WO2012139454A1 - Method, terminal device, and network side device for determining timing advance - Google Patents

Abstract

A method, terminal device, and network side device for determining timing advance (TA). The method comprises: receiving a CSI-RS configuration or activation message of the network side device, the message is for use in configuring or activating a CSI-RS; transmitting a synchronization signal to the network side device on the basis of the CSI-RS configuration or activation message; receiving a TA adjustment message transmitted by the network side device, the message having attached thereto a TA value determined by the network side device on the basis of the synchronization signal; determining, on the basis of the TA value attached to the TA adjustment message, the TA value corresponding to the CSI-RS configured or activated. The synchronization signal is transmitted by the terminal to the network side on the basis of the CSI-RS configuration or activation message of the network side, and the corresponding TA value is calculated by the network side on the basis of the synchronization signal and then returned to the terminal, thus allowing the terminal to learn the corresponding relation between the TA value and the CSI-RS, thereby improving the precision of uplink timing, and allowing for uplink synchronization.

Description

 Method for determining timing advance, terminal device, and network side device

 This application claims priority to Chinese Patent Application No. 201110092611.X, which is entitled "Method for Determining Timing Advance, Terminal Equipment and Network Side Equipment", which was submitted to the Chinese Patent Office on April 13, 2011. The content is incorporated herein by reference. Technical field

 Embodiments of the present invention relate to the field of wireless communications, and more particularly, to a method of determining a timing advance, a terminal device, and a network side device. Background technique

In the R11 version of LTE (Long Term Evolution), a new operational scenario will be introduced, namely coordinated multi-point transmission/reception, called CoMP (coordinated multi-point). Performing Collaboration The main benefit of multipoint transmission is that it can increase the rate of data transmission, such as the smooth transmission of video services, thereby increasing user satisfaction. Currently, there are four specific scenarios that need to focus on research, namely:

Scenario 1: CoMP in a homogeneous website point;

Scenario 2: A homogeneous network with a high-power remote radio head (RRH); Scenario 3: A heterogeneous network scenario with low-power RRH, a micro-cell with low transmit power and a macro cell (Macro Cell) Serving the UE together, the scenario 3 is characterized in that each micro cell is connected to the macro cell through a high-speed fiber, the transmission delay is negligible, and the Pico Cell covered by each RRH is an independent cell. With respective independent cell identifiers (Cell ID) Scenario 4: Heterogeneous network scenario with low power RRH, the micro cell with low transmit power works with the macro cell to serve the UE. Scene 4 and Scene 3 have in common that the micro-area covered by the RRH and the Macro are also connected by a high-speed fiber, and the main difference from the scenario 3 is that each RRH Rather than being a separate cell, these RRHs, the Pico Point, do not have separate Cell IDs, but share the same Cell ID with the Macro site. In the above scenario 4, when the data is transmitted in the CoMP mode between the network and the UE (User Equipment), different sites will transmit different CSI-RSs (Channel state Information-Reference Signals). ) to support the UE to perform channel measurement and the like through the CSI-RS. The macro site and the microsite will configure different CSI-RSs for CSI-RS transmission. Therefore, multiple CSI-RSs exist in a CoMP scenario. In the current LTE system, when the UE maintains the uplink synchronization state, the eNB sends a Timing.

Advance Command MAC (Medium Access Control) PDU (Protocol Data Unit) to inform the UE to adjust the TA value to achieve greater synchronization accuracy.

 However, in a CoMP scenario, the time at which a signal arrives at a different node may be different due to the different distance between the UE and the different nodes. And because a plurality of CSI-RSs exist, after the UE receives a TA, if the timing adjustment is performed on multiple CSI-RSs based on the same TA, the adjustment result may be inaccurate. If the UE's Timing Advance adjustment is not accurate enough, it will directly affect the UE's throughput, which greatly reduces the benefits of CoMP transmission.

Summary of the invention

 Embodiments of the present invention provide a method for determining a timing advance, a terminal device, a network side device, and a communication system, which can improve the accuracy of uplink timing.

In one aspect, a method for determining a timing advance TA value is provided, including: receiving a channel state information reference signal CSI-RS configuration or activation message of a network side device, and using a CSI-RS configuration or activation message for configuring or activating CSI- RS; sending a synchronization signal to the network side device according to the CSI-RS configuration or activation message; receiving the TA adjustment message sent by the network side device, and the TA adjustment message carries the network side setting And determining a TA value determined based on the synchronization signal; determining a TA value corresponding to the configured or activated CSI-RS according to the TA value carried in the TA adjustment message.

 In another aspect, a method for determining a timing advance TA value is provided, comprising: transmitting a channel state information reference signal CSI-RS configuration or activation message to a terminal device, and a CSI-RS configuration or activation message is used to configure or activate CSI- And receiving a synchronization signal sent by the terminal device according to the CSI-RS configuration or activation message; determining a TA value based on the synchronization signal; and transmitting a TA adjustment message to the terminal device, where the TA adjustment message carries the determined TA value.

 In another aspect, a method for determining a timing advance TA value is provided, including: receiving a channel state information reference signal CSI-RS configuration or activation message of a network side device, and using a CSI-RS configuration or activation message for configuring or activating CSI -RS and includes indication information, the indication information is used to indicate whether the terminal device needs to perform uplink synchronization; and the TA value is obtained according to the indication information.

 In another aspect, a method for determining a timing advance TA value is provided, comprising: generating a channel state information reference signal CSI-RS configuration or activation message, the CSI-RS configuration or activation message for configuring or activating a CSI-RS and including The indication information is used to indicate whether the terminal device needs to perform uplink synchronization; and the indication information is sent to the terminal device to indicate the TA value to the terminal device by using the indication information.

 In another aspect, a method for determining a timing advance TA value is provided, including: receiving a channel state information reference signal CSI-RS configuration or activation message of a network side device, and using a CSI-RS configuration or activation message for configuring or activating CSI -RS; determining the TA value of the configured or activated CSI-RS according to the downlink timing difference between the currently used CSI-RS and the configured or activated CSI-RS and the TA value of the currently used CSI-RS.

In another aspect, a method for determining a timing advance TA value is provided, including: receiving a channel state information reference signal CSI-RS configuration or activation message of a network side device, and using a CSI-RS configuration or activation message for configuring or activating CSI -RS; determining to perform uplink synchronization to acquire a TA value corresponding to the configured or activated CSI-RS according to the CSI-RS configuration or activation message and the group information of the CSI-RS, or configuring or activating the message according to the CSI-RS Group information with CSI-RS, determined and configured or activated The corresponding T value of the CSI-RS, where the CSI-RS group refers to a set of one or more CSI-RSs that share the same TA value.

