WO2013040905A1

WO2013040905A1 - Method, base station and terminal for secondary cell uplink synchronization

Info

Publication number: WO2013040905A1
Application number: PCT/CN2012/075673
Authority: WO
Inventors: 王坚; 马伟; 朱昀; 尚国强
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-09-20
Filing date: 2012-05-17
Publication date: 2013-03-28
Also published as: CN103024890B; CN103024890A

Abstract

The present invention provides a method, a base station and a terminal for secondary cell uplink synchronization, wherein the method comprises: the base station receives a random access preamble sent by the terminal according to the uplink scheduling of the primary cell on the terminal-side in a secondary cell; the base station compares the receiving time of the random access preamble with a downlink scheduling of the primary cell on the base station-side; the base station creates a scheduling adjusting indication information according to the compare result,and then sends the scheduling adjusting indication information to the terminal, wherein the scheduling adjusting indication information is used to indicate the terminal to adjust the uplink scheduling of the secondary cell on the terminal-side to synchronize with the uplink scheduling of the primary cell on the base station-side. The present invention solves the technique problem that in the prior art, the uplink scheduling synchronization could not be implemented between the primary cell and the secondary cell. The present invention guarantees the normal communication between the base station and the terminal.

Description

The present invention relates to the field of communications, and in particular to an uplink synchronization method, a base station, and a terminal of a secondary cell. The carrier aggregation is a core function in an enhanced version of the long-term evolution system. The uplink and downlink rates of the UE (User Equipment) are greatly improved by using a plurality of carriers or cells in parallel. A cell aggregated by a UE with carrier aggregation function is divided into a primary cell (Primary Cell, abbreviated as Pcell) and a number of secondary cells (Scells), and the primary cell is responsible for radio resource control (Radio Resource Control, referred to as RRC). Connection establishment, re-establishment, and handover, providing non-access stratum (Non Access Stratum, NAS for short) mobile information (such as Tracking Area Indicator (referred to as Tracking Area Indicator) for each serving cell (ie, Pcell or Scell) TAI)), and connection re-establishment and handover of each serving cell in RRC, the primary cell provides security input, and the downlink carrier used by the primary cell is called Downlink Primary Component Carrier (DL PCC), uplink The carrier is called the uplink primary component carrier (ULBC), the downlink carrier used by the secondary cell is called the downlink secondary component carrier (DL SCC), and the uplink carrier is called the uplink secondary component. Uplink Secondary Component Carrier (UL S for short) CC). For each secondary cell, when the UE uses the uplink resource and the downlink resource, the number of the configured downlink secondary component carrier is greater than or equal to the number of the uplink secondary component carrier, and all the resources on the Scell cannot be configured as the uplink resource. From the perspective of the UE, each uplink resource belongs to only one serving cell (ie, Pcell or Scell), and the number of serving cells configured by the UE may be changed according to the carrier capability of the UE, such as adding and/or deleting the serving cell, and This also changes the security key and the RACH (Random Access Channel) process.

