182 results about "Frequency separation" patented technology

Methods and apparatus for transmitting communications signals that are both power efficient and effective at avoiding or reducing transmitter-generated receive band noise. An exemplary transceiver apparatus includes a multi-mode transmitter that is configurable to operate in a plurality of operating modes (e.g., a polar mode, a quadrature mode and a hybrid mode), a receiver, and an operating mode controller. The operating mode controller is configured to control which operating mode the transmitter is to operate, depending on one or more of a transmit (Tx) power, receive (Rx) power, the Tx power relative to the Rx power, a level of frequency separation between a Tx frequency band and a Rx frequency band (Tx / Rx band separation), and modulation type employed by the transmitter.

Methods and systems for carrying different signals required for MIMO communication using a single coaxial cable between two endpoints of a distributed antenna system (DAS) network. Original MIMO signals having the same frequency are frequency-separated at a first endpoint of the network. The frequency-separated signals are propagated together over the single coaxial cable and then reconstructed to their original frequency at a second endpoint of the network.

The present invention provides a distance measurement method and device using ultrasonic waves. The present invention includes sufficiently amplifying a received ultrasonic wave signal and separating a specific frequency from an ultrasonic wave signal mixed with an unnecessary signal to extract an arrival signal of a first pulse. It is thus possible to calculate a distance of an object safely.

An optical processor for controlling a phased antenna array uses a frequency-shifted feedback cavity (FSFC), which includes a traveling-wave cavity. The FSFC incrementally delays and incrementally frequency shifts optical signals circulating in the traveling-wave cavity. Optical signals coupled out of the FSFC are separated by frequency, hence by delay, and processed to control either or both transmit and receive beam-forming operations. The FSFC provides a receiver with multiple receive signals which have incremental values of frequency. Each frequency corresponds to an incremental time sampling of optical signals input into the FSFC. Transmit signals coupled out of the FSFC have frequency and phase relationships that result in short time-domain pulses when combined. Controlling modulation and frequency of the transmit signals achieves carrier interference multiple access, a new type of spread-spectrum communications.

A jammer for jamming communications in a communications system where the communications system operates with digital bursts having burst periods measured in time and occurring in a communication frequency band such as GSM having a transmit band and a receive band. The jammer includes a tone comb generator for providing repetitions of jamming signals for the communication frequency band where the jamming signals have jamming signal intervals providing frequency separation between the jamming signals. The jamming signals are generated with a dwell time substantially less than a burst period for the communications system. The jamming signals are generated concurrently for the transmit band and the receive band and are transmitted as RF jamming signals to jam communications for mobile stations.

A method of cell search in a wireless communication systems having a plurality of base stations and a mobile station, each of the plurality of base stations serving a separate cell within a service area and transmitting a common primary synchronization code (PSC) in a primary synchronization channel within a slot of a radio frame, the method including the steps of: (a) scanning (72) through radio channels in scanning increments corresponding to a standard channel raster; (b) estimating (98) the PSC signal-to-noise ratio of each radio channel; (c) if a PSC signal-to-noise ratio is above a first predetermined threshold level (100), completing a cell search procedure including slot synchronization, frame synchronization and scrambling code detection steps for that radio channel; (d) if the cell search procedure is successfully completed (112) for the radio channel in step (c), increasing the scanning increments to the broadcast frequency separation between cells; (e) when all radio channels are scanned in step (d), sorting (74) the scanned radio channels in descending order by PSC signal-to-noise ratio; and (f) performing (76) the cell search procedure on each sorted radio channel in descending order.

A MEMS resonator includes two resonating masses having an anti-phase and in-phase resonance mode, each mode having a resonance frequency, and an anti-phase resonance levering system coupled to the two resonating masses to stiffen and / or dampen the in-phase resonance mode while leaving the anti-phase resonance mode compliant. This effectively raises the in-phase resonance frequency above the anti-phase resonance frequency, and potentially creates a large frequency separation between the two resonance modes. This reduces the energy transfer between the two modes, allowing for robustness to external acceleration, because the in-phase mode is of a higher frequency. The anti-phase resonance levering system is disposed between the two resonating masses as an internal levering mechanism, or is disposed around the two resonating masses as an external levering mechanism.

An acoustic microwave filter comprises an input and an output, and a plurality of acoustic resonators coupled between the input and the output. The difference between the lowest resonant frequency and the highest resonant frequency of a plurality of resonators in the filter is at least 1.25 times the frequency separation of the resonator with the highest resonant frequency in the plurality of resonators. Another acoustic microwave filter comprises an input and an output, and a plurality of acoustic resonators coupled between the input and the output to form a passband. The frequency difference between a local minimum or a local maximum of a return loss magnitude of the acoustic microwave filter and the edge of the passband is at least once the frequency separation of the resonator with the highest resonant frequency.

An airborne jammer for transport by an aircraft for jamming communications in a communications system where the communications system operates with digital bursts having burst periods measured in time and occurring in a communication frequency band such as GSM having a transmit band and a receive band. The jammer includes a tone comb generator for providing repetitions of jamming signals for the communication frequency band where the jamming signals have jamming signal intervals providing frequency separation between the jamming signals. The jamming signals are generated with a dwell time substantially less than a burst period for the communications system. The jamming signals are transmitted as RF jamming signals to jam communications for mobile stations.

Disclosed is an apparatus and a method for performing time synchronization by using Global Positioning System (GPS) information in a communication system. The apparatus comprises a grand-master node having a GPS receiver, for generating a synchronizing message required to synchronize time on slave nodes by using Time Of Day (TOD) information received from the GPS receiver and at least one slave node for receiving the synchronizing message required to synchronize time from the grand-master node or from another slave node, for carrying out time synchronization operation by using an Offset and Frequency Compensation Clock (OFCC) synchronization process supporting time offset and frequency separation compensation, and for generating a synchronizing message required to synchronize time on other slave nodes.