The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014
ABSTRACT The main objective of this paper is to present major challenges regarding the fifth gene... more ABSTRACT The main objective of this paper is to present major challenges regarding the fifth generation (5G) mobile communications propagation modelling work in the European 7 th framework project METIS (Mobile and wireless communications Enablers for the Twenty-twenty Information Society). The goal of the propagation work in METIS is to provide adequate propagation models for 5G. For this purpose corresponding deficiencies of present commonly used models are identified. Further, the lack of available channel models for several propagation scenarios has been assessed. Based on this assessment the framework of 5G channel modelling is sketched. As propagation measurement campaigns are a crucial part of this work they are illustrated with a few examples.
This paper presents the structure, radiation patterns and surface current distributions of a dual... more This paper presents the structure, radiation patterns and surface current distributions of a dual-polarized patch antenna operating at 10.1 GHz center frequency. The antenna structure is designed for a virtual antenna array which is part of a vector network analyzer based radio channel measurement system. The antenna shows 700 MHz -10 dB impedance bandwidth. The measured isolation between the antenna ports is better than 33 dB across the aforementioned bandwidth. The measured total efficiency is between -3 and -1 dB, the maximum gain between 2.5 and 4 dB, and the cross polarization discrimination better than 18 dB over the operating bandwidth.
Proceedings of the 1st International Conference on 5G for Ubiquitous Connectivity, 2014
ABSTRACT This paper presents the elevation of departure analysis for the urban microcell radio ch... more ABSTRACT This paper presents the elevation of departure analysis for the urban microcell radio channel measurements at 2.3 GHz center frequency. The measurements were conducted with EB Propsound CSTM for 30 x 16 antenna configuration for the transmitter (Tx) antenna heights of 5 m and 10 m in Oulu city center, Finland. The Tx antenna elements were arranged in the plus shape and nine antenna elements were placed with linear spacing in the vertical dimension providing high elevation resolution and an accurate elevation angle estimate for the departure angles. The measurement results indicate that the Laplacian distribution can be used for modelling the elevation angles of departure. The results indicate a smaller elevation spread of departure (ESD) for the higher Tx antenna height and a significant difference in ESDs between the lineof-sight (LOS) and the non-line-of-sight (NLOS) propagation environment. The ESD with respect to distance was observed to follow the negative exponential model and the linear model in the LOS propagation environment and the NLOS propagation environment, respectively.
Proceedings of the 1st International Conference on 5G for Ubiquitous Connectivity, 2014
ABSTRACT This paper presents the results and analysis of diffraction measurements around a buildi... more ABSTRACT This paper presents the results and analysis of diffraction measurements around a building corner at 10 GHz. Radio channel measurement setup contains a 4-port vector network analyzer and two virtual antenna arrays. Angle of arrival analysis is carried out to distinguish the diffracted path from the other multipath components in the impulse response. Results are analyzed with respect to the Fresnel diffraction parameter and diffraction angle, and compared with the knife edge diffraction (KED) and absorbing screen diffraction losses, respectively. The absorbing screen approach is concluded to give reasonable fit for the measurements in the shadow region, but a poor fit near to the shadow boundary and in the illuminated region. The analysis of the corner diffraction shows that a building corner can be modeled by the KED-theory at 10 GHz.
ABSTRACT This paper presents MIMO channel sounding measurements performed in the underground road... more ABSTRACT This paper presents MIMO channel sounding measurements performed in the underground road tunnel of Roux, in south of France, at 5.8 GHz. Different scenarios for antennas (spacing and polarization) and moving vehicles speeds were carried out in the tunnel. The aim was to be as close as possible to scenarios one can encountered in railway environments. From these measurements, MIMO channel matrices are computed, in order to determine the correlation level of the channel and its capacity along the tunnel, according to different antenna spacing and polarization.
This paper studies the performance of ultra wideband (UWB) communication systems in AWGN channels... more This paper studies the performance of ultra wideband (UWB) communication systems in AWGN channels. The studied UWB systems are utilizing different kinds of modulation schemes. The propagating information signal is jammed with a signal having a spectrum in the UMTS or in the GSM band. The simulations showed that the time hopping UWB system utilizing binary PAM modulation outperforms the
This paper compares the performances of an ultra wideband (UWB) system in additive white Gaussian... more This paper compares the performances of an ultra wideband (UWB) system in additive white Gaussian noise (AWGN) channel in presence of a pulsed jamming or a coloured Gaussian noise allocated in the UMTS-FDD (FDD = Frequency Division Duplex) uplink band. Several modulation schemes have been implemented in order to analyze the efficiency and the robustness of different UWB systems when the studied interferences are present in the channel. Results showed that the particular UWB modulation scheme chosen doesn't affect effectively the degradation of performances introduced by the interference, giving a precise rank order for the different UWB concepts. Nevertheless, due to the band allocation of the interference, the pulsed jamming source worsens the performance of the system more significantly than the coloured noise for low interference power. For high values, instead, the behaviour is inverted.
