JP6220903B2 - Method and apparatus for processing uplink transmissions in a wireless communication system - Google Patents

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present invention relates to US Provisional Patent Application No. 62 / 107,834 filed Jan. 26, 2015 and U.S. Patent Application No. 62 / 183,439 filed Jun. 23, 2015. Claims the benefit of the priority of the issue, the contents of which are fully open, are hereby incorporated by reference.

  The present invention relates generally to wireless communication networks, and more particularly to a method and apparatus for processing uplink transmissions in a wireless communication system.

  With the rapid increase in demand for large amounts of data communication between mobile communication devices, conventional mobile voice communication networks have evolved into networks that communicate with Internet Protocol (IP) data packets. Such IP data packet communication can provide voice over IP, multimedia, multicast and on-demand communication services to users of mobile communication devices.

  A typical network structure that is currently being standardized is the evolved universal terrestrial radio access network (E-UTRAN). The E-UTRAN system provides high data throughput and can realize the above-described VoIP service and multimedia service. E-UTRAN standardization work is currently being carried out by the 3GPP standardization organization. Therefore, changes to the current 3GPP standard are currently being presented and considered in order to evolve and complete the 3GPP standard.

  A method and apparatus for handling uplink transmissions in a wireless communication system is disclosed. In one method, a user equipment (UE) connects to at least two base stations including a first base station that controls a first serving cell and a second base station that controls a second serving cell. The method further includes the user equipment receiving downlink signaling in the second serving cell. The method further causes the user equipment to transmit reference signaling in the first serving cell in response to receiving the downlink signaling.

1 is a schematic diagram of a wireless communication system according to one exemplary embodiment. FIG. 1 is a block diagram of a transmitter system (also known as an access network) and a receiver system (also known as a user equipment (UE)) according to one exemplary embodiment. 1 is a functional block diagram of a communication system according to one exemplary embodiment. FIG. FIG. 4 is a functional block diagram of the program code of FIG. 3 according to one exemplary embodiment. FIG. 6 is a flow diagram according to one exemplary embodiment. FIG. 6 is a flow diagram according to one exemplary embodiment. FIG. 6 is a flow diagram according to another exemplary embodiment. FIG. 6 is a flow diagram according to yet another exemplary embodiment. FIG. 3 illustrates a signaling flow according to one exemplary embodiment. FIG. 3 illustrates a signaling flow according to one exemplary embodiment. FIG. 3 illustrates a signaling flow according to one exemplary embodiment.

  Exemplary wireless communication systems and devices described below utilize a wireless communication system to support broadcast services. Wireless communication systems are widely deployed to provide various communications such as voice and data. These systems include code division multiple access (CDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), 3GPP LTE (Long Term Evolution) radio access, 3GPP LTE-A or LTE-Advanced (Long Term Evolution Advanced), 3GPP2 UMB (Ultra Mobile Broadband), WiMax, or some other modulation technology.

  In particular, the exemplary wireless communication system / apparatus described below can be designed according to wireless technologies described in various documents of the DOCOMO 5G white paper (NTT DOCOMO; July 2014). Further, the exemplary wireless communication system / device described below is a standard provided by an organization named “3rd Generation Mobile Communication System Standardization Project” (referred to herein as 3GPP), eg: 3GPP R2 -145410, “Introduction of Dual Connectivity”; 3GPP TS36.321 Vl2.3.0, “E-UTRAN MAC Protocol Specification”; 3GPP TS36.300 Vl2.3.0, “E-UTRAN RRC protocol description”; 3GPP TS36.300 V2. 3.0, “E-UTRAN and E-UTRAN overall description”: Can be designed to support one or more standards. The above standards and documents are expressly incorporated herein by reference in their entirety.

  FIG. 1 shows a multi-access wireless communication system according to an embodiment of the present invention. Access network (AN) 100 includes a plurality of antenna groups, one group including antennas 104 and 106, another group including antennas 108 and 110, and an additional group including antennas 112 and 114. Although only two antennas are shown for each antenna group in FIG. 1, more or fewer antennas may be used for each antenna group. Access terminal (AT) 116 is in communication with antennas 112 and 114, which transmit information to access terminal 116 over forward link 120 and transmit information from access terminal 116 over reverse link 118. Receive via. Access terminal (AT) 122 is in communication with antennas 106 and 108, and antennas 106 and 108 transmit information to access terminal (AT) 122 via forward link 126 and receive information from access terminal (AT) 122. Are received via the reverse link 124. In an FDD system, the communication links 118, 120, 124 and 126 can use different frequencies for communication. For example, forward link 120 may use a different frequency than that used for reverse link 118.

  Each group of antennas and / or the area in which they are designed to communicate is often referred to as a sector of the access network. In this embodiment, each antenna group is designed to communicate with access terminals in one sector of the area covered by the access network 100.

  In communication via the forward links 120 and 126, the transmit antenna of the access network 100 can utilize beamforming techniques to improve the signal-to-noise ratio of the forward links of different access terminals 116 and 122. . In addition, an access network that uses a beamforming technique for transmission to access terminals randomly scattered in the coverage area is more adjacent to an adjacent cell than an access network that transmits to all access terminals with a single antenna. It is hard to cause interference to the terminal.

  An access network (AN) can be a fixed station or base station used to communicate with a terminal and is also referred to as an access point, Node B, base station, enhanced base station, evolved Node B (eNB), etc. Yes. An access terminal (AT) is also referred to as a user equipment (UE), a radio communication device, an access terminal, and the like.

  FIG. 2 illustrates an exemplary implementation of a transmitter system 210 (also known as an access network) and a receiver system 250 (also known as an access terminal (AT) or user equipment (UE)) within the MIMO system 200. It is a simplified block diagram which shows a form. At transmitter system 210, traffic data for multiple data streams is provided from a data source 212 to a transmit (TX) data processor 214.

  In one embodiment, each data stream can be transmitted on a respective transmit antenna. TX data processor 214 can format, encode, and interleave traffic data for each data stream based on a particular encoding scheme selected for that data stream to provide encoded data.

