Jan Järveläinen

• Doctor of Science
• Chief Digital Officer at Premix Oy

The multiplicity of targets of the 5G and further future technologies, set by the modern societies and industry, lacks the establishment of design methods for the highly multidisciplinary application of wireless platforms for small cells. Constraints are set by the overall energy concept, structural safety and sustainability. Various Smart poles an...

Fused filament fabrication (FFF) is a well-known and greatly accessible additive manufacturing technology, that has found great use in the prototyping and manufacture of radiofrequency componentry, by using a range of composite thermoplastic materials that possess superior properties, when compared to standard materials for 3D printing. However, du...

In this paper, we have characterized dielectric properties of low-loss radome materials with three different measurement methods, at microwave and mmWave frequencies. The techniques include an over-the-air (OTA) far-field measurement at 55-95 GHz, a Fabry-Perot open resonator (10-60 GHz), and a split-post dielectric resonator whose empty resonance...

Microwave radars represent a viable solution to perform rapid and non-destructive snowpack analyses. Depending on the working frequency, they are required to provide a suitable compromise between the penetration depth and the spatial resolution. For these reasons, antennas able to cover relatively large fractional bandwidths at a few gigahertz are...

In this paper, we parameterize an excess loss-based multipath component (MPC) cross-polarization ratio (XPR) model in indoor and outdoor environments for above-6 GHz frequency bands. The results are based on 28 measurement campaigns in several frequency bands ranging from 15 to 80 GHz. A conventional XPR model of an MPC assuming a constant mean val...

In this paper, we parameterize an excess loss-based multipath component (MPC) cross-polarization ratio (XPR) model in indoor and outdoor environments for above-6 GHz frequency bands. The results are based on 28 measurement campaigns in several frequency bands ranging from 15 to 80 GHz. A conventional XPR model of an MPC assuming a constant mean val...

In this paper, we propose a new technique for the future fifth generation cellular network wireless backhauling. We show that hundreds of bits per second per Hertz (bits per second per Hz) of spectral efficiency can be attained at a high carrier frequency (such as 26 GHz) between large antenna arrays deployed along structures (such as lamp posts) t...

This paper studies a gain of an antenna array embedded on a mobile device operating at a millimeter-wave radio frequency. Assuming that mobile phones at millimeter-wave range operate with a single baseband unit and analog beamforming like phased arrays, we define a total array gain denoting a path gain of the phased antenna array in excess to the o...

In this paper, we compare the radio propagation channels characteristics between 28 and 140 GHz bands based on the wideband (several GHz) and directional channel sounding in a shopping mall environment. The measurements and data processing are conducted in such a way to meet requirements for a fair comparison of large- and small- scale channel para...

This deliverable describes the extensive multi-frequency channel measurement and simulation campaigns conducted in the mmMAGIC project, covering mm-wave 5G propagation scenarios. The data is evaluated to characterize environment-specific propagation effects. Based on the findings, refined modelling approaches are developed and embedded in a geometr...

In wireless channel measurements, the relatively weak cross-polarized multipath components (MPCs) are typically severely affected by the measurement noise level. As shown in this letter, the typical cross-polarization ratio (XPR) model parameter estimation, which ignores the existence of censored samples, may lead to significant errors. We demonstr...

Deterministic field prediction has been widely used to provide channel data for coverage analysis. Among these prediction tools, point cloud-based methods have been developed for millimeter-wave frequencies in order to characterize the environment with higher precision, but they have not taken into account all the necessary propagation mechanisms....

Line-of-sight (LOS) probability is an integral part of radio channel models for cellular network design and evaluation. The probability along with the pathloss models in LOS and non-LOS scenarios gives us an estimate of the cellular coverage. In this letter, we present a novel method to evaluate the LOS probability by using point cloud data obtaine...

Channel sounding above 6 GHz often uses directional antennas to compensate for the more influential pathloss than below 6 GHz, and rotates the antennas over angles to obtain directional channels. The sounding method sets a nontrivial challenge of estimating omni-directional pathloss, which refers to the pathloss when omni-directional antennas would...

