181 results about "Frequency division duplexing" patented technology

A radioterminal communications system includes an ancillary terrestrial component configured to receive from at least some of a plurality of radioterminals using frequencies from a first satellite frequency band (e.g., an L-band) and to transmit to at least some of the plurality of radioterminals using frequencies from a second satellite frequency band (e.g., an S-band). The system further includes a space-based component configured to communicate with the plurality of radioterminals using at least some of the frequencies from the first satellite frequency band and / or at least some of the frequencies from the second satellite frequency band. In some embodiments the ancillary terrestrial component communicates with radioterminals using a Time Division Duplex (TDD) mode and the space-based component communicates with the same or other radioterminals using a Frequency Division Duplex (FDD) and / or a TDD mode.

Provided is a method and apparatus for controlling soft buffer for TDD-FDD carrier aggregation. The method includes: establishing a Radio Resource Control (RRC) connection with a base station through a first serving cell, the first serving cell supporting a Time Division Duplex (TDD) mode; receiving an RRC message from the base station through the first serving cell, the RRC message comprising carrier aggregation (CA) configuration information, the CA configuration information comprising information of a second serving cell supporting a Frequency Division Duplex (FDD) mode; determining a maximum number of DL HARQ processes for the second serving cell, the maximum number of DL HARQ processes for the second serving cell being differently determined according to a DL reference timing; and storing soft channel bits for a received transport block (TB) based on the determined maximum number of DL HARQ processes for the second serving cell.

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.

Integrating dual antennae into a single rigid assembly guarantees parallel alignment between the antennae and provides higher isolation with lower insertion loss than duplexing methods can achieve through a single antenna. The resulting higher performance at lower cost can benefit two-way communication systems using time division duplexing, frequency division duplexing, or polarization division duplexing; or combinations of these methods.

Radio devices having separate transmission and reception reflectors for transmitting and receiving wireless signals that detect interference in a transmission channel and may be automatically or manually switch duplexing schemes when reflections, radar or other interference is detected. These devices typically include both a transmission antenna reflector and a receiving transmitter reflector, which may be connected or formed of a single housing, that are operatively coupled to radio circuitry for transmission and reception of wireless signals. Interference, and particularly reflected signals between the transmitter and receiver, are avoided by including a detector coupled to either (or both) reflectors that monitors the transmitting frequency channel; reflections and / or radar signals may be detected and may trigger switching (manual or automatic switching) to a different duplexing modes such as frequency-division duplexing (FDD), time-division duplexing (TDD), etc.

The invention discloses methods and device for transmitting and receiving ACK / NACK (acknowledgement / negative acknowledgement). The method for transmitting the ACK / NACK comprises: when a PUSCH (physical uplink shared channel) used for transmitting uplink control information and determined by user equipment (UE) is a PUSCH which has no corresponding PDCCH (physical downlink control channel), or a PUSCH under the uplink configuration and downlink configuration 0 in a TDD (time division duplexing) system, or a PUSCH in an FDD (frequency division duplexing) system, if the UE does not receive the PDSCH in a downlink subframe which performs ACK / NACK feedback in an uplink subframe which sends the PUSCH correspondingly, or if the UE instructs the PDCCH released by downlink SPS (semi-persistent scheduling) resources, the UE determines the ACK / NACK feedback information transmitted on the PUSCH; the UE determines the resources for transmitting the ACK / NACK feedback information on the PUSCH; and the UE transmits the ACK / NACK feedback information on the determined resources for transmitting the ACK / NACK feedback information on the PUSCH. According to the invention, the inconformity of understanding on whether the ACK / NACK is transmitted on the PUSCH by a base station and the UE caused by the UE downlink data loss can be avoided, and the transmission reliability of the downlink data and ACK / NACK feedback information can be improved.