The coded data for each data stream can be multiplexed with pilot data using OFDM techniques. The pilot data is typically a well-known data pattern that is processed in a well-known manner and can be used to evaluate channel response at the receiving system. The multiplexed pilot and code data for each data stream is then modulated based on the particular modulation scheme selected for that data stream (eg, BPSK, QPSK, M-PSK, or M-QAM) to produce modulation symbols I will provide a. The data rate, coding, and modulation for each data stream can be determined by instructions executed by processor 230.

The modulation symbols for all data streams are then transmitted to TX MIMO processor 220, which may further process the modulation symbols (eg, for OFDM). TX MIMO processor 220 then provides N _T modulation symbol streams to N _T transmitters (TMTR) 222a through 222t. According to a particular embodiment, TX MIMO processor 220 provides beamforming weights to the symbols of the data stream and the antenna that transmits the symbols.

Each transmitter 222 receives and processes a respective symbol stream to provide one or more analog signals, and further adjusts, i.e. amplifies, filters, and upconverts the analog signals for transmission over a MIMO channel. Provide a modulated signal. _{N T} modulated signals from transmitters 222a~222t are then transmitted from _{N T} antennas 224a~224t respectively.

  In the receiver system 250, the transmitted modulated signals are received by the NR antennas 252a to 252r, and the received signals from the respective antennas 252 are supplied to the respective receivers (RCVR) 254a to 254r. Each receiver 254 adjusts, ie filters, amplifies, and downconverts the respective received signal, digitizes the adjusted signal to provide samples, and further processes the samples to provide corresponding “receive” symbols. Provide a stream.

RX data processor 260 receives the N _R received symbol streams from N _R receivers 254 provides N _T "detected" symbol streams by processing based on a particular receiver processing technique. RX data processor 260 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data of the data stream. The processing by RX data processor 260 is complementary to that performed by TX MIMO processor 220 and TX data processor 214 in transmitter system 210.

  The processor 270 periodically determines which precoding matrix to use, as described below. Processor 270 may form a reverse link message that includes a matrix index portion and a rank value portion.

  The reverse link message can include various information regarding the communication link and / or the received data stream. The reverse link message is then processed by TX data processor 238, which also receives traffic data for multiple data streams from data source 236 and is coordinated by transmitters 254 a-254 r and returned to transmitter system 210.

  At transmitter system 210, the modulated signal from receiver system 250 is received by antenna 224, conditioned by receiver 222, demodulated by demodulator 240, and extracted from the reverse link message transmitted by receiver system 250. Are processed by the RX data processor 242. The processor 230 then determines which precoding matrix to use for determining the beamforming weights and then processes the extracted message.

  Referring to FIG. 3, this figure shows a simplified functional block diagram of a communication device according to an embodiment of the present invention. As shown in FIG. 3, a communication device 300 in a wireless communication system can be used to implement the UE (or AT) 116 and 122 of FIG. 1 or the base station (or AN) of FIG. The wireless communication system can be an LTE system. The communication device 300 can include an input device 302, an output device 304, a control circuit 306, a central processing unit (CPU) 308, a memory 310, program code 312, and a transceiver 314. The control circuit 306 controls the operation of the communication apparatus 300 by executing the program code in the memory 310 by the CPU 308. The communication device 300 can receive a signal input by a user via an input device 302 such as a keyboard or a keypad, and can output an output image and sound via an output device 304 such as a monitor or a speaker. The transceiver 314 is used to receive and transmit wireless signals, sends the received signal to the control circuit 306, and sends the signal generated by the control circuit 306. The communication device 300 in the wireless communication system can also be used to implement the AN 100 of FIG.

  FIG. 4 shows a simplified block diagram of the program code 312 shown in FIG. 3 according to one embodiment of the invention. In this embodiment, program code 312 includes application layer 400, layer 3 portion 402, and layer 2 portion 404, and is coupled to layer 1 portion 406. The layer 3 portion 402 generally performs radio resource control. The layer 2 portion 404 generally performs link control. Layer 1 portion 406 generally performs a physical connection.

  For LTE or LTE-A systems, the layer 2 portion 404 can include a radio link control (RLC) layer and a media access control (MAC) layer. Layer 3 portion 402 may include a radio resource control (RRC) layer.

  The concept of 5G wireless access is described in the DoCoMo 5G white paper. One key point described in this white paper is to efficiently integrate the low frequency band and the high frequency band. The high frequency band provides a wider spectrum opportunity but has coverage limitations due to high path loss. Therefore, the docomo 5G white paper proposes that the 5G system has a two-layer structure including a coverage layer (for example, composed of macro cells) and a capacity layer (for example, composed of small cells or phantom cells). The coverage layer uses existing low frequency bands to provide basic coverage and mobility. And the capacity layer uses a new high frequency band to provide high data rate transmission. The coverage layer can be supported by the enhanced term evolution radio access technology (LTERAT), while the capacity layer can be supported by a new radio access technology dedicated to the high frequency band. Efficient integration of the coverage layer and the capacity layer is made possible by the close cooperation (dual connectivity) between the enhanced LTE radio access technology and the new radio access technology.

  Dual connectivity disclosed in 3GPP R2-145410 is one mode of operation of user equipment (UE) during RRC_CONNECTED, which is a group of serving cells associated with a master cell group (ie, a master eNB (MeNB), a primary cell (PCell)). And optionally including one or more secondary cells (SCell)) and a secondary cell group (ie, a group of serving cells associated with the secondary eNB (SeNB), primary cell SCell (PSCell) and optionally one or more secondary cells). Cell SCell). A UE configured for dual connectivity will allow the UE to use radio resources provided by separate schedulers in two eNBs (eg, MeNB and SeNB) connected via a non-ideal return on the X2 interface. Indicates that it will be set. Other details of dual connectivity are disclosed in 3GPP R2-145410.

  In order to maintain uplink time alignment in a serving cell or group of serving cells, a timing advance command (in a MAC control element or a random access response message) and a time alignment timer are disclosed in 3GPPTS 36.321 V12.3.0 And used in LTE as follows.

