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Geijer Lundin, Erik
Publications (10 of 22) Show all publications
Geijer Lundin, E., Gunnarsson, F. & Gustafsson, F. (2005). Robust Uplink Resource Allocation in CDMA Cellular Radio Systems. In: Proceedings of the 44th IEEE Conference on Decision and Control and European Control Conference 2005. Paper presented at 44th IEEE Conference on Decision and Control and European Control Conference 2005, Seville, Spain, December, 2005 (pp. 1848-1853).
Open this publication in new window or tab >>Robust Uplink Resource Allocation in CDMA Cellular Radio Systems
2005 (English)In: Proceedings of the 44th IEEE Conference on Decision and Control and European Control Conference 2005, 2005, p. 1848-1853Conference paper, Published paper (Refereed)
Abstract [en]

Radio resource management (RRM) in cellular radio system is an example of automatic control. The system performance may be increased by introducing decentralization, shorter delays and increased adaptation to local demands. However, it is hard to guarantee system stability without being, too conservative while using decentralized resource management. In this paper, two algorithms that both guarantee system stability and use local resource control are proposed for the uplink (mobile to base station). While one of the algorithms uses only local decisions, the other uses a central node to coordinate resources among different local nodes. In the chosen design approach, a feasible solution to the optimization problems corresponds to a stable system. Therefore, the algorithms will never assign resources that lead to an unstable system. Simulations indicate that the proposed algorithms also provide high capacity at any given uplink load level.

Keywords
Optimization, Communication, Robust
National Category
Engineering and Technology Control Engineering
Identifiers
urn:nbn:se:liu:diva-74549 (URN)10.1109/CDC.2005.1582429 (DOI)000240653701140 ()0-7803-9567-0 (ISBN)
Conference
44th IEEE Conference on Decision and Control and European Control Conference 2005, Seville, Spain, December, 2005
Available from: 2012-02-01 Created: 2012-02-01 Last updated: 2013-02-26
Geijer Lundin, E., Gunnarsson, F. & Gustafsson, F. (2005). Robust Uplink Resource Allocation in CDMA Cellular Radio Systems. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Robust Uplink Resource Allocation in CDMA Cellular Radio Systems
2005 (English)Report (Other academic)
Abstract [en]

Radio resource management (RRM) in cellular radio system is an example of automatic control. The system performance may be increased by introducing decentralization, shorter delays and increased adaptation to local demands. However, it is hard to guarantee system stability without being, too conservative while using decentralized resource management. In this paper, two algorithms that both guarantee system stability and use local resource control are proposed for the uplink (mobile to base station). While one of the algorithms uses only local decisions, the other uses a central node to coordinate resources among different local nodes. In the chosen design approach, a feasible solution to the optimization problems corresponds to a stable system. Therefore, the algorithms will never assign resources that lead to an unstable system. Simulations indicate that the proposed algorithms also provide high capacity at any given uplink load level.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2005. p. 16
Series
LiTH-ISY-R, ISSN 1400-3902 ; 2703
Keywords
Optimization, Communication, Robust
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-56040 (URN)LiTH-ISY-R-2703 (ISRN)
Available from: 2010-04-30 Created: 2010-04-30 Last updated: 2014-06-23
Gunnarsson, F., Geijer Lundin, E. & Gustafsson, F. (2005). Uplink Load and Link Budget with Stochastic Noise Rise Levels in CDMA Cellular Systems. In: Proceedings of Radiovetenskap och Kommunikation 2005. Paper presented at Radiovetenskap och Kommunikation, Linköping, Sweden, June, 2005 (pp. 491).
Open this publication in new window or tab >>Uplink Load and Link Budget with Stochastic Noise Rise Levels in CDMA Cellular Systems
2005 (English)In: Proceedings of Radiovetenskap och Kommunikation 2005, 2005, p. 491-Conference paper, Published paper (Other academic)
Abstract [en]

The limiting factor in the uplink of all CDMA cellular systems is the relation between uplink noise rise and intended coverage. In link budgets, noise rise is usually simply handled as a constant contribution to the background noise in logarithmic scale, often referred to as interference margin. In practice, however, it is not constant. We model the uplink noise rise as a lognormal distribution, and investigate the impact to link budgets. Simulations and numerical calculations show that the uplink noise rise variance does not critically affect the uplink capacity and coverage. System feasibility and its relation to the uplink load is also discussed. It is shown that approximative load expressions provides an upper bound on the uplink load and therefore they can be used to imply system feasibility. Furthermore, the uplink load expressions provide accurate approximations of the load given that the load is within the practical limits given by the link budgets.

