Emeritus Professor (Profesor Emérito) at Universidad Politécnica de Madrid, ETSI de Telecomunicación, Signals, Systems and Radiocommunications Department (Departamento SSR)
ABSTRACT In this paper, we analyze the performance of smart antennas (SA) in typical user scenari... more ABSTRACT In this paper, we analyze the performance of smart antennas (SA) in typical user scenarios such as mixed-set and hot spot environments. In particular, we compare the results obtained with switched-beam and fully adaptive antennas with respect to a conventional sectored antenna. The scope of this contribution is two-fold: first, we compare the performance obtained with several SA solutions with different complexity, from switched-beam antennas to adaptive arrays controlled by different beamforming algorithms. Second, we analyse the results from a complexity vs. performance trade-off perspective. Through extensive link-level simulations, we show that final performance depends on the spatial user distribution and the individual demanded service. In addition, we analyse not only average values but also cumulative distribution functions for speech and data users in different scenarios. Finally, it is important to emphasize that link-level simulation results can be transferred to system level simulations for use in the planning phase in order to calculate the coverage and capacity increase that can be achieved with SAs in a multiple cell scenario.
One of the environmental effects of wind farms is that wind turbines act as scattering devices of ... more One of the environmental effects of wind farms is that wind turbines act as scattering devices of the electromagnetic RF waves and thus, may cause interferences to different telecommunication services around them. A software application that has been developed to predict the interference caused by wind farms to TV broadcast service is presented in this paper. The implemented RCS models of a wind turbine, along with different measurements carried out to adjust and validate the functionality of the software is shown. Finally, a wideband terrain-sensitive channel response model has been developed from narrow-band model. The complex wideband channel transfer function is transformed here to time domain through the use of a fast Fourier transform (FFT), so that calculating the power delay profile (PDP).
The capacity and the interference statistics of the sectors of the cigar-shaped W-CDMA microcell ... more The capacity and the interference statistics of the sectors of the cigar-shaped W-CDMA microcell are studied. A model of 5 microcells is used to analyze the uplink. The microcells are assumed to exist in rural zones. The capacity and the interference statistics of the microcell are studied for different sector range, different antenna side lobe levels, different values of the break point distance, different values of the propagation parameter s 2 and different standard deviation of the power control error.
The capacity (the maximum number of users per sector that the system can support) and the interfe... more The capacity (the maximum number of users per sector that the system can support) and the interfer-ence statistics (expected value and variance) of sectors composed of cigar-shaped WCDMA microcells are studied. A model of 5 microcells is used to analyze the uplink ...
The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectr... more The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectrum for unlicensed use of ultra-wideband (UWB) devices for communication applications in the 3.1–10.6 GHz frequency band, the move represented a victory in a long hard-fought battle that dated back decades. With its origins in the 1960s, when it was called time-domain electromagnetic, UWB came to be known for the operation of sending and receiving extremely short bursts of RF energy. With its outstanding ability for applications that require precision distance or positioning measurements, as well as high-speed wireless connectivity, the largest spectrum allocation ever granted by the FCC is unique because it overlaps other services in the same frequency of operation. Previous spectrum allocations for unlicensed use, such as the Unlicensed National Information Infrastructure (UNII) band have opened up bandwidth dedicated to unlicensed devices based on the assumption that “operation is subj...
IEEE Benelux Chapter on Vehicular Technology and Communications. Symposium on Communications and Vehicular Technology. SCVT-2000. Proceedings (Cat. No.00EX465), 2000
New mobile communication services are appearing, and the rate of demand is rapidly increasing. Ne... more New mobile communication services are appearing, and the rate of demand is rapidly increasing. New technologies are needed to give service to the higher number of users with the minimum of spectrum requirements. One of these technologies is the dynamic reconfiguration of the antenna radiation pattern at the base station site. Although this technique can be applied to TDMA and FDMA systems, the main improvement is obtained when using CDMA. These antennas systems pretend to minimize the interference power received from non-desired users, and maximize C/I values. This paper presents simulation results obtained for the vehicular scenario of WCDMA UMTS systems using switched beam antenna technology. Performance improvement obtained with respect to 120' three-sectorial antenna systems is shown. Both intracell and out-of-cell interference are calculated, and user mobility is taken into account in the simulator.