5.2 Maintaining uplink time alignment The UE has a timer (time alignment timer) that can be set for each TAG. The time alignment timer is used to control the period of time that the UE considers serving cells belonging to the associated TAG to be uplink time aligned [8].
The UE
When a timing advance command MAC control element is received,
Apply the timing advance command to the indicated TAG;
Start or restart the time alignment timer associated with the indicated TAG;
When a time advance command is received in a random access response message for a serving cell belonging to a TAG,
If the random access preamble is not selected by UEMAC:
Apply the time advanced command to this TAG;
Start or restart the time alignment timer associated with this TAG;
If the time alignment timer associated with this TAG is not running:
Apply the timing advance command to this TAG;
Start the time alignment timer associated with this TAG;
When the contention analysis is deemed unsuccessful as described in subclause 5.1.5, stop the time alignment timer associated with this TAG.
-Otherwise:
-Ignore the received timing advance command.
• When the timing alignment timer ends:
If the time alignment timer is associated with pTAG:
Flush all HARQ buffers for all serving cells;
Notifying RRC that PUCCH / SRS will be released to all serving cells;
Clear the configured downlink assignment and uplink grant;
• considers that all active time alignment timers have expired;
Otherwise, if a time alignment timer is associated with the sTAG, for all serving cells belonging to this TAG:
Flush all HARQ buffers;
Notifying RRC that SRS will be released;
When the time alignment timer associated with the TAG to which the serving cell belongs is not operating, the UE does not perform any uplink transmission on that serving cell except for transmission of random access preamble. Furthermore, when the time alignment timer associated with the pTAG is not operating, the UE does not perform any uplink transmission on any serving cell except for random access preamble transmission on the PCell.
Note: The UE stores or maintains N _TA at the end of the associated time alignment timer, where N _TA is defined in [7]. The UE uses the receive timing advance command MAC control element to start the associated time alignment timer even when the time alignment timer is not operating.

  Also, cells on the capacity layer can use beamforming. Beamforming is a signal processing technique used in antenna arrays for directional signal transmission or reception. This is accomplished by combining the elements of the phased array so that certain angle signals are subject to constructive interference while other signals are subject to destructive interference. Beamforming can be used on the transmitting and receiving sides to achieve spatial selectivity. It is known that reception / transmission gain can be improved as compared to omnidirectional transmission / reception.

  Beam forming is applied to radar systems. The beam produced by the phased array radar is relatively thin and highly agile compared to mobile parabolic antennas. This property gives the radar the ability to detect small high-speed targets such as ballistic missiles in addition to airplanes.

  Because of the benefits of co-channel interference reduction, beamforming can also be an attractive option in mobile communication systems. For example, the concept of beam division multiple access (BDMA) based on beamforming technology is used. In BDMA, a base station can communicate with a mobile device with a narrow beam to obtain transmit / receive gain. In addition, two mobile devices located in different beams can share the same radio resources at the same time, thus greatly increasing the capacity of the mobile communication system. To achieve this, the base station needs to know in which beam the mobile device is located.

  As described above, it is assumed that a cell using a high frequency band has a coverage limitation and needs to be a small cell. As a result, mechanisms that maintain uplink time alignment, such as timing advance commands and time alignment timers, do not have to assume that UEs in a small cell are always uplink time aligned due to the small coverage of the small cell. It may be. In other words, the UE does not need to maintain a timer associated with the small cell to determine whether the uplink time is aligned. Alternatively, the timer value can be set to infinity.

  However, if the time alignment timer is not used (for example, the hybrid automatic repeat request (HARQ) buffer for the associated serving cell is flushed and the physical uplink control channel (PUCCH) and / or sounding reference signal (SRS) is associated) The UE does not stop any uplink transmission on the cell due to time out (by notifying the radio resource control (RCC) to release to the serving cell). In the absence of uplink (UL) or downlink (DL) traffic associated with the UE, certain transmissions of uplink transmissions (eg, periodic SRS and periodic channel quality indicator (CQI)) are not required. Bringing up power consumption. Therefore, it should be considered to stop unnecessary uplink transmissions and resume transmissions when necessary.

There are currently several alternatives to LTE:

  As disclosed, none of the existing alternatives is a good replacement for the time alignment timer. Therefore, it is necessary to stop unnecessary uplink transmissions and resume transmissions when necessary in a dual frequency band system.

  Stopping and resuming certain UL transmissions in the serving cell may be performed explicitly by signaling from the base station, e.g. physical downlink control channel (PDCCH) signaling or media access control (MAC) control element, or not by the UE Can be executed explicitly. Specific UL transmissions include the following signaling: periodic reference signals, eg SRS (defined in 3GPPTS 36.321 V12.3.0); periodic channel state reports, eg CQI reports (3GPPTS 36.321 V12.3. And / or semi-permanent uplink transmissions, eg using at least one configured uplink grant (defined in 3GPPTS 36.321 V12.3.0): .

  More specifically, when a UE stops a particular UL transmission, the (RRC) settings associated with the particular UL transmission are not released. And when a particular UL transmission is stopped, the UE is signaling the following: scheduling request (defined in 3GPPTS36.321 V12.3.0); and / or random access preamble (3GPPTS36.321 V12.3) Do not stop at least one of the following:

  For implicit suspension, a timer associated with a cell maintained by the UE can be used to determine whether a particular UL transmission should be performed within that cell. In one embodiment, at the end of the timer, the UE stops certain UL transmissions in the cell. Alternatively, the UE does not perform a specific UL transmission in the cell at least when the timer is not running. The timer is when one or more of the following conditions occur: when the drx inactivity timer associated with the cell (defined in 3GPPTS 36.321 V12.3.0) starts; When the activity timer (defined in 3GPPTS 36.321 V12.3.0) expires; when the drx short cycle timer associated with the cell (defined in 3GPPTS 36.321 V12.3.0) starts; When the drx short cycle timer associated with the cell (defined in 3GPPTS 36.321 V12.3.0) expires; the UE is a DRX command MAC control element (defined in 3GPPTS 36.321 V12.3.0) When the UE receives a downlink transmission in the cell Start (or restart) when the UE receives a downlink transmission associated with the cell; when the UE receives an uplink grant within the cell and / or when the UE receives an uplink grant associated with the cell: )

  This timer can be a drx activity timer or a drx short cycle timer.

