Abstract: A feed array is provided that may be installed in a reflector antenna provided with a single or dual reflector optics. The feed array includes a radiating array for transmitting/receiving radiofrequency signals, a digital beam forming network, a reception conversion unit for applying a frequency down-conversion and an analog-to-digital conversion to incoming radiofrequency signals to obtain incoming digital signals. The feed array includes a transmission conversion unit for applying a digital-to-analog conversion and a frequency up-conversion to outgoing digital signals generated by the digital beam forming network to obtain outgoing radiofrequency signals. The digital beam forming network processes the incoming digital signals by using a reception matrix, and generates the outgoing digital signals by using a transmission matrix, with the matrices computed based on electric field values measured by the radiating array in the focal region.

Abstract: A radio communications method includes carrying out, by a transmitter, transmission operations that include generating digital transmission signals carrying symbols to be transmitted and having a predefined time length; and transmitting a radio frequency signal carrying, in successive, non-overlapped time frames or slots having the predefined time length, the digital transmission signals generated.

Abstract: A multistatic radar system is provided for detecting and tracking targets moving in a surveillance area that includes: a radar transmitter and a plurality of radar receivers located in different positions in the surveillance area and processing means. The radar transmitter and the radar receivers each include a GNSS receiver configured to receive GNSS signals. The radar transmitter and the radar receivers are configured to obtain a GNSS-based time reference based on the GNSS signals received by the respective GNSS receiver, wherein the GNSS-based time reference is common to the radar transmitter and the radar receivers. The radar transmitter is configured to transmit radar signals according to a predefined transmission time and frequency pattern and on the basis of the GNSS-based time reference. The radar receivers are configured to receive radar echoes from one or more targets moving in the surveillance area and illuminated by the radar signals transmitted by the radar transmitter.

Abstract: A feed array for reflector antennas is provided that may be installed in a reflector antenna provided with a single or dual reflector optics and that includes: a radiating array arranged in a focal region of the single/dual reflector optics and operable to transmit and receive radiofrequency signals; digital beam forming means; reception conversion means connected between the radiating array and the digital beam forming means and designed to apply a frequency down-conversion and an analog-to-digital conversion to incoming radiofrequency signals received by the radiating array thereby obtaining incoming digital signals, and provide the digital beam forming means with the incoming digital signals; and transmission conversion means connected between the radiating array and the digital beam forming means and designed to apply a digital-to-analog conversion and a frequency up-conversion to outgoing digital signals generated by the digital beam forming means thereby obtaining outgoing radiofrequency signals, and pr

Abstract: A radio communications method includes carrying out, by a transmitter, transmission operations that include generating digital transmission signals carrying symbols to be transmitted and having a predefined time length; and transmitting a radio frequency signal carrying, in successive, non-overlapped time frames or slots having the predefined time length, the digital transmission signals generated.

Abstract: A radio communications method includes carrying out, by a transmitter, transmission operations that make use of different filters for the transmission of main mode signals and twisted wave signals. The radio communications method further includes carrying out, by a receiver, reception operations. The different filters include a first transmission filter and a second transmission filter that have different filtering characteristics.

Abstract: A radio communications method includes carrying out, by a transmitter, transmission operations that make use of different filters for the transmission of main mode signals and twisted wave signals. The radio communications method further includes carrying out, by a receiver, reception operations. The different filters include a first transmission filter and a second transmission filter that have different filtering characteristics.

Abstract: A system combining OFDM standard modulation with a superimposition of Orbital Angular Momentum modes, each OAM modes consisting in an overlapping decimated IFFTs with the main mode standard OFDM signal. Orthogonality of the OAM modes is assessed. A frame structure embodying both main mode OFDM samples and overlapping OAM modes is proposed.