 In another aspect, a method for determining a timing advance TA value is provided, including: transmitting, to a terminal device, information of a channel state information reference signal CSI-RS group, where the CSI-RS group refers to a one sharing the same TA value. Or a set of multiple CSI-RSs; sending a CSI-RS configuration or activation message to the terminal device, the CSI-RS configuration or activation message is used to configure or activate the CSI-RS, so that the terminal device configures or activates the message according to the CSI-RS. And the group information determines a TA value corresponding to the configured or activated CSI-RS.

 In another aspect, a terminal device is provided, including: a receiving unit, configured to receive a channel state information reference signal CSI-RS configuration or activation message of a network side device, and a CSI-RS configuration or activation message is used to configure or activate CSI- The sending unit is configured to send a synchronization signal to the network side device according to the CSI-RS configuration or the activation message, and the receiving unit is further configured to receive the TA adjustment message sent by the network side device, where the TA adjustment message carries the network side device based on the synchronization. a signal determined TA value; a determining unit, configured to determine a TA value corresponding to the configured or activated CSI-RS according to the TA value carried in the TA adjustment message.

 In another aspect, a terminal device is provided, including: a receiving unit, configured to receive a channel state information reference signal CSI-RS configuration or activation message of a network side device, and a CSI-RS configuration or activation message is used to configure or activate CSI- And the indication information is used to indicate whether the terminal device needs to perform uplink synchronization. The acquiring unit is configured to acquire the TA value according to the indication information.

 In another aspect, a terminal device is provided, including: a receiving unit, configured to receive a channel state information reference signal CSI-RS configuration or activation message of a network side device, and a CSI-RS configuration or activation message is used to configure or activate CSI- And a determining unit, configured to determine a configured or activated CSI-RS according to a downlink timing difference between the currently used CSI-RS and the configured or activated CSI-RS and a TA value of a currently used CSI-RS TA value.

In another aspect, a terminal device is provided, including: a receiving unit, configured to receive a network side device Channel state information reference signal CSI-RS configuration or activation message, CSI-RS configuration or activation message is used to configure or activate CSI-RS; determining unit for configuring or activating messages and CSI-RS groups according to CSI-RS The information is determined to perform uplink synchronization to obtain a TA value corresponding to the configured or activated CSI-RS, or to determine the CSI configured or activated according to the CSI-RS configuration or activation message and the group information of the CSI-RS. The TA value corresponding to the RS, where the CSI-RS group refers to a set of one or more CSI-RSs sharing the same TA value.

 In another aspect, a network side device is provided, including: a sending unit, configured to send a channel state information reference signal CSI-RS configuration or an activation message to a terminal device, where a CSI-RS configuration or activation message is used to configure or activate CSI- a receiving unit, configured to receive a synchronization signal sent by the terminal device according to a CSI-RS configuration or an activation message; a determining unit, configured to determine a TA value based on the synchronization signal; and a sending unit, configured to send a TA adjustment message to the terminal device, where The adjustment message carries the determined TA value.

 In another aspect, a network side device is provided, including: a generating unit, configured to generate a channel state information reference signal CSI-RS configuration or an activation message, where a CSI-RS configuration or activation message is used to configure or activate the CSI-RS and includes The indication information, the indication information is used to indicate whether the terminal device needs to perform uplink synchronization, and the sending unit is configured to send the indication information to the terminal device, to indicate the TA value to the terminal device by using the indication information.

 On the other hand, a network side device is provided, including: a sending unit, configured to send information about a channel state information reference signal CSI-RS group to a terminal device, where the CSI-RS group refers to one that shares the same TA value. Or a set of multiple CSI-RSs; the sending unit is further configured to send a CSI-RS configuration or an activation message to the terminal device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS, so that the terminal device is configured according to the CSI. The RS configuration or activation message and group information determine the TA value corresponding to the configured or activated CSI-RS.

In another aspect, a communication system is provided, including the above terminal device or the above network side device. The embodiment of the invention causes the terminal to send a synchronization signal to the network side according to the CSI-RS configuration or activation message on the network side, and the network side calculates the corresponding TA value according to the synchronization signal and returns to the terminal, thereby ending The terminal can know the correspondence between the TA value and the CSI-RS, thereby improving the accuracy of the uplink timing, and implementing the uplink synchronization diagram.

 In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only the present invention. In some embodiments, other drawings may be obtained from those of ordinary skill in the art in light of the inventive work.

 Figure 1 is a contention based random access method.

 Figure 2 is a non-contention random access method.

 3 is a schematic structural diagram of a random access response message.

 4 is a schematic flow chart of a method of determining a TA value in accordance with an embodiment of the present invention.

 Figure 5 is a schematic flow diagram of a method of determining a TA value in accordance with an embodiment of the present invention.

 6 is a schematic flow chart of an example of an uplink synchronization process in accordance with an embodiment of the present invention. 7 is a schematic flow chart of another example of an uplink synchronization process in accordance with an embodiment of the present invention. FIG. 8 is a schematic flow chart of another example of an uplink synchronization process according to an embodiment of the present invention. 9 is a schematic flow chart of another example of an uplink synchronization process in accordance with an embodiment of the present invention. FIG. 10 is a schematic flow chart of another example of an uplink synchronization process according to an embodiment of the present invention. 11 is a schematic flow chart of a method of determining a TA value according to another embodiment of the present invention.

 Figure 12 is a schematic flow chart of a method of determining a TA value in accordance with another embodiment of the present invention.

 Figure 13 is a schematic flow chart of a method of determining a T A value in accordance with another embodiment of the present invention.

 Figure 14 is a schematic flow chart of a method of determining a TA value in accordance with another embodiment of the present invention.

 Figure 15 is a schematic flow chart of a method of determining a T A value in accordance with another embodiment of the present invention.

 Figure 16 is a schematic block diagram of a terminal device in accordance with one embodiment of the present invention.

Figure 17 is a schematic block diagram of a terminal device in accordance with another embodiment of the present invention. Figure 18 is a schematic block diagram of a terminal device in accordance with another embodiment of the present invention.

 Figure 19 is a schematic block diagram of a terminal device in accordance with another embodiment of the present invention.

 Figure 20 is a schematic block diagram of a network side device in accordance with one embodiment of the present invention.

 21 is a schematic block diagram of a network side device according to another embodiment of the present invention.

 Figure 22 is a schematic block diagram of a network side device in accordance with another embodiment of the present invention. detailed description

 The technical solutions in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

 The technical solution of the present invention can be applied to various communication systems, for example, GSM, Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), general packet Wireless Service (GPRS, General Packet Radio Service), Long Term Evolution (LTE), etc.