The change of the configuration relationship between the Pcell and the terminal or the base station can only be implemented by means of handover. The PCell is used to transmit a Physical Uplingk Control Channel (PUCCH) and is always in an active state. When the Pcell experiences a radio link failure (Radio Link Failure, RLF for short), the UE re-establishes a radio link for the Pcell. When the Scell experiences RLF, the UE does not re-establish a radio link for the Scell. The NAS information is derived from the Pcell. . Scell reconfiguration, addition and removal are all done by RRC, in LTE (Long Term Evolution, In the long-term evolution) intra-ring handover, the RRC can add, delete, and reconfigure the Scell to be applicable to the target PCell. When a new Scell is added, the dedicated RRC signaling is used to transmit all necessary system information of the Scell. To save power, the Scell can be activated and deactivated. The Scell in the deactivated state does not need to receive the physical downlink control channel (Physical Downlink Control Channel, PDCCH for short) or the Physical Downlink Sharing Channel (PDSCH), and cannot perform uplink transmission. It is not necessary to perform channel quality indication (Channel). Quality Indicator, referred to as CQI) measurement. The activation and deactivation of the Scell is controlled by a MAC (Media Access Control) control unit and a deactivation timer. When the UE receives the MAC Control Unit Control, if the corresponding bit is 1, the Scell controlled by the MAC Control Unit will be activated, otherwise it will be deactivated, and when the Deactivation Timer expires, the Scell will be deactivated. The Scell from the deactivated state to the active state will perform uplink synchronization. For the serving cell in the same band (band), the uplink of the Scell is synchronized with the uplink of the Pcell, and for different bands. For the serving cell, the uplink of the Scell cannot be synchronized with the uplink of the Pcell. As shown in Figure 1, the two serving cells deployed under e B (E-UTRAN NodeB, evolved base station) are respectively cell 1 ( Cell 1) and cell 2 (Cell 2), cell 1 is deployed on frequency F1, cell2 is deployed on frequency F2, and RRH/repeater (transponder) will form an enhanced signal for cell 2 portion 2 (area 2, equivalent) Scell), if UE1 is in the port 2, the uplink signal of the UE1 is different from the uplink signal timing of the UE2 in the cell 2 portion 1 (corresponding to the Pcell) after being forwarded by the RRH/repeater. However, according to the provisions of the existing protocol, the uplink timing synchronization of the Pcell and the Scell cannot be performed, resulting in abnormal communication between the UE and the base station. SUMMARY OF THE INVENTION The present invention provides an uplink synchronization method, a base station, and a terminal of a secondary cell, to at least solve the technical problem that uplink timing synchronization cannot be performed on the primary cell and the secondary cell in the prior art. According to an aspect of the present invention, a method for uplink synchronization of a secondary cell is provided, including: a base station receiving a random access preamble sent by a terminal on a secondary cell according to an uplink timing of a primary cell on a terminal side; The receiving time is compared with the downlink timing of the primary cell on the base station side; the base station generates the timing adjustment indication information according to the comparison result, and sends the timing adjustment indication information to the terminal, where the timing adjustment indication information is used to indicate that the terminal uses the secondary cell in the terminal. The uplink timing of the side is adjusted to be synchronized with the uplink timing of the primary cell on the base station side. Preferably, the step of comparing, by the base station, the receiving time of the random access preamble with the downlink timing of the primary cell at the base station side comprises: calculating a difference between the receiving time and the current subframe start time of the downlink timing of the primary cell at the base station side The step of generating the timing adjustment indication information by the base station according to the comparison result includes: if the receiving time is equal to the current subframe start time of the downlink timing of the primary cell at the base station side, generating first timing adjustment indication information, configured to indicate The terminal does not perform the operation of adjusting the uplink timing of the secondary cell on the terminal side or indicates that the uplink timing of the secondary cell on the terminal side of the terminal is synchronized with the uplink timing of the primary cell on the base station side; if the receiving time is greater than And the second timing adjustment indication information is used to indicate that the terminal advances the uplink timing of the secondary cell on the terminal side; if the receiving time is smaller than the downlink of the primary cell on the base station side, where the primary cell starts at the current subframe start time of the downlink sequence of the base station side. The timing of the current subframe start time is used to generate third timing adjustment indication information, which is used to instruct the terminal to delay the uplink timing of the secondary cell on the terminal side. Preferably, the timing adjustment indication information includes information of an uplink timing advance group to which the secondary cell belongs, where the uplink timing advance group is used to adjust the uplink timing of the secondary cell on the terminal side to be synchronized with the uplink timing of the primary cell on the base station side. Preferably, after the timing adjustment indication information is sent to the terminal, the uplink synchronization method of the secondary cell further includes: the terminal receives the timing adjustment indication information; and the terminal adjusts the uplink timing of the secondary cell on the terminal side to the primary according to the timing adjustment indication information. The uplink timing of the cell on the base station side is synchronized. Preferably, the step of the terminal adjusting the uplink timing of the secondary cell on the terminal side to the uplink timing of the primary cell on the base station side according to the timing adjustment indication information includes: the terminal adjusts the uplink timing of the secondary cell according to the timing adjustment indication information The information of the advance group adjusts the secondary cell to belong to the uplink timing advance group. Preferably, the primary cell and the secondary cell are carriers after carrier aggregation. According to another aspect of the present invention, a base station is provided, including: a receiving unit, configured to receive, by