... ROSHADY M. HAFEZ PCS Research Laboratory, Department of Systems and Computer Engineering, Car... more ... ROSHADY M. HAFEZ PCS Research Laboratory, Department of Systems and Computer Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6 Abstract. ... 5. DN Hatfield, Measure of Spectral Efficiency in Land Mobile Radio, IEEE Trans. ...
The capacity and the interference statistics of the sectors of the shaped W-CDMA cell are studied... more The capacity and the interference statistics of the sectors of the shaped W-CDMA cell are studied. A model of five cells is used to analyze the uplink. The cells are assumed to exist in rural zones. The capacity and the interference statistics of the cell are studied using a two-slope propagation model. The expected value and the variance of the interference are given for different propagation exponent.
- In this work, the performance of HAPs (High Altitudes Platforms) WiMAX is studied for different... more - In this work, the performance of HAPs (High Altitudes Platforms) WiMAX is studied for different HAPs height h, transmitted power level and antenna boresight separation assuming a 7 cells network. Theeffect of the rain on the coverage zone radius is also studied. It is ...
The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectr... more The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectrum for unlicensed use of ultra-wideband (UWB) devices for communication applications in the 3.1–10.6 GHz frequency band, the move represented a victory in a long hard-fought battle that dated back decades. With its origins in the 1960s, when it was called time-domain electromagnetic, UWB came to be known for the operation of sending and receiving extremely short bursts of RF energy. With its outstanding ability for applications that require precision distance or positioning measurements, as well as high-speed wireless connectivity, the largest spectrum allocation ever granted by the FCC is unique because it overlaps other services in the same frequency of operation. Previous spectrum allocations for unlicensed use, such as the Unlicensed National Information Infrastructure (UNII) band have opened up bandwidth dedicated to unlicensed devices based on the assumption that “operation is subj...
The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectr... more The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectrum, in the 3.1 GHz to 10.6 GHz frequency band, for unlicensed use of ultra wide band (UWB) devices for communication applications. The move represented a victory in a long hard-fought battle that dated back decades. With its origins in the 1960s, when it was called time-domain electromagnetics, UWB came to be denoting the operation of sending and receiving extremely short bursts of RF energy. With its outstanding ability for applications that require precision distance or positioning measurements, as well as highspeed wireless connectivity, the largest spectrum allocation ever granted by the FCC is unique because it overlaps other services in the same frequency of operation. Previous spectrum allocations for unlicensed use have opened up bandwidth dedicated to unlicensed devices based on the assumption that operation is subject to the following two conditions:
Proceecings of Ever Monaco 2010 Ever Monaco 2010 25 03 2010 28 03 2010 Monaco Francia, 2010
One of the environmental effects of wind farms is that wind turbines act as scattering devices of... more One of the environmental effects of wind farms is that wind turbines act as scattering devices of the electromagnetic RF waves and thus, may cause interferences to different telecommunication services around them. To carry on with a previous work [4], the model of the nacelle and the wind turbine is shown and validated. Finally, a wideband terrain-sensitive channel response model has been developed from narrow-band model. The complex wideband channel transfer function is transformed here to the time domain through the use of a fast Fourier transform (FFT), so that calculating the power delay profile (PDP).
Ix Simposium Nacional Las Palmas De Gran Canaria 21 23 De Septiembre De 1994 Vol 1 1994 Pags 503 507, 1994
... por Manuel J. Betancor García, Rafael Pérez Jiménez, Eugenio Jiménez Yguacel, Vol. 1, 1994 , ... more ... por Manuel J. Betancor García, Rafael Pérez Jiménez, Eugenio Jiménez Yguacel, Vol. 1, 1994 , págs. 503-507; Recoge los contenidos presentados a: Unión Científica Internacional de Radio. Comité Español. Simposium Nacional (9. 1994. Las Palmas de Gran Canaria). ...
