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: 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: 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 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: An RF signal generator has an optical part for outputting optical carrier signals separated in optical frequency, and a modulator arranged to modulate the optical carrier signals with an intermediate frequency to generate sidebands. A phase modulation is applied to one or more of the sidebands or the optical carriers, without applying the phase modulation to others of the signals, and the modulator has integrated optical paths for both the phase modulated signals and for the others of the signals. A detector part carries out heterodyne detection to combine the phase modulated and other signals to output an RF signal having the phase modulation. By having integrated optical paths, the relative phase of these optical paths can be more stable than using a fiber sagnac interferometer and optical isolator thus enabling use in advanced radio communications.

Abstract: An optical label extractor (10) comprising a non-linear optical element (12), a pump source (14) and optical filter apparatus (16). Said non-linear optical element (12) is arranged to receive optical data packets (18) at data signal wavelengths. Each said data packet comprises at least one data bit and at least one label bit. Said pump source (14) is arranged to pump said non-linear optical element such that any non-zero label bit experiences a non-linear optical effect on propagation through said non-linear optical element and an output label bit (20) comprising a respective further wavelength is thereby generated. Said optical filter apparatus (16) is arranged to receive any said output label bit from said non-linear optical element and being further arranged to prevent transmission of a part of said output label at said respective data signal wavelength and to transmit a part of said output label bit at said respective further wavelength.

Abstract: A receiver scheme for optical signals in Return-to-zero (RZ) systems comprises a conventional receiver at the input of which is placed an all-optical decision element realized with nonlinear optical elements. This allows obtaining a substantial increase in performance compared with a simple conventional receiver optimized for NRZ signals. In particular, an optical decision is made up advantageously of two non-linear optical loop mirrors (NOLMs) arranged in cascade with an optical amplifier at the input and a pass-band filter at the output. The loops lengths may be different, as may be the splitting ratios of the couplers of the NOLMs.

Abstract: An apparatus and method for generating a train of optical pulses. The apparatus comprises an optical resonant cavity (1) for confining an optical signal in the cavity to a number of modes, a modulator (3), and a control signal generator (101). The modulator comprises an interferometer arranged to cause interference of the optical signal with itself to produce an output and controllable material, such as an electro-optic crystal, arranged in a path of the optical signal, an optical property of the controllable material dependent on a control signal (3b) applied to the controllable material such that changes in the optical property alter optical signals travelling that path to affect the interference of the optical signals, and therefore the output of the modulator.