1512 results about "Random-access channel" patented technology

The invention relates to methods for adjusting the transmit power utilized by a mobile terminal for uplink transmissions, and to methods for adjusting the transmit power used by a mobile terminal for one or more RACH procedures. The invention is also providing apparatus and system for performing these methods, and computer readable media the instructions of which cause the apparatus and system to perform the methods described herein. In order to allow for adjusting the transmit power of uplink transmissions on uplink component carriers, the invention suggests introducing a power scaling for uplink PRACH transmissions performing RACH procedures on an uplink component carrier. The power scaling is proposed on the basis of a prioritization among multiple uplink transmissions or on the basis of the uplink component carriers on which RACH procedures are performed.

The present invention relates to Random Access Channel (RACH) access apparatus for mobile satellite communication system and method therefor. The method for accessing random access channel (RACH) on satellite system, random access channel (RACH) carrying message from a plurality of mobile stations to the satellite system, the method includes the steps of: receiving preamble and the message, the message successively transmitted with the preamble from the plurality of mobile stations; and transmitting acquisition response signal corresponding to the preamble or the message to the plurality of mobile stations. Accordingly, success of packet reception of satellite system is improved and transmission delay is reduced.

A system and method for initializing a system communication without previous reservations for random access channel (RACH) access includes a first step of defining at least one spread sequence derived from at least one constant amplitude zero autocorrelation sequence. A next step includes combining the spread sequence with a Walsh code to form an extended spread sequence. A next step includes using the extended spread sequence in a preamble for a RACH. A next step includes sending the preamble to a BTS for acquisition. A next step includes monitoring for a positive acquisition indicator from the BTS. A next step includes scheduling the sending of a RACH message. A next step includes sending the RACH message.

A method and apparatus for handover in a wireless communication system. A handover indication can be received from a source base station (120) that is connected with a mobile station (110). The handover indication can include a random access channel preamble. The random access channel preamble can include a temporary mobile equipment identifier. The random access channel preamble can be received from the mobile station. A timing advance message can be sent in response to receiving random access channel preamble. The timing advance message can be addressed by the random access channel preamble and a source base station identifier. The connection with the mobile station can be switched from the source base station to a target base station (130).

In a closed-loop wireless communication system (200), channel-side information—such as CQI information, rank adaptation information or MIMO codebook selection information—is randomly or autonomously fed back to the transmitter (202) by having the receiver (206.i) initiate the feedback instead of using a scheduled feedback approach so that all receiving devices do not simultaneously feed back channel-side information to the transmitting device. The receiver (206.i) uses one or more antennas (209.i) to feed back channel-side information using data non-associated control multiplexing with uplink data and without uplink data, such as by using a contention-based physical channel or a synchronized random access channel.

In a method of avoiding multiple detection of the same random access channel (RACH) preamble in a wireless communication system, and within a given set of access slots, a given sub-set of available preamble signatures corresponding to a RACH preamble of a user may be detected, so as to avoid multiple RACH preamble detection in a given access slot. Another method may be directed to switching operations of a base station in a communication network. Base station operations may be switched back and forth between multi-sector / single cell operations and single sector / multi-cell operations without changing an existing antenna configuration.

A method of coordinating resources for repetition of random access bursts performed by a mobile terminal, the method comprising: determining groups of access slots based on parameters from a network, wherein each access slot is defined by any combination of frequency, time and code, and the access slots are organized according to a frequency pattern; transmitting an access burst on an access slot from a chosen group of access slots; and re-transmitting the access burst on the next access slot from the chosen group of access slots.

Embodiment of the present invention can be used to select random access channels to be assigned to user terminals. In one embodiment, the invention includes a base station receiving a signal from a second radio, the received signal containing information about the second radio, and selecting one or more channels to be used by the second radio for random access to the base station using the information about the second radio. Then the base station sends a signal to the second radio, the sent signal containing information about the selected one or more channels.

Systems and methods of pre-allocating identifiers to wireless devices for use in requesting resources over a random access channel are described. A wireless communication system includes a random access channel over which wireless devices can anonymously send requests for resources. The base stations receiving and processing the anonymous requests reduces the probability of random access channel collisions and conserves the resources needed to support the anonymous requests by pre-allocating one or more codes to select wireless devices. The wireless devices having the pre-allocated codes can transmit a particular code over the random access channel as a request for resources that uniquely identifies the requester.