A comprehensive measurement campaign has been carried out under ESA contract for characterizing s... more A comprehensive measurement campaign has been carried out under ESA contract for characterizing satellite-to-indoor links at C-Band. The channel at L- and S-Bands has been widely studied; however, frequency extrapolation is not easily carried out. Measurements have been performed using a helicopter embarking both a CW transmitter and a wideband channel sounder operating at about 5.2 GHz. The receivers were
the use of C-band has been identified as a potential candidate for future GNSS (Global Navigation... more the use of C-band has been identified as a potential candidate for future GNSS (Global Navigation Satellite System) services. The understanding of the environmental propagation channel at this band is a key element to analyse the feasibility of the use of this frequency band for GNSS. The present paper describes an activity to study the environmental propagation conditions at c-band for satellite-to-indoor environment and the land mobile satellite environment for vehicles (but also applicable to pedestrian users) under different scenarios with particular attention to those where attenuation by vegetation plays an important role.
The multipath characteristics of the wireless local loop (WLL) channel were studied over both sho... more The multipath characteristics of the wireless local loop (WLL) channel were studied over both short and long time periods in urban and sub-urban high-rise and small-house environments. Wideband measurements were performed at a centre frequency of 1.3 GHz with a sliding correlation measurement system using a chip rate of 15 MHz. The receiver was situated at regular cellular base stations, and the transmitter with an omnidirectional antenna was moved to several rooms in different buildings around the base station sites. During the recordings the movement of people in the measurement rooms was restricted. The short-term results show a high degree of similarity in the multipath characteristics of the WLL channel in urban and sub-urban high-rise environments. The maximum measured values of delay spreads for the urban and suburban high-rise environments were 410 ns and 360 ns, respectively. For the sub-urban small-house environment the data indicate lower values of delay spread. The channel was shown to be very slowly fading, being in most situations essentially static over short time periods of the order of several tens of seconds. The variation of the channel characteristics over long time periods was shown to be significant
The paper presents ultra wideband (UWB) channel measurements from 3.1 to 8.0 GHz in office and le... more The paper presents ultra wideband (UWB) channel measurements from 3.1 to 8.0 GHz in office and lecture hall environments carried out at the premises of University of Oulu. Both line-of-sight (LOS) and non-LOS (NLOS) channels were measured having transmitter-receiver separation from 4 to 10 m. Channel parameters that are corresponding to the modified IEEE 802.15.3a model are extracted from the measurement data. In addition, delay spread and path loss are studied. In the study, the measured frequency band is divided into sub-bands and analysed separately. The effect of frequency over the UWB band on the channel statistics is pointed out.
Most of the wideband radio channel models available today are not accurate enough for ultra wideb... more Most of the wideband radio channel models available today are not accurate enough for ultra wideband (UWB) applications occupying an extremely large bandwidth. In this paper, a procedure for indoor UWB radio channel measurements and modelling is presented. The example discussed here is based on the measurements carried out in the main building of the University of Oulu, Oulu, Finland. An average size lecture room was selected to represent typical university environment, and various radio links were measured for statistical variance. A radio frequency band from 2 to 8 GHz was covered by a vector network analyzer, and the measured S 21 data were inverse Fourier transformed to achieve the corresponding impulse responses.
This paper explains the realization and the performance of a digital stepping correlator in a wid... more This paper explains the realization and the performance of a digital stepping correlator in a wideband radio channel measurement system. Radio channel sounding is based on the estimation of the radio channel by use of maximum length sequence (m-sequence) as an effective sounding signal. Signal is detected using the stepping correlator receiver. The received signal is not converted to the baseband but the sampling is done direct from the IF-frequency. Digital implementation gives also a possibility to use a windowing property when those parts of the impulse responses that do not contain signal power are abandoned during measurements. The windowing enables high radio channel sampling rates.
