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In this paper, we consider capacities of single-antenna terminals communicating to large antenna arrays that are deployed on surfaces. That is, the entire surface is used as an intelligent receiving antenna array. Under the condition that the surface area is sufficiently large, the received signal after matched-filtering (MF) can be well approximated by an intersymbol interference (ISI) channel wh
Non-Orthogonal Multiple Access (NOMA) for a multi-user single- input single-output (SISO) setup is studied in the power and the frequency domains simultaneously. The problem of sum-bandwidth minimization under perfect channel state information is solved for various combinations of rate requirements and user pairings. In this process, an iterative Tabu-search based algorithm is applied to avoid an
Non-Orthogonal Multiple Access (NOMA) is studied under statistical Channel State Information (CSI) and probabilistic constraints. Unlike the conventional power domain only NOMA, the definition of NOMA here considers both the power and the frequency domains simultaneously, where a flat power spectrum is assumed for each UE. This increases the capacity region when compared to the conventional definiti
For a pair of closely located and cooperating user equipments (UEs), a precoder is designed at the base station (BS) which considers the UE cooperation. The UEs collaborate over an out-of-band side-link with a finite capacity. The side-link may be used for interference cancellation (IC) or for relaying decoded symbols. The precoder has two parts, a cooperative part based on channel inversion and a
We use Markov state models (MSMs) to analyze the dynamics of a β-hairpin-forming peptide in Monte Carlo (MC) simulations with interacting protein crowders, for two different types of crowder proteins [bovine pancreatic trypsin inhibitor (BPTI) and GB1]. In these systems, at the temperature used, the peptide can be folded or unfolded and bound or unbound to crowder molecules. Four or five major fre
Downlink beamforming in Massive MIMO either relies on uplink pilot measurements--exploiting reciprocity and time-division duplexing (TDD) operation, or on the use of a predetermined grid of beams with user equipments reporting their preferred beams, mostly in frequency-division duplexing (FDD) operation. Massive MIMO in its originally conceived form uses the first strategy, with uplink pilots, whe
Vehicle-to-vehicle (V2V) wireless communications can improve traffic safety at road intersections and enable congestion avoidance. However, detailed knowledge about the wireless propagation channel is needed for the development and realistic assessment of V2V communication systems. We present a novel geometry-based stochastic MIMO channel model with support for frequencies in the band of 5.2-6.2 G
A channel sounder is an advanced measurement system to estimate the behavior of wireless propagation channels. In this paper, we present the antenna array design for a 28GHz massive multiple-input multiple-output system, capable of measuring 256×128 dual-polarized channels, including dynamic properties of angular, delay, Doppler, and polarization parameters, respectively. Unique in comparison to o
I detta kapitel i boken Geografisk information Behandling beskrivs och behandlas metoder för hur geografisk data analyseras. Kapitlet omfattar såväl geografisk teori som exempel på tillämpningar. Geografisk informationsbehandling baseras på insamling, lagring, analys och visualisering av geografiska data. Denna indelning utgör också grunden för bokens disposition. Boken är i första hand avsedd för
Large intelligent surface (LIS) is a new technology yet to be developed. However, this technology is likely to be implemented using cheap components so as to facilitate its deployment. Therefore, we can expect a performance degradation due to hardware impairments. In this paper, we present a model for these hardware impairments in a receiving LIS and we analyze their effect on the achievable rate
Multiple-input multiple-output (MIMO) over-the-air (OTA) testing is a standardized procedure to evaluate the performance of MIMO-capable devices such as mobile phones and laptops. With the growth of the vehicle-to-everything (V2X) service, the need for vehicular communication testing is expected to increase significantly. The so-called multi-probe anechoic chamber (MPAC) setup is standardized for
In this paper, we perform a threshold analysis of braided convolutional codes on the additive white Gaussian noise (AWGN) channel. The decoding thresholds are estimated by Monte-Carlo density evolution techniques and compared with approximate thresholds from an erasure channel prediction. The results show that, with spatial coupling, the predicted thresholds are very accurate and quickly approach
In multiuser multiple–input multiple–output (MU–MIMO) systems, channel correlation is detrimental to system performance. We demonstrate that widely used, yet overly simplified, correlation models that generate identical correlation profiles for each terminal tend to severely underestimate the system performance. In sharp contrast, more physically motivated models that capture variations in the pow
Spatially distributed transmission points connected to the same source, known as distributed antenna systems, can improve system performance compared to single-link traditional systems. However, the anticipated gain depends heavily on the cross-correlation properties of the large-scale parameters (LSPs) of the different links. Usually, measured LSPs—except the large-scale fading
The Theory of Characteristic Modes (TCM) has recently been shown to be beneficial in solving a wide variety of complex electromagnetic problems. However, there are still open issues in using TCM to analyze objects which consist of simple or complex media. Either a volume integral equation (VIE) or a surface integral equation (SIE) is required to solve for the characteristic modes of these objects.
The 15 and 28 GHz frequency bands have been identified as interesting candidates for future 5G cellular communication systems. In this paper, based on ray-tracing simulations, we investigate the channel capacities at 15 and 28 GHz for a number of different array processing techniques, including beamforming, spatial multiplexing, and two types of hybrid beamforming. This is done for an 8x32 multipl
The non line-of-sight (NLOS) scenario in urban intersections is critical in terms of traffic safety—a scenario where Vehicle-to-Vehicle (V2V) communication really can make a difference by enabling communication and detection of vehicles around building corners. A few NLOS V2V channel models exist in the literature but they all have some form of limitation, and therefore further research is need. I
BackgroundPower output and force development during exercise are thought to be important indices of performance in elite athletes. The aim of this preliminary study was to determine the forces applied at the footrest during ergometric kayaking in individual kayakers at different competitive levels.MethodsThree elite female kayakers participated voluntarily in the study. Oxygen consumption (VO2) an
Connected autonomous vehicles and industry 4.0 productions scenarios require ultra-reliable low-latency communication links. The varying positions of transmitter, reflecting objects and receiver cause a non-stationary time- and frequency-selective fading process. In this paper, we present the necessary hardware architecture and signal processing algorithms for a real-time geometry-based channel em