Abstract: A radio communications method includes carrying out, by a transmitter: providing a digital time signal carrying digital symbols to be transmitted; and transmitting a radio frequency signal carrying the digital time signal. The method further includes carrying out, by a receiver: receiving the radio frequency signal transmitted by the transmitter; processing the received radio frequency signal to obtain a corresponding incoming digital signal; and extracting, from the incoming digital signal, the digital symbols carried by the incoming digital signal. The digital time signal carrying the digital symbols to be transmitted results from an approximation of the Hilbert transform in frequency domain, which approximation is based on a frequency main mode and one or more frequency twisted modes, wherein the frequency main and twisted modes carry, each, respective digital symbols to be transmitted.

Abstract: A radio communications method, includes carrying out, by a transmitter: generating or receiving digital symbols to be transmitted; generating, every S digital symbols generated/received (with S integer higher than three), a corresponding multi-mode digital signal; generating a multi-frame digital signal comprising successive, non-overlapped time frames, each of which has the predefined time length and carries a respective multi-mode digital signal generated; and transmitting a radio frequency signal carrying the multi-frame digital signal. The radio communications method further includes carrying out, by a receiver: receiving the radio frequency signal transmitted by the transmitter; processing the received radio frequency signal to obtain a corresponding incoming digital signal; performing, on the basis of the incoming digital signal, carrier synchronization, clock synchronization, and frame synchronization; and extracting, on the basis of the carrier, clock and frame synchronizations.

Abstract: A radio communications system includes a transmitter and a receiver. The transmitter generates or receives digital symbols having a given symbol rate associated with a corresponding symbol period; and generates, every S digital symbols generated/received (S>3), a respective multi-mode digital signal, which has a predefined time length shorter than S times the symbol period, which is sampled with a predefined sampling rate higher than the symbol rate, and which carries the S digital symbols by a plurality of orthogonal harmonic modes including a main mode which is a real harmonic mode and carries P of the S digital symbols (P<S). The receiver receives and processes the radio frequency signal to obtain a corresponding incoming digital signal; and extracts, from successive, non-overlapped portions of the incoming digital signal sampled with the predefined sampling rate, the S digital symbols respectively carried by each incoming digital signal portion by the orthogonal harmonic modes.

Abstract: A method of implementing Orbital Angular Momentum (OAM) for radio communications in general and LTE in particular. Common prior art so far recreate the vorticity (axial rotation of the Poynting vector) by using ring-shaped antenna arrays. This application proposes to create the vorticity in signal processing without the need of any space diversity (i.e. work with a single antenna). An Hilbert transform is applied in frequency domain to the Fourier transform of the analytical representation of a band-limited OFDM signal. The Hilbert transform is then approximated by a development in series into orthogonal twisted modes. This can be seen as an inverse Fourier transform of the complex analytical signal. Therefore an OAM IFFT based transmitter is proposed where parallel IFFTs are performed for each OAM mode and superimposed.

Abstract: A system combining OFDM standard modulation with a superimposition of Orbital Angular Momentum modes, each OAM modes consisting in an overlapping decimated IFFTs with the main mode standard OFDM signal, Orthogonality of the OAM modes is assessed, A frame structure embodying both main mode OFDM samples and overlapping OAM modes is proposed.

Abstract: A method of implementing Orbital Angular Momentum (OAM) for radio communications in general and LTE in particular. Common prior art so far recreate the vorticity (axial rotation of the Poynting vector) by using ring-shaped antenna arrays. This application proposes to create the vorticity in signal processing without the need of any space diversity (i.e. work with a single antenna). An Hilbert transform is applied in frequency domain to the Fourier transform of the analytical representation of a band-limited OFDM signal. The Hilbert transform is then approximated by a development in series into orthogonal twisted modes. This can be seen as an inverse Fourier transform of the complex analytical signal. Therefore an OAM IFFT based transmitter is proposed where parallel IFFTs are performed for each OAM mode and superimposed.

