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Stefan Parkvall

Bio: Stefan Parkvall is an academic researcher from Ericsson. The author has contributed to research in topics: Telecommunications link & Node (networking). The author has an hindex of 58, co-authored 502 publications receiving 19083 citations. Previous affiliations of Stefan Parkvall include Royal Institute of Technology & University of California, San Diego.


Papers
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Patent
Karl Werner1, Stefan Parkvall1, Erik Dahlman1, Baldemair Robert1, Björkegren Håkan1 
17 Nov 2015
TL;DR: In this article, the first and second signals are transmitted in a frequency band, such that the first signal is frequency domain multiplexed in the frequency band and the second signal is aligned with a corresponding symbol interval starting time in the second one at least once per time interval.
Abstract: In one aspect, a wireless transmitter forms (1110) a first signal having a first integer number of symbol intervals in each of one or more time intervals of a predetermined length and forms (1120) a second signal having a second integer number of symbol intervals in each of the one or more time intervals of the predetermined length, the second integer number differing from the first integer number. The wireless transmitter simultaneously transmits(1130) the first and second signals in a frequency band, such that the first and second signals are frequency- domain multiplexed in the frequency band and such that a symbol interval starting time in the first signal is aligned with a corresponding symbol interval starting time in the second signal at least once per time interval.

13 citations

Patent
Gabor Fodor1, Erik Dahlman1, Göran N. Klang1, Stefan Parkvall1, Leif Wilhelmsson1 
18 Sep 2012
TL;DR: In this paper, a method in a first network node (16) for enabling device-to-device (D2D) communication between a first device (10) and a second device (13) is presented.
Abstract: Embodiments herein relate to a method in a first network node (16) for enabling device to device, D2D, communication between a first device (10) and a second device (13). The first device (10) is served by a first public land mobile network comprising the first network node (16) and the second device (13) is served by a second public land mobile network. The first network node (16) receives, from the second device (13), via the second public land mobile network, or from the first device (10), a request for permission for the second device (13) of roaming to the first public land mobile network enabling the D2D communication. The request requests access to a resource controlled by the first network node (16) of the first public land mobile network. The first network node (16) decides whether to grant the request based on a position related information of the second device (13) and/or the first device (10).

12 citations

Patent
23 Aug 2006
TL;DR: In this paper, a collective positioning measurement order (50) is issued to a multitude of mobile terminals (40) in a first cell (10) of the cellular communication system (1).
Abstract: Methods and devices for managing a cellular communication system (1) and mobile terminals (40) are presented. A collective positioning measurement order (50) is issued to a multitude of mobile terminals (40) in a first cell (10) of the cellular communication system (1). This issuing is preferably performed intermittently at a multitude of times according to a predetermined rule. Each mobile terminal (40) receives information concerning a collective positioning measurement order. The mobile terminal (40) performs a positioning operation, typically a positioning measurement on a ranging signal (51 , 52) or transmission of a ranging signal (53). preferably intermittently at a multitude of times, according to a predetermined rule based on the information concerning the collective positioning measurement order. An updating of a storage with positioning data can preferably be obtained. In terrestrially based positioning systems, signal resources dedicated to positioning measurement can be reserved in the cellular communication system.

12 citations

Patent
Stefan Parkvall1
27 Jan 2014
TL;DR: In this paper, a method and arrangement for transmitting and receiving control information in a radio access network is described, where the intermediate node receives and decodes the first control information at the end of the first part.
Abstract: The invention relates to a method and arrangement for transmitting and receiving control information in a radio-access network. A network node transmits first control information in a first part and second control information in a second part of a time-frequency region that is transmitted after a control region in a subframe. The second part is located later in the subframe than the first part. The second control information may be less time-critical than the first control information. An intermediate node receives and decodes the first control information at the end of the first part. When the first control information indicates that the subframe comprises data payload to the intermediate node, the intermediate node receives and decodes the data payload. The intermediate node receives second control information at the end of the second part.

