Abstract: Transmitting and receiving apparatuses, transmitting and receiving methods, and a transceiver for a phased array antenna are provided. The transmitting apparatus may comprise a laser light source configured to provide an optical beam comprising one or more spectral components. The transmitting apparatus may comprise a modulator configured to modulate the optical beam with a signal to be transmitted. The transmitting apparatus may comprise one or more group delay controlling units configured to add one or more controllable time delays to the one or more spectral components. Further, the transmitting apparatus may comprise a plurality of waveguides each having a chromatic dispersion configured to guide the optical beam, wherein the laser light source is tunable to control time delays added by the plurality of waveguides.

Abstract: A receiver (1) for a phased array antenna comprises a laser light source (2) arranged to provide an optical spectrum comprising a first spectral component having a first wavelength and a second spectral component having a second wavelength. The first wavelength is spaced from the second wavelength. A wavelength separator (4) is configured to separate the first spectral component from the second spectral component, such that the first spectral component is directed onto a first path (A) and the second spectral component is directed onto a second path (B). A first delay unit (16) is configured to add a controllable time delay to the first spectral component on the first path. A second delay unit (42) is configured to add the time delay to the second spectral component on the second path. A modulator (14) is configured to modulate the first spectral component on the first path with a received RF signal from the phased array antenna.

Abstract: A signal generator for a phased array antenna comprises a laser light source arranged to provide an optical spectrum comprising a plurality of spaced wavelengths. The signal generator further comprises a dispersion unit arranged to introduce a delay to a plurality of spectral components of the optical spectrum associated with the spaced wavelengths. The delay is dependent on the wavelength of the spectral components of the optical spectrum. The signal generator further comprises a heterodyning device configured to generate a signal for the phased array antenna by heterodyning the spectral components associated with different ones of the spaced wavelengths of the laser light source.

Abstract: A periodic phase modulation, having a period shorter than a symbol period, is applied as a source modulation, in addition to a symbol modulation, to signals transmitted between a transmitter and a receiver in a communication network. Symbol value elements can be sent from multiple transmitters (203, 303, 603, 703) to a receiver (607, 207) in the same symbol period can be processed on the basis of the source modulation without destructive interference. In some embodiments, the symbol value elements sent by different transmitters can be combined in the receiver. In some embodiments, symbol value elements sent by different transmitters can be distinguished in the receiver.

Abstract: An opto-electronic oscillator (10) comprising: an optical source (12) to generate an optical carrier signal having a carrier wavelength; an optical phase modulator (14) to apply a sinusoidal phase modulation to the optical carrier signal to generate two first order sidebands having a ? phase difference between them; an optical phase shifter (16) comprising an optical resonator configured to apply a substantially ? phase-shift to one of the first order sidebands at a preselected wavelength within an optical spectrum of said first order sideband; and a photodetector (18) configured to perform optical heterodyne detection of the optical carrier signal with both: said one of the first order sidebands substantially it phase shifted by the optical resonator; and the other of the first order sidebands, to generate an electrical carrier signal (20), and wherein a first part of the electrical carrier signal (20a) is delivered to an electrical output (22) and a second part of the electrical carrier signal (20b) is deli

Abstract: A plurality of sub-cells are defined within a cell area of a radio communication network by the intersection of a radio paths of a plurality of directional radio antennas. The plurality of directional radio antennas are arranged to broadcast radio signals simultaneously, and to receive radio signals simultaneously. This disclosure relates to determining of signal values transmitted by or received from the plurality of directional radio antennas in a radio communication network.

Abstract: Transmitting and receiving apparatuses, transmitting and receiving methods, and a transceiver for a phased array antenna are provided. The transmitting apparatus may comprise a laser light source configured to provide an optical beam comprising one or more spectral components. The transmitting apparatus may comprise a modulator configured to modulate the optical beam with a signal to be transmitted. The transmitting apparatus may comprise one or more group delay controlling units configured to add one or more controllable time delays to the one or more spectral components. Further, the transmitting apparatus may comprise a plurality of waveguides each having a chromatic dispersion configured to guide the optical beam, wherein the laser light source is tunable to control time delays added by the plurality of waveguides.