 A mobile terminal (Mobile Terminal), which may also be called a mobile user (UE, User Equipment), a mobile user equipment, etc., can communicate with one or more core networks via a radio access network (eg, RAN, Radio Access Network). The mobile terminal may be a mobile terminal, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal, for example, a mobile device that can be portable, pocket, handheld, computer built, or in-vehicle, The wireless access network exchanges languages and/or data.

The base station may be a base station (BTS, Base Transceiver Station) in GSM or CDMA, or may be a base station (NodeB) in WCDMA, or may be an evolved base station (eNB or e-NodeB, evolutional Node B) in LTE. The present invention is not limited, but for convenience of description, the following embodiments are described by taking an e-Node B as an example. In the existing 3GPP (The 3rd Generation Partnership Project) LTE system, there are two random access methods that enable the UE to acquire uplink synchronization with a certain component carrier. Figure 1 is a contention based random access method, and Figure 2 is a non-contention random access method.

 In the process of the contention-based random access method of Figure 1,

 11 : Message 1 "Random Access Preamble" is transmitted on the uplink RACH (Random Access Channel) channel, and the selected preamble preamble (64 in total) implies that the UE needs to send The size of the message 3.

 12: Message 2 is a "Random Access Response" sent and received on the DL-SCH (Down Link-Share Channel) channel, which is generated by the MAC layer. The specific Random Access Response content is shown in Figure 3.

 The Timing Advance Command field includes the TA value that the eNB calculates that the UE needs to adjust when transmitting in the uplink. The UL Grant field indicates information for the bandwidth resource allocated by the UE to transmit the message 3. The Temporary C-RNTI represents a temporary identifier assigned to the UE. The RAPID in the MAC Header indicates the identifier of the preamble preamble sent by the UE, namely: Random Access Preamble ID.

 13: Message 3 sends the first scheduled uplink message on the UL-SCH (Up Link-Share Channel) channel according to the indication of message 2.

 14: Message 4 is used to resolve conflicts caused when multiple UEs use the same preamble. In the non-contention random access method of Figure 2,

 20: First, the eNB allocates a dedicated random access preamble to the UE, so there is no problem that the multiple UEs compete for the preamble;

 21: The UE sends a dedicated preamble to the eNB;

After receiving the dedicated preamble, the eNB sends a random access response message to the UE, where the structure of the random access response message and the random access response in the above-mentioned contention-based random access cancellation The interest (12) is the same.

 However, the random access response message of the random access procedure of FIG. 1 and FIG. 2 cannot be adapted to multiple CSI-RSs in a CoMP scenario.

 In the CoMP scenario, due to the existence of multiple CSI-RSs, after receiving a TA, the UE does not know which CSI-RS should be applied to this TA. When the UE uses multiple points (Macro and RRH, or multiple RRHs) to transmit uplink data at the same time, because the distance between the UE and different nodes is different, the time when the signal arrives at different nodes may be different, if the UE The Timing Advance adjustment is not accurate enough, which will directly affect the throughput of the UE, thus greatly reducing the benefits of performing CoMP transmission.

 4 is a schematic flow chart of a method of determining a TA value in accordance with an embodiment of the present invention. Figure 4

40 is performed by a terminal device (e.g., a UE).

 At 401, a channel state information reference signal CSI-RS configuration or activation message of a network side device (for example, an eNB or an RRH) is received, and the CSI-RS configuration or activation message is used to configure or activate the CSI-RS.

 At 402, a synchronization signal is sent to the network side device according to the CSI-RS configuration or activation message. At 403, a TA adjustment message sent by the network side device is received, where the TA adjustment message carries a TA value determined by the network side device based on the synchronization signal.

 At 404, a TA value corresponding to the configured or activated CSI-RS is determined according to the TA value carried in the TA adjustment message.

 Therefore, the embodiment of the present invention causes the terminal to send a synchronization signal to the network side according to the CSI-RS configuration or activation message on the network side, and the network side calculates a corresponding TA value according to the synchronization signal and returns the terminal, so that the terminal can know the TA value and the CSI. The correspondence relationship of -RS improves the accuracy of the uplink timing and realizes uplink synchronization.

FIG. 5 is a schematic flow chart of a method of determining a TA value according to an embodiment of the present invention. The method 50 of FIG. 5 is performed by a network side device (eg, an eNB or an RRH) and is opposite to the method 40 of FIG. Should.

 At 501, a channel state information reference signal CSI-RS configuration or activation message is sent to a terminal device (e.g., a UE) for configuring or activating a CSI-RS.

 At 502, the synchronization signal sent by the terminal device according to the CSI-RS configuration or activation message is received. At 503, a TA value is determined based on the synchronization signal received in 502.

 At 504, a TA adjustment message is sent to the terminal device, and the TA adjustment message carries the TA value determined in 503.

 Therefore, the embodiment of the present invention causes the terminal to send a synchronization signal to the network side according to the CSI-RS configuration or activation message on the network side, and the network side calculates a corresponding TA value according to the synchronization signal and returns the terminal, so that the terminal can know the TA value and the CSI. The correspondence relationship of -RS improves the accuracy of the uplink timing and realizes uplink synchronization.

 Embodiments of the present invention are described below in conjunction with specific examples.

 6 is a schematic flow chart of an example of an uplink synchronization process in accordance with an embodiment of the present invention. As shown in FIG. 6, at 601, the network side (for example, an eNB or an RHH) sends a CSI-RS configuration or activation message to the UE, where the message may include an identifier of the CSI-RS, indicating that the UE uses the CSI-RS.

Specifically, the configuration message or the activation message of the CSI-RS is RRC (Radio Resource Control) signaling, for example, is sent to the UE through an RRC connection reconfiguration message, or is a MAC (Media Access Control) CE (Control Element) or physical layer signaling. In addition, the network may first send configuration information of the CSI-RS to the UE by using an RRC message, and then the network further activates the CSI-RS by sending a MAC CE or a physical layer command to instruct the UE to use the CSI-RS. Similarly, the network can further deactivate certain CSI-RS configurations by sending MAC CE or physical layer commands. Here, the MAC CE or the physical layer signaling may explicitly include the identification information of the CSI-RS to be activated, or may use a Bitmap and indicate the corresponding CSI-RS through each bit (bit) in the Bitmap. Whether it is activated or deactivated. For example, an 8-bit Bitmap can be used to indicate the corresponding 8 Whether the CSI-RS is activated or deactivated. For example, when the corresponding bit is 1, the corresponding CSI-RS may be indicated to be activated. After a certain CSI-RS is activated, the UE may perform measurement and feedback of the CSI-RS, and the like. In addition, when the corresponding bit is 0, it may indicate that the corresponding CSI-RS is deactivated, and the UE may stop the measurement and feedback of the CSI-RS, and vice versa.