A method and apparatus are provided for defining terminal behavior in a case where the terminal detects that it cannot receive the HS-DSCH from a serving cell reliably when the DCCH is mapped to HS-DSCH (e.g. does not receive any radio link control (RLC) acknowledged mode feedback for the uplink measurement reports or in general the common pilot channel (CPICH) level drops too low in the serving HS-DSCH cell). The terminal is autonomously moved to a cell forward access channel (CELL_FACH) state and uplink signaling is initiated on a random access channel (RACH) to inform a network node and ask for HS-DSCH re-establishment in a suitable cell (preferably in the one being strongest one in the active set or according to the measurements done prior the connection from the serving HS-DSCH cell was lost), or setting up a regular R′99 / R′5 DPCH in order to restore the RRC signaling connection in the CELL_DCH state.

An apparatus and method for transmitting / receiving an random access channel (RACH) signal in a broadband wireless communication system where a total uplink frequency band is divided into M sub-bands are provided. In the RACH transmitting apparatus, a generator generates an access code. A sub-carrier allocator divides the access code into M sub-blocks and allocates each of the M sub-blocks to successive sub-carriers in a sub-band. An inverse fast Fourier transform (IFFT) processor generates an orthogonal frequency division multiplexing (OFDM) symbol by performing an IFFT on the allocated sub-blocks.

The embodiment of the invention discloses a random access method and equipment, relating to the technical field of radio communication and being used for solving the problem of random access way in a carrier aggregation system. In the invention, the method comprises the following steps of: sending a random access leader sequence to a base station by a terminal through a PRACH (Physical Random Access Channel) resource on a cell; confirming a random access radio network temporary identification (RA-RNTI) corresponding to the random access leader sequence according to the carrier identification information of the cell and the information of the PRACH resource, and detecting a physical downlink control channel (PDCCH) scrambled by using the RA-RNTI in a public searching space of a main cell; and receiving a physical downlink sharing channel (PDSCH) bearing a random access response corresponding to the random access leader sequence according to the detected PDCCH, and carrying out uplink synchronization adjustment on the cell according to an uplink timing advance (TA) in the random access response. By adopting the random access method and equipment, random access in an auxiliary cell or simultaneous random access in multiple cells in the carrier aggregation system is realized.

The present invention relates to a wireless communication system, and discloses a method and an apparatus for performing random access in a multi-carrier wireless communication system. According to one embodiment of the present invention, the method in which user equipment carries out a process for random access to a base station in a multi-carrier wireless communication system comprises: a step of measuring the channel qualities of one or more uplink component carriers, and determining the uplink component carrier having the highest channel quality; a step of selecting a physical random access channel (PRACH) resource on the uplink component carrier having the highest channel quality; and a step of transmitting a random access preamble to the base station using the selected PRACH resource.

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. A method for receiving system information (SI) by a user equipment (UE) in a wireless communication system is provided. The method includes receiving, from a base station (BS), first type SI associated with SI which is essential for communication with the BS, transmitting, to the BS, a physical random access channel (PRACH) preamble based on the first type SI, receiving, from the BS, a random access response (RAR) message, and receiving, from the BS, second type SI associated with at least one SI which the UE needs.

The present invention provides a method and an apparatus for balancing traffic load between a plurality of users on one or more shared wireless channels, e.g., from a communication node associated with a network of a plurality of cells including a first and a second cell. The method comprises determining a first indication of traffic load for a first cell and a second indication of traffic load for a second cell on the one or more shared wireless channels and redistributing the traffic load on the one or more shared wireless channels associated with the first cell and the second cell based on the first indication of traffic load for the first cell and the second indication of traffic load for the second cell. A scheduler, e.g., at a Node B and a decision algorithm at a controller, e.g., a radio network controller may be used in a wireless telecommunication system that uses wireless channels including a shared channel, a forward access channel, a random access channel, as well as a dedicated channel to switch traffic associated with at least one user of a multiplicity of users on a shared wireless channel from a cell to another cell. In this manner, for user equipment, e.g., a Universal Mobile Telecommunications System mobile station, a decision algorithm in a Universal Mobile Telecommunications System Terrestrial Radio Access Network may direct at least a part of the traffic load on a shared channel from a source cell to a target cell by moving a cell border without affecting a traffic load on a dedicated channel.