Abstract: A radio communications method includes carrying out, by a transmitter: providing a digital time signal carrying digital symbols to be transmitted; and transmitting a radio frequency signal carrying the digital time signal. The method further includes carrying out, by a receiver: receiving the radio frequency signal transmitted by the transmitter; processing the received radio frequency signal to obtain a corresponding incoming digital signal; and extracting, from the incoming digital signal, the digital symbols carried by the incoming digital signal. The digital time signal carrying the digital symbols to be transmitted results from an approximation of the Hilbert transform in frequency domain, which approximation is based on a frequency main mode and one or more frequency twisted modes, wherein the frequency main and twisted modes carry, each, respective digital symbols to be transmitted.

Abstract: A radio communications method, includes carrying out, by a transmitter: generating or receiving digital symbols to be transmitted; generating, every S digital symbols generated/received (with S integer higher than three), a corresponding multi-mode digital signal; generating a multi-frame digital signal comprising successive, non-overlapped time frames, each of which has the predefined time length and carries a respective multi-mode digital signal generated; and transmitting a radio frequency signal carrying the multi-frame digital signal. The radio communications method further includes carrying out, by a receiver: receiving the radio frequency signal transmitted by the transmitter; processing the received radio frequency signal to obtain a corresponding incoming digital signal; performing, on the basis of the incoming digital signal, carrier synchronization, clock synchronization, and frame synchronization; and extracting, on the basis of the carrier, clock and frame synchronizations.

Abstract: A radio communications system includes a transmitter and a receiver. The transmitter generates or receives digital symbols having a given symbol rate associated with a corresponding symbol period; and generates, every S digital symbols generated/received (S>3), a respective multi-mode digital signal, which has a predefined time length shorter than S times the symbol period, which is sampled with a predefined sampling rate higher than the symbol rate, and which carries the S digital symbols by a plurality of orthogonal harmonic modes including a main mode which is a real harmonic mode and carries P of the S digital symbols (P<S). The receiver receives and processes the radio frequency signal to obtain a corresponding incoming digital signal; and extracts, from successive, non-overlapped portions of the incoming digital signal sampled with the predefined sampling rate, the S digital symbols respectively carried by each incoming digital signal portion by the orthogonal harmonic modes.

Abstract: The present invention relates to a satellite communication system for extending communications between a vehicle and a satellite in an area of non-visibility of the satellite. The satellite communication system comprises a fixed transceiver system and a mobile transceiver system. The fixed transceiver system includes a first antenna intended to be positioned outside the area of non-visibility of the satellite, and at least one second antenna coupled with the first antenna and intended to be positioned in the area of non-visibility of the satellite. The fixed transceiver system is configured to receive through the first antenna downlink signals transmitted by the satellite on at least one downlink carrier frequency and to transmit the received downlink signals on the at least one downlink carrier frequency in the area of non-visibility of the satellite through the at least one second antenna.

Abstract: In a synthetic aperture radar system monitoring an area containing at least one moving target for identification, the target is equipped with an identification device, which receives the radar signal transmitted by the radar system, and transmits a processed radar signal obtained by modulating the incoming radar signal with a modulating signal containing target information, such as identification and status information, and by amplifying the modulated radar signal; the radar echo signal reflected by the monitored area and containing the processed radar signal is received and processed by a control station of the radar system to locate the target on a map of the monitored area, and to extract the target information to identify the target.

Abstract: The present invention relates to a satellite communication system for extending communications between a vehicle and a satellite in an area of non-visibility of the satellite. The satellite communication system comprises a fixed transceiver system and a mobile transceiver system. The fixed transceiver system includes a first antenna intended to be positioned outside the area of non-visibility of the satellite, and at least one second antenna coupled with the first antenna and intended to be positioned in the area of non-visibility of the satellite. The fixed transceiver system is configured to receive through the first antenna downlink signals transmitted by the satellite on at least one downlink carrier frequency and to transmit the received downlink signals on the at least one downlink carrier frequency in the area of non-visibility of the satellite through the at least one second antenna.