a terminal, a random access preamble sent by a terminal on a secondary cell according to an uplink timing of a primary cell on a terminal side; The receiving time of the random access preamble is compared with the downlink timing of the primary cell on the base station side; the generating unit is configured to generate timing adjustment indication information according to the comparison result, where the timing adjustment indication information is used to indicate that the terminal sets the secondary cell on the terminal side The uplink timing is adjusted to be synchronized with the uplink timing of the primary cell on the base station side, and the sending unit is configured to send timing adjustment indication information to the terminal. Preferably, the generating unit includes: a first generating module, configured to: if the receiving time is equal to a current subframe start time of a downlink sequence of the primary cell, generate first timing adjustment indication information, where the terminal is configured to not perform adjustment of the secondary cell at the terminal The operation of the uplink sequence of the side or the uplink timing of the secondary cell on the terminal side of the terminal is synchronized with the uplink timing of the primary cell on the base station side; and the second generation module is configured to: if the receiving time is greater than the primary And the second timing adjustment indication information is used to indicate that the terminal advances the uplink timing of the secondary cell on the terminal side, and the third generation module is configured to: if the receiving time is smaller than the downlink of the primary cell, The timing of the current subframe start time is used to generate third timing adjustment indication information, which is used to instruct the terminal to delay the uplink timing of the secondary cell on the terminal side. According to still another aspect of the present invention, a terminal is provided, including: a sending unit, configured to send a random access preamble according to an uplink timing of a primary cell on a terminal side of a secondary cell of a base station; and a receiving unit, configured to receive a base station The timing adjustment indication information is generated by the base station according to a comparison result between the receiving time of the random access preamble and the downlink timing of the primary cell on the base station side, and the timing adjustment indication information is used to indicate that the terminal supplements The uplink timing of the cell on the terminal side is adjusted to be synchronized with the uplink timing of the primary cell on the base station side; and the adjusting unit is configured to adjust the uplink timing of the secondary cell on the terminal side to the uplink timing of the primary cell on the base station side according to the timing adjustment indication information. Synchronize. Preferably, the adjusting unit is further configured to adjust the secondary cell to belong to the uplink timing advance group according to the information of the uplink timing advance group to which the secondary cell belongs in the timing adjustment indication information. In the present invention, the base station can adjust the uplink timing of the secondary cell on the terminal side by using the timing adjustment indication information, so that the uplink timing of the adjusted secondary cell on the terminal side is synchronized with the uplink timing of the primary cell on the base station side, thereby The technical problem that the uplink timing of the primary cell and the secondary cell cannot be synchronized in the prior art is solved, and normal communication between the base station and the terminal is ensured. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a schematic diagram of a wireless communication system deployment according to the related art; FIG. 2 is a preferred structural diagram of an uplink synchronization system of a secondary cell according to an embodiment of the present invention; A preferred block diagram of a base station; FIG. 4 is a block diagram of a preferred structure of a terminal according to an embodiment of the present invention; FIG. 5 is a preferred flowchart of an uplink synchronization method of a secondary cell according to an embodiment of the present invention; It is a preferred schematic diagram of the relationship between the uplink timing and the downlink timing according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. Embodiment 1 FIG. 2 is a preferred structural diagram of an uplink synchronization system of a secondary cell according to an embodiment of the present invention, which includes: a base station 202 and a terminal 204 that communicate with each other. In the process of synchronizing the uplink sequence of the secondary cell, the terminal 204 transmits a random access preamble to the base station 202 according to the uplink timing of the primary cell on the terminal 204 side on the secondary cell of the base station 202; the base station 202 receives the random access preamble Then, the receiving time of the random access preamble is compared with the downlink timing of the primary cell at the base station 202 side, and the timing adjustment indication information is generated according to the comparison result, where the timing adjustment indication information is used to indicate that the terminal 204 is the secondary cell at the terminal 204. The uplink timing of the side is adjusted to be synchronized with the uplink timing of the primary cell on the base station 202 side; the base station 202 sends the timing adjustment indication information to the terminal 204; after receiving the timing adjustment indication information, the terminal 204 adjusts the indication information according to the timing adjustment indication information to the secondary cell. The uplink timing on the terminal 204 side is adjusted to be synchronized with the uplink timing of the primary cell on the base station 202 side. In the above preferred embodiment, the base station can adjust the uplink timing of the secondary cell on the terminal side by using the timing adjustment indication information, so that the uplink timing of the adjusted secondary cell on the terminal side and the uplink timing of the primary cell on the base station side are adjusted. Synchronization, thereby solving the technical problem that the uplink timing synchronization of the primary cell and the secondary cell cannot be performed in the prior art, and ensuring normal communication between the base station and the terminal. On the basis of the system shown in FIG. 2, the present invention further provides a preferred base station. As shown in FIG. 3, the base station includes: a receiving unit 302, configured to receive, by the terminal, a secondary cell according to the primary cell. a random access preamble sent by the uplink timing of the terminal side; the