  For implicit resumption, the UE receives a specific UL transmission upon occurrence of at least one of the following conditions: when the UE receives a downlink transmission in the cell; the UE receives a downlink transmission associated with the cell When the UE receives an uplink grant in the cell; when the UE receives an uplink grant associated with the cell; the UE makes a scheduling request (defined in 3GPPTS 36.321 V12.3.0) A particular UL transmission can be resumed when triggering; and / or when the UE detects a change in the beam set of a cell for the UE.

  For explicit restart, if the serving cell in the capacity layer uses beamforming, the first base station (eg, SeNB) controlling the serving cell (eg, SCell or PSCell) Without it, the direction to the UE for a while cannot be identified. As a result, the first base station cannot know which beam will send signaling requesting the UE to resume a specific UL transmission. Therefore, explicit resumption requires assistance from a second base station, eg, a MeNB controlling another serving cell in the coverage layer. The second base station instructs the UE to perform the following operations: resume a specific UL transmission in the serving cell; start a random access procedure in the serving cell; send a scheduling request in the serving cell; and / or in the serving cell DL signaling, eg PDCCH signaling or MAC control element can be sent to request to perform at least one of the following: aperiodic reference signal, eg aperiodic SRS transmission. More specifically, the serving cell can schedule transmissions within the serving cell, eg, PDCCH signaling can be transmitted within the serving cell.

  More specifically, DL signaling can indicate a dedicated preamble used in a random access procedure. The DL signaling can be in PDCCH order (defined in 3GPPTS 36.321 V12.3.0). More specifically, the second base station transmits DL signaling for receiving a request from the first base station.

  FIG. 5 shows a flow diagram 500 from a UE perspective according to one exemplary embodiment. In step 502, the UE connects to two or more base stations including the MeNB and SeNB. In step 504, the scheduling request is transmitted in the serving cell of the SeNB regardless of the timer state. In step 506, downlink signaling is monitored in the serving cell regardless of timer status. In step 508, a specific UL transmission is transmitted in the serving cell when the timer is operating, and no specific UL transmission is transmitted when the timer is not operating.

  FIG. 6 shows a flow diagram 600 from a UE perspective according to one exemplary embodiment. In step 602, the UE connects to two or more base stations including the MeNB and SeNB. In step 604, a scheduling request is transmitted in the serving cell of the SeNB regardless of the UE state, where the UE state includes at least a first state and a second state. In step 606, downlink signaling is monitored in the serving cell regardless of UE status. In step 608, when the UE is in the first state, a specific UL transmission is transmitted in the serving cell, and when the UE is in the second state, the specific UL transmission is not transmitted, and the UE is within the serving cell. The UE switches from the second state to the first state when it has data to transmit on.

  FIG. 7 shows a flow diagram 700 from the perspective of a UE according to one exemplary embodiment. In step 702, the UE connects to two or more base stations including the MeNB and SeNB. In step 704, the scheduling request is transmitted in the serving cell of the SeNB regardless of the UE state. The state of the UE includes at least a first state and a second state. In step 706, downlink signaling is monitored in the serving cell regardless of UE status. In step 708, when the UE is in the first state, a specific UL transmission is transmitted in the serving cell, and when the UE is in the second state, the specific UL transmission is not transmitted and is detected by the UE. When one or more beams of the serving cell change, the UE switches from the second state to the first state.

  FIG. 8 shows a flow diagram 800 from a UE perspective according to one exemplary embodiment. In step 802, the UE connects to two or more base stations including the MeNB and SeNB. In step 804, the specific UL transmission is suspended in the first serving cell of the SeNB. In step 806, downlink signaling is received in the second serving cell of the MeNB. In step 808, the specific UL transmission is resumed in the first serving cell in response to receiving the downlink signaling.

  According to one exemplary embodiment in which the UE is served by a serving cell, at least one specific uplink transmission is stopped when the timer is not running. Whether the timer is running or not, a scheduling request is sent in the serving cell and the timer does not affect the timing of downlink signaling monitoring in the serving cell.

  In another exemplary method in which the UE is served by a serving cell, at least one specific uplink transmission is stopped due to the expiration of the timer. Whether the timer expires or not, a scheduling request is sent in the serving cell and the timer does not affect the timing of downlink signaling monitoring in the serving cell.

  In another embodiment of these exemplary methods, the UE transmits a specific uplink transmission when the timer is running.

  In these exemplary methods, the timer is associated with the serving cell, but the timer is not necessarily associated with every serving cell to which the UE is connected.

  In these exemplary methods, the timer is started when the DRX timer associated with the serving cell starts. In another exemplary method, the timer is restarted when the DRX timer associated with the serving cell expires. The DRX timer can be a drx activity timer or a drx short cycle timer.

  In another method, the timer is started when downlink signaling is received in the serving cell. In yet another method, the timer is restarted when downlink signaling associated with the scheduling cell is received.

  In another method, the timer is started when a DRX command MAC control element is received in the serving cell. In yet another method, the timer is restarted when a DRX command MAC control element is received in the serving cell.

  In one exemplary method where a UE is served by a serving cell, the UE enters a first state. In this first state, the UE is allowed to perform at least certain uplink transmission and scheduling requests in the serving cell. When the UE changes to the second state, the UE is allowed to execute at least a scheduling request, and the UE suspends certain uplink transmissions in the serving cell. The UE switches from the second state to the first state when an event occurs. The UE monitors downlink signaling in the serving cell whether the UE is in the first state or the second state.