Disclosed is an uplink random access procedure in an NB-TDD (Narrow Band Time Division Duplexing) system. To achieve an acknowledgement for data transmission from a UTRAN (UMTS Terrestrial Radio Access Network), a UE selects one of a plurality of sync codes by which the UTRAN identifies UEs that request data transmission and transmits the selected sync code in a time slot of a sub-frame to the UTRAN. Then, the UE receives the sync code information, information about the arrival time of the sync code, time update information indicating a variation in the transmission time of data, and power information indicating an adjustment to a power gain in the UE from the UTRAN on an FPACH (Fast Physical Access Channel). The UE transmits the data on a P-RACH (Physical Random Access Channel) mapped from the FPACH according to the time update information and the power information.

Disclosed is a method of allocating resources in a packet data system to a User Equipment (UE) with an active data session, such as a Voice over Internet Protocol (VoIP) call, using dedicated resources to transmit scheduling requests, thereby reducing latency which may occur as a result of collisions associated with transmitting scheduling requests over a random access channel. The method comprises the step of transmitting over dedicated resources a scheduling request, and receiving a scheduling grant in response thereto. The scheduling request indicates that a transmitter in a data session has a data packet to transmit. The scheduling grant indicates resources allocated for transmitting the data packet.

A method for transmitting a preamble over a Random Access CHannel (RACH) in a wireless communication system is provided. The method includes generating a preamble having a length longer than a basic transmission unit, and dividing the preamble into preambles having a length less than the basic transmission unit; and sequentially transmitting the divided preambles over the RACH using different antennas.

The present invention provides a method and an apparatus for assigning a channel in response to a request for service for a mobile station in a wireless communication network serving a plurality of regions, such as cells in a digital cellular network. The mobile station may be located in one of the plurality of regions. The method comprises determining a first indication of congestion on a forward access channel and a second indication of congestion on a random access channel and assigning at least one channel of a plurality of channels to the mobile station based on the determined first and second indications of congestion. Based on the first indication of congestion, a first threshold may be adjusted for the forward access channel and a second threshold may be adjusted based on the second indication of congestion on the random access channel. A service type of the request for service and a condition of wireless communication environment may be determined for transmission of data over the wireless communication network and to decide if a specific signaling connection for the mobile station located in one of plurality of regions shall be established in a particular mobile station state including a cell dedicated channel state and a cell forward access channel state based on the service type and the condition of wireless communication environment. In this manner, signaling requests, such as radio resource control signaling requests may be classified into different service types and different radio frequency environment conditions, providing an efficient packet data transmission in a wireless communication system by deciding which state to use under different scenarios. By including a wireless communication environment condition, such as the current radio frequency environment status in a channel assignment decision making, a signaling connection may not experience an inferior quality and may avoid a delay and occurrences of dropped connections.

A random access channel transmission method in which a user terminal selects a preamble pattern from among a plurality of known preamble patterns and transmits that preamble pattern to a base station, where that transmission method comprises: a step of dividing a cell into a plurality of areas, and setting one or more preamble patterns and the number of repetitions for transmitting the preamble pattern for each area; and a step wherein a user terminal that exists in an are close to the base station transmits a specified preamble pattern one time, and a user terminal that exists in an area far from the base station transmits another specified preamble pattern a plurality of times.

A method for transmitting a random access preamble using a random access procedure in a mobile communication system. The random access preamble transmission method includes selecting, upon triggering of the random access procedure, one of random access preamble sets predefined between a User Equipment (UE) and an Evolved Node B (ENB) according to whether a radio channel condition is greater than a radio channel condition threshold and a size of a message that the UE will transmit after transmission of the random access preamble is greater than a minimum message size, randomly selecting a random access preamble from the selected random access preamble set, and transmitting the selected random access preamble to the ENB over a random access channel.

