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.

Method and devices for providing feedback in a communication system

Abstract: The disclosure relates to a method 20 of providing feedback performed in a receiving device 8. The receiving device 8 is capable of wireless communication with a transmitting device 12, 5. The method 20 comprises: receiving 21, from the transmitting device 12, 5, an encoded message block 10, the message block 10 comprising a number N of sub-blocks, S 1 ,..., S N ; decoding 22 the received N sub-blocks, S 1 ,..., S N ; detecting 23 at least one and less than N sub-blocks being erroneously decoded; and providing 24 feedback information to the transmitting node 5, the feedback information indicating the at least one and less than N sub-blocks detected as erroneously decoded sub-blocks. The disclosure also relates to corresponding method in a transmitting device, to receiving device, transmitting device, computer programs and computer program products.

가변 처리 시간들을 갖는 노드들에 대한 harq 핸들링

Abstract: 전송기에서 이용하기 위한 방법은 하나 이상의 코드 블록 그룹(CBG)으로 배열된 복수의 코드 블록(CB)을 포함하는 전송 블록(TB)을 포함하는 전송을 보내는 단계를 포함한다. 각각의 코드 블록 그룹은 하나 이상의 코드 블록을 포함하고, 각각의 코드 블록은 복수의 코딩된 비트를 포함한다. 전송은 전송 블록마다 다중 비트 HARQ 피드백을 이용하도록 구성된 수신기에게 보내진다. 이 방법은 전송 블록의 하나 이상의 코드 블록 그룹 중 하나 이상에 대한 HARQ ACK 또는 NACK 피드백을 수신기로부터 수신하는 단계를 더 포함한다. 이 방법은 적어도 수신된 HARQ ACK 또는 NACK 피드백에 기반하여 재전송에서 수신기에게 보낼 코드 블록들 또는 코드 블록 그룹들의 수를 결정하는 단계를 더 포함한다.

Complexity reduction of linear interference canceling scheme

Abstract: A system, method and apparatus for demodulating a received signal using a configurable receiver. The receiver performs the demodulation of a signal according to a selected interference cancellation demodulation scheme. The same receiver can be configured, by setting certain parameters, to behave as a successive interference cancellation (SIC) scheme receiver, a parallel interference cancellation (PIC) scheme receiver, or a hybrid interference cancellation (HIC) scheme receiver. In another aspect of the present invention, the receiver performs its demodulation operation using a single interference cancellation unit (ICU). In addition, the ICU's despreading and respreading functions may be performed by the same processing element.

High-speed uplink packet access

Abstract: High-Speed Uplink Packet Access (HSUPA), also known as Enhanced Uplink , was introduced in WCDMA release 6. It provides improvements in WCDMA uplink capabilities and performance in terms of higher data rates, reduced latency, and improved system capacity and is therefore a natural complement to HSDPA. Together, the two are commonly referred to as High-Speed Packet Access (HSPA). This chapter describes in detail release 6 HSUPA since HSUPA is the fundamental uplink building block of the subsequent HSPA evolution. Subsequent chapters then elaborate on the enhancements to the release 6 HSUPA framework that were introduced in later releases.

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. >