This paper presents and compares two candidate large-scale propagation path loss models, the alpha-beta-gamma (ABG) model and the close-in (CI) free space reference distance model, for the design of fifth generation (5G) wireless communication systems in urban micro- and macro-cellular scenarios. Comparisons are made using the data obtained from 20...

In this report, the end user scenarios, test cases and requirements envisioned by the METIS project are mapped to propagation scenarios. Furthermore they are analysed for deriving a new set of requirements relevant for radio channel and propagation modelling. Since none of the existing channel models in the literature satisfies all these requiremen...

Millimeter-wave radios have great potential of spatial interference management through its physically small but possibly electrically large antenna aperture. It is expected that the interference management becomes a major challenge after massive deployment of millimeter-wave devices. This paper therefore discusses design guidelines and an influenti...

Millimeter-wave radios operating at unlicensed 60 GHz and licensed 70 GHz bands are attractive solutions to realize short-range backhaul links for flexible wireless network deployment. We present a measurement-based spatio-temporal statistical channel model for short-range millimeter-wave links in large office rooms, shopping mall, and station scen...

In this paper, we derive parameters of the WINNER II channel model for a shopping mall environment at 60 GHz band, covering both line-of-sight and obstructed-line-of-sight scenarios. The model parameters are derived mostly based on channel measurements reported in this paper. Due to a large measurement bandwidth and the highly specular nature of th...

Mutual orthogonal user channels in multiuser (MU)-multiple-input multiple-output (MIMO) systems are desirable and can be approximately obtained under independent and identically distributed (i.i.d.) Rayleigh fading assumption with a very large number of base station antennas. However, it has been shown that at millimeter-wave (mmW) frequencies, thi...

Accurate indoor radio wave propagation prediction requires a model of the environment which also includes fixtures such as furniture. By laser scanning we can obtain this detailed structural data in the form of a point cloud. Since conventional field prediction tools are not applicable to the point cloud data format, we predict the electromagnetic...

Site-specific millimeter-wave propagation prediction requires data of the environment under study, which is usually not available for indoor scenarios. With means of laser scanning the details of the indoor environment can be captured accurately in the form of a point cloud. The total field is estimated as a sum of paths backscattering from the poi...

In this report, the results of the measurement campaigns are provided based on the propagation scenarios defined in METIS project. Channel modelling approaches are discussed and the Initial METIS Channel Model is described in detail. The initial METIS channel model includes both stochastic (generic) and map-based (site-specific) models. Moreover, t...

Millimeter-wave radios operating at unlicensed 60 GHz and licensed 70 GHz bands are attractive solutions to realize short-range backhaul links for future flexible network deployment. In this work, we report directional radio channel sounding performed at 60 and 70 GHz in large indoor short-range scenarios such as offices, a shopping mall, and a rai...

In radio system deployment the main focus is on assuring sufficient coverage, which can be estimated with pathloss models for specific scenarios. When more detailed performance metrics such as peak throughput are studied, the environment has to be modeledaccurately in order to estimate multipath behavior. By means of laser scanning we can acquire v...

We have studied beam-steering radio in the E-band., e.g. for high-capacity communication links. Lens antennas provide high gain and are suitable for integration at millimeter wave frequencies, e.g., for beam-switching a planar antenna array with a switching network may be integrated to the surface of the lens; one patch is activated at a time for e...

Accurate radio wave propagation prediction is crucial in designing wireless instruments for medical use. In this paper we simulate the 60 GHz radio channel in a hospital ultrasonic inspection room using ray tracing based on single-bounce scattering. The scattering is calculated with a single-lobe directive model and the room structure is modeled wi...

In this Master's thesis the influence of a time-harmonic electromagnetic field on the operation of a direct-mode bioorganic fuel cell is investigated. Also coaxial tapering is studied and a tapered matching part is manufactured. The frequency under focus ranged from 50 MHz to 5 GHz.