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.

LTE-Advanced Pro: Part 3 [Guest Editorial]

Abstract: The mobile Internet that will be enabled by LTE-Advanced Pro and the way in which we interact with it will change significantly within the next few years. From a usage point of view, it is anticipated that by 2020, each person, globally speaking, will consume on average as much as 5 GB of data each month, in addition to the traffic generated by 20-30 billion connected things. More significantly, not only will the mobile network be significantly faster, but even more applications will become possible. The video experience will be improved globally; mobile virtual reality will be available; networked vehicles and perhaps self-driving cars will roam our streets; the Internet of Things will enrich and make our lives more productive; and a mobile cloud will allow access to our data anytime, anywhere.

Method and apapratus for sending control information in a communications network

Abstract: The invention relates to a method of sending control information from a first node to a second node in a communications system providing a plurality of resource units for the transmission of data. The control information is sent by use of a code book comprising at least one code word identifying control information relating to data transmission over a resource unit. The code book is dynamically updated by means of repeatedly transmitting an updated version of code book information from the first node to the second node. The invention also relates to a first communications node comprising means for transmitting control information to a second node. The means for transmitting control information is adapted to transmitting the control information by use of a code book; and to repeatedly transmitting an updated version of code book information in order to achieve that the code book is dynamic.

Data Transmissions in Control Regions

Abstract: According to some embodiments, a method in a wireless device comprises: receiving a control channel (e.g., physical downlink control channel (PDCCH)) that includes control information that indicates a set of time and frequency resources allocated for the wireless device to receive a data transmission; determining that the set of time and frequency resources allocated for data transmission overlaps with a control resource region (e.g., control resource set (CORESET)); and receiving the data transmission in the set of time and frequency resources allocated for data transmission. The control information may include a bitmap that indicates at one or more groups of time and frequency resources excluded/included for the data transmission region.

Interference control between different radio communication systems involving user equipments

Abstract: A first User Equipment (UE), a second UE, a first Radio Network Node (RNN), and methods therein for controlling interference between transmissions in a first system and transmissions in a second system. The first system comprises the first UE and the first RNN serving the first UE. The second system comprises the second UE and a second RNN serving the second UE. The first system has a first priority in a first part of a shared spectrum and the second system has a second priority in the first part of the shared spectrum, wherein the first priority is higher than the second priority. The method in the first UE comprises transmitting a signal to a second RNN that is to perform a downlink transmission to the second UE, which signal is configured to control the transmission of the second RNN.

Noncooperative Cellular Wireless with Unlimited Numbers of Base Station Antennas

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.

Scaling Up MIMO: Opportunities and Challenges with Very Large Arrays

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].

Two decades of array signal processing research: the parametric approach

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.

On the capacity of a cellular CDMA system

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. >