ABSTRACT In this paper, we analyze the performance of smart antennas (SA) in typical user scenari... more ABSTRACT In this paper, we analyze the performance of smart antennas (SA) in typical user scenarios such as mixed-set and hot spot environments. In particular, we compare the results obtained with switched-beam and fully adaptive antennas with respect to a conventional sectored antenna. The scope of this contribution is two-fold: first, we compare the performance obtained with several SA solutions with different complexity, from switched-beam antennas to adaptive arrays controlled by different beamforming algorithms. Second, we analyse the results from a complexity vs. performance trade-off perspective. Through extensive link-level simulations, we show that final performance depends on the spatial user distribution and the individual demanded service. In addition, we analyse not only average values but also cumulative distribution functions for speech and data users in different scenarios. Finally, it is important to emphasize that link-level simulation results can be transferred to system level simulations for use in the planning phase in order to calculate the coverage and capacity increase that can be achieved with SAs in a multiple cell scenario.
One of the environmental effects of wind farms is that wind turbines act as scattering devices of ... more One of the environmental effects of wind farms is that wind turbines act as scattering devices of the electromagnetic RF waves and thus, may cause interferences to different telecommunication services around them. A software application that has been developed to predict the interference caused by wind farms to TV broadcast service is presented in this paper. The implemented RCS models of a wind turbine, along with different measurements carried out to adjust and validate the functionality of the software is shown. Finally, a wideband terrain-sensitive channel response model has been developed from narrow-band model. The complex wideband channel transfer function is transformed here to time domain through the use of a fast Fourier transform (FFT), so that calculating the power delay profile (PDP).
The capacity and the interference statistics of the sectors of the cigar-shaped W-CDMA microcell ... more The capacity and the interference statistics of the sectors of the cigar-shaped W-CDMA microcell are studied. A model of 5 microcells is used to analyze the uplink. The microcells are assumed to exist in rural zones. The capacity and the interference statistics of the microcell are studied for different sector range, different antenna side lobe levels, different values of the break point distance, different values of the propagation parameter s 2 and different standard deviation of the power control error.
The capacity (the maximum number of users per sector that the system can support) and the interfe... more The capacity (the maximum number of users per sector that the system can support) and the interfer-ence statistics (expected value and variance) of sectors composed of cigar-shaped WCDMA microcells are studied. A model of 5 microcells is used to analyze the uplink ...
The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectr... more The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectrum for unlicensed use of ultra-wideband (UWB) devices for communication applications in the 3.1–10.6 GHz frequency band, the move represented a victory in a long hard-fought battle that dated back decades. With its origins in the 1960s, when it was called time-domain electromagnetic, UWB came to be known for the operation of sending and receiving extremely short bursts of RF energy. With its outstanding ability for applications that require precision distance or positioning measurements, as well as high-speed wireless connectivity, the largest spectrum allocation ever granted by the FCC is unique because it overlaps other services in the same frequency of operation. Previous spectrum allocations for unlicensed use, such as the Unlicensed National Information Infrastructure (UNII) band have opened up bandwidth dedicated to unlicensed devices based on the assumption that “operation is subj...
IEEE Benelux Chapter on Vehicular Technology and Communications. Symposium on Communications and Vehicular Technology. SCVT-2000. Proceedings (Cat. No.00EX465), 2000
New mobile communication services are appearing, and the rate of demand is rapidly increasing. Ne... more New mobile communication services are appearing, and the rate of demand is rapidly increasing. New technologies are needed to give service to the higher number of users with the minimum of spectrum requirements. One of these technologies is the dynamic reconfiguration of the antenna radiation pattern at the base station site. Although this technique can be applied to TDMA and FDMA systems, the main improvement is obtained when using CDMA. These antennas systems pretend to minimize the interference power received from non-desired users, and maximize C/I values. This paper presents simulation results obtained for the vehicular scenario of WCDMA UMTS systems using switched beam antenna technology. Performance improvement obtained with respect to 120' three-sectorial antenna systems is shown. Both intracell and out-of-cell interference are calculated, and user mobility is taken into account in the simulator.