A radioterminal communications system includes an ancillary terrestrial component configured to receive from at least some of a plurality of radioterminals using frequencies from a first satellite frequency band (e.g., an L-band) and to transmit to at least some of the plurality of radioterminals using frequencies from a second satellite frequency band (e.g., an S-band). The system further includes a space-based component configured to communicate with the plurality of radioterminals using at least some of the frequencies from the first satellite frequency band and / or at least some of the frequencies from the second satellite frequency band. In some embodiments the ancillary terrestrial component communicates with radioterminals using a Time Division Duplex (TDD) mode and the space-based component communicates with the same or other radioterminals using a Frequency Division Duplex (FDD) and / or a TDD mode.

A method for allocating an Acknowledgement / Negative Acknowledgement (ACK / NACK) channel by a Base Station (BS) in a Frequency Division Duplexing (FDD) system is provided. The method includes allocating downlink resources in one or more cells to a User Equipment (UE), transmitting, Physical Downlink Control Channel (PDCCH) information and downlink data using the downlink resources, allocating at least four ACK / NACK channels to the UE, receiving ACK / NACK information for the PDCCH information and the downlink data fed back by using two antennas from the UE, and performing re-transmission or transmitting new data according to the ACK / NACK information, wherein at least two of the at least four ACK / NACK channels are the same as at least two ACK / NACK channels allocated by the BS in a mode not using a Spatial Orthogonal Resource Transmit Diversity (SORTD) scheme, and the at least two of the at least four ACK / NACK channels are allocated to different antennas.

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.

An object of the present invention is to provide a mechanism of measuring a reference signal that is less over head consuming and less time consuming. The object is achieved by a method for managing uplink channel estimation in a base station. The base station is comprised in a radio access network using Frequency Division Duplex (FDD). The base station is associated with a first cell of a number of cells within the radio access network. The base station is adapted to connect at least one mobile terminal, being situated in the first cell, to a network infrastructure. The method comprises the step of transmitting a redirected reference signal on an uplink band to the mobile terminal. The redirected reference signal is intended for uplink channel estimation.

A method, apparatus, and computer-readable medium for performing asymmetric frequency division duplexing (FDD) are provided. The method includes allocating a first bandwidth for an uplink portion of an FDD data transmission; and allocating a second bandwidth for a downlink portion of the FDD data transmission; wherein the first bandwidth and the second bandwidth have different sizes.

A frequency division duplex radio access telecommunications terminal comprises a transmitter for transmitting a transmission signal at a first frequency. The transmitter is arranged to switch between a peak power mode in which the transmission signal is transmitted at a peak power level, and a reduced power mode. A receiver receives a reception signal at a second frequency different from the first frequency. A detector measures the signal strength of the reception signal. A controller is arranged to cause the detector to measure the signal strength of the reception signal whilst the transmitter is operating in the reduced power mode, and at a predetermined time before the transmitter switches to the peak power mode.

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.

There is provided to an RF calibration apparatus and method for a multi-antenna mobile communication system, which calibrates a phase error and gain error of an RF path by calculating the minimum value of a sum of an initialized reference signal and a comparison signal by a simple operation and controlling the phase value of a phase converter and the gain of a variable amplifier on the RF path, in calibrating the RF path of a multi-antenna mobile communication system of a TDD (Time Division Duplexing) type or FDD (Frequency Division Duplexing) type.

The invention discloses an FDD antenna based on a dual-mode resonator. The FDD antenna comprises a square patch with a square groove, a stacked parasitic square patch, a first short-circuit patch and a second short-circuit patch loaded on the inner edge of the square patch, an emission channel feed probe, a reception channel feed probe, a reflection floor, an emission port, a reception port, an emission channel feed network, and a reception channel feed network. The square patch is printed on the top surface of a middle medium substrate, the parasitic square patch is printed on the top surface of an upper medium substrate, the reflection floor is printed on the top surface of a lower medium substrate, and the emission channel feed network and the reception channel feed network are printed on the bottom surface of the lower medium substrate. Designed is the antenna serving as a feed network and having a frequency division duplex function through induction of a dual-mode resonator. The antenna enables emission and reception to be conducted at the same time, and electromagnetic waves for emission and reception by the antenna are linearly polarized electromagnetic waves.