comparing unit 304 is configured to communicate with the receiving unit 302, where the receiving time of the random access preamble is compared with the downlink timing of the primary cell on the base station side; The generating unit 306 is configured to be in communication with the comparing unit 304, configured to generate timing adjustment indication information according to the comparison result, where the timing adjustment indication information is used to indicate that the terminal adjusts an uplink timing of the secondary cell on the terminal side to The uplink timing synchronization with the primary cell on the base station side; the sending unit 308 is in communication with the generating unit 306, and configured to send the timing adjustment indication information to the terminal. In the preferred embodiment, the base station can adjust the uplink timing of the secondary cell on the terminal side by using the timing adjustment indication information, so as to adjust the uplink timing of the adjusted secondary cell on the terminal side and the uplink timing of the primary cell on the base station side. Synchronization, thereby solving the technical problem that the uplink timing synchronization of the primary cell and the secondary cell cannot be performed in the prior art, and ensuring normal communication between the base station and the terminal. The present invention further provides a preferred generating unit 306, including: a first generating module, configured to generate a first timing adjustment indication if the receiving time is equal to a current subframe start time of a downlink timing of the primary cell And the information that is used to indicate that the terminal does not perform an operation of adjusting an uplink timing of the secondary cell on the terminal side, or indicates that an uplink timing of the secondary cell on the terminal side of the terminal and the primary cell are in the An uplink timing synchronization on the base station side, where the second generation module is configured to: if the receiving time is greater than a current sub-time of the primary cell a frame start time, where the second timing adjustment indication information is generated, used to indicate that the terminal advances the uplink timing of the secondary cell on the terminal side, and preferably, the receiving time and the downlink timing of the primary cell are calculated. a difference between the start time of the current subframe, the second timing adjustment indication information indicating a time when the terminal advances the uplink timing of the secondary cell on the terminal side to the difference; the third generation module, And a third timing adjustment indication information, configured to indicate, by the terminal, an uplink timing of the secondary cell on the terminal side, if the receiving time is less than a current subframe start time of a downlink sequence of the primary cell. Deferred, preferably, calculating a difference between the receiving time and a current subframe start time of the downlink timing of the primary cell, where the second timing adjustment indication information indicates that the terminal is to use the secondary cell in the The uplink timing delay length on the terminal side is the time of the above difference. Through the different timing adjustment indication information, the uplink timing of the secondary cell can be accurately adjusted to be synchronized with the uplink timing of the primary cell in different scenarios. Preferably, the timing adjustment indication information includes information about an uplink timing advance group to which the secondary cell belongs, where the uplink timing advance group is used to adjust an uplink timing of the secondary cell on the terminal side to The uplink timing of the primary cell on the base station side is synchronized. In the preferred embodiment, the information of the uplink timing advance group can quickly adjust the uplink timing of the secondary cell on the terminal side. Preferably, the primary cell and the secondary cell are carriers after carrier aggregation. In the preferred embodiment, the present invention is made applicable to the scenario of carrier aggregation. On the basis of the system shown in FIG. 2, the present invention further provides a preferred terminal. As shown in FIG. 4, the terminal includes: a sending unit 402, configured to perform, according to the primary cell, on the secondary cell of the base station. The uplink timing of the terminal side sends a random access preamble; the receiving unit 404 is configured to communicate with the sending unit 402, and is configured to receive timing adjustment indication information sent by the base station, where the timing adjustment indication information is used by the base station according to the random And a result of the comparison between the receiving time of the access preamble and the downlink timing of the primary cell on the base station side, where the timing adjustment indication information is used to indicate that the terminal uses the secondary cell on the terminal side The uplink timing is adjusted to be synchronized with the uplink timing of the primary cell on the base station side; the adjusting unit 406 is configured to communicate with the receiving unit 404, configured to use the timing adjustment indication information to uplink the secondary cell on the terminal side. The timing is adjusted to be synchronized with the uplink timing of the primary cell on the base station side. In the preferred embodiment, the base station can adjust the uplink timing of the secondary cell on the terminal side by using the timing adjustment indication information, so as to adjust the uplink timing of the adjusted secondary cell on the terminal side and the uplink timing of the primary cell on the base station side. Synchronization, thereby solving the technical problem that the uplink timing synchronization of the primary cell and the secondary cell cannot be performed in the prior art, and ensuring normal communication between the base station and the terminal. Preferably, the present invention also improves the above adjustment unit. Specifically, when the adjustment timing of the secondary cell on the terminal side is adjusted, the adjusting unit 406 adjusts the secondary cell to the information according to the information of the uplink timing advance group to which the secondary cell belongs in the timing adjustment indication information. It belongs to the uplink timing advance group. In this In a preferred embodiment, the information of the uplink timing advance group can quickly adjust the uplink timing of the secondary cell on the terminal side. Embodiment 2 On the basis of the system and apparatus shown in FIG. 2 to FIG. 4, the present invention further provides a preferred uplink synchronization method of a secondary cell. As shown in FIG. 5, the uplink synchronization method of the secondary cell includes the following: step:

S502. The base station receiving, by the terminal, a random access preamble sent by the primary cell according to an uplink timing of the primary cell on the terminal side;

S504. The base station compares a receiving time of the random access preamble with a downlink timing of the primary cell at the base station side.

S506. The base station generates the timing adjustment indication information according to the comparison result, and sends the timing adjustment indication information to the terminal, where the timing adjustment indication information is used to indicate that the terminal adjusts the uplink timing of the secondary cell on the terminal side to be opposite to the primary cell on the base station side. Uplink timing synchronization. In the preferred embodiment, the base station can adjust the uplink timing of the secondary cell on the terminal side by using the timing adjustment indication information, so as to adjust the uplink timing of the adjusted secondary cell on the terminal side and the uplink timing of the primary cell on the base station side. Synchronization, thereby solving the technical problem that the uplink timing synchronization of the primary cell and the secondary cell cannot be performed in the prior art, and ensuring normal communication between the base station and the terminal. Preferably, the step of comparing, by the base station, the receiving time of the random access preamble with the downlink timing of the primary cell at the base station side comprises: calculating a difference between the receiving time and the current subframe start time of the downlink timing of the primary cell at the base station side The step of generating, by the base station, the timing adjustment indication information according to the comparison result includes: if the receiving time is equal to the current subframe start time of the downlink timing of the primary cell at the base station side, generating the first timing adjustment indication information, where the indicating that the terminal does not perform the adjustment auxiliary The operation of the uplink timing of the cell on the terminal side or the uplink timing of the secondary cell on the terminal side of the terminal is synchronized with the uplink timing of the primary cell on the base station side; if the reception time is greater than the primary cell on the base station side And generating a second timing adjustment indication information, where the terminal is configured to instruct the terminal to advance the uplink timing of the secondary cell on the terminal side, and preferably, calculating the receiving time and the downlink timing of the primary cell. The difference between the start times of the current subframes, and the second timing adjustment indication information indicates that The terminal sets the uplink timing advancement length of the secondary cell on the terminal side to the time of the difference; if the receiving time is less than the current subframe start time of the downlink timing of the primary cell on the base station side, generating a third timing adjustment indication information And indicating that the terminal delays the uplink timing of the secondary cell on the terminal side, and preferably, calculates a difference between the receiving time and a current subframe start time of the downlink timing of the primary cell, and the second timing adjustment indication The information indicates that the terminal delays the uplink timing of the secondary cell on the terminal side by the difference. Through the above Different timing adjustment indication information may accurately adjust the uplink timing of the secondary cell to be synchronized with the uplink timing of the primary cell in different scenarios. Preferably, the timing adjustment indication information includes information of an uplink timing advance group to which the secondary cell belongs, where the uplink timing advance group is used to adjust the uplink timing of the secondary cell on the terminal side to be synchronized with the uplink timing of the primary cell on the base station side. In the preferred embodiment, the information of the uplink timing advance group can quickly adjust the uplink timing of the secondary cell on the terminal side. Preferably, after the timing adjustment indication information is sent to the terminal, the method further includes: the terminal receiving the timing adjustment indication information; the terminal adjusting the uplink timing of the secondary cell on the terminal side to the uplink of the primary cell on the base station side according to the timing adjustment indication information Timing synchronization. Preferably, the step of the terminal adjusting the uplink timing of the secondary cell on the terminal side to the uplink timing of the primary cell on the base station side according to the timing adjustment indication information includes: the terminal adjusts the uplink timing of the secondary cell according to the timing adjustment indication information The information of the advance group adjusts the secondary cell to belong to the uplink timing advance group. Preferably, the primary cell and the secondary cell are carriers after carrier aggregation. In the preferred embodiment, the present invention is made applicable to the scenario of carrier aggregation. The uplink synchronization method of a specific secondary cell will be described below.