12 citations

Patent
18 Oct 2007
TL;DR: In this paper, the authors proposed a method and an arrangement for reducing power consumption in the user equipments in power saving mode in a communication network, comprising a communication node transmitting information on shared control channels (SCCH) to one or more user equipment.
Abstract: The present invention relates to a method and an arrangement for reducing power consumption in the user equipments in power saving mode in a communication network, comprising a communication network node transmitting information on shared control channels (SCCH) to one or more user equipments. The information is transmitted over either a narrow or a wide bandwidth depending on which mode said one or more user equipments are, either a power saving mode or an active mode.

12 citations


Cited by
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Book
01 Jan 2005

9,038 citations

Journal ArticleDOI
Thomas L. Marzetta1
TL;DR: A cellular base station serves a multiplicity of single-antenna terminals over the same time-frequency interval and a complete multi-cellular analysis yields a number of mathematically exact conclusions and points to a desirable direction towards which cellular wireless could evolve.
Abstract: A cellular base station serves a multiplicity of single-antenna terminals over the same time-frequency interval. Time-division duplex operation combined with reverse-link pilots enables the base station to estimate the reciprocal forward- and reverse-link channels. The conjugate-transpose of the channel estimates are used as a linear precoder and combiner respectively on the forward and reverse links. Propagation, unknown to both terminals and base station, comprises fast fading, log-normal shadow fading, and geometric attenuation. In the limit of an infinite number of antennas a complete multi-cellular analysis, which accounts for inter-cellular interference and the overhead and errors associated with channel-state information, yields a number of mathematically exact conclusions and points to a desirable direction towards which cellular wireless could evolve. In particular the effects of uncorrelated noise and fast fading vanish, throughput and the number of terminals are independent of the size of the cells, spectral efficiency is independent of bandwidth, and the required transmitted energy per bit vanishes. The only remaining impairment is inter-cellular interference caused by re-use of the pilot sequences in other cells (pilot contamination) which does not vanish with unlimited number of antennas.

6,248 citations

Journal ArticleDOI
TL;DR: The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time.
Abstract: Multiple-input multiple-output (MIMO) technology is maturing and is being incorporated into emerging wireless broadband standards like long-term evolution (LTE) [1]. For example, the LTE standard allows for up to eight antenna ports at the base station. Basically, the more antennas the transmitter/receiver is equipped with, and the more degrees of freedom that the propagation channel can provide, the better the performance in terms of data rate or link reliability. More precisely, on a quasi static channel where a code word spans across only one time and frequency coherence interval, the reliability of a point-to-point MIMO link scales according to Prob(link outage) ` SNR-ntnr where nt and nr are the numbers of transmit and receive antennas, respectively, and signal-to-noise ratio is denoted by SNR. On a channel that varies rapidly as a function of time and frequency, and where circumstances permit coding across many channel coherence intervals, the achievable rate scales as min(nt, nr) log(1 + SNR). The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time [2].

5,158 citations

Journal ArticleDOI
TL;DR: The article consists of background material and of the basic problem formulation, and introduces spectral-based algorithmic solutions to the signal parameter estimation problem and contrast these suboptimal solutions to parametric methods.
Abstract: The quintessential goal of sensor array signal processing is the estimation of parameters by fusing temporal and spatial information, captured via sampling a wavefield with a set of judiciously placed antenna sensors. The wavefield is assumed to be generated by a finite number of emitters, and contains information about signal parameters characterizing the emitters. A review of the area of array processing is given. The focus is on parameter estimation methods, and many relevant problems are only briefly mentioned. We emphasize the relatively more recent subspace-based methods in relation to beamforming. The article consists of background material and of the basic problem formulation. Then we introduce spectral-based algorithmic solutions to the signal parameter estimation problem. We contrast these suboptimal solutions to parametric methods. Techniques derived from maximum likelihood principles as well as geometric arguments are covered. Later, a number of more specialized research topics are briefly reviewed. Then, we look at a number of real-world problems for which sensor array processing methods have been applied. We also include an example with real experimental data involving closely spaced emitters and highly correlated signals, as well as a manufacturing application example.

4,410 citations

Proceedings Article
01 Jan 1991
TL;DR: It is concluded that properly augmented and power-controlled multiple-cell CDMA (code division multiple access) promises a quantum increase in current cellular capacity.
Abstract: It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

2,951 citations