networks. In Chapter 3, we therefore bring up a few in our opinion important aspects of power control. In addition, the algorithms implemented in MOSE are described and discussed briefly. For a more thorough discussion, we refer to [1]. The simulation environment should be fairly intuitive and user friendly. However, some examples are given in Chapter 4 in order to illuminate some basic features. Finally some motivations of the implementation are given in Appendix A, and in Appendix B a somewhat complete reference to the ....

....For example, it is common to assume that the transmission quality is only dependent on the SIR and that this value is at hand. On the other hand when discussing a complete solution that fits into interfaces of real systems, we use the term Power Regulator (PR) For further details, we refer to [1]. In MOSE, the focus is on the behavior and dynamics of power control algorithms. Issues related to quality, are assumed to be dealt with in outer loops, which aim to update the reference values to the inner loops. Consequently, SIR is a relevant quality measure, and the objective can be ....

[Article contains additional citation context not shown here]

J. Blom and F. Gunnarsson. Power Control in Cellular Radio Systems. Licenciate Thesis, Linkopings universitet, Sweden, June 1998. Available at http://www.control.isy.liu.se.

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J. Blom and F. Gunnarsson, Power Control in Cellular Radio Systems, Ph.D. thesis, Linkoepings Universitet, EE, Linkoeping, Sweden, 1998.

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J. Blom, F. Gunnarsson, Power control in cellular radio systems, Ph.D. thesis, Linkoepings Universitet, EE, Linkoeping, Sweden (1998).

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J. Blom and F. Gunnarsson, Power Control in Cellular Radio Systems, Ph.D. thesis, Linkoepings Universitet, EE, Linkoeping, Sweden, 1998.

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Blom J. and Gunnarsson F., Power Control in Cellular Radio Systems, Licenciate Thesis, Linkoping University, 1998.

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J. Blom and F. Gunnarsson. Power Control in Cellular Radio Systems. Licenciate thesis, Division of Automatic Control, Linkpings Universitet, 1998.

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