(1) Scenario 1 In this scenario, the uplink synchronization method of the secondary cell includes the following steps: Step 1: The e B sends the RRC signaling including the configured Scell to the UE, and notifies the UE of the dedicated random access preamble used on the Scell. . Step 2: The eNB sends an activation command to the UE for the Scell. Step 3: After receiving the activation signaling of the eNB, the UE uses the dedicated random access preamble to initiate random access on the Scell, where the transmission time of the random access preamble can refer to the uplink timing of the Pcell (UL timing) ). Step 4: The eNB receives the random access preamble. At this time, the eNB compares the reception time of the random access preamble with the downlink time of the Pcell of the eNB, and selects a TA group (uplink timing advance group) for the Scell according to the comparison result. For example, as shown in FIG. 6, the eNB may determine the Scell. The TA value corresponding to the TA group to which it belongs. Specifically, the TA value of the Pcell is the time difference between the uplink timing and the downlink timing of the UE. When the UE activates the SCell, the uplink timing is initially adjusted to be the same as the uplink timing of the Pcell, and the dedicated random access preamble is sent, and the eNB receives the uplink access preamble. After the random access preamble, the difference between the time of receiving the random access preamble and the Pcell DL timing at eNB, that is, delta TA, can be calculated. If delta TA=0, the uplink timing of the Scell is the same as the uplink timing of the Pcell; if delta TA>0, then later; if delta TA<0, it is advanced. Based on this delta value, the eNB can select the appropriate TAgroup for the UE. For example, Scell with delta ta=0 can be selected as a group with Pcell. In addition, according to the delta ta value, the eNB may send a MAC command to adjust the UL timing to the UE, for example, may be adjusted to a delta ta value. Step 5: The eNB sends the MAC signaling to the UE, and is used to notify the UE of the TA group to which the Scell belongs, and configure the TAT, where the MAC signaling includes the TA value generated by the eNB for adjustment. Step 6: After receiving the MAC signaling, the UE adjusts the TA group to which the Scell belongs according to the TA value, so that the UL timing of the Scell is resynchronized to the UL timing of the Pcell. Step 7: The UE activates the Scell, including SRS transmission, and sends a channel quality indication/precoding matrix/rank indication/precoding type indication for the Scell (CQI/PMI/RI/PTI, Channel Quality Indicator/Precoding Matrix/Rank Indicator/ The Precoding Type Indicator reports that the PDCCH is monitored on the Scell, and the PDCCH monitoring for the Scell on other cells is started.

(2) Scenario 2 In this scenario, the uplink synchronization method of the secondary cell includes the following steps: Step 1: The eNB sends an RRC signaling that adds the Scell to the UE. Step 2: The eNB notifies the UE of the dedicated random access preamble of the Scell. Step 3: After receiving the RRC signaling, the UE configures related functions of the UE. Step 4: The eNB sends the activation signaling of the Scell to the UE. Step 5: After receiving the activation signaling of the eNB, the UE uses the dedicated random access preamble to initiate random access on the Scell. The transmission time of the random access preamble may refer to the UL timing of the Pcell. Step 6: The eNB receives the random access preamble. At this time, the eNB compares the reception time of the random access preamble with the downlink time of the Pcell of the eNB, and selects a TA group (uplink timing advance group) for the Scell according to the comparison result. The TAgroup includes: a TAgroup group number, and a TAT configuration. For example, as shown in FIG. 6, the eNB may determine the TA value corresponding to the TA group to which the Scell belongs. Specifically, the TA value of the Pcell is the time difference between the uplink timing and the downlink timing of the UE. When the UE activates the SCell, the uplink timing is initially adjusted to be the same as the uplink timing of the Pcell, and the dedicated random access preamble is sent, and the eNB receives the uplink access preamble. After random access preamble, the difference between the time of receiving the random access preamble and the Pcell DL timing at eNB, that is, delta TA (ΔTA), can be calculated. If delta TA=0, the uplink timing of the Scell is the same as the uplink timing of the Pcell; if delta TA>0, then later; if delta TA<0, it is advanced. Based on this delta value, the eNB can select the appropriate TAgroup for the UE. For example, Scell with delta ta=0 can be selected as a group with Pcell. In addition, according to the delta ta value, the eNB may send a MAC command to adjust the UL timing to the UE, for example, may be adjusted to a delta ta value. Step 7: The eNB sends the MAC signaling to the UE, and is used to notify the UE of the TA group to which the Scell belongs, and configure the TAT, where the MAC signaling includes the TA value generated by the eNB for adjustment. Step 8: After receiving the MAC signaling, the UE adjusts the TA group to which the Scell belongs according to the TA value, so that the UL timing of the Scell is resynchronized to the UL timing of the Pcell. Step 9: The UE activates the Scell, including SRS transmission, and sends a channel quality indication/precoding matrix/rank indication/precoding type indication (CQI/PMI/RI/PTI, Channel Quality Indicator/Precoding Matrix/Rank Indicator/) for the Scell. The Precoding Type Indicator reports that the PDCCH is monitored on the Scell, and the PDCCH monitoring for the Scell on other cells is started.

