284 results about "Listen before talk" patented technology

The present invention relates to a method and apparatus for using a RFID reader network to provide a large operating area, thereby enabling multiple RFID readers to simultaneously operate with minimal interference among all the RFID readers in the same network. The RFID network comprises a plurality of RFID readers connected to a server via a network backbone. Each operating RFID reader is associated with a group of neighboring RFID readers. A neighboring RFID reader is defined as a RFID reader that can detect tag responses for the communication between the operating RFID reader and its RFID tags. Each operating RFID reader sends its neighboring RFID readers at least one Tag Operation (TO) packet before starting to communicate with RFID tags and at least one End of Tag Operation (ETO) packet after the tag operation is completed. To avoid interference, each RFID reader uses a listen-before-talk scheme in which it checks if any TO packet has been sent by neighboring RFID readers before starting radio transmission. If both RFID readers are allowed to transmit, the RFID reader with a neighboring RFID reader just finishing transmission has the higher priority. This approach improves the throughput by taking advantage of the overlapped areas of neighboring RFID readers.

There is provided, for example, an apparatus, which is caused to select a transmission power configuration for a communication with at least one user terminal taking place on component carriers of a carrier aggregation configuration within a shared band, wherein the selection is between a low transmission power configuration applying a transmission power below a predetermined power threshold without a listen-before-talk approach and a high transmission power configuration applying a transmission power of at least the predetermined power threshold; and upon detecting that the selected transmission power configuration needs to be informed, cause an indication of the selected transmission power configuration to the at least one user terminal and at least one secondary cell.

The invention provides an adjustment method for channel occupation probability, an adjustment system for the channel occupation probability and equipment with a base station function. The adjustment method for the channel occupation probability comprises the following steps: adjusting parameter information, corresponding to a signal detection mechanism, of data to be sent according to the data type of the data to be sent of the equipment with the base station function; and adjusting the possibility of occupying a downstream channel of the data to be sent according to the adjusted parameter information, wherein the data type of the data to be sent comprises a found reference signal and / or downstream data. According to the adjustment method for the channel occupation probability, the capability of occupying the channel by an LBT (Listen Before Talk) mechanism for sending a DRS (Discovery Reference Signal) can be improved so that the found reference signal can more easily occupy the channel or at least has the channel occupation probability the same as that of an LBT mechanism for sending common downstream data, so that the power consumption caused by the fact that the reference signal DRS is measured by a terminal, and ell identification, downstream synchronization and time frequency estimation are carried out is reduced, and the accuracy is improved.

The invention provides an HARQ-ACK sending method and apparatus. The method comprises the following steps: determining a to-be-sent HARQ-ACK and a resource position on an unauthorized carrier sending the HARQ-ACK in a predefined manner or a signaling indication manner; executing Listen Before Talk LBT on the unauthorized carrier; and after the LBT is successfully executed, sending the HARQ-ACK on the resource position. By adoption of the HARQ-ACK sending method and apparatus provided by the invention, the influence of a novel frame structure and LBT influence to the original timing relationship sending is solved, the HARQ-ACK sending probability and the feedback flexibility are improved, and the system performance is effectively improved.

The invention discloses a conflict avoiding method for unlicensed bands in an embodiment. The conflict avoiding method comprises the following steps: setting conflict avoidance parameter values of different data types and based on the Listen Before Talk (LBT) mechanism of a load; solving conflict by use of the conflict avoidance parameter values according to the current data type in the unlicensed bands; and sending the conflict avoidance parameter values to user equipment (UE) so that the UE solves conflict by use of the conflict avoidance parameter values according to the current data type in the unlicensed bands. According to the conflict avoiding method for the unlicensed bands of the embodiment, LTE equipment of the unlicensed bands avoids and solves conflict by use of different conflict avoidance parameter values according to the type of the transmitted data so as to ensure that the high-priority service of the LTE equipment can be served preferentially; as a result, the transmission of data of different types can be effectively supported in the unlicensed bands.

The invention provides a base station, and a method and a system for measuring and feeding CSI (channel state information) when an LTE (long term evolution) system works on unauthorized frequency bands. The method includes detecting current downlink channel states when downlink service arrives, and transmitting CSI measurement configuration signals and CSI feedback configuration signals, which correspond to the current downlink channel states, to terminals according to the current downlink channel states; or transmitting CSI measurement configuration signals and CSI feedback configuration signals, which correspond to specified downlink channel states, to the terminals when the downlink service arrives, and enabling the terminals to measure and feed the CSI according to the CSI measurement configuration signals and the CSI configuration signals, which correspond to the downlink channel states, after the downlink channel states are acquired. According to the technical scheme, the base station, the method and the system have the advantage that the CSI can be effectively assuredly normally measured and fed after LBT (listen before talk) mechanisms are introduced onto the LTE system on the unauthorized frequency bands.