  In one method, the UE changes from the first state to the second state when the timer expires. Alternatively, the UE changes from the first state to the second state upon receiving a command from the network. In some embodiments, the event that triggers the UE to switch from the second state to the first state includes receiving downlink signaling in the serving cell, receiving downlink signaling associated with the serving cell, triggering a scheduling request. Detecting a change in the beam set of the UE in the serving cell and / or changing one or more beams in the serving cell detected by the UE.

  In another method, beam detection is whether the power of the DL reference signal associated with the beam received at the UE is greater than a threshold. In other methods, the transmission timing of the DL reference signal associated with the beam can be utilized at the UE for beam identification or detection, ie, to derive the beam identifier. Also, the transmission resource of the DL reference signal associated with the beam can be utilized at the UE for the identification or detection of the beam, ie, to derive the beam identifier.

  In another method, whether the UE is in the first state or the second state is determined based on whether the timer is operating.

  In other methods, the UE needs to periodically perform certain uplink transmissions in the first state. The UE does not need to periodically perform a specific uplink transmission in the second state.

  In another exemplary method for a UE, the method connects to at least two base stations including a first base station that controls one serving cell and a second base station that controls another serving cell. Suspending a specific uplink transmission within the one serving cell, receiving downlink signaling within the other serving cell, and responding to the downlink signaling with the specific uplink transmission within the one serving cell. Restart link transmission.

  In one exemplary method for a first base station, the method includes serving a UE and transmitting a request to a second base station, wherein the request includes the first base station. Requesting a second base station to transmit downlink signaling to the UE to instruct the UE to resume a specific uplink transmission within a serving cell controlled by the base station.

  In one exemplary method for a second base station, the method serves to serve a UE and to transmit downlink signaling from the first base station to the UE. Receiving a request to request, and transmitting the downlink signaling to the UE to instruct the UE to resume a specific uplink transmission in a serving cell controlled by a first base station. And including.

  In another method for the UE, the first base station and the second base station, the downlink signaling directs a specific uplink transmission to resume in the serving cell. Thus, in other methods, the UE is allowed to transmit scheduling requests in the serving cell when suspending certain uplink transmissions in the serving cell.

  In another exemplary method, a UE connects to at least two base stations including a first base station that controls one serving cell and a second base station that controls another serving cell; Receiving a downlink signaling and transmitting a reference signal in the one serving cell in response to receiving the downlink signaling.

  In another exemplary method, a first base station serves a UE and sends a request to a second base station, which requests a reference signal in a serving cell controlled by the first base station. Requesting a second base station to transmit downlink signaling to the UE to instruct the UE to transmit.

  In another exemplary method, a second base station serves a UE and receives a request from the first base station, the request to the second base station to send downlink signaling to the UE. Request and send the downlink signaling to the UE to instruct the UE to send a reference signal in a serving cell controlled by the first base station.

  In another method for the UE, the first base station, and the second base station, downlink signaling instructs the UE to transmit a reference signal in the serving cell. In yet another method, the reference signal is an aperiodic reference signal. In some embodiments, the UE suspends certain uplink transmissions in the serving cell upon receipt of downlink signaling. In another method, the UE resumes certain uplink transmissions in response to receiving downlink signaling.

  In various methods, the first base station is a SeNB and the second base station is a MeNB. In some methods, the serving cell is a PSCell. In the alternative, the serving cell is an SCell. In various methods disclosed herein, the base station is an eNB.

  In various exemplary methods, upon suspension of a particular uplink transmission, the UE maintains a specific uplink transmission (RRC) setting. In other methods, transmissions within the serving cell can be scheduled at the serving cell, eg, PDCCH signaling can be transmitted within the serving cell.

  In various methods disclosed herein, a UE connects to multiple serving cells. In some embodiments, multiple serving cells are controlled by more base stations. The plurality of serving cells are controlled by different base stations. In some methods, the serving cell is controlled by a base station, eg, a SeNB that does not control the PCell.

  In various methods disclosed herein, certain uplink transmissions are transmitted periodically, eg, based on settings received from the network. In the various methods disclosed herein, a specific uplink transmission is a reference signal: SRS; CQI report; Precoding Matrix Index (PMI) report (defined in 3GPPTS 36.321 V12.3.0); Rank Indicator (RI) report (defined in 3GPPTS 36.321 V12.3.0); Precoding Type Indicator (PTI) report (defined in 3GPPTS 36.321 V12.3.0); and / or semi-persistent Uplink transmission (eg, semi-persistent scheduling (SPS)) can be included. In various methods disclosed herein, a particular uplink transmission does not include a random access preamble.

  In various methods disclosed herein, a scheduling request is sent due to a buffer status report (BSR) trigger (defined in 3GPPTS 36.321 V12.3.0). In other methods, scheduling requests are used to request uplink resources.

  In various methods disclosed herein, downlink signaling indicates a downlink assignment within the serving cell or an uplink grant within the serving cell. Downlink signaling is also used for new transmissions. In other methods, the uplink grant is for new transmissions.

  In various methods, downlink signaling is transmitted via PDCCH or physical downlink shared channel (PDSCH). In other methods, the downlink signaling is a downlink assignment or MAC control element.

  As described above, a cell using a high frequency band has a coverage limitation. A UE in a cell may always be uplink time aligned due to the small coverage or current mechanism still maintained, and its uplink time for the UE is subject to several scenarios (3GPPTS 36.321 V12.3.0). Defined), for example, it can be considered unaligned with respect to the end of time alignment. In other words, whether UL timing advance may still be needed for the UE, and whether the time alignment timer (defined in 3GPPTS 36.321 V12.3.0) associated with the cell is needed for the UE do not know.

  Nevertheless, some uplink transmissions within the capacity layer serving cell may need to be stopped due to UE power saving and then resumed, eg, for DL data arrival and transmission within the serving cell. Specific uplink transmissions include the following signaling: periodic reference signals, eg SRS (defined in 3GPPTS 36.321 V12.3.0); periodic channel status reports, eg CQI reports (3GPPTS 36.321 V12.3) And / or semi-persistent uplink transmission, eg using a configured uplink grant (defined in 3GPPTS 36.321 V12.3.0): Including one.