Keywords
Link budget, Noise rise variance, Maximum noise rise, System load
National Category
Engineering and Technology Control Engineering
Identifiers
urn:nbn:se:liu:diva-29719 (URN)15113 (Local ID)15113 (Archive number)15113 (OAI)
Conference
Radiovetenskap och Kommunikation, Linköping, Sweden, June, 2005
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2013-04-08
Geijer Lundin, E. (2005). Uplink Load in CDMA Cellular Radio Systems. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Uplink Load in CDMA Cellular Radio Systems
2005 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

The uplink of code division multiple access (CDMA) cellular radio systems is often interference limited. The interference originates from many users whose transmission powers are not observable for the system. This thesis introduces uplink load and applies means of explicitly considering the users’ radio environment when approximating and controlling the load.

A desirable property of all cellular radio systems is uplink feasibility, i.e., existence of finite user transmission powers to support the allocated services. Uplink load can be considered as a measure of how far from infeasibility the system is. The performed characterization of uplink load lead to two concrete definitions related to the amount of received and transmitted power, respectively.

An important part of the total load is the intercell load which is caused by users connected to neighboring base stations. If not carefully handled, the intercell load can jeopardize uplink feasibility. Conversely, knowledge of a lower intercell load can be used to increase the resource assignments. A common denominator in all the work in this thesis is that the intercell load is explicitly considered.

When approximating uplink load, a centralized approach is adopted to study information gathered in several base stations. This yields good approximations of the average load. However, centralized approximations can not detect momentarily peaks in the load. A number of resource allocation algorithms making control decisions in the local base stations are proposed based on experience from characterizing uplink load. As the algorithms study the intercell load, yet without measuring the interference power, they are robust in the sense that they will never assign resources yielding an infeasible system.

A straightforward way of controlling the uplink load is to use measurements of the received interference power. This approach, just as the proposed load approximations, can gain from knowing the background noise power. The same framework used for designing robust resource allocation algorithms, is also used for estimating the background noise power.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2005. p. 168
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 977
Keywords
CDMA, Uplink Load, Radio Resource Management, Automatic Control, Cellular Radio
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-16299 (URN)91-85457-49-3 (ISBN)
Public defence
2005-11-25, Visionen, Hus B, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2009-05-15Bibliographically approved
Geijer Lundin, E. & Gunnarsson, F. (2004). Characterizing Uplink Load: Concepts and Algorithms. In: Mohsen Guizani (Ed.), Wireless Communications Systems and Networks: (pp. 425-441). Springer US
Open this publication in new window or tab >>Characterizing Uplink Load: Concepts and Algorithms
2004 (English)In: Wireless Communications Systems and Networks / [ed] Mohsen Guizani, Springer US , 2004, p. 425-441Chapter in book (Refereed)
Abstract [en]

The maximum capacity of a CDMA cellular system’s radio interface depends on the time varying radio environment. This makes it hard to establish the amount of currently available capacity. The received interference power is the primarily resource in the uplink. Ability to predict how different resource management decisions affect this spatial quantity is therefore of utmost importance. The uplink interference power is related to the uplink load through the pole equation. In this chapter, we discuss both theoretical and practical aspects of uplink load estimation.

