169 results about "Frequency division duplexing" patented technology

A space-based component, such as a satellite, is configured to receive wireless communications from radiotelephones in a satellite footprint over an uplink satellite radiotelephone frequency, and to transmit wireless communications to the radiotelephones over a downlink radiotelephone frequency. An ancillary terrestrial network, that may include one or more ancillary terrestrial components, is configured to transmit wireless communications to, and receive wireless communications from, the radiotelephones over the uplink satellite radiotelephone frequency in a time-division duplex mode. An interference reducer is configured to reduce interference from the wireless communications that are received by the space-based component from the second radiotelephone and / or from the ancillary terrestrial network over the uplink satellite radiotelephone frequency, using the wireless communications that are transmitted by the ancillary terrestrial to, and / or received by the ancillary terrestrial network from, the second radiotelephone over the uplink satellite radiotelephone frequency.

In the method of estimating a time offset between link points in a communication network operating in frequency division duplex mode, a time offset between first and second link points is estimated based on communication measurements made by user equipment communicating with the first and second link points.

The intelligent antenna subsystem correcting method and device is used in frequency division duplex and wideband CDMA system and the device consists of intelligent antenna and correcting detection system linked together. The correcting method includes correcting and detecting the antenna units in the antenina array and the cables in feeding cable in advance; testing the transmission parameters ofthe coupling structure comprising the coupler assembly and the correcting detection system and storing the test results in the correcting detection system; correcting the transmission parameters of the upward and downward transceiving channels of the detecting system when the system is in normal operation state and calculating the correcting weight value output to the base band beam shaper for weighting.

Accordingly, a method and apparatus are provided wherein a receiver system selects a pre-coding matrix, comprising eigen-beamforming weights, to use and provides rank value and matrix index associated with the selected matrix to the transmitter system. The transmitter system upon receiving the rank value and matrix index, determine if the matrix associated with the matrix index provided by the receiver system can be used. If not, them transmitter system selects another matrix for determining eigen-beamforming weights.

The present invention relates generally to a cellular telecommunications network. Each cell has at least one base station for sending messages on a downlink of a Frequency Division Duplex (FDD) to end user equipments within the cell and for receiving messages on an uplink from end user equipments within the cell. Other end user equipment located within the cell which have no or only poor communication directly with the base station over the FDD communicate with the base station indirectly via an intermediate end user equipment, such as a mobile telephone. The intermediate end user equipment includes an FDD transceiver and a Time Division Duplex (TDD) transceiver and an FDD / TDD interface. The intermediate end user equipment receives signals from the base station over the FDD using the FDD transceiver and relays them via the FDD / TDD Interface and the TDD transceiver towards a relevant one of the other end user equipments over a TDD and receives signals from the other end user equipment over the TDD using the TDD transceiver and relays them via the FDD / TDD interface and the FDD transceiver to the base station over the FDD. The network provider thereby improves capacity and coverage by utilising TDD channels without having to deploy and TDD infrastructure.

The invention belonging to the field of the wireless communication technology relates to a channel estimation algorithm of a multi-user large-scale multiple-input multiple-output (MIMO) system in a frequency division duplexing (FDD) mode. According to joint sparsity of a multi-user large-scale MIMO channel, channel estimation and reconstruction are carried out by approximate replacement and iterative estimation algorithms based on a Bayesian compressed sensing theory. With the method provided by the invention, the process of direct matrix inversion of the posterior probability of X obtained by the EM algorithm is avoided, so that the operation complexity is reduced, the operation load is reduced, the operation speed is increased, and the operation precision is improved.

Disclosed is a method and an apparatus for transmitting a downlink Synchronization CHannel (SCH) in an Orthogonal Frequency Division Multiplexing (OFDM)-based cellular wireless communication system supporting a scalable bandwidth. Herein, initial cell search and neighbor cell search are seamlessly performed. The disclosed method and apparatus disclose a synchronization channel structure applicable to both a Frequency Division Duplex (FDD) system and a Time Division Duplex (TDD) system.

Certain embodiments of the invention may be found in a method and system for a simplified user group selection scheme with finite-rate channel state information feedback for frequency division duplex (FDD) multiuser multiple-input-multiple-output (MIMO) downlink transmission. Aspects of the method may include selecting, from a plurality of users, a first user having a channel gain that is greater than a channel gain corresponding to a remaining portion of the plurality of users. At least a second user may be selected from a portion of the remaining portion of the plurality of users. The selected at least the second user has a channel direction that may be approximately orthogonal to that of the first user. The channel gain may be defined by a quantized channel gain. A quantized channel direction of the selected first user may be determined for the selecting the at least the second user.

The invention provides a wireless communication system based on an E waveband and a signal processing method thereof, which are used for realizing frequency division duplex wireless communication based on the E waveband. The wireless communication system based on the E waveband comprises a communication processing subsystem, a millimeter wave front-end subsystem and a dual-polarized antenna, wherein the communication processing subsystem is used for receiving a baseband signal and a control signal by means of a baseband signal processing module, carrying out specific scrambling, encoding, interleaving, modulation and digital pre-distortion compensation processing on the baseband signal according to the control signal, and then transmitting the processed baseband signal to a radio frequencysignal processing module; the processed baseband signal is converted into an E-band signal through up-conversion and then transmitted to the millimeter wave front-end subsystem, and the millimeter wave front-end subsystem amplifies the E-band signal through using a power amplification module, and then transmits the amplified E-band signal to the dual-polarized antenna to be transmitted; and the dual-polarized antenna is further used for receiving the E-band signal and transmitting the E-band signal to the millimeter wave front-end subsystem, then the E-band signal is transmitted to the communication processing subsystem by the millimeter wave front-end subsystem and is converted into the baseband signal through down-conversion, and the baseband signal is transmitted to the baseband signalprocessing module for output.

A transceiver suitable for frequency duplex division communication is disclosed. The transceiver comprises a transmitter, wherein the transmitter comprises a power amplifier; a receiver; an auxiliary power amplifier which is arranged to provide a controllable phase shift and gain output; a first filter arranged at an output of the power amplifier arranged to attenuate frequencies at a receiving frequency of the receiver; a second filter arrangement at an output of the auxiliary power amplifier arranged to attenuate frequencies at a receiving frequency of the receiver; and a signal transmission arrangement. The signal transmission arrangement is arranged to transmit signals provided from the transmitter through its power amplifier to a radio frequency, RF, connecting point, receive signals from the RF connecting point and provide the signals to the receiver, and provide signals from the auxiliary amplifier towards an input of the receiver. The transceiver also comprises a controller, wherein the controller is arranged to control the auxiliary power amplifier output to provide a signal that has a phase and amplitude in relation to the output of the power amplifier of the transmitter such that the transmitter contribution to the signal at the input of the receiver is suppressed. A method of controlling the transceiver, a communication device and computer program are also disclosed.