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It is known that the compactness of mobile terminals complicates the design of multiple antennas, since coupling between the antennas increases when they are placed in proximity of one another. While it is possible to mitigate coupling between closely spaced antennas, a tradeoff in bandwidth is required. In this paper, we highlight ground plane excitation as an additional dimension to consider in
A simple and intuitive metric of multiplexing efficiency is proposed for evaluating the performance of MIMO antennas in the spatial multiplexing mode of operation. The metric is particularly useful for antenna engineers whose goal is to achieve the optimum antenna system design. Experimental results involving prototype mobile terminals highlight the effectiveness of our proposal.
Multiplexing efficiency is proposed as a simple and intuitive metric for characterizing multiple antenna systems in the spatial multiplexing mode of operation. Instead of comparing channel capacities of MIMO systems with different antennas, the metric offers valuable insights into the impact of antenna efficiency, efficiency imbalance and correlation on multiplexing performance. It is particularly
Antenna systems are provided including a chassi (115) and first and second radiating (110, 120) elements coupled to the chassi. The first radiating element is configured to amplify excitation of the chassi and the second radiating element is configured to reduce excitation of the chassi so as to reduce mutual coupling in the antenna system. Related co- located antennas and methods of controlling m
Interference between femto-cell systems is a critical factor for the deployment of such systems in, e.g., resedential areas. In this paper we report on a residential channel measurement campaign focusing on the channel properties for femtocell systems. We characterize basic channel properties such as delay spread and interference levels between different furnished residential houses. In addition w
The development of MIMO over-the-air (OTA) test methodology is an ongoing activity in 3GPP RAN4, CTIA and EU COST Action 2100. In this paper, the focus is on the anechoic chamber approach, which uses a uniform circular array of probe antennas to replicate directional channels for the device under test (DUT) at the array center. In particular, we study in simulation the complexity requirements of i
This contribution comprises a comparison of capacity performances of MIMO terminal antenna configurations for smart phones at 2.65 GHz, measured in an extensive 2×2 MIMO measurement campaign in noise- and interference-limited urban environments. Whereas, on average along the route, the performances where dictated by the received power, locally the eigenvalue dispersion of the communication channel
In this paper, we discuss research problems for enabling content distribution and supporting real-time interpersonal communication services (e.g. voice and video) over best effort networks with sufficient quality. We take a practical view of content distribution and quality, and this is the reason for the term “sufficient”. We argue that the understanding of quality as perceived by the user is a k
The limited volume of mobile handset and the phenomenon of chassis excitation complicate the design of multiple antennas for MIMO applications. In this work, a compact co-located dual-antenna system implemented on one edge of a 100 mm by 40 mm chassis is proposed for operation below 1 GHz. The dual-antenna structure includes a folded monopole to excite the fundamental electric dipole mode of the c
In this paper, signal strengths from known WiFi access points are used together with a particle filter to perform indoor navigation. It is shown that more information is obtained by using signals of both 2.4 and 5.0 GHz, compared to using only one frequency. Thus, using both frequencies provides a more accurate positioning. The second contribution is an algorithm where WiFi measurements are combin
Multivariate versions of the Kronecker theorem in the continuous multivariate setting has recently been published, that characterize the generating functions that give rise to finite rank multidimensional Hankel and Toeplitz type operators defined on general domains. In this paper we study how the additional assumption of positive semi-definite affects the characterization of the corresponding gen
Telecommunication monitoring data requires the automation of data analysis workflows. A data mining tool provides data workflow management systems to process and perform analysis tasks. This paper presents an evaluation of two example data mining tools following the principles of design of experiment (DOE) to run forecasting and clustering workflows for telecom monitoring data. We conduct both qua
Recent changes in user employment of Internet based services, new deployment technologies for mobile networks as well as an ongoing realisation of fixed and mobile converged networks e.g. the EU FP7 project COMBO, are significant examples of enablers for increasing demands on DSL links. Investigating cross-layer dependencies between all layers in the OSI reference model becomes increasingly import
With industrial robots ready to take the next step in mastering manufacturing tasks new approaches to reduce the programming effort are needed. This is achieved by introducing skills as robot "know-how" and using them as a higher abstraction level of robot instructions during programming. The skills are reusable items providing motion control and rich declarative descriptions of complex robot capa
We present a rigorous phase noise analysis of a generic harmonic oscillator where the active core can be modeled as a transconductor. Phase noise equations are derived without any specific assumption on the nature of the resonator in the oscillator; furthermore, we provide closed-form 1/f2 phase noise equations when the resonator consists of an arbitrary number of cascaded LC tanks, each tuned at
A background on the Europan Spallation Source is given, and our work on three control problems important for the design of its linear accelerator are presented.