Place, publisher, year, edition, pages
Springer US, 2004
Series
Information Technology: Transmission, Processing and Storage
Keywords
Uplink load, Pole capacity, Soft capacity, Hard capacity
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-56321 (URN)10.1007/0-306-48642-3_14 (DOI)0-306-48190-1 (ISBN)0-306-48642-3 (ISBN)
Available from: 2010-05-07 Created: 2010-05-07 Last updated: 2013-12-16Bibliographically approved
Gustafsson, F., Gunnarsson, F., Geijer Lundin, E. & Törnqvist, D. (2004). Transmission Timing - A Control Approach to Distributed Uplink Scheduling in WCDMA. In: Proceedings of Reglermöte 2004. Paper presented at Reglermöte 2004, Göteborg, Sweden, May, 2004.
Open this publication in new window or tab >>Transmission Timing - A Control Approach to Distributed Uplink Scheduling in WCDMA
2004 (English)In: Proceedings of Reglermöte 2004, 2004Conference paper, Published paper (Other academic)
Abstract [en]

Centralized control and coordination of the connections in a wireless network is not possible in practice. To keep the delay from measure-ment instants to actuating the decisions, distributed control is required. This paper focuses on the uplink (from mobiles to base stations) and dis-cusses distributing the decision of when and when not to transmit data (distributed scheduling) to the mobiles. The scheme, uplink transmission timing, utilizes mobile transmitter power control feedback from the base station receiver to determine whether the channel is favorable or not compared to the average channel condition. Thereby, the battery consumption and disturbing power to other connections are reduced. The algorithm can be described as a feedback control system. Some transient behaviors are analyzed using systems theory, and supported by wireless network simulations of a system with a WCDMA (Wideband Code Division Multiple Access) radio interface as in most 3G systems.

Keywords
UMTS, Power control, Distributed systems
National Category
Engineering and Technology Control Engineering
Identifiers
urn:nbn:se:liu:diva-90354 (URN)
Conference
Reglermöte 2004, Göteborg, Sweden, May, 2004
Available from: 2013-03-25 Created: 2013-03-24 Last updated: 2013-03-25
Törnqvist, D., Geijer Lundin, E., Gunnarsson, F. & Gustafsson, F. (2004). Transmission Timing - A Control Approach to Distributed Uplink Scheduling in WCDMA. In: Proceedings of the 2004 American Control Conference. Paper presented at 2004 American Control Conference, Boston, MA, USA, June-July, 2004 (pp. 1667-1672 vol.2).
Open this publication in new window or tab >>Transmission Timing - A Control Approach to Distributed Uplink Scheduling in WCDMA
2004 (English)In: Proceedings of the 2004 American Control Conference, 2004, p. 1667-1672 vol.2Conference paper, Published paper (Refereed)
Abstract [en]

Centralized control and coordination of the connections in a wireless network is not possible in practice. To keep the delay from measurement instants to actuating the decisions, distributed control is required. This paper focuses on the uplink (from mobiles to base stations) and discusses distributing the decision of when and when not to transmit data (distributed scheduling) to the mobiles. The scheme, uplink transmission timing, utilizes mobile transmitter power control feedback from the base station receiver to determine whether the channel is favorable or not compared to the average channel condition. Thereby, the battery consumption and disturbing power to other connections are reduced. The algorithm can be described as a feedback control system. Some transient behaviors are analyzed using systems theory, and supported by wireless network simulations of a system with a WCDMA (Wideband Code Division Multiple Access) radio interface as in most 3G systems.

Keywords
UMTS, Power Control, Distributed systems
National Category
Engineering and Technology Control Engineering
Identifiers
urn:nbn:se:liu:diva-24059 (URN)3618 (Local ID)0-7803-8335-4 (ISBN)3618 (Archive number)3618 (OAI)
Conference
2004 American Control Conference, Boston, MA, USA, June-July, 2004
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2013-03-26
Törnqvist, D., Geijer Lundin, E., Gunnarsson, F. & Gustafsson, F. (2004). Transmission Timing - A Control Approach to Distributed Uplink Scheduling in WCDMA. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Transmission Timing - A Control Approach to Distributed Uplink Scheduling in WCDMA
2004 (English)Report (Other academic)
Abstract [en]