Abstract: An opto-electronic oscillator (10) comprising: an optical source (12) to generate an optical carrier signal having a carrier wavelength; an optical phase modulator (14) to apply a sinusoidal phase modulation to the optical carrier signal to generate two first order sidebands having a ? phase difference between them; an optical phase shifter (16) comprising an optical resonator configured to apply a substantially ? phase-shift to one of the first order sidebands at a preselected wavelength within an optical spectrum of said first order sideband; and a photodetector (18) configured to perform optical heterodyne detection of the optical carrier signal with both: said one of the first order sidebands substantially it phase shifted by the optical resonator; and the other of the first order sidebands, to generate an electrical carrier signal (20), and wherein a first part of the electrical carrier signal (20a) is delivered to an electrical output (22) and a second part of the electrical carrier signal (20b) is deli

Abstract: A transceiver for a phased array antenna comprises a laser light source arranged to provide an optical spectrum comprising a plurality of spaced wavelengths. The transceiver further comprises a dispersion unit arranged to introduce a delay to a plurality of spectral components of the optical spectrum associated with the spaced wavelengths. The delay is dependent on the wavelength of the spectral components of the optical spectrum. The transceiver further comprises a first optical filter configured to select a plurality of spectral components received from the dispersion unit. The transceiver further comprises a first heterodyning device configured to generate a signal for transmission by the phased array antenna by heterodyning the selected spectral components associated with different ones of the spaced wavelengths of the laser light source. The transceiver is configured to receive signals from the phased array antenna.

Abstract: The invention provides a free space optical (FSO) communications terminal for a first telecommunications card or a backplane. The FSO terminal comprises a plurality of transmission interfaces. The FSO terminal further comprises a light signal generating unit adapted to generate a plurality of light signals. Each of the plurality of light signals carries the same information as the other one or more of the plurality of light signals and is arranged for transmission through a respective one of the plurality of transmission interfaces. Each of the plurality of light signals is at a different orthogonal mode from the other one or more of the plurality of light signals. The invention further provides a free space optical (FSO) communications terminal for a second telecommunications card or a backplane. The FSO terminal comprises a plurality of receive interfaces. Each of the plurality of receive interfaces adapted to receive a light signal carrying information.

Abstract: An optical switch (10) comprising: inputs (12) to receive input optical signals at respective wavelengths and having planar wavefronts; conversion apparatus (14) to convert each input optical signal into a respective optical signal having a respective helical wavefront, each helical wavefront having a different orbital angular momentum, OAM; optical multiplexing apparatus (16) to receive each helical wavefront optical signal from the conversion apparatus and to multiplex the helical wavefront optical signals into an OAM multiplexed optical signal; and optical demultiplexing apparatus (18) comprising a plurality of outputs (20), the optical demultiplexing apparatus arranged to: receive the OAM multiplexed optical signal; demultiplex the OAM multiplexed optical signal into a plurality of wavelength multiplexed optical signals each having a different OAM; reconvert each wavelength multiplexed optical signal from its helical wavefront into a respective planar wavefront; and deliver each planar wavefront wavelengt

Abstract: A periodic phase modulation, having a period shorter than a symbol period, is applied as a source modulation, in addition to a symbol modulation, to signals transmitted between a transmitter and a receiver in a communication network. Symbol value elements can be sent from multiple transmitters (203, 303, 603, 703) to a receiver (607, 207) in the same symbol period can be processed on the basis of the source modulation without destructive interference. In some embodiments, the symbol value elements sent by different transmitters can be combined in the receiver. In some embodiments, symbol value elements sent by different transmitters can be distinguished in the receiver.

Abstract: A receiver (1) for a phased array antenna comprises a laser light source (2) arranged to provide an optical spectrum comprising a first spectral component having a first wavelength and a second spectral component having a second wavelength. The first wavelength is spaced from the second wavelength. A wavelength separator (4) is configured to separate the first spectral component from the second spectral component, such that the first spectral component is directed onto a first path (A) and the second spectral component is directed onto a second path (B). A first delay unit (16) is configured to add a controllable time delay to the first spectral component on the first path. A second delay unit (42) is configured to add the time delay to the second spectral component on the second path. A modulator (14) is configured to modulate the first spectral component on the first path with a received RF signal from the phased array antenna.

