7 results about "Single-sideband modulation" patented technology

This invention discloses a simple, multifunctional, integrated 5G analog fronthaul in-band full-duplex communication method for remote units (RUs). This method primarily relates to the fields of optical communication technology and microwave technology. The system structure of the method, as shown in Figure 1 of the specification, includes a laser, downlink vector signal, electrical local oscillator signal, downlink interference signal, target signal, reference signal, 90° electrical coupler, dual-polarization quadrature phase-shift keying modulator, phase modulator, single-mode fiber, optical coupler, polarization beamsplitter, polarization beam combiner, polarization controller, polarizer, and photodetector. The remote unit (RU) uses a single phase (PM) modulator to achieve self-interference cancellation (SIC) combined with anti-fiber dispersion transmission and down-conversion, eliminating the need for bias control and additional local oscillator (LO) branches, resulting in a simple structure. At the central office (CO), the carried downlink signal and local oscillator signal are single-sideband modulated to achieve anti-fiber dispersion transmission. The RU uses wavelength reuse technology to perform PM cascaded down-conversion on the signal received from the uplink, and the SIC is moved from the RU to the CO to simplify the RU. The entire link has no optical filter and is reconfigurable.

The present disclosure relates to a device and a communication method with which it is possible to perform appropriate filtering / image suppression when single side band modulation is used for D2R transmission of an A-IoT device. A device that has a lower complexity than an NB-IoT device comprises: a transmission unit that transmits to a wireless base station by using single side band modulation; and a control unit that selects either an upper side band or a lower side band in the single side band modulation, and uses the selected side band to perform transmission control of a transmission signal to the wireless base station.

This invention discloses a dispersion measurement system based on microwave photonics technology. It uses a microwave signal generated by a first signal generator to perform carrier-suppressed single-sideband modulation (CSSM) on an optical signal generated by a laser. Then, the primary modulated optical signal is used as the carrier signal of a second electro-optic modulator. The microwave signal generated by the second signal generator is then used to perform carrier-unsuppressed CSSM on this optical carrier signal, and the modulated signal is split into two paths. One CSSM-modulated optical carrier microwave signal is used as a probe light to sense the dispersion of the dispersive element under test (DIST), and the other path is used as a reference light. The probe light signal passing through the DIST is converted into a corresponding dispersion-sensing electrical signal, while the reference light signal not passing through the DIST is converted into a corresponding reference electrical signal. The phase difference between the two electrical signals is detected to obtain a voltage value related to the phase difference, and the dispersion coefficient of the DIST corresponding to the current optical carrier wavelength is calculated based on the voltage value.

FIELD: communications.SUBSTANCE: devices for generating amplitude modulation (AM) signals, used in communications equipment. A low-frequency modulating signal source, an analog-to-digital transducer, a first additional adder, a third multiplier, an inverter, a third adder, an additional Hilbert transducer, a second additional adder, a fourth multiplier, a fourth adder, and an additional phase shifter are additionally introduced into the single-sideband modulator.EFFECT: formation of an AM signal, the sidebands of the spectrum of which contain information from a discrete information source and an analog information source.1 cl, 2 dwg

The application relates to a multi-scattering point radar target echo simulation method and device based on a wide-spectrum light source, wherein the method comprises the following steps: dividing the wide-spectrum light source through a polarizer into wide-spectrum light signals of an upper branch and wide-spectrum light signals of a lower branch; modulating radar signals on the wide-spectrum light signals of the upper branch through single sideband modulation with carrier suppression; regulating the amplitudes and phases of the wide-spectrum light signals of the lower branch to change the impulse response of a radar target simulator to be tested; combining the modulated wide-spectrum light signals of the upper branch and the regulated wide-spectrum light signals of the lower branch, and transmitting the combined light signals through a dispersion medium; and obtaining simulated radar target echo signals through photoelectric conversion to simulate the scattering characteristics of a radar target. Therefore, the problems that related technologies are difficult to process signals with large bandwidth, are restricted by storage depth and computing power, are difficult to realize modulation of complex scattering characteristics of signals with large bandwidth, and are difficult to simulate complex scattering characteristics of targets are solved.