Centralized control and coordination of the connections in a wireless network is not possible in practice. To keep the delay from measure-ment instants to actuating the decisions, distributed control is required. This paper focuses on the uplink (from mobiles to base stations) and dis-cusses distributing the decision of when and when not to transmit data (distributed scheduling) to the mobiles. The scheme, uplink transmission timing, utilizes mobile transmitter power control feedback from the base station receiver to determine whether the channel is favorable or not compared to the average channel condition. Thereby, the battery consumption and disturbing power to other connections are reduced. The algorithm can be described as a feedback control system. Some transient behaviors are analyzed using systems theory, and supported by wireless network simulations of a system with a WCDMA (Wideband Code Division Multiple Access) radio interface as in most 3G systems.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2004. p. 8
Series
LiTH-ISY-R, ISSN 1400-3902 ; 2610
Keywords
UMTS, Power control, Distributed systems
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-56004 (URN)LiTH-ISY-R-2610 (ISRN)
Available from: 2010-04-30 Created: 2010-04-30 Last updated: 2018-07-03Bibliographically approved
Gustafsson, F., Geijer Lundin, E. & Gunnarsson, F. (2004). Uplink Load and Link Budget with Stochastic Noise Rise Levels in CDMA Cellular Systems. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Uplink Load and Link Budget with Stochastic Noise Rise Levels in CDMA Cellular Systems
2004 (English)Report (Other academic)
Abstract [en]

The limiting factor in the uplink of all CDMA cellular systems is the relation between uplink noise rise and intended coverage. In link budgets, noise rise is usually simply handled as a constant contribution to the background noise in logarithmic scale, often referred to as interference margin. In practice, however, it is not constant. We model the uplink noise rise as a lognormal distribution, and investigate the impact to link budgets. Simulations and numerical calculations show that the uplink noise rise variance does not critically affect the uplink capacity and coverage. System feasibility and its relation to the uplink load is also discussed. It is shown that approximative load expressions provides an upper bound on the uplink load and therefore they can be used to imply system feasibility. Furthermore, the uplink load expressions provide accurate approximations of the load given that the load is within the practical limits given by the link budgets.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2004. p. 8
Series
LiTH-ISY-R, ISSN 1400-3902 ; 2609
Keywords
Link budget, Noise rise variance, Maximum noise rise, System load
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-55988 (URN)LiTH-ISY-R-2609 (ISRN)
Available from: 2010-04-30 Created: 2010-04-30 Last updated: 2014-08-13Bibliographically approved
Geijer Lundin, E., Gunnarsson, F. & Gustafsson, F. (2003). Adaptive Filtering Applied to an Uplink Load Estimate in WCDMA. In: Proceedings of the 57th IEEE Semiannual Vehicular Technology Conference. Paper presented at 57th IEEE Semiannual Vehicular Technology Conference, Cheju, South Korea, April, 2003 (pp. 452-456). , 1
Open this publication in new window or tab >>Adaptive Filtering Applied to an Uplink Load Estimate in WCDMA
2003 (English)In: Proceedings of the 57th IEEE Semiannual Vehicular Technology Conference, 2003, Vol. 1, p. 452-456Conference paper, Published paper (Refereed)
Abstract [en]

In the uplink of a WCDMA system, a natural choice of resource quantity is the uplink noise rise, i.e., total received power over noise power. Unfortunately this quantity is hard to measure and estimates are often noisy. This paper focuses on relative load which is closely related to the noise rise. Model-based signal processing with change detection techniques is herein used to suppress noise and minor oscillations while being alert on fast load changes. The time varying model identified in the process can also be used for prediction of future values, something which resource management algorithms can benefit from.

Keywords
Adaptive filters, Power systems modeling, Signal processing, Broadband networks
National Category
Engineering and Technology Control Engineering
Identifiers
urn:nbn:se:liu:diva-74553 (URN)10.1109/VETECS.2003.1207581 (DOI)0-7803-7757-5 (ISBN)
Conference
57th IEEE Semiannual Vehicular Technology Conference, Cheju, South Korea, April, 2003
Available from: 2012-02-01 Created: 2012-02-01 Last updated: 2013-04-10
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