  Stopping a specific UL transmission can be performed explicitly by signaling from the base station, e.g. PDCCH signaling or MAC control elements, or implicitly by e.g. a timer controlled UE. More specifically, when the UE stops a specific UL transmission, the RRC configuration associated with the specific UL transmission is not released.

  For resumption, DL signaling, eg PDCCH signal G navigates to a first base station that controls one serving cell, eg, a second base station, eg, MeNB, that controls another serving cell in the coverage layer. Request to transmit a ring or MAC control element and perform the following operations: resumption of a specific UL transmission within the serving cell; start of random access preamble transmission within the serving cell (as defined in 3GPPTS 36.321 V12.3.0) ), For example, the start of a random access procedure; transmission of a scheduling request in the serving cell (as defined in 3GPPTS 36.321 V12.3.0); and / or an aperiodic reference signal in the serving cell, eg aperiodic SRS ( 3GP TS36.321 V12.3.0 Defined) sending to: request the UE to perform at least one of.

  More specifically, DL signaling can instruct to use a dedicated preamble in a random access procedure. The DL signaling can be in PDCCH order (defined in 3GPPTS 36.321 V12.3.0). More specifically, the second base station transmits DL signaling due to reception of a request from the first base station. Some examples are shown in FIGS.

  In FIG. 9, base station 2 (906) has DL data available for transmission. A request is sent by base station 2 (906) to base station 1 (904). Base station 1 (904) sends the PDCCH order to UE 902. UE 902 then starts preamble transmission and sends one or more preamble transmissions to base station 2 (906).

  In FIG. 10, the base station 2 (1006) has DL data that can be used for transmission. A request is sent by the base station 2 (1006) to the base station 1 (1004). Base station 1 (1004) sends a periodic or aperiodic reference signal request to UE 1002. UE1002 starts reference signal transmission after that, and sends one or more reference signals to base station 2 (1006).

  Alternatively, the first base station can send more than one request requesting the second base station to send more than one DL signaling, each of these DL signaling to the UE Can be used to request that at least one of the operations be performed. An example is shown in FIG. Base station 2 (1106) may first request UE 1102 to transmit a reference signal in the serving cell via base station 1 (1104). Therefore, base station 2 (1106) can identify the beam where UE 1102 is located. Base station 2 (1106) then sends a random access preamble transmission to UE 1102 via base station 1 (1104) to identify the UL timing advance (defined in 3GPPTS 36.321 V12.3.0). You can request to do it.

  In one exemplary method for a UE, the method includes transmitting the UE to at least two base stations including a first base station that controls one serving cell and a second base station that controls another serving cell. Connecting, receiving a second downlink signaling in the other serving cell after stopping a first specific uplink transmission in the one serving cell, and responding to receiving the second downlink signaling And transmitting at least one random access preamble in the one serving cell.

  In another exemplary embodiment, the UE transmits at least one second specific uplink signal in the one serving cell in response to receiving the second downlink signaling.

  In one exemplary method for a UE, the method connects the UE to at least two base stations including a first base station that controls one serving cell and a second base station that controls another serving cell. Receiving the first downlink signaling in the other serving cell after stopping the first specific uplink transmission in the one serving cell, and receiving the first downlink signaling. In response, transmitting at least one second specific uplink signal in the one serving cell; and second transmission in the other serving cell after transmitting the at least one second specific uplink signal. Receiving downlink signaling; and in response to receiving the second downlink signaling And transmitting at least one random access preamble in the single serving cell.

  In another exemplary method, the UE stops transmitting the first specific uplink signal due to expiration of a timer, eg, a time alignment timer. In another method, the UE stops transmitting the first specific uplink signal due to reception of an indication from the first base station. In yet another method, the UE stops transmitting the first specific uplink signal due to reception of an indication from the second base station.

  In another exemplary method, the UE initiates a random access procedure in the one serving cell in response to receiving the second downlink signaling. In another method, when the UE transmits at least one second specific uplink signal in the one serving cell in response to receiving the first downlink signaling, a timer, eg, a time alignment timer, is Not working.

  In another exemplary method for a first base station serving a UE, the method includes transmitting a second request to a second base station, wherein the second request includes: Requesting the second base station to send a second downlink signaling to the UE to instruct the UE to send at least one random access preamble in a serving cell controlled by the base station. is there. In another method, the second downlink signaling instructs the UE to also transmit at least one second specific uplink signal in the serving cell.

  In another exemplary method for a first base station serving a UE, the method includes transmitting a first request to a second base station, wherein the first request is a first A second base to transmit a first downlink signaling to the UE to instruct the UE to transmit at least one second specific uplink signal in a serving cell controlled by the base station In response to receiving the at least one second specific uplink signal from the UE, and receiving the at least one second specific uplink signal. Transmitting a second request to a second base station, wherein the second request transmits at least one random access preamble in the serving cell. To instruct cormorants the UE, is to request a second downlink signaling to the second base station to transmit to the UE

  In another method, the first base station determines a beam of a serving cell in which the UE is located based at least on reception of the random access preamble. In another method, the first base station determines a beam of a serving cell in which the UE is located based at least on reception of the second specific uplink signal

  In another method, the first base station transmits a first request to the second base station based at least on the presence of data to be transmitted to the UE in the serving cell. In another method, the first base station transmits a second request to the second base station based at least on the presence of data to be transmitted to the UE in the serving cell.

  In an exemplary method for a second base station serving a UE, the method includes receiving a second request from a first base station, wherein the second request is a second downlink. Requesting a second base station to send signaling to the UE, and in response to receiving the second request, sending the second downlink signaling to the UE; Instructing the UE to transmit at least one random access preamble in a serving cell controlled by one base station.

  In another method, the second downlink signaling instructs the UE to transmit at least one specific uplink signal in the serving cell.