(3) Scenario 3 In this scenario, the uplink synchronization method of the secondary cell includes the following steps: Step 1: The eNB sends an RRC signaling that adds the Scell to the UE. Step 2: After receiving the RRC signaling, the UE configures related functions of the UE. Step 3: The eNB sends the activation signaling of the Scell to the UE, where the activation signaling includes a dedicated random access preamble. Step 4: After receiving the activation signaling of the eNB, the UE uses the dedicated random access preamble to initiate random access on the Scell, where the transmission time of the random access preamble refers to the UL timing of the Pcell. Step 5: The eNB receives the random access preamble. At this time, the eNB compares the receiving time of the random access preamble with the downlink time of the Pcell of the eNB, and selects a TA group (uplink timing advance group) for the Scell according to the comparison result, where the TA group includes: a TAgroup group number, and a TAT configuration. . For example, as shown in FIG. 6, the eNB may determine the TA value corresponding to the TA group to which the Scell belongs. Specifically, the TA value of the Pcell is the time difference between the uplink timing and the downlink timing of the UE. When the UE activates the SCell, the uplink timing is initially adjusted to be the same as the uplink timing of the Pcell, and the dedicated random access preamble is sent, and the eNB receives the uplink access preamble. After the random access preamble, the difference between the time of receiving the random access preamble and the Pcell DL timing at eNB, that is, delta TA, can be calculated. If delta TA=0, the uplink timing of the Scell is the same as the uplink timing of the Pcell; if delta TA>0, then later; if delta TA<0, it is advanced. Based on this delta value, the eNB can select the appropriate TA group for the UE. For example, Scell with delta ta=0 can be selected as a group with Pcell. In addition, according to the delta ta value, the eNB may send a MAC command to adjust the UL timing to the UE, for example, may be adjusted to a delta ta value. Step 6: The eNB sends the MAC signaling to the UE, and is used to notify the UE of the TA group to which the Scell belongs, and configure the TAT, where the MAC signaling includes the TA value generated by the eNB for adjustment. Step 7: After receiving the MAC signaling, the UE adjusts the TA group to which the Scell belongs according to the TA value, so that the UE

Scell's UL timing is resynchronized to Pcell's UL timing. Step 8: The UE activates the Scell, including SRS transmission, and sends a channel quality indication/precoding matrix/rank indication/precoding type indication for the Scell (CQI/PM/RI/PTI, Channel Quality Indicator/Precoding Matrix/Rank Indicator/ The Precoding Type Indicator reports that the PDCCH is monitored on the Scell, and the PDCCH monitoring for the Scell on other cells is started. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A method for uplink synchronization of a secondary cell, comprising:

Receiving, by the base station, a random access preamble sent by the terminal on the secondary cell according to the uplink timing of the primary cell on the terminal side;

And comparing, by the base station, a receiving time of the random access preamble with a downlink timing of the primary cell at the base station side;

The base station generates timing adjustment indication information according to the comparison result, and sends the timing adjustment indication information to the terminal, where the timing adjustment indication information is used to instruct the terminal to use the secondary cell on the terminal side. The uplink timing is adjusted to be less than the uplink timing of the primary cell on the base station side.