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014
ABSTRACT The main objective of this paper is to present major challenges regarding the fifth gene... more ABSTRACT The main objective of this paper is to present major challenges regarding the fifth generation (5G) mobile communications propagation modelling work in the European 7 th framework project METIS (Mobile and wireless communications Enablers for the Twenty-twenty Information Society). The goal of the propagation work in METIS is to provide adequate propagation models for 5G. For this purpose corresponding deficiencies of present commonly used models are identified. Further, the lack of available channel models for several propagation scenarios has been assessed. Based on this assessment the framework of 5G channel modelling is sketched. As propagation measurement campaigns are a crucial part of this work they are illustrated with a few examples.
This paper presents the structure, radiation patterns and surface current distributions of a dual... more This paper presents the structure, radiation patterns and surface current distributions of a dual-polarized patch antenna operating at 10.1 GHz center frequency. The antenna structure is designed for a virtual antenna array which is part of a vector network analyzer based radio channel measurement system. The antenna shows 700 MHz -10 dB impedance bandwidth. The measured isolation between the antenna ports is better than 33 dB across the aforementioned bandwidth. The measured total efficiency is between -3 and -1 dB, the maximum gain between 2.5 and 4 dB, and the cross polarization discrimination better than 18 dB over the operating bandwidth.
Proceedings of the 1st International Conference on 5G for Ubiquitous Connectivity, 2014
ABSTRACT This paper presents the elevation of departure analysis for the urban microcell radio ch... more ABSTRACT This paper presents the elevation of departure analysis for the urban microcell radio channel measurements at 2.3 GHz center frequency. The measurements were conducted with EB Propsound CSTM for 30 x 16 antenna configuration for the transmitter (Tx) antenna heights of 5 m and 10 m in Oulu city center, Finland. The Tx antenna elements were arranged in the plus shape and nine antenna elements were placed with linear spacing in the vertical dimension providing high elevation resolution and an accurate elevation angle estimate for the departure angles. The measurement results indicate that the Laplacian distribution can be used for modelling the elevation angles of departure. The results indicate a smaller elevation spread of departure (ESD) for the higher Tx antenna height and a significant difference in ESDs between the lineof-sight (LOS) and the non-line-of-sight (NLOS) propagation environment. The ESD with respect to distance was observed to follow the negative exponential model and the linear model in the LOS propagation environment and the NLOS propagation environment, respectively.
Proceedings of the 1st International Conference on 5G for Ubiquitous Connectivity, 2014
ABSTRACT This paper presents the results and analysis of diffraction measurements around a buildi... more ABSTRACT This paper presents the results and analysis of diffraction measurements around a building corner at 10 GHz. Radio channel measurement setup contains a 4-port vector network analyzer and two virtual antenna arrays. Angle of arrival analysis is carried out to distinguish the diffracted path from the other multipath components in the impulse response. Results are analyzed with respect to the Fresnel diffraction parameter and diffraction angle, and compared with the knife edge diffraction (KED) and absorbing screen diffraction losses, respectively. The absorbing screen approach is concluded to give reasonable fit for the measurements in the shadow region, but a poor fit near to the shadow boundary and in the illuminated region. The analysis of the corner diffraction shows that a building corner can be modeled by the KED-theory at 10 GHz.
ABSTRACT This paper presents MIMO channel sounding measurements performed in the underground road... more ABSTRACT This paper presents MIMO channel sounding measurements performed in the underground road tunnel of Roux, in south of France, at 5.8 GHz. Different scenarios for antennas (spacing and polarization) and moving vehicles speeds were carried out in the tunnel. The aim was to be as close as possible to scenarios one can encountered in railway environments. From these measurements, MIMO channel matrices are computed, in order to determine the correlation level of the channel and its capacity along the tunnel, according to different antenna spacing and polarization.
This paper studies the performance of ultra wideband (UWB) communication systems in AWGN channels... more This paper studies the performance of ultra wideband (UWB) communication systems in AWGN channels. The studied UWB systems are utilizing different kinds of modulation schemes. The propagating information signal is jammed with a signal having a spectrum in the UMTS or in the GSM band. The simulations showed that the time hopping UWB system utilizing binary PAM modulation outperforms the
This paper compares the performances of an ultra wideband (UWB) system in additive white Gaussian... more This paper compares the performances of an ultra wideband (UWB) system in additive white Gaussian noise (AWGN) channel in presence of a pulsed jamming or a coloured Gaussian noise allocated in the UMTS-FDD (FDD = Frequency Division Duplex) uplink band. Several modulation schemes have been implemented in order to analyze the efficiency and the robustness of different UWB systems when the studied interferences are present in the channel. Results showed that the particular UWB modulation scheme chosen doesn't affect effectively the degradation of performances introduced by the interference, giving a precise rank order for the different UWB concepts. Nevertheless, due to the band allocation of the interference, the pulsed jamming source worsens the performance of the system more significantly than the coloured noise for low interference power. For high values, instead, the behaviour is inverted.