 At 602, after receiving the CSI-RS configuration or activation message, the UE initiates an uplink synchronization process and sends a synchronization signal. At this time, the UE may randomly select a preamble Preamble for transmission as the synchronization signal.

 According to another embodiment of the present invention, in 602, after receiving the CSI-RS configuration or activation message, the UE determines the downlink measured on the configured or activated CSI-RS and the CSI-RS currently configured and used. The timing offset value or the deviation value of the downlink path loss, when the downlink timing corresponding to the configured or activated CSI-RS is different from the downlink timing of the already used CSI-RS by a threshold value (or both downlink path loss) When the difference is a threshold, the UE performs an uplink synchronization process (random access procedure). Or the UE performs the uplink synchronization process when the downlink timing corresponding to the configured or activated CSI-RS is different from the downlink timing of the used CSI-RS (or the downlink path loss of the two is deviated). The situation is equivalent to a threshold of zero.

 At 603, the eNB or RRH calculates the TA value based on the received Preamble.

 Since the UE sends a randomly selected Preamble at 602, the eNB calculates the TA value corresponding to the Preamble received by the eNB and the TA value corresponding to the Preamble forwarded by the RRH. Alternatively, the eNB and the RRH respectively calculate the TA value corresponding to the Preamble received by the eNB, and then the eNB receives the TA value of the RRH calculation and feedback.

 At 604, after acquiring the TA value associated with the configured or activated CSI-RS, the eNB sends a TA adjustment message to the UE to notify the UE of the configured or activated CSI-RS associated TA value. Here, the TA adjustment message may be carried by a random access response message.

Since the TA value is obtained by the Preamble calculation randomly selected by the UE, if the eNB obtains more than one TA value based on the Preamble in 603, the eNB will be based on the randomly selected The TA value acquired by the Preamble and the identifier of the CSI-RS associated with the TA value are sent to the UE in a random access response message.

 Alternatively, in order to further reduce the TA adjustment message size, when the TA value is sent in the TA adjustment message, each TA value may not be transmitted, but the TA end value (the maximum TA value and/or the minimum TA value) may be transmitted. Specifically, a maximum TA value and a minimum TA value and an intermediate step value can be transmitted to the UE. At the same time, a Bitmap corresponding to each CSI-RS configuration in the network can be sent to the UE. Each bit in the Bitmap corresponds to a CSI-RS configuration. Then, the 0 and 1 symbols of the bit respectively indicate whether the TA value of the corresponding CSI-RS is included in the current TA adjustment message. Through the foregoing terminal value, the step size, and the Bitmap indication information, the UE can sequentially acquire each TA value and the CSI-RS corresponding to each TA value. In this way, it is possible to avoid sending the identifier of each CSI-RS and each TA value to the UE, so that the size of the message can be adjusted by ', TA.

 In addition, each TA value can also be calculated by sending a starting maximum TA value (or minimum TA value) and decreasing (or accumulating) the step size. At this time, it is necessary to define a minimum cutoff value (or a maximum cutoff value), that is, when the UE calculates each TA value according to the initial TA value, if the calculated TA value is smaller than the minimum cutoff value (or greater than the maximum value) When the cutoff value is), the calculation continues to calculate the TA value. Thus, in the same way as the bitmap, the UE can know which CSI-RS the calculated TA values correspond to.

 Alternatively, the step value/cutoff value mentioned in the above method may also be fixed in advance, for example, by the UE and the network side, without having to interact with the step value/cutoff value in the random access procedure. At this point, you can further save the size of the TA adjustment message.

Alternatively, the TA value may be sequentially sent according to the sequence number sequence of the CSI-RS in the TA adjustment message, and a Bitmap corresponding to each CSI-RS configuration may be sent to the UE to the UE. Each bit in the Bitmap corresponds to one CSI-RS configuration, and the 0 and 1 symbols of the bit respectively indicate whether the TA value of the corresponding CSI-RS is included in the current TA adjustment message. In this way, by sequentially transmitting the respective TA values and the Bitmap indication information, the UE can acquire the matching in sequence. The TA value corresponding to the activated or activated CSI-RS.

 At 605, after receiving the TA adjustment message (for example, by the random access response message), the UE determines the TA value corresponding to each configured or activated CSI-RS after the activated CSI-RS.

 If the UE determines that one or more CSI-RSs that are configured or activated fail to obtain the corresponding TA value from the TA adjustment message received in 604, the UE initiates retransmission of the random access preamble to re-pass random access. The process gets the corresponding TA value.

 At 606, the UE feeds back to the network the identification information of the CSI-RS that did not obtain the TA value in the TA adjustment message. Preferably, the UE sends a random access message 3 to the network, where the message carries the identifier of the UE and the identifier information of the CSI-RS that does not obtain the TA value in the TA adjustment message.

 At 607, the UE receives the contention resolution message sent by the network, that is, the RACH message 4.

 At 608, after obtaining the TA value corresponding to the configured CSI-RS, the UE may use multiple TA values for uplink data transmission.

 Specifically, the UE may dynamically or semi-statically select the TA value corresponding to the best CSI-RS for uplink transmission. Specifically, the UE may select the TA value corresponding to the best CSI-RS for uplink transmission at a unit time of each scheduling or within a certain time.

 Alternatively, the UE determines the TA value that can be used based on the indication information on the network side. The indication information may be an ID of the CSI-RS or an ID of the TA value. For example, when the PDCCH (Physical Downlink Control Channel) scheduling command is sent to the UE, the CSI-RS ID or the TA ID is carried in the PDCCH to indicate that the UE uses the corresponding TA value to perform uplink data transmission.

Alternatively, the UE may always perform uplink data transmission based on the TA value corresponding to the primary CSI-RS. Here, the primary CSI-RS may be determined by the network, and then the UE is notified by RRC message, MAC CE or physical layer signaling. It may also be that the UE determines itself based on the signal quality of the CSI-RS. Specifically, the determining of the primary CSI-RS may be determined based on the coverage of the CSI-RS, for example, selecting the site with the largest coverage. The transmitted CSI-RS acts as the primary CSI-RS. Alternatively, it may be determined based on the best CSI-RS of the signal as the main CSI-RS. Of course, the CSI-RS can also be determined in other ways, and these determination manners do not limit the scope of the embodiments of the present invention.

 According to another embodiment of the present invention, the UE may also detect the PDCCH channel and acquire scheduling information sent by the network. After acquiring the resource block (Resource Block), the UE sequentially transmits the sequence of the plurality of TA values corresponding to the multiple CSI-RS configurations on the scheduled RB (Resource Block).