The invention provides a data synchronization method for an LTE (Long Term Evolution) system working under a time division duplex mode at an unlicensed frequency band, a data synchronization system for the LTE system working under the time division duplex mode at the unlicensed frequency band, equipment having base station functions and a terminal. The data synchronization method for the LTE system working under the time division duplex mode at the unlicensed frequency band comprises that a downlink channel detection subframe which is arranged inside a time division duplex mode frame structure and used for periodically detecting whether the downlink channel at the unlicensed frequency band is free or not sends a first reference signal when detects that the downlink channel is busy at any detection period to enable the equipment having the base station functions and the terminal of a current community in which the equipment having the base station functions is arranged to keep data synchronization. According to the technical scheme, the data synchronization between the equipment having the base station function and the terminal is guaranteed and the equipment having the base station function and the terminal are avoided from losing touch under the premise that the LTE system utilizes an LBT (Listen Before Talk) detection mechanism.

A radio terminal (3) includes: a wireless transceiver (2001) configured to communicate with one or more radio stations using a licensed frequency and an unlicensed frequency; and at least one processor (2002). The at least one processor (2002) is configured to recognize whether LBT on the unlicensed frequency prior to uplink transmission needs to be performed, start the uplink transmission on the unlicensed frequency after performing the LBT when the LBT is needed, and start the uplink transmission without performing the LBT when the LBT is not needed. As a result, for example, the radio terminal can adaptively cope with the situation in which Listen Before Talk (LBT) by the radio terminal is needed and the situation in which it is not needed.

Methods, systems, and devices for wireless communication are described. A wireless node may receive stress beacons on a channel. Each stress beacon may include an indication of an allowable interference level for a corresponding wireless node that transmitted the stress beacon on the channel. The wireless node may update a backoff window for the channel based on the allowable interference levels indicated in the stress beacons.

A communication device of a wireless communication system for handling a random access procedure includes a processing means and a storage unit. The processing means is used for executing a program. The storage unit, coupled to the processing means, is used for storing the program which instructs the processing means to perform the following steps: receiving a configuration message for the random access procedure from a network of the wireless communication system, wherein the configuration message configures the communication device to transmit a first random access preamble; performing a clear channel assessment (CCA) or listen before talk (LBT) operation before transmitting the first random access preamble; and increasing a preamble transmission counter of the first random access preamble by 1 when performing the CCA or LBT operation.

The invention discloses a channel sending state indication method and a terminal; wherein the method comprises following steps of obtaining resources on a second frequency band; indicating the channel sending state of the resources scheduled to a first frequency band through the resources on the second frequency band, wherein the first frequency band is the frequency band needing to carry out listen-before-talk LBT, and the second frequency band is the frequency band not needing to carry out the LBT or the frequency band occupying a current channel through the LBT. According to the method and the terminal provided by the invention, the technical problem of low uplink transmission efficiency in the prior art is solved; and the technical problem is resulted from the fact that an uplink transmission method cannot give the channel sending state accurately.

The invention relates to LTE-U uplink waveform and variable multi-subframe scheduling. Uplink waveforms for operating long term evolution (LTE) in an unlicensed band (i.e., long term evolution-unlicensed (LTE-U) communication) are disclosed. Carrier aggregation (CA) and standalone (SA) are disclosed. LTE on the licensed channel may provide both control and data, and LTE on the unlicensed channel may provide data. Managing variable transmission time interval (TTI) continuous transmission is disclosed for transmission over multiple subframes of an unlicensed carrier in LTE-U. Listen-before-talk (LBT) requirements of unlicensed carriers provide for additional channel occupancy constraints when scheduling resources for multiple UEs for variable TTI continuous uplink transmissions over multiple subframes. A joint control channel is disclosed that provides control information for all of the potentially available subframes to be scheduled for the uplink transmissions. In addition to management of the variable TTI continuous transmissions, adjustments to uplink signal parameters are also disclosed that address the constraints due to the LBT requirements of unlicensed carriers.

A method, adapted to a communication device, for uplink transmission by using unlicensed spectrum is provided. The method includes following steps. Acquiring transmission resource based on a listen-before-talk (LBT) procedure. Sending an LBT indicator to a base station after successfully acquiring the transmission resource. Receiving a uplink resource grant from the base station. Performing uplink data transmission with the base station on the unlicensed spectrum according to the uplink resource grant.