The embodiment of the invention provides a dual-connection communication structure and an uplink method thereof, which relate to the field of communication and can satisfy the SAR (Specific AbsorptionRate) limit requirement while guaranteeing the uplink coverage. The method includes the following steps: a user terminal sends a scheduling request containing the maximum uplink transmission power toa TDD (Time Division Duplexing) base station and an FDD (Frequency Division Duplexing) base station; when the maximum uplink transmission power is determined to be greater than a preset power, the TDD base station sends a first uplink duty cycle to the FDD base station; the FDD base station sets a second uplink duty cycle according to the first uplink duty cycle to enable the average uplink transmission power of each wireless frame length in the communication connection between the two terminal and a target base station to be less than or equal to the preset power; and the TDD base station and the FDD base station respectively send a first scheduling consent permission including a first uplink slot and a second scheduling consent permission containing a second uplink slot generated thereby to the user terminal so that the user terminal can transmit uplink information to the target base station in the first uplink slot and the second uplink slot.

A method and device for realizing frequency spectrum coordination between Time Division Duplexing (TDD) system and Frequency Division Duplexing (FDD) system, which include that: obtaining resource assignment result and user information to be scheduled of the TDD system and the FDD system (100), accounting the needed uplink bandwidth of the TDD system and the useable uplink bandwidth of the FDD system (101); based on the accounted result, realizing that the TDD system transmits upwardly on the uplink resource of the FDD system (102). By the method of the present invention, when the uplink bandwidth of the FDD system is residual and the uplink bandwidth of the TDD system is lacking, the TDD system can transmit upwardly on the uplink frequency band of the FDD system, the flexible assignment of the frequency spectrum between the TDD system and the FDD system is realized, the utilization ratio of the frequency spectrum and the throughput of the system are improved.

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.

This invention relates to a quick hop-expansion communication method based on OFDM, in which, an transmission end generates frequency expansion sequence, sub-carrier distribution signals and FH sequences according to user request, carries out direct sequence frequency expansion or code process then to modulate symbols then distributes the modulated signals to the sub-carriers of communication signals of users according to the sub-carrier distribution signals to be added with circulation prefix for D / A conversion then modulates the received analog signal to the carrier frequency generated according to the FH sequence, the receiving end receives signals then carries out de-FH, A / D conversion and removing the circulation prefix and de-modulates the modulation signals on the sub-carrier of the user communication signals to be output in series to get the user data after the symbol is de-modulated, de-coding or de-FH.

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.

Techniques for extending coverage of a wireless communication network (e.g., a cellular network) to indoor and other locations are described. A wireless device may communicate with a base station in awireless network via downlink and uplink frequency channels in a licensed frequency band using frequency division duplexing (FDD). The wireless device may communicate with a piconet base station (PBS) in a pico network (piconet) via the uplink frequency channel using time division duplexing (TDD). The PBS may communicate with the wireless device on the uplink frequency channel and may exchange data with the wireless network via a wireline communication link. The PBS may forward data received from the wireless device to the wireless network and may also forward data received from the wirelessnetwork for the wireless device to the wireless device. The PBS may receive paging messages from the wireless network for the wireless device and may forward the paging messages to the wireless device.

Disclosed are an apparatus and a method for performing communication using a half-frequency division duplex (H-FDD) frame structure in a mobile communication system. A user equipment for performing communication using an H-FDD frame structure according to the present invention comprises an RF unit in which each user equipment group receives and transmits signals using the H-FDD frame structure wherein the order of the downlink zone and uplink zone are reversely allocated to each of the groups. The downlink zone and uplink zone, which are allocated to each of the user equipment groups in the H-FDD frame structure, include a sub-frame wherein one or more symbols are allocated to idle time slots or are punctured. Each of the user equipment groups can receive and transmit signals using symbols that are not allocated to the idle time slots or are not punctured in the sub-frame.