... ROSHADY M. HAFEZ PCS Research Laboratory, Department of Systems and Computer Engineering, Car... more ... ROSHADY M. HAFEZ PCS Research Laboratory, Department of Systems and Computer Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6 Abstract. ... 5. DN Hatfield, Measure of Spectral Efficiency in Land Mobile Radio, IEEE Trans. ...
The capacity and the interference statistics of the sectors of the shaped W-CDMA cell are studied... more The capacity and the interference statistics of the sectors of the shaped W-CDMA cell are studied. A model of five cells is used to analyze the uplink. The cells are assumed to exist in rural zones. The capacity and the interference statistics of the cell are studied using a two-slope propagation model. The expected value and the variance of the interference are given for different propagation exponent.
- In this work, the performance of HAPs (High Altitudes Platforms) WiMAX is studied for different... more - In this work, the performance of HAPs (High Altitudes Platforms) WiMAX is studied for different HAPs height h, transmitted power level and antenna boresight separation assuming a 7 cells network. Theeffect of the rain on the coverage zone radius is also studied. It is ...
The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectr... more The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectrum for unlicensed use of ultra-wideband (UWB) devices for communication applications in the 3.1–10.6 GHz frequency band, the move represented a victory in a long hard-fought battle that dated back decades. With its origins in the 1960s, when it was called time-domain electromagnetic, UWB came to be known for the operation of sending and receiving extremely short bursts of RF energy. With its outstanding ability for applications that require precision distance or positioning measurements, as well as high-speed wireless connectivity, the largest spectrum allocation ever granted by the FCC is unique because it overlaps other services in the same frequency of operation. Previous spectrum allocations for unlicensed use, such as the Unlicensed National Information Infrastructure (UNII) band have opened up bandwidth dedicated to unlicensed devices based on the assumption that “operation is subj...
The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectr... more The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectrum, in the 3.1 GHz to 10.6 GHz frequency band, for unlicensed use of ultra wide band (UWB) devices for communication applications. The move represented a victory in a long hard-fought battle that dated back decades. With its origins in the 1960s, when it was called time-domain electromagnetics, UWB came to be denoting the operation of sending and receiving extremely short bursts of RF energy. With its outstanding ability for applications that require precision distance or positioning measurements, as well as highspeed wireless connectivity, the largest spectrum allocation ever granted by the FCC is unique because it overlaps other services in the same frequency of operation. Previous spectrum allocations for unlicensed use have opened up bandwidth dedicated to unlicensed devices based on the assumption that operation is subject to the following two conditions:
Proceecings of Ever Monaco 2010 Ever Monaco 2010 25 03 2010 28 03 2010 Monaco Francia, 2010
One of the environmental effects of wind farms is that wind turbines act as scattering devices of... more One of the environmental effects of wind farms is that wind turbines act as scattering devices of the electromagnetic RF waves and thus, may cause interferences to different telecommunication services around them. To carry on with a previous work [4], the model of the nacelle and the wind turbine is shown and validated. Finally, a wideband terrain-sensitive channel response model has been developed from narrow-band model. The complex wideband channel transfer function is transformed here to the time domain through the use of a fast Fourier transform (FFT), so that calculating the power delay profile (PDP).
Ix Simposium Nacional Las Palmas De Gran Canaria 21 23 De Septiembre De 1994 Vol 1 1994 Pags 503 507, 1994
... por Manuel J. Betancor García, Rafael Pérez Jiménez, Eugenio Jiménez Yguacel, Vol. 1, 1994 , ... more ... por Manuel J. Betancor García, Rafael Pérez Jiménez, Eugenio Jiménez Yguacel, Vol. 1, 1994 , págs. 503-507; Recoge los contenidos presentados a: Unión Científica Internacional de Radio. Comité Español. Simposium Nacional (9. 1994. Las Palmas de Gran Canaria). ...
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Papers by Miguel Calvo