The embodiments of the present invention provide a configurable homodyne / heterodyne RF receiver including first and second mixers. The configurable homodyne / heterodyne RF receiver functions as a homodyne receiver when the first and second mixers are configured to operate in parallel, and as a heterodyne receiver when the first and second mixers are configured to operate in series. The embodiments of the present invention further provides an RFID reader employing the configurable homodyne / heterodyne RF receiver to facilitate a listen-before-talk function.

The invention provides a random access method and device and user equipment. The random access method comprises the steps of determining listen before talk (LBT) priority levels for executing an LBT mechanism corresponding to messages sent during a random access process, and / or LBT priority levels of an LBT mechanism corresponding to different physical random access channels (PRACHs); sending the messages for random access according to the determined LBT priority levels corresponding to the messages and / or the LBT priority level corresponding to different PRACH formats after successfully executing the LBT mechanism. According to the invention, a problem in the related art that optimization is required to be performed on random access of UE is solved, and the effects of optimizing the random access and improving the random access success rate are achieved.

Provided are a method for transmitting data in an unlicensed band and a device using the same. A transmission node generates a signal to be transmitted in the unlicensed band, and performs listen before talk (LBT) according to the type of the generated signal. If a wireless medium is idle as a result of the LBT, the transmission node transmits the generated node in the unlicensed band.

The application provides a method and device for transmitting a sounding reference signal (SRS), relating to the field of wireless communication. The method comprises the following steps: competing the use rights of unauthorized carriers according to listen before talk (LBT) or clear channel assessment (CCA) detection; and when the use rights of the unauthorized carriers are successfully competed, transmitting the SRS on the unauthorized carriers. The method for transmitting the SRS when the SRS and a PUSCH are synchronously or asynchronously transmitted and partial sub-frames are uplinked is provided, and more SRS transmission opportunities are provided; and an SRS sequence is taken as an occupied signal during downlink transmission, and thus the design of the occupied signal can be simplified.

The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. Embodiments of the present disclosure provides method for transmitting signals on an Unlicensed Frequency Band (UFB), comprising: performing, by a transmitting node, a first type of Listen Before Talk (LBT) on a direction i; transmitting, by the transmitting node, signals on a direction j after passing the first type of LBT, wherein the direction i is omnidirectional, or one or multiple beam directions corresponding to the direction j. The technical scheme of the present disclosure may be applied to high-frequency-band signal transmission and LBT and avoid interference with other nodes on the UFB.

The invention discloses a method and apparatus for determining LBT mode and the method for accomplishing LBT mode switching, comprising: based on related instruction information and / or priority information and / or measurement information, determining the listen before talk (LBT) mode or the LBT mode parameter set; and carrying out by a transmission device the contention access of channel according to the determined LBT mode and / or the LBT mode parameter set. According to the invention, it is possible to determine a LBT mode. Through the choice of the LBT mode, it is possible to avoid the wastes on the channel resources and instruction information by an improper LBT mode, therefore, increasing the efficiency of contention access of channel.

A method and apparatus for performing a random access procedure in a wireless communication system is provided. A user equipment (UE) performs a contention free random access procedure on a first frequency, detects a failure of the contention free random access procedure, and performs a contention based random access procedure. When the first frequency is occupied by other media as a result of listen-before-talk (LBT) operation, the contention based random access procedure may be performed on a second frequency.

Measurement and demodulation may be impacted by varying transmit power due to varying numbers of carriers in a shared radio frequency (RF) spectrum band. Methods, systems, and devices are described for wireless communication. One method includes monitoring at least one carrier of a RF spectrum band for a first reference signal transmitted in a number of listen-before-talk (LBT) radio frames from a plurality of LBT radio frames associated with the plurality of carriers, where the plurality of LBT radio frames are received at the user equipment (UE) in different sets of at least one carrier of the RF spectrum band at different times, and where the first reference signal is associated with a first fixed transmit power; receiving a plurality of instances of the first reference signal; measuring the plurality of instances; and determining a cell measurement based at least in part on the measurements of the plurality of instances.

Methods, systems and apparatuses for RFID readers forming a reader network are described. In an aspect of the present invention, readers communicate according to a “Listen Before Talk” (LBT) protocol to avoid undesirable interference.

The invention provides a data transmission method, a data receiving method, a data transmission device, a data receiving device, a base station and a terminal. The data transmission method comprises the following steps: obtaining predefined information; confirming whether executing the Listen Before Talk (LBT) mechanism before transmission or not according to the predefined information; and executing the LBT mechanism before a transmission device carries out transmission according to the predetermined transmission mode if the predefined information carries the LBT indicating information; or, executing non LBT predefined processing operation before a transmission device carries out the transmission according to the predetermined transmission mode if the predefined information does not carrythe LBT indicating information. Through the above steps, the signal in the beamforming system is processed separately by executing the LBT mechanism or executing the non LBT predefined process operation, therefore, the problem that the efficiency of the signal transmission is low in the beamforming system is solved.