  In an exemplary method for a second base station serving a UE, the method includes receiving a first request from a first base station, wherein the first request is a first downlink. Requesting a second base station to send signaling to the UE; and in response to receiving the first request, sending the first downlink signaling to the UE; Instructing the UE to transmit at least one second specific uplink signal in a serving cell controlled by one base station; and first after transmitting the first downlink signaling to the UE Receiving at least a second request from a second base station, wherein the second request requests the second base station to send a second downlink signaling to the UE. And, in response to receiving the second request, transmitting the second downlink signaling to the UE to instruct the UE to perform at least one random access preamble in the serving cell. And including.

  In various exemplary methods, the second downlink signaling instructs the UE to initiate a random access procedure in the serving cell. In another exemplary method, the UE maintains a (RRC) setting of the first uplink signal when transmission of the first specific uplink signal is stopped.

  In various exemplary methods, the first specific uplink signal is transmitted periodically, eg, based on settings received from the network.

  In various exemplary methods, the first specific uplink signal is a reference signal, SRS, CQI report, PMI report, RI report, PTI report, or semi-persistent uplink transmission.

  In various exemplary methods, the second specific uplink signal is the first specific uplink signal, a periodic reference signal, or a scheduling request.

  In various exemplary methods, the first downlink signaling is PDCCH signaling, a MAC control element, or an RRC message.

  In various exemplary methods, the second downlink signaling is PDCCH signaling, PRCCH order, MAC control element, or RRC message.

  In various exemplary methods, the first base station is an eNB or SeNB. In various exemplary methods, the second base station is a MeNB. In various exemplary methods, the serving cell is a PSCell or SCell. In various exemplary methods, another serving cell is a PCell.

  Returning to FIGS. 3 and 4, in one embodiment from an apparatus perspective, the apparatus 300 includes program code 312 stored in a memory 310. CPU 308 executes plug cord 312 to (i) at least two base stations including a first base station that controls the first serving cell and a second base station that controls the second serving cell. Connecting, (ii) receiving downlink signaling in the second serving cell, and (iii) transmitting a reference signal in the first serving cell in response to receiving the downlink signaling. Further, CPU 308 may execute program code 312 to perform all of the operations and steps described above, and may perform other operations and steps described herein.

  Returning to FIGS. 3 and 4, in one embodiment from the perspective of the first base station, the first base station 300 includes program code 312 stored in the memory 310. The CPU 308 can execute the plug code 312 to (i) serve the UE and (ii) send a request to the second base station, the request being in a serving cell controlled by the first base station. In order to instruct the UE to transmit a reference signal, the second base station is requested to transmit downlink signaling to the UE. Further, CPU 308 may execute program code 312 to perform all of the operations and steps described above, and may perform other operations and steps described herein.

  Returning to FIGS. 3 and 4, in one embodiment from the perspective of the second base station, the first base station 300 includes program code 312 stored in the memory 310. CPU 308 may execute plug code 312 to (i) serve the UE and (ii) receive a request from the first base station, which will downlink and send a glan ring to the UE. (Iii) transmit downlink signaling to the UE to instruct the UE to transmit a reference signal in a serving cell controlled by the first base station. To do. Further, CPU 308 may execute program code 312 to perform all of the operations and steps described above, and may perform other operations and steps described herein.

  Various aspects of the invention have been described above. The teachings of the present disclosure may be embodied in various forms, and the specific structures and functions disclosed herein are merely exemplary. Based on the teachings of the present disclosure, one of ordinary skill in the art will be able to implement one embodiment disclosed herein independently of any other embodiment, and may combine two or more of these embodiments in various ways. Be recognized. For example, an apparatus or method can be implemented or implemented using any number of the aspects disclosed herein. Moreover, such an apparatus or method may be implemented or implemented using other structures, functions or structures and functions in addition to one or more of the aspects disclosed herein. As an example of some of the above concepts, in one aspect, a simultaneous channel can be established based on the pulse repetition frequency. In certain aspects, simultaneous channels can be established based on pulse positions or offsets. In one aspect, simultaneous channels can be established based on time hopping sequences. In one aspect, simultaneous channels can be established based on pulse repetition frequency, pulse position or offset, and time hopping sequence.

  Those skilled in the art will appreciate that information and signals can be represented in any of a wide variety of techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips referenced throughout the above description may be expressed as voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof. Can do.

  Those skilled in the art further recognize that the various exemplary logic blocks, modules, processors, means, circuits, and algorithm steps described in connection with the aspects disclosed herein are electronic hardware (eg, source coding or other Digital implementation, analog implementation, or a combination of both) that can be designed using technology, various forms of programs or design codes that contain instructions (herein referred to as “software” or “software modules”), or a combination of both It will be understood that it can be implemented as: To clearly illustrate this hardware and software compatibility, various illustrative components, blocks, modules, circuits, and steps are generally described above in terms of their functionality. Whether such functions are implemented as hardware or software depends on specific applications and design constraints imposed on the entire system. Those skilled in the art can implement the described functionality in a variety of ways for each particular application, but such implementation decisions should not be construed as departing from the scope of the invention.

  Additionally, the various exemplary logic blocks, modules, and circuits described in connection with the features disclosed herein can be implemented in an integrated circuit (IC), access terminal, or access point, and Can be implemented by them. The IC may be a general purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field program gate array (FPGA) or other programmable logic device designed to perform the functions described herein. A discrete gate or transistor logic circuit, a discrete hardware component, an electrical component, an optical component, a mechanical component, or any combination thereof, to execute code or instructions that reside inside or outside the IC, or both it can. A general purpose processor may be a microprocessor, but in the alternative, the program may be any conventional processor, controller, microcontroller, or state machine. The processor may be implemented as a computer device, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any such configuration.

  It should be understood that the specific order or order of steps in any process of the disclosure is only an example for illustration. It should be understood that the order or order of the process steps can be rearranged within the scope of this disclosure based on design preferences. The accompanying method claims present an exemplary order of the elements of the various steps, and are not intended to be limited to the specific order or order of presentation.

