Author
Stefan Parkvall
Other affiliations: Royal Institute of Technology, University of California, San Diego, Wilmington University
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 published on a yearly basis
Papers
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01 Jan 2015
TL;DR: This chapter provides a brief overview of WCDMA release 99 to serve as a background to subsequent chapters, and HSPA and the HSPA enhancements that are described in subsequent chapters can be seen in context.
Abstract: This chapter provides a brief overview of WCDMA release 99 to serve as a background to subsequent chapters. WCDMA is a versatile and highly flexible radio interface that can be configured to meet the requirements from a large number of services, but the focus for the description is the functionality commonly used to support packet-data transmissions. The goal of this description is to provide sufficient background to the underlying release 99 WCDMA specifications such that HSPA and the HSPA enhancements that are described in subsequent chapters can be seen in context.
01 Jan 2015
TL;DR: In this article, the authors reviewed some of the basics of spread spectrum techniques and building blocks that are required for a successful communications link and developed a baseband transmitter model, together with a short overview of receiver equalization strategies.
Abstract: HSPA is built upon release 99 Wideband CDMA, which is a technology based on the concept of spread spectrum transmission. The spread spectrum technique emerged out of military research as a basis for communications that aim to flexibly multiplex multiple users and services and to provide robustness against external interference. This chapter reviews some of the basics of spread spectrum techniques and building blocks that are required for a successful communications link and develops a baseband transmitter model. Impacts of multipath radio propagation effects on spread spectrum signals are examined, together with a short overview of receiver equalization strategies.
Patent•
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18 Jun 2019
TL;DR: In this article, the authors discuss UE(102A) and UE(101B) UE( 102A), 102B, and 102B UE(100B) respectively.
Abstract: 하나 이상의 신규한 심볼 구조, 제어 시그널링 및 무선 신호 전송/수신을 위한 스케줄링을 선택하고 사용하는 기술이 제안된다. 일례의 방법은, 슬롯에 대응하는 제어 정보에 기반해서, 네트워크 노드(106)와 통신하는 UE(102A) 또는 다른 UE(102B)가 슬롯에서 UE(102A) 또는 다른 UE(102B)에 의해서 수신된 다운링크 신호에 대해서 슬롯에서 ACK 또는 NACK 피드백을 전송하는 것을 결정(302)하는 것을 제안한다. 추가적으로, 예시적인 방법은, 다운링크 신호가 완전히 수신된 후 및 ACK 또는 NACK 피드백의 전송이 시작하기 전에, 네트워크 노드(106)에 중간 업링크 신호를 전송(304)하거나 또는 네트워크 노드(106)로부터 중간 다운링크 신호를 수신하는 것을 포함한다. UE 및 네트워크 노드와 같은 일례의 장치 및 컴퓨터 프로그램/코드가 제안된다.
Patent•
18 Jun 2019
TL;DR: For example, the authors reported that 1.5% of the users in the survey reported that they were concerned with the following: 1.1% and 2.2% of users reported negative experiences.
Abstract: 기지국과 같은 네트워크 노드는 제1리소스 참조 스킴을 사용하여 전체 대역폭 내의 무선 리소스들을 식별하고, 반면 무선 통신 장치는 제2리소스 참조 스킴을 사용하여 상기 전체 대역폭의 할당된 부분 내의 무선 리소스들을 식별한다. 장점적으로, 상기 장치는 2개의 스킴을 관련시키는 맵핑 정보에 따라 제2리소스 참조 스킴으로 리소스 식별자를 트랜슬레이팅함으로써, 제1리소스 참조 스킴에 따라 표현된 리소스 식별자에 의해 지시된 주어진 무선 리소스들을 정확하게 식별한다. 대응적으로, 상기 네트워크 노드는 상기 무선 통신 장치가 암시적으로 또는 명시적으로 상기 맵핑 정보를 제공함으로써 그와 같은 트랜슬레이션을 수행할 수 있게 한다.
Patent•
17 Jan 2020
TL;DR: In this article, the use of sequences of demodulation reference signals (DMRS), which are numbered relative to the complete system bandwidth, while enabling the wireless communication device to determine DRMS sequence elements converted into their dispatched bandwidth in the system bandwidth.
Abstract: FIELD: communication equipment.SUBSTANCE: invention relates to communication. Methods and equipment disclosed herein provide the use of sequences of demodulation reference signals (DMRS), which are numbered relative to the complete system bandwidth, while enabling the wireless communication device to determine DRMS sequence elements converted into their dispatched bandwidth in the system bandwidth. Advantageously, wireless communication devices need not necessarily know the system bandwidth or even have information on where their dispatched bandwidths are constantly placed in the system bandwidth.EFFECT: disclosed methods and equipment for transmitting service signals and determining reference signal offsets.20 cl, 9 dwg
Cited by
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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
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
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 1991TL;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