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Incorporating a multi-year grass ley into an arable crop rotation can increase soil organic carbon stocks, reduce carbon emissions and provide feedstock for biogas. This thesis set out to study how a policy promoting agricultural biomass for biogas impacts GHG emissions and carbon sequestration on a regional level over a temporal scale of 20 years. This was done in the specific case of policy prom
The aim of this study was to investigate a possible relationship between depression and memory performance, hypothesizing a decrease in performance among participants with depression tendencies. The cognitive memory task of pattern separation was tested with four different levels of difficulty by use of a computerized memory test and the self-rating MADRS-S depression scale was used to assess the
With increasing number of wirelessly connected devices having limited energy resources, energy efficient solutions become more and more important. Many studies have addressed schemes where low-power wake-up receivers are used to improve energy efficiency in networks with low traffic intensity (per node) and demands on availability. One such scheme is the duty-cycled wake-up receiver medium access
In this paper, full-and sub-structure characteristic modes (CMs) are explored through the effect of coupling between the target and background structures. The eigenvalues and eigen-current distributions of the first few modes are compared for different coupling levels in the numerical example. Similarities and differences between the two types of CMs in specific conditions are revealed, paving the
This paper presents a broadside antenna with three ports operating at the same frequency. The TM030 and TM003 modes of a patch are excited by two coaxial cables to generate two orthogonal linear polarizations. The patch can be transformed into a slotted SIW cavity whose TE201 and TE102 modes are jointly excited by the third cable. A matching cavity and a matching patch are introduced to broaden th
We present recent results on spatially coupled turbolike codes and point out a connection to the self-concatenatedtrellis construction proposed by Loeliger in 1997 [1].
This paper proposes a pragmatic methodology to characterize mutual coupling in uniform linear arrays (ULAs). The classical coupling model used in the literature of multiple input multiple output (MIMO) antenna arrays is based on impedance parameters, resulting valid only for electromagnetically small antennas, e.g. short dipole. To test the robustness and accuracy of the proposed coupling model we
Massive multiple-input multiple-output (MIMO) has gained a tremendous amount of attention as a key enabler of fifth-generation cellular systems. The majority of the vast literature on massive MIMO is based on fully digital processing, where each antenna element in the massive array is equipped with an up/down-conversion chain. Unlike previous works, we present a suite of greedy algorithms using pu
Favorable propagation (FP) and channel hardening (CH) are desired properties in massive multiple-input multiple-output (MIMO) systems. To date, these properties have primarily been analyzed for classical statistical channel models, or ray-based models with very specific angular parameters and distributions. This paper presents a thorough mathematical analysis of the asymptotic system behavior for
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
Multiple-input multiple-out (MIMO) is a mature technology in modern wireless communications. However, it is challenging to implement multi-antennas for MIMO operation in compact mobile terminals, due to high mutual coupling and correlation among closely spaced antenna elements. Moreover, a conventional terminal chassis only offers one resonant mode below 1 GHz, complicating multi-antenna design. R
It is known that the fundamental radiation mode of a mobile terminal chassis enables wideband coverage below 1 GHz. However, in theory, the bandwidth of this chassis mode extends infinitely beyond 1 GHz. In this paper, we investigate the use of inductive coupling element (ICE) to significantly increase the antenna bandwidth obtainable from the fundamental mode. Using characteristic mode analysis,
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
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
The blood flow in rat liver was measured with Xe-133. Three techniques for administering the activity to the liver were employed: injection via the portal vein, via the hepatic artery, and directly into the liver parenchyma. Use of intraparenchymal injection of Xe-133 gave 60% higher flow values than by portal or arterial injection techniques. Mean flow index (k1) was for portal injection 0.52, fo
We present and analyze a new approach to improve energy efficiency in cellular IoT devices. The new approach consists of employment of ultra low power wake-up receivers in combination with robust non-coherent modulation. The results show that we can achieve very competitive power consumption, reducing it by up to 50 times, compared to two conventional power saving solutions we use as references. T
Massive MIMO is a promising technology to connect very large numbers of energy constrained nodes, as it offers both extensive spatial multiplexing and large array gain. A challenge resides in partitioning the many nodes in groups that can communicate simultaneously such that the mutual interference is minimized. We here propose node partitioning strategies that do not require full channel state in
We examine the favorable propagation (FP) behavior of a massive multi-user multiple-input-multiple-output (MU-MIMO) system equipped with a uniform linear array (ULA), horizontal uniform rectangular array (HURA) or uniform circular array (UCA) using a ray-based channel model with user cluster sharing. We demonstrate FP for these systems and provide analytical expressions for the mean-squared distan
Efficient mitigation of power amplifier (PA) nonlinear distortion in multi-user hybrid precoding based broadband mmWave systems is an open research problem. In this article, we carry out detailed signal and distortion modeling in broadband multi-user hybrid MIMO systems, with a bank of nonlinear PAs in each subarray, while also take the inevitable crosstalk between the antenna/PA branches into acc