  The method or algorithm steps described in connection with the features disclosed herein may be embodied in hardware, in software modules executed in a process, or in a combination of both. Software modules (eg, including executable instructions and associated data) and other data may be data memory, eg, RAM memory, flash memory, ROM memory, EPROM memory, EEPROM, registers, hard disk, removable disk, CD-ROM, or It can be present in any other form of computer readable storage media known in the art. A sample storage medium can be coupled to a machine, such as a computer / processor (herein referred to as a “processor” for convenience), such that the processor reads and stores information (eg, code) from the storage medium. Information can be written to the medium. The sample storage medium can be integral to the processor. The processor and the storage medium can exist in the ASIC. The ASIC can be present in the user device. In the alternative, the processor and the storage medium may reside as discrete computers in a user device. Further, in some aspects, any suitable computer program product may comprise a computer-readable medium comprising k-degrees related to one or more of the disclosed features. In some aspects, the computer program product can comprise packaging material.

  While the invention has been described in connection with various aspects, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses, or modifications of the invention in accordance with the principles of the invention, and such deviations from the invention fall within the scope of well-known techniques in the field to which the invention belongs.

Claims (20)

A method for processing uplink transmission in a wireless communication system, the method comprising:
Connecting a user equipment (UE) to at least two base stations including a first base station that controls a first serving cell and a second base station that controls a second serving cell;
Periodically transmitting a specific uplink transmission by the UE in the first serving cell;
By the UE, stopping the specific uplink transmission in the first serving cell;
Receiving downlink signaling by the UE in the second serving cell;
By the UE, and transmits an aperiodic reference signal in said first serving cell in response to receiving the downlink signaling, comprising the steps of: resuming said specific uplink transmission within the first serving cell,
A method comprising: The specific uplink transmission, the reference signals, the sounding reference signal (SRS), or a channel quality indication (CQI) report method of claim 1, wherein.   The method of claim 1, wherein the UE maintains a setting of the specific uplink transmission when stopping the specific uplink transmission.   The method of claim 1, wherein the downlink signaling indicates an uplink grant in the first serving cell.   The method of claim 1, wherein the downlink signaling is transmitted via a physical downlink control channel (PDCCH) or a media access control (MAC) control element. A method for handling uplink transmissions in a wireless communication system in which a second base station serves a user equipment (UE), the method comprising:
Receiving, by the second base station, a request from the first base station requesting the second base station to transmit downlink signaling to the UE;
The second base station transmits an aperiodic reference signal in a serving cell controlled by the first base station and instructs the UE to resume periodic transmission of a specific uplink transmission To send the downlink signaling to the UE;
A method comprising: 7. The method of claim 6 , wherein the periodic specific uplink transmission is a reference signal , a sounding reference signal (SRS), or a channel quality indication (CQI) report . The method of claim 6 , wherein the downlink signaling indicates an uplink grant in the serving cell. The method of claim 6 , wherein the downlink signaling is transmitted via a physical downlink control channel (PDCCH) or a media access control (MAC) control element. A communication device for processing uplink transmission in a wireless communication system, the communication device comprising:
A control circuit;
A processor embedded in the control circuit;
A memory embedded in the control circuit and operably coupled to the processor;
The processor is configured to execute program code stored in the memory for processing uplink transmissions, the program code comprising:
Connecting the communication device to at least two base stations including a first base station controlling a first serving cell and a second base station controlling a second serving cell;
Periodically transmitting a specific uplink transmission in the first serving cell by the communication device;
Stopping the specific uplink transmission in the first serving cell by the communication device;
Receiving downlink signaling by the communication device in the second serving cell;
By the communication device, it transmits the aperiodic reference signal in said first serving cell in response to receiving the downlink signaling, the step of resuming the specific uplink transmission within the first serving cell,
A communication device comprising: The communication apparatus according to claim 10 , wherein the specific uplink transmission is a reference signal, a sounding reference signal (SRS), or a channel quality indication (CQI) report. The communication apparatus according to claim 10, wherein the UE maintains a setting of the specific uplink transmission when stopping the specific uplink transmission. The communication apparatus according to claim 10 , wherein the downlink signaling indicates an uplink grant in the first serving cell. The communication apparatus according to claim 10 , wherein the downlink signaling is transmitted via a physical downlink control channel (PDCCH) or a media access control (MAC) control element. A method for processing uplink transmission in a wireless communication system, the method comprising:
  Connecting a user equipment (UE) to at least two base stations including a first base station that controls a first serving cell and a second base station that controls a second serving cell;
  Periodically transmitting a specific uplink transmission by the UE in the first serving cell;
  By the UE, stopping the specific uplink transmission in the first serving cell;
  At least when the UE triggers a scheduling request, or when the UE detects a change in the serving cell beam set for the UE, the specific uplink transmission in the first serving cell. A step to resume;
A method comprising:   The method of claim 15, wherein the specific uplink transmission is a reference signal, a sounding reference signal (SRS), or a channel quality indication (CQI) report.   The method of claim 15, wherein the reference signal is an aperiodic reference signal or a periodic reference signal.   A communication device for processing uplink transmission in a wireless communication system, the communication device comprising:
  A control circuit;
  A processor embedded in the control circuit;
  A memory embedded in the control circuit and operably coupled to the processor;
  The processor is configured to execute program code stored in the memory for processing uplink transmissions, the program code comprising:
  Connecting the communication device to at least two base stations including a first base station controlling a first serving cell and a second base station controlling a second serving cell;
  Periodically transmitting a specific uplink transmission in the first serving cell by the communication device;
  Stopping the specific uplink transmission in the first serving cell by the communication device;
  By the communication device, at least when the communication device triggers a scheduling request, or when the communication device detects a change of a beam set of a serving cell for the communication device, the specific serving cell in the first serving cell Resuming uplink transmission,
A communication device comprising:   The communication apparatus according to claim 18, wherein the specific uplink transmission is a reference signal, a sounding reference signal (SRS), or a channel quality indication (CQI) report.   The communication device according to claim 18, wherein the reference signal is an aperiodic reference signal or a periodic reference signal.