 Alternatively, the UE detects the PDCCH channel, acquires scheduling information transmitted by the network, and then the UE transmits using TA values for different CSI-RS configurations using different antennas or different antenna ports. The UE may use different antennas or different antenna ports to simultaneously perform parallel uplink data transmission using TA values for different CSI-RS configurations, or perform serial uplink data transmission according to a certain timing.

 At 609, further, in the process of the UE transmitting data using multiple TA values and the network, it may be necessary to adjust the TA value frequently. In order to explicitly let the UE know the TA value corresponding to which CSI-RS should be applied by the transmitted TA adjustment command, when performing TA adjustment, the TA adjustment message sent by the network needs to include the corresponding "CSI-RS ID" (CSI-RS identifier). , CSI-RS port number or CSI-RS group ID or "TA ID" (TA flag) to instruct the UE to adjust the corresponding TA value.

 7 is a schematic flow chart of another example of an uplink synchronization process in accordance with an embodiment of the present invention. In the example of Fig. 6, a randomly selected preamble is used as the synchronization signal. The dedicated preamble is used as the synchronization signal in the example of Fig. 7.

 701 is similar to 601 of FIG. 6, and the network side (eg, eNB or RHH) sends a CSI-RS configuration or activation message to the UE. The difference is that the CSI-RS configuration or activation message sent in 701 contains a dedicated preamble Preamble assigned to the UE.

At 702, the UE initiates an uplink synchronization process after receiving the CSI-RS configuration or activation message. At this time, the UE will transmit the dedicated preamble Preamble. At this point, you can also judge the configured or activated The downlink timing offset value or the downlink path loss offset value of the CSI-RS and the currently used CSI-RS, and initiates an uplink synchronization process according to the judgment result.

 At 703, the eNB or RRH calculates the TA value based on the received Preamble. The method for calculating the TA value by the eNB or RRH based on the dedicated Preamble is as follows:

 If the dedicated Preamble is allocated to the UE with the configuration or activation of the CSI-RS of the eNB, the eNB calculates the TA value by using the Preamble signal received by itself;

 If the dedicated Preamble is allocated to the UE in association with the configuration or activation of the CSI-RS of the RRH, the eNB calculates the TA value according to the Preamble received by the RRH (ie, the Preamble forwarded by the RRH to the eNB), or the RRH receives the TA value. The TA value is calculated after the dedicated Preamble and then transmitted to the eNB.

 At 704, after acquiring the TA value associated with the configuration or the activated CSI-RS, the eNB sends a TA adjustment message to the UE to notify the UE of the configured or activated CSI-RS associated TA value. Here, the TA adjustment message can be carried by the random access response message 7.

 Since the TA value is obtained through the dedicated Preamble, the eNB transmits the TA value associated with the CSI-RS configured or activated in 701 to the UE in the random access response message. When more than one CSI-RS is configured or activated in 701, in order to assist the UE in distinguishing the TA values corresponding to different CSI-RSs, the random access response message should indicate the CSI-RS configuration corresponding to each TA value. ID, CSI-RS group ID or TA ID. Alternatively, the eNB may also sort the respective TA values according to the size of the identifier of the CSI-RS configured or activated in 701, and then send the same to the UE.

 Alternatively, as described above with reference to 604, the TA adjustment message of 704 may also carry a TA end value, or a TA end value and a step value, or a TA end value and a cutoff value, to save the message size.

 705-706 are the same as 605-606 of Fig. 6, respectively. Since the UE transmits a dedicated preamble in 702, there is no need for a contention resolution in the embodiment of Fig. 7, that is, the RACH message 4 is not required.

 707 is the same as 608 of FIG. 6, and the UE uses the TA value for uplink data transmission.

The synchronization signal of the embodiment of the present invention is not limited to the preamble. FIG. 8 is an uplink according to an embodiment of the present invention. A schematic flow chart of another example of a synchronization process. In the example of Fig. 8, the sounding reference signal SRS (Sounding Reference Signal) is used as the synchronization signal.

 At 801, the network sends a CSI-RS configuration or an activation message to the UE, where the message may include an identifier of the CSI-RS, indicating that the UE uses the CSI-RS. The CSI-RS configuration or activation message may further include configuration information of the SRS that the UE needs to send. The configuration information of the SRS may be at least one of time-frequency location information of the SRS for transmitting the UE, or an SRS sequence, or an identifier of the SRS. Here, the SRS sequence or SRS identifier may be associated with the configured/activated CSI-RS.

 The descriptions of other related CSI-RS configurations or activation messages are the same as those described in 601, and are not repeated here.

 At 802, after receiving the CSI-RS configuration or activation message, the UE sends a sounding reference signal SRS to the network. The SRS reference signal sent by the UE may be an SRS pre-configured by the system for the UE, or an SRS reference signal configured for the UE in the CSI-RS configuration or activation message in 801.

 At this time, the downlink timing offset value or the downlink path loss offset value of the configured or activated CSI-RS and the currently used CSI-RS may be determined first, and an uplink synchronization process is initiated according to the judgment result.

 At 803, the eNB or RRH calculates a TA value based on the received SRS reference signal. Specifically, the method of calculating the TA value is similar to the calculation method based on the dedicated preamble in 703, and will not be repeated here.

 At 804, after calculating the TA value associated with the configuration or the activated CSI-RS, the eNB sends a TA adjustment message to the UE to notify the UE of the configured or activated CSI-RS associated TA value. Specifically, the information carried in the TA adjustment message is similar to the case where the current pilot code in 704 is a dedicated preamble.

 At 805, after receiving the TA adjustment message, the UE determines each configured or activated CSI-RS according to the TA value corresponding to each CSI-RS carried in the TA adjustment message and the CSI-RS configured or activated for the UE in 801. Corresponding TA value.

Similar to the above 605, if the UE determines that one or more CSI-RSs that are configured or activated are not If the corresponding TA value is successfully obtained from the received TA adjustment message, the UE initiates retransmission of the SRS signal to re-acquire the corresponding TA value through the uplink synchronization process.

 In this way, the embodiment of the present invention causes the terminal to send a synchronization signal to the network side according to the CSI-RS configuration or activation message on the network side, and the network side calculates a corresponding TA value according to the synchronization signal and returns the terminal, so that the terminal can know the TA value and the CSI. The correspondence relationship of -RS improves the accuracy of the uplink timing and realizes uplink synchronization.

 Examples of maintaining and using multiple TA values are described above. Embodiments of the present invention are not limited thereto, and a TA value (final TA value) may also be maintained and used. Figure 9 is a schematic flow diagram of another example of an uplink synchronization process in accordance with an embodiment of the present invention.