2. The method according to claim 1, wherein

The step of comparing, by the base station, the receiving time of the random access preamble with the downlink timing of the primary cell on the base station side includes:

Calculating a difference between the receiving time and a current subframe start time of the downlink timing of the primary cell on the base station side;

The step of generating the timing adjustment indication information by the base station according to the comparison result includes: if the receiving time is equal to the current subframe start time of the downlink timing of the primary cell on the base station side, generating first timing adjustment indication information, Instructing the terminal not to perform an operation of adjusting an uplink sequence of the secondary cell on the terminal side or indicating an uplink timing of the secondary cell on the terminal side of the terminal and the primary cell on the base station side Uplink timing synchronization;

If the receiving time is greater than a current subframe start time of the downlink sequence of the primary cell on the base station side, generating second timing adjustment indication information, where the terminal is configured to indicate that the secondary cell is on the terminal side The uplink timing is advanced;

And generating, by the terminal, the secondary cell on the terminal side, if the receiving time is less than a current subframe start time of the downlink sequence of the primary cell on the base station side, The uplink timing is delayed.

The method according to claim 1, wherein the timing adjustment indication information includes information of an uplink timing advance group to which the secondary cell belongs, where the uplink timing advance group is used to set the secondary cell in The uplink timing of the terminal side is adjusted to be synchronized with the uplink timing of the primary cell on the base station side.

The method according to any one of claims 1 to 3, further comprising: after transmitting the timing adjustment indication information to the terminal,

Receiving, by the terminal, the timing adjustment indication information;

And the terminal adjusts, according to the timing adjustment indication information, an uplink timing of the secondary cell on the terminal side to be synchronized with an uplink timing of the primary cell on the base station side.

The method according to claim 4, wherein the terminal adjusts an uplink timing of the secondary cell on the terminal side to an uplink with the primary cell on the base station side according to the timing adjustment indication information. The steps of timing synchronization include:

And the terminal adjusts the secondary cell to belong to the uplink timing advance group according to the information of the uplink timing advance group to which the secondary cell belongs in the timing adjustment indication information.

The method according to claim 1, wherein the primary cell and the secondary cell are carriers after carrier aggregation.

7. A base station comprising:

a receiving unit, configured to receive, by the receiving terminal, a random access preamble sent by the primary cell according to an uplink timing of the primary cell on the terminal side;

a comparing unit, configured to compare a receiving time of the random access preamble with a downlink timing of the primary cell on the base station side;

a generating unit, configured to generate timing adjustment indication information according to the comparison result, where the timing adjustment indication information is used to indicate that the terminal adjusts an uplink timing of the secondary cell on the terminal side to be in a location with the primary cell The uplink timing synchronization on the base station side;

And a sending unit, configured to send the timing adjustment indication information to the terminal.

The base station according to claim 7, wherein the generating unit comprises: a first generating module, configured to generate a first if the receiving time is equal to a current subframe start time of a downlink timing of the primary cell The timing adjustment indication information is used to indicate that the terminal does not perform an operation of adjusting an uplink timing of the secondary cell on the terminal side or an uplink timing of the secondary cell on the terminal side of the terminal and the primary cell Uplink timing synchronization on the base station side; a second generation module, configured to: if the receiving time is greater than a current subframe start time of the downlink timing of the primary cell, generate second timing adjustment indication information, where the terminal is configured to indicate that the secondary cell is in the The uplink timing on the terminal side is advanced;

a third generation module, configured to: if the receiving time is less than a current subframe start time of the downlink timing of the primary cell, generate third timing adjustment indication information, where the terminal is configured to indicate that the secondary cell is in the The uplink timing on the terminal side is delayed.

9. A terminal comprising:

a sending unit, configured to send a random access preamble according to an uplink timing of the primary cell at the terminal side on a secondary cell of the base station;

a receiving unit, configured to receive the timing adjustment indication information sent by the base station, where the timing adjustment indication information is used by the base station according to the receiving time of the random access preamble and the downlink of the primary cell at the base station side The result of the comparison between the timings is generated, and the timing adjustment indication information is used to indicate that the terminal adjusts an uplink timing of the secondary cell on the terminal side to be synchronized with an uplink timing of the primary cell on the base station side. ;

And an adjusting unit, configured to adjust, according to the timing adjustment indication information, an uplink timing of the secondary cell on the terminal side to be synchronized with an uplink timing of the primary cell on the base station side.

The terminal according to claim 9, wherein the adjusting unit is further configured to adjust the secondary cell to belong to the location according to the information of the uplink timing advance group to which the secondary cell belongs in the timing adjustment indication information. The upstream timing advance group is described.