The invention discloses a downlink channel estimation method for use in an FDD (Frequency Division Duplexing) large-scale MIMO (Multiple-Input Multiple-Output) system. The method comprises the following steps: constructing an uplink pilot signal receiving model of the FDD large-scale MIMO system; performing compressed sensing channel estimation on an uplink space channel; acquiring a support set of the uplink space channel according to an estimated value of the uplink space channel, and estimating a support set of a downlink space channel according to the support set of the uplink space channel; constructing a downlink pilot signal receiving model of the FDD large-scale MIMO system; and performing downlink compressed sensing channel estimation based on estimation support set information ofthe downlink space channel. According to the method disclosed by the invention, a sparse support set of the downlink space channel is estimated according to an estimation result of the uplink space channel by means of the spatial correlation between the uplink channel and the downlink channel, thereby improving the performance of downlink channel estimation.

Disclosed is a method for transmitting uplink semi-persistent scheduling SPS service data in a frequency division duplexing FDD system. The method comprises: initially transmitting or retransmitting a data packet using transmission time interval TTI bundling of an uplink SPS service; and when a retransmission indication of the data packet is received, retransmitting the data packet, wherein under the condition of ensuring that the transmission data does not collide, the size of the TTI bundling of the initially transmitted data packet is different from that of the TTI bundling of the retransmitted data packet and / or the round-trip time delay RTT of the initial transmission or the first retransmission is different from the RTT of two adjacent retransmissions. Correspondingly, also disclosed are a method, user equipment and a base station for receiving SPS service data. The present invention increases the transmission time density when SPS service uplink data is transmitted.

The invention discloses mode converting method, device and system in a FDD (Frequency Division Duplex) scene, which relates to the field of wireless communication and can solve the problem that a MS can not realize mode conversion. The method comprises the following steps of: receiving a request message of mode conversion, which is transmitted by an Access Station, wherein the request message requests the MS to convert into an H-FDD (Half-Frequency Division Duplex) mode from an F-FDD (Full-Frequency Division Duplex) mode or convert into the F-FDD mode from the H-FDD mode; and converting to the appointed mode in the request message. The mode converting method in the FDD scene of the other embodiment comprises the following steps of: transmitting the request message of mode conversion to the Access Station, wherein the request message requests the MS to convert into the H-FDD mode from the F-FDD mode or convert into the F-FDD mode from the H-FDD mode; receiving a feedback message that the Access Station agrees to convert and then converting to the appointed mode in the request message. The invention is suitable for the mode conversion in the FDD scene.

The present disclosure relates to packaging of feedback information bits in a wireless communication system. Some embodiments are applicable to both Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD) systems, whereas other embodiments are particularly well-suited for TDD systems. In some embodiments, a method of operation of a wireless device in a cellular communications networkcomprises receiving, from the cellular communications network, an indication of one of a plurality of predefined sets of feedback information codebook sizes, the plurality of predefined sets of feedback information codebook sizes being disjoint subsets of a plurality of predefined feedback information codebook sizes. In some embodiments, the indication enables the wireless device to return an expected number of feedback information bits to the cellular communications network, particularly in a saturation where the wireless device misses one or more downlink assignments.

A physical-layer device includes a first sublayer to receive a first continuous bitstream from a media-independent interface and to provide a second continuous bitstream to the media-independent interface. The physical-layer device also includes a second sublayer to transmit first signals corresponding to the first continuous bitstream and to receive second signals corresponding to the second continuous bitstream. The second sublayer is to transmit the first signals and receive the second signals using time-division duplexing in a first mode of operation and using frequency-division duplexing in a second mode of operation.