 901 is the same as 601 of FIG. 6, the network sends a CSI-RS configuration or an activation message to the UE, and the message may include an identifier of the CSI-RS, indicating that the UE uses the CSI-RS.

 At 902, after receiving the CSI-RS configuration or activation message, the UE performs an uplink synchronization process (random access procedure), and sends a synchronization signal to acquire a new TA value. At this time, the UE may randomly select one preamble Preamble for transmission, or send a network pre-configured SRS signal, or if the CSI-RS configuration message or the activation message includes information of a dedicated Preamble or SRS signal, the UE transmits a dedicated Preamble or SRS. signal.

 At 903, the eNB or RRH calculates a TA value based on the received synchronization signal.

 Specifically, if the synchronization signal sent by the UE is a dedicated preamble, or an SRS signal, the method for calculating the TA value by the eNB or the RRH based on the dedicated preamble or the SRS signal is as follows:

 The eNB calculates a final TA value by using the synchronization signal received by the RRH (or the corresponding RRH and eNB) corresponding to each configured/activated CSI-RS. For example, the eNB may separately calculate the TA value corresponding to the synchronization signal on the RRH corresponding to each CSI-RS, and then average each TA value as the final TA value, for example:

N N is the number of TAs corresponding to the CSI-RS currently configured or activated by the UE, and D is the corresponding TA value.

Alternatively, the eNB may assign different weight values to different TA values, and then perform weighted averaging to calculate the final TA value. E.g

Where Ν is the number of ΤΑ corresponding to the CSI-RS currently configured or activated by the UE, and D is the corresponding TA value. ^{≤ 1} , the weight value corresponding to each TA value, and 1 .

 If the UE sends a randomly selected preamble, the eNB calculates the TA value corresponding to the Preamble received by the eNB and the TA value corresponding to the Preamble forwarded by the RRH. Or the eNB calculates the TA value corresponding to the Preamble received by the eNB, and receives the TA value corresponding to the Preamble calculated and fed back by the RRH. The eNB can then calculate the average or weighted average of the individual TA values as the final TA value as described above.

 At 904, after acquiring the TA value (final TA value) associated with the configured or activated CSI-RS, the eNB transmits a TA adjustment message to the UE. When the UE sends a preamble, the TA adjustment message may be carried by a random access response message. The eNB sends the final TA value to the UE in the TA adjustment message.

 At 905, after receiving the TA adjustment message, the UE finds that the TA adjustment message carries the final TA value determined by the eNB, and the UE uses the final TA value in the subsequent uplink output transmission process.

 FIG. 10 is a schematic flow chart of another example of an uplink synchronization process according to an embodiment of the present invention. In Fig. 10, the same or similar processes as those of Fig. 9 use the same or similar reference numerals, and detailed description thereof will be omitted as appropriate.

 901-902 of Fig. 10 are the same as 901-902 of Fig. 9, and the description will not be repeated.

At 903a, the eNB calculates a TA value (possibly a plurality of TA values) in a similar manner to 603, 703, or 803 above. At 904a, similar to 604, 704, or 804, the eNB sends a TA adjustment message to the UE to inform the UE of the configured or activated CSI-RS associated TA value. Here, the TA adjustment message may be carried by the random access response message 7.

 At 905a, after receiving the TA adjustment message (e.g., carried by the random access response message), the UE calculates the final TA value as follows:

The UE determines the TA values corresponding to all CSI-RSs that have been configured or activated, and then calculates a TA value (final TA value) for final use based on the TA values corresponding to these CSI-RSs. specifically,

 N

 N is the number of TAs corresponding to the CSI-RS currently configured or activated by the UE, and D is the corresponding TA value.

 Alternatively, the UE may assign different weight values to different TA values, and then perform weighted averaging to calculate the final TA value. E.g

ΤΑ = ^ _ι α _ι ΤΑ _ι

Where Ν is the number of TAs corresponding to the CSI-RS currently configured or activated by the UE, and D is the corresponding TA value. ^≤1 , the weight value corresponding to each TA value, and 1 ¹ .

 Thus, the UE determines the final TA value and can directly use the final TA value during subsequent uplink output transmission.

 The embodiment of the present invention may also determine the TA value by the UE. Figure 11 is a schematic flow chart of a method of determining a timing advance TA value in accordance with another embodiment of the present invention. The method of Figure 11 is performed by a terminal device (e.g., a UE).

1101. Receive a channel state information reference signal CSI-RS configuration or activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS. 1102. Determine a TA value of the configured or activated CSI-RS according to a downlink timing difference between the currently used CSI-RS and the configured or activated CSI-RS and a TA value of a currently used CSI-RS.

 Therefore, the embodiment of the present invention can determine, by the terminal, the TA value corresponding to the configured or activated CRI-RS.

 The currently used CRI-RS is a CRI-RS that has been configured/activated in the previous process. In the embodiment of the present invention, the terminal can calculate the TA value of the configured/activated CRI-RS according to the timing information of the currently configured/activated CRI-RS.

 For example, if the downlink timing of the CSI-RS that has been configured/activated is referenced, the calculation formula of the uplink timing value of the configured/activated CSI-RS is: ΤΑ2' = ΤΑ1+Δ, where 厶 is Downlink timing difference.

 If the downlink timing of the configured/activated CSI-RS is referenced, the calculation formula of the uplink timing value of the configured/activated CSI-RS is: ΤΑ2 = ΤΑ1+2Δ, where Δ is the downlink timing difference . TA1 is the uplink timing of the CSI-RS that has been configured/activated.

 After obtaining the uplink timing value corresponding to the configured/activated CSI-RS, the UE may use the TA value to send uplink data to the network.

 Alternatively, before performing the uplink data transmission, the UE first sends the SRS signal to the network by using the TA value corresponding to each CSI-RS and the initial power, and after receiving the SRS signal sent by the UE, the network feeds back the TA adjustment message to the UE. . The sending of the TA adjustment message is the same as the method in the previous embodiment, and is not repeated here. After receiving the TA adjustment message, the UE performs uplink data transmission by using the TA value corresponding to the CSI-RS indicated in the TA adjustment message.

Specifically, the certain initial power P _{SRS of} the transmitting _SRS may be calculated by using the following method:

Among them, P. For the system-specific power parameters, the P. It can be specific to each site, that is, each CSI-RS can correspond to a different P _Q , indicating the desired receiving work on the site corresponding to each CSI-RS. Rate. The PL is a path loss value measured by the UE for the configured or activated CSI-RS, and is a parameter configured by the network for the UE, whose value is less than or equal to 1, different CSI-RS (or different CSI-RS corresponding sites) ) can correspond to different values.