Methods, systems, and devices are described for wireless communications. The described techniques include separation of communication resources into resource sets based on data service sets for multiple base stations operating over a carrier of a shared spectrum. The base stations may use synchronized communication time resources. Each data service set may include one or more QoS types and / or communication services. Listen before talk (LBT) parameters for contention procedures performed in different resource sets may be different. A UE configured for communication over the carrier may employ a resource set based discontinuous reception (DRX) mode where a sleep mode is entered for resource sets not associated with active communications by the UE. Channel state information (CSI) reporting may be separated by resource sets for the carrier.

According to some embodiments, a method for use in a user equipment (UE) of managing a listen-before-talk (LBT) contention window size comprises receiving scheduling for a current burst of contiguous uplink subframes. For each subframe the scheduling comprises an associated hybrid automatic repeat request (HARQ) process identifier and a new data indicator (NDI). The method determines a reference subframe based on a previously-scheduled burst of contiguous uplink subframes. The reference subframe is associated with a reference HARQ process identifier. When the UE determines the HARQ process identifier associated with a subframe of the current scheduled burst of contiguous uplink subframes matches the reference HARQ process identifier and the NDI indicates new data, the method resets the LBT contention window. When the reference HARQ process identifier matches, but the associated NDI indicates a retransmission, or the HARQ process identifier does not match, the method increments the LBT contention window. According to another embodiment, a method is presented for performing uplink transmission according to LBT type and LBT priority class. According to a further embodiment, the contention window size for a UK is determined and sent to the UK.

According to some embodiments, a method for use in a user equipment (UE) of transmitting uplink data in unlicensed spectrum comprises receiving, from a network node, an uplink grant comprising an indication of one or more subframes to use for transmitting uplink data. Each subframe comprises a plurality of symbols. The method further comprises obtaining an indication of a listen-before-talk (LBT) type. The LBT type indicates a type of LBT procedure that the UE should perform before transmitting uplink data. The method further comprises determining, using the obtained LBT type, at least one of a starting symbol and a stopping symbol for transmitting uplink data, and transmitting uplink data according to at least one of the determined starting symbol and the determined stopping symbol.

The embodiment of the invention provides a channel detection control method, correlative equipment, and system. The channel detection control method comprises a step that a base station receives a scheduling request transmitted by a randomly-accessed terminal supporting carrier aggregation via a physical uplink control channel (PUCCH), acquires the activation time information that the main cell of the terminal activates the auxiliary cell of the terminal, and transmits uplink authorization information and indication information to the terminal in response to the scheduling request, wherein the indication information is used for indicating the initial time when the terminal performs physical uplink shared channel (PUSCH) transmission with the base station in response to the physical uplink control channel in order that listen before talk (LBT) detection is not carried out on the PUSCH when the terminal and the base station performs PUSCH transmission. The channel detection control method may reduce the number of LBT detection times and decreases the power consumption of the terminal.

Detection and reporting techniques for collisions between transmitters of two different radio access technologies (RATs) transmitting in a shared radio frequency spectrum band is described. The collision may occur following a listen-before-talk procedure but prior to transmission of data, and may not affect the reception of the transmitted data. Collisions may be detected using for example, energy sensing, preamble or ready-to-send (RTS) signal detection, or unsuccessful decoding of all or part of a channel reservation signal. A transmitting device may determine a collision has occurred by detecting an energy level during a preamble transmission is greater than a threshold level or by detecting that an energy level during a transmission gap of a time-domain energy pattern is above a threshold level. A receiving device, such as a user equipment (UE), that detects the collision may report the collision to the transmitter.

Techniques are described for wireless communication. A method for wireless communication includes identifying a frame structure for transmissions using an unlicensed radio frequency spectrum band, the frame structure including at least two special subframes; and performing a procedure to gain access to the unlicensed radio frequency spectrum band during at least a portion of at least one of the at least two special subframes.

According to some embodiments, a method for use in a user equipment (UE) of managing a listen-before-talk (LBT) contention window size comprises transmitting a first burst of uplink subframes after a first LBT procedure performed using an LBT contention window size, and determining a reference subframe based on the first burst. The reference subframe is associated with a reference hybrid automatic repeat request (HARQ) process identifier. The method further comprises receiving scheduling for a second burst of uplink subframes. The scheduling comprises an associated HARQ process identifier and an associated new data indicator (NDI) for each subframe. When the UE determines the HARQ process identifier associated with at least one of the subframes of the second burst matches the reference HARQ process identifier, then if the associated NDI indicates new data, the method resets the LBT contention window size, else the method increments the LBT contention window size.