A system and method for random access channel (RACH) capture, where user equipment (UE) transmits a series of time-spaced access preambles each having an increasing power level to Node B and terminates access preamble transmission in response to an acquisition indicator (AI) signal returned from Node B and transmits its RACH message part. A collision detection preamble (CDP) is sent immediately after the message or embedded with the message. A collision detection indicator (CDI) signal matching the CDP is transmitted from Node B to the UE identified as having the failed RACH message requesting retransmission of the message. Optionally, the relative retransmission power level is also specified to the UE along with the CDI signal.

The present invention relates to a wireless communication system providing a wireless communication and a mobile terminal. During data communication between a base station and a terminal in a long term evolution (LTE) system, while the terminal performs a random access channel (RACH) procedure for requesting a radio resource allocation from the base station, if the terminal is allocated with a radio resource using its radio terminal identifier, the terminal is allowed to appropriately select a radio resource, thereby preventing the consumption of radio resources and increasing efficiency.

A disclosed base station apparatus in a mobile communication system includes a receiving unit receiving a random access channel transmitted from a mobile station apparatus, an acquisition unit acquiring random access channel quality based on a measurement of the received random access channel or a report from the mobile station apparatus, a calculation unit calculating random access channel parameters based on the acquired random access channel quality, and a broadcast unit broadcasting the calculated random access channel parameters to all the mobile stations within a coverage area of the base station.

In a code division multiple access (CDMA) communications system including one or more terminals (such as customer premise equipments, CPEs) that communicate with a node (such as an Internet gateway) via at least a random access channel and a reservation-oriented channel, various schemes of managing communications traffic among the channels are provided. Decisions as to the channel on which a given terminal may transmit may be based on: traffic statistics (such as packet size or average data rate over a time period), traffic content (such as packet type), the terminal's output buffer loading (queue state, or “Q-state”), a history of the terminal's output buffer loading (one or more Q-states), and so forth. In one application, decisions in managing traffic in a live user's web browsing sessions may involve intelligent ascertainment of whether a given terminal is busy based on traffic analysis or output buffer loading.

A mobile station accesses a base station by randomly selecting a first reverse link common control channel from a set of random access channels. The mobile station transmits a request portion of an access probe over the first reverse link common control channel. The request portion is subject to collision with other signals. The request portion comprises a hash identification which is derived from a uniquely identifying number using a hash function. The hash identification quasi-uniquely identifies the mobile station. The mobile station receives a channel assignment message from the base station designating the hash identification and a reserved access channel. The reserved access channel provides communication with a low probability of contention. The mobile station transmits a message portion of the access probe over the reserved access channel.

A method of performing beamforming in a base station is provided. The method includes receiving random access channel signals transmitted in one or more transmit beams from a terminal, using one or more receive beams, determining at least one best transmit beam from the one or more transmit beams and at least one best receive beam from the one or more receive beams, and transmitting information about the best transmit beam and the best receive beam to the terminal.

A random access scheme for preventing unnecessary retransmission and a user equipment for the same are disclosed. If a Contention Resolution (CR) timer expires in contention resolution during a random access procedure or if a Physical Downlink Control Channel (PDCCH) signal or a Physical Downlink Shared Channel (PDSCH) signal associated with the PDCCH signal does not match an identifier of a terminal, a Hybrid Automatic Repeat Request (HARQ) buffer for storing a Medium Access Control Packet Data Unit (MAC PDU) transmitted in the random access procedure is flushed such that unnecessary data retransmission can be prevented.

A method and apparatus for transmitting / receiving a Random Access Channel (RACH) signal in a communication system. A User Equipment (UE) selects one of Contention Resolution (CR) channels allocated for collision detection, and transmits the selected CR channel and a connection request message to an Evolved Node B (E-NB), and receives a response signal from the E-NB. The UE transmits the RACH signal, if a collision indicator is included in the response signal. The E-NB receives from each of UEs a connection request message and a CR channel, decodes the connection request message, and detects a collision between the UEs using the CR channel. The E-NB generates a response signal to the connection request message according to the decoding result, generates a collision indicator according to the collision detection result, and transmits to the UEs at least one of the generated response signal, the generated collision indicator, and a unique ID of a corresponding UE.