Abstract: A plurality of sub-cells are defined within a cell area of a radio communication network by the intersection of a radio paths of a plurality of directional radio antennas. The plurality of directional radio antennas are arranged to broadcast radio signals simultaneously, and to receive radio signals simultaneously. This disclosure relates to determining of signal values transmitted by or received from the plurality of directional radio antennas in a radio communication network.

Abstract: A transceiver for a phased array antenna comprises a laser light source arranged to provide an optical spectrum comprising a plurality of spaced wavelengths. The transceiver further comprises a dispersion unit arranged to introduce a delay to a plurality of spectral components of the optical spectrum associated with the spaced wavelengths. The delay is dependent on the wavelength of the spectral components of the optical spectrum. The transceiver further comprises a first optical filter configured to select a plurality of spectral components received from the dispersion unit. The transceiver further comprises a first heterodyning device configured to generate a signal for transmission by the phased array antenna by heterodyning the selected spectral components associated with different ones of the spaced wavelengths of the laser light source. The transceiver is configured to receive signals from the phased array antenna.

Abstract: An RF signal transceiver comprising a mode-locked laser to output an optical signal having a plurality of phase-locked modes, an optical splitter to power split the optical signal into a transmitter optical signal and a receiver optical signal; a transmitter apparatus to receive the transmitter optical signal and comprising an optical filter to select two of the modes, an optical modulator to modulate a part of the transmitter optical signal to form at least one phase modulated optical signal, and a photodetector to heterodyne the phase modulated optical signal with one of the modes without a corresponding phase modulation to form an RF signal for transmission; and a receiver apparatus arranged to receive an RF signal and the receiver optical signal and comprising an optical modulator to modulate the receiver optical signal with the received RF signal; and an optical to electrical signal conversion apparatus to convert the modulated receiver optical signal into a corresponding electrical signal.

Abstract: The invention provides a free space optical (FSO) communications terminal for a first telecommunications card or a backplane. The FSO terminal comprises a plurality of transmission interfaces. The FSO terminal further comprises a light signal generating unit adapted to generate a plurality of light signals. Each of the plurality of light signals carries the same information as the other one or more of the plurality of light signals and is arranged for transmission through a respective one of the plurality of transmission interfaces. Each of the plurality of light signals is at a different orthogonal mode from the other one or more of the plurality of light signals. The invention further provides a free space optical (FSO) communications terminal for a second telecommunications card or a backplane. The FSO terminal comprises a plurality of receive interfaces. Each of the plurality of receive interfaces adapted to receive a light signal carrying information.

Abstract: A method of converting an optical communications signal having a differentially encoded multilevel modulation format into communications traffic bits, the multilevel modulation format having a plurality of constellation points, the method comprising: receiving a consecutive pair of symbol signals of said optical communications signal, the pair of symbol signals being arranged to differentially encode a plurality of communications traffic bits; and generating a plurality of optical binary signals in dependence on the symbol signals, each optical binary signal having a respective binary signal level, wherein the optical binary signals form optical versions of the encoded communications traffic bits.

Abstract: A signal generator for a phased array antenna comprises a laser light source arranged to provide an optical spectrum comprising a plurality of spaced wavelengths. The signal generator further comprises a dispersion unit arranged to introduce a delay to a plurality of spectral components of the optical spectrum associated with the spaced wavelengths. The delay is dependent on the wavelength of the spectral components of the optical spectrum. The signal generator further comprises a heterodyning device configured to generate a signal for the phased array antenna by heterodyning the spectral components associated with different ones of the spaced wavelengths of the laser light source.

Abstract: An optical switch (10) comprising: inputs (12) to receive input optical signals at respective wavelengths and having planar wavefronts; conversion apparatus (14) to convert each input optical signal into a respective optical signal having a respective helical wavefront, each helical wavefront having a different orbital angular momentum, OAM; optical multiplexing apparatus (16) to receive each helical wavefront optical signal from the conversion apparatus and to multiplex the helical wavefront optical signals into an OAM multiplexed optical signal; and optical demultiplexing apparatus (18) comprising a plurality of outputs (20), the optical demultiplexing apparatus arranged to: receive the OAM multiplexed optical signal; demultiplex the OAM multiplexed optical signal into a plurality of wavelength multiplexed optical signals each having a different OAM; reconvert each wavelength multiplexed optical signal from its helical wavefront into a respective planar wavefront; and deliver each planar wavefront wavelengt