A comprehensive measurement campaign has been carried out under ESA contract for characterizing s... more A comprehensive measurement campaign has been carried out under ESA contract for characterizing satellite-to-indoor links at C-Band. The channel at L- and S-Bands has been widely studied; however, frequency extrapolation is not easily carried out. Measurements have been performed using a helicopter embarking both a CW transmitter and a wideband channel sounder operating at about 5.2 GHz. The receivers were
the use of C-band has been identified as a potential candidate for future GNSS (Global Navigation... more the use of C-band has been identified as a potential candidate for future GNSS (Global Navigation Satellite System) services. The understanding of the environmental propagation channel at this band is a key element to analyse the feasibility of the use of this frequency band for GNSS. The present paper describes an activity to study the environmental propagation conditions at c-band for satellite-to-indoor environment and the land mobile satellite environment for vehicles (but also applicable to pedestrian users) under different scenarios with particular attention to those where attenuation by vegetation plays an important role.
The multipath characteristics of the wireless local loop (WLL) channel were studied over both sho... more The multipath characteristics of the wireless local loop (WLL) channel were studied over both short and long time periods in urban and sub-urban high-rise and small-house environments. Wideband measurements were performed at a centre frequency of 1.3 GHz with a sliding correlation measurement system using a chip rate of 15 MHz. The receiver was situated at regular cellular base stations, and the transmitter with an omnidirectional antenna was moved to several rooms in different buildings around the base station sites. During the recordings the movement of people in the measurement rooms was restricted. The short-term results show a high degree of similarity in the multipath characteristics of the WLL channel in urban and sub-urban high-rise environments. The maximum measured values of delay spreads for the urban and suburban high-rise environments were 410 ns and 360 ns, respectively. For the sub-urban small-house environment the data indicate lower values of delay spread. The channel was shown to be very slowly fading, being in most situations essentially static over short time periods of the order of several tens of seconds. The variation of the channel characteristics over long time periods was shown to be significant
The paper presents ultra wideband (UWB) channel measurements from 3.1 to 8.0 GHz in office and le... more The paper presents ultra wideband (UWB) channel measurements from 3.1 to 8.0 GHz in office and lecture hall environments carried out at the premises of University of Oulu. Both line-of-sight (LOS) and non-LOS (NLOS) channels were measured having transmitter-receiver separation from 4 to 10 m. Channel parameters that are corresponding to the modified IEEE 802.15.3a model are extracted from the measurement data. In addition, delay spread and path loss are studied. In the study, the measured frequency band is divided into sub-bands and analysed separately. The effect of frequency over the UWB band on the channel statistics is pointed out.
Most of the wideband radio channel models available today are not accurate enough for ultra wideb... more Most of the wideband radio channel models available today are not accurate enough for ultra wideband (UWB) applications occupying an extremely large bandwidth. In this paper, a procedure for indoor UWB radio channel measurements and modelling is presented. The example discussed here is based on the measurements carried out in the main building of the University of Oulu, Oulu, Finland. An average size lecture room was selected to represent typical university environment, and various radio links were measured for statistical variance. A radio frequency band from 2 to 8 GHz was covered by a vector network analyzer, and the measured S 21 data were inverse Fourier transformed to achieve the corresponding impulse responses.
This paper explains the realization and the performance of a digital stepping correlator in a wid... more This paper explains the realization and the performance of a digital stepping correlator in a wideband radio channel measurement system. Radio channel sounding is based on the estimation of the radio channel by use of maximum length sequence (m-sequence) as an effective sounding signal. Signal is detected using the stepping correlator receiver. The received signal is not converted to the baseband but the sampling is done direct from the IF-frequency. Digital implementation gives also a possibility to use a windowing property when those parts of the impulse responses that do not contain signal power are abandoned during measurements. The windowing enables high radio channel sampling rates.
Uploads
Papers by Veikko Hovinen