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 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 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 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 device for generating Orbital Angular Momentum (OAM) modes for radio communications. The device is designed to receive one or more input digital signals, each of which has a respective sampling period which is a respective multiple of a given sampling period, and occupies a frequency bandwidth which is a respective fraction of a given available frequency bandwidth. The device is operable to apply, to each input digital signal, a respective space modulation associated with a respective OAM mode having a respective topological charge to generate a corresponding digital signal carrying the respective OAM mode. The device is configured to apply, to each input digital signal, the respective space modulation by interpolating said input digital signal and phase-modulating the interpolated input digital signal so as to generate a corresponding phase-modulated digital signal carrying the respective OAM mode, having the given sampling period, and occupying the given available frequency bandwidth.

Abstract: A device for generating Orbital Angular Momentum (OAM) modes for radio communications. The device is designed to receive one or more input digital signals, each of which has a respective sampling period which is a respective multiple of a given sampling period, and occupies a frequency bandwidth which is a respective fraction of a given available frequency bandwidth. The device is operable to apply, to each input digital signal, a respective space modulation associated with a respective OAM mode having a respective topological charge to generate a corresponding digital signal carrying the respective OAM mode. The device is configured to apply, to each input digital signal, the respective space modulation by interpolating said input digital signal and phase-modulating the interpolated input digital signal so as to generate a corresponding phase-modulated digital signal carrying the respective OAM mode, having the given sampling period, and occupying the given available frequency bandwidth.

Abstract: A method for establishing radiofrequency links via a telecommunication satellite having several spots, designated a multispot satellite, between at least one terrestrial station and a service area composed of a plurality of elementary covering zones, designated cells, each cell comprising a plurality of terrestrial terminals is disclosed. This type of satellite allows the use of several spots of antennae on board the satellite to cover contiguous geographical zones or cells, instead of a single broad spot. Each cell is associated with a spot to which a frequency band is attributed. In the case of the loss of a spot associated with a cell, designated a faulty cell, the spot (FR1, FR2, FB1, FB2, FV1, FV2) associated with at least one contiguous cell (CR1, CR2, CB1, CB2, CV1, CV2) to the said faulty cell is likewise associated with a part of the said faulty cell so that the area (CPJ?) of said faulty cell is reduced.

Abstract: A method for establishing radiofrequency links via a telecommunication satellite having several spots, designated a multispot satellite, between at least one terrestrial station and a service area composed of a plurality of elementary covering zones, designated cells, each cell comprising a plurality of terrestrial terminals is disclosed. This type of satellite allows the use of several spots of antennae on board the satellite to cover contiguous geographical zones or cells, instead of a single broad spot. Each cell is associated with a spot to which a frequency band is attributed. In the case of the loss of a spot associated with a cell, designated a faulty cell, the spot (FR1, FR2, FB1, FB2, FV1, FV2) associated with at least one contiguous cell (CR1, CR2, CB1, CB2, CV1, CV2) to the said faulty cell is likewise associated with a part of the said faulty cell so that the area (CPJ?) of said faulty cell is reduced.

Abstract: Apparatus provides the capability to receive data signals in more than one format and the capability to receive data signals of two or more formats and/or over two or more frequency bandwidth ranges so as to allow a plurality of broadcast data receivers to be connected to receive data and to be operated independently of the other apparatus.