 In addition, the embodiment of the present invention may indicate, by using the indication information, whether the terminal needs to perform uplink synchronization. FIG. 12 is a schematic flow chart of a method of determining a timing advance amount threshold according to another embodiment of the present invention. The method of Figure 12 is performed by a terminal device (e.g., a UE).

 1201. Receive a channel state information reference signal CSI-RS configuration or activation message of a network side device, where the CSI-RS configuration or activation message is used to configure or activate a CSI-RS, and include indication information, where the indication information is used to indicate whether the terminal device is Need to perform uplink synchronization.

 1202. Obtain a TA value according to the indication information.

 In this way, the terminal can determine whether it is necessary to perform uplink synchronization according to the indication on the network side, and obtain the corresponding TA value according to different manners.

 Figure 13 is a schematic flow diagram of a method of determining a timing advance TA value in accordance with another embodiment of the present invention. The method of FIG. 13 is performed by a network side device (for example, an eNB or an RRH) and corresponds to the method of FIG.

 1301: Generate a channel state information reference signal CSI-RS configuration or an activation message, where the CSI-RS configuration or activation message is used to configure or activate a CSI-RS, and include indication information, where the indication information is used to indicate whether the terminal device needs to perform uplink synchronization. ;

 1302. Send a CSI-RS configuration or activation message to the terminal device to indicate the TA value to the terminal device by using the indication information.

 In this way, the terminal can determine whether it is necessary to perform uplink synchronization according to the indication on the network side, and obtain the corresponding TA value according to different manners.

According to the indication of the indication information, the terminal can acquire the TA value in various ways. For example, when the indication information indicates that the uplink synchronization is not required to be performed, the network side may carry a new TA value in the CSI-RS configuration or activation message, and the UE performs uplink data transmission according to the TA value carried in the message. The new TA The value may be obtained by the eNB based on the SRS signal sent by the UE or the uplink data sent by the UE. Alternatively, the UE may calculate the TA value by itself, for example, according to the method shown in FIG. Alternatively, the UE may also acquire the TA value by other means, such as the CSI-RS group mode described below.

 On the other hand, when the indication information indicates that uplink synchronization needs to be performed, the terminal may initiate uplink synchronization to obtain the TA value in the manner described in FIG. 4, FIG. 6-10, and the like. For example, the UE may send a random access preamble to the network side device as a synchronization signal, so that the network side device calculates the TA value according to the preamble signal, and then the UE receives the TA value calculated by the network side device. Alternatively, the UE sends the sounding reference signal or the uplink data to the network side device, so that the network side device calculates the TA value according to the sounding reference signal or the uplink data, and receives the TA value calculated by the network side device.

 Considering that if a station can transmit multiple CSI-RSs, the CSI-RSs can be grouped, that is, a plurality of CSI-RSs that can share the same timing advance TA value are grouped into one group. In general, multiple CSI-RSs belonging to one CSI-RS group are configured for use by one site. This can further improve the efficiency of TA value acquisition.

 Figure 14 is a schematic flow chart of a method of determining a timing advance TA value according to another embodiment of the present invention. The method of Figure 14 is performed by a terminal device (e.g., a UE).

 1401. Receive a channel state information reference signal CSI-RS configuration or activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS.

 1402. Determine, according to the CSI-RS configuration or activation message and the group information of the CSI-RS, perform uplink synchronization to obtain a TA value corresponding to the configured or activated CSI-RS, or configure or activate the message according to the CSI-RS. The group information of the CSI-RS determines a TA value corresponding to the configured or activated CSI-RS, wherein the CSI-RS group refers to a set of one or more CSI-RSs that share the same TA value.

For example, when the configured or activated CSI-RS belongs to the same CSI-RS group as one CSI-RS currently used, determining that the TA value corresponding to the configured or activated CSI-RS is the CSI-RS group TA value. Or, the CSI-RS configured or activated does not belong to the currently used CSI-RS. When the same CSI-RS group, it is determined to perform uplink synchronization to acquire a TA value corresponding to the configured or activated CSI-RS. At this time, the terminal may initiate uplink synchronization to obtain the TA value in the manner described in FIG. 4, FIG. 6-10, and the like. Similar to the manner of obtaining uplink synchronization described in FIG. 4, FIG. 6-10, etc., in this embodiment, in order to further reduce the TA adjustment message size, when the TA value is sent in the TA adjustment message, each TA value may not be sent. Instead, the TA end value (maximum TA value and / or minimum TA value) is sent. Specifically, a maximum TA value and a minimum TA value and an intermediate step value may be transmitted to the UE. At the same time, a Bitmap corresponding to each CSI-RS group or each CSI-RS may be sent to the UE. Each bit in the Bitmap corresponds to one CSI-RS group or CSI-RS. Then, the 0 and 1 symbols of the bit respectively indicate whether the TA value of the corresponding CSI-RS group or CSI-RS is included in the current TA adjustment message. Through the foregoing terminal value, the step size, and the Bitmap indication information, the UE may sequentially acquire each TA value, and a CSI-RS or CSI-RS group corresponding to each TA value. In this way, the identifier of each CSI-RS and each TA value can be avoided from being sent to the UE, or the identifier of each CSI-RS group and each TA value can be avoided from being sent to the UE, so that the TA adjustment message can be reduced. size of.

 In this way, by means of the CSI-RS group sharing the same TA value, the UE does not have to perform uplink synchronization every time to determine the TA value, which saves signaling resources and improves system efficiency.

The UE can obtain group information of the CSI-RS in various manners. One way is for the UE to determine the group of CSI-RSs by itself. For example, the UE may base the downlink timing between the downlink timing of the configured/activated CSI-RS and the currently configured/activated one or more CSI-RSs based on the configuration received in 1401 or the message of activating the CSI-RS. Deviation, determine the CSI-RS group. Specifically, when the UE detects that the timing deviation between the downlink timing of the configured/activated CSI-RS and the downlink timing between the currently configured/activated one or more CSI-RSs exceeds a preset The threshold is that the UE determines that the configured/activated CSI-RS does not belong to the same CSI-RS group as the currently configured/activated one or more CSI-RSs. Otherwise, when the current timing difference is less than the preset threshold, the UE determines that the configured/activated CSI-RS belongs to the same one of the currently configured/activated one or more CSI-RSs. CSI-RS group.

 According to another embodiment of the present invention, the UE may also learn the group information of the CSI-RS from the network side. Figure 15 is a schematic flow chart of a method of determining a timing advance TA value according to another embodiment of the present invention. The method of Figure 15 is performed by a network side device (e.g., an eNB or an RRH).

 1501. Send, to the terminal device, channel state information reference signal CSI-RS group information,

A CSI-RS group refers to a set of one or more CSI-RSs that share the same TA value.

 1502. Send a CSI-RS configuration or activation message to the terminal device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS, so that the terminal device determines the location according to the CSI-RS configuration or the activation message and the group information. The TA value corresponding to the configured or activated CSI-RS.

 In this way, by means of the CSI-RS group sharing the same TA value, the UE does not have to perform uplink synchronization every time to determine the TA value, which saves signaling resources and improves system efficiency.

 The group information that the eNB can carry by broadcasting system messages, dedicated signaling, or cell handover commands. For example, the eNB groups the different CSI-RSs according to the ability to share one TA value, divides the CSI-RSs that can share one TA into one group, and then the eNB broadcasts the CSI-RS group to the UE by broadcasting the system message. information.

 Alternatively, the eNB may also use dedicated signaling to notify the UE of the already connected state about the packet information of the CSI-RS. The eNB may send the information of the CSI-RS group to the UE after the UE establishes the RRC connection for the first time, that is, by using a dedicated signaling. When the cell handover is performed, the group information of the CSI-RS may be sent to the UE by using a handover command.

 The various ways in which the network side sends group information can be replaced by each other, or can be used simultaneously. Figure 16 is a schematic block diagram of a terminal device in accordance with one embodiment of the present invention. The terminal device 160 of Fig. 16 includes a receiving unit 161, a transmitting unit 162, and a determining unit 163.

 The receiving unit 161 is configured to receive a channel state information reference signal CSI-RS configuration or an activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS.

The sending unit 162 is configured to send synchronization to the network side device according to the CSI-RS configuration or activation message. Signal.

 The receiving unit 161 is further configured to receive a TA adjustment message sent by the network side device, where the TA adjustment message carries a TA value determined by the network side device based on the synchronization signal.

 The determining unit 163 is configured to determine a TA value corresponding to the configured or activated CSI-RS according to the TA value carried in the TA adjustment message.

 The receiving unit 161 and the transmitting unit 162 may be interfaces and may be combined into one unit. The determining unit 163 can be a processor.

 Therefore, the embodiment of the present invention causes the terminal to send a synchronization signal to the network side according to the CSI-RS configuration or activation message on the network side, and the network side calculates a corresponding TA value according to the synchronization signal and returns the terminal, so that the terminal can know the TA value and the CSI. The correspondence relationship of -RS improves the accuracy of the uplink timing and realizes uplink synchronization.

 An example of the terminal device 160 is the above-mentioned UE, and the processes involved in the terminal in the method described in FIG. 4 to FIG. 10 may be performed. To avoid repetition, details are not described in detail. For example, the transmitting unit 162 may transmit a dedicated preamble or SRS signal configured by the network side device, or transmit a randomly selected preamble as the synchronization signal. The TA adjustment message received by the receiving unit 161 may include at least one of a CSI-RS identifier, a CSI-RS port number, a CSI-RS group identifier, and a TA identifier.

 Figure 17 is a schematic block diagram of a terminal device in accordance with another embodiment of the present invention. The terminal device 170 of Fig. 17 includes a receiving unit 171 and an obtaining unit 172.

 The receiving unit 171 is configured to receive a channel state information reference signal CSI-RS configuration or activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS, and includes indication information, where the indication information is used to indicate Whether the terminal device needs to perform uplink synchronization.

 The obtaining unit 172 is configured to acquire a TA value according to the indication information.

 The receiving unit 171 can be an interface. The acquisition unit 172 can be a processor.

In this way, the terminal can determine whether it is necessary to perform uplink synchronization according to the indication on the network side, and obtain corresponding TA values in different manners. An example of the terminal device 170 is the foregoing UE, and various processes related to the terminal in the method described in FIG. 12 may be performed. To avoid repetition, details are not described in detail.

 For example, the obtaining unit 172 acquires the TA value carried in the CSI-RS configuration or activation message when the indication information indicates that uplink synchronization is not required to be performed.

 On the other hand, when the indication information indicates that uplink synchronization needs to be performed, the acquisition unit of the terminal 170

172 may initiate uplink synchronization to obtain a TA value in the manner described in FIG. 4, FIG. 6-10, and the like. For example, the UE may send a random access preamble to the network side device as a synchronization signal, so that the network side device calculates the TA value according to the preamble signal, and then the UE receives the TA value calculated by the network side device. Alternatively, the UE sends the sounding reference signal or the uplink data to the network side device, so that the network side device calculates the TA value according to the sounding reference signal or the uplink data, and receives the TA value calculated by the network side device.

 Figure 18 is a schematic block diagram of a terminal device in accordance with another embodiment of the present invention. The terminal device 180 of Fig. 18 includes a receiving unit 181 and a determining unit 182.

 The receiving unit 181 is configured to receive a channel state information reference signal CSI-RS configuration or an activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS.

 The determining unit 182 is configured to determine the configured or activated CSI according to a downlink timing difference between the currently used CSI-RS and the configured or activated CSI-RS and a TA value of the currently used CSI-RS. The TA value of the RS.

 The receiving unit 181 can be an interface. The determining unit 182 can be a processor.

 Therefore, the embodiment of the present invention can determine, by the terminal, the TA value corresponding to the configured or activated CRI-RS.

 An example of the terminal device 180 is the above-mentioned UE, and various processes involving the terminal in the method described in FIG. 11 can be performed. To avoid repetition, details are not described in detail.

For example, if the downlink timing of the CSI-RS that has been configured/activated is referenced, the calculation formula of the uplink timing value of the configured/activated CSI-RS is: ΤΑ2' = ΤΑ1+Δ, where 厶 is Downlink timing difference. If the downlink timing of the configured/activated CSI-RS is referenced, the calculation formula of the uplink timing value of the configured/activated CSI-RS is: ΤΑ2 = ΤΑ1+2Δ, where Δ is the downlink timing difference .

 Figure 19 is a schematic block diagram of a terminal device in accordance with another embodiment of the present invention. The terminal device 190 of Fig. 19 includes a receiving unit 191 and a determining unit 192.

 The receiving unit 191 is configured to receive a channel state information reference signal CSI-RS configuration or an activation message of the network side device, and the CSI-RS configuration or activation message is used to configure or activate the CSI-RS.

 The determining unit 192 is configured to determine, according to the CSI-RS configuration or the group information of the activation message and the CSI-RS, perform uplink synchronization to obtain a TA value corresponding to the configured or activated CSI-RS, or according to a CSI-RS configuration or Activating the message and the group information of the CSI-RS, determining a TA value corresponding to the configured or activated CSI-RS, wherein the CSI-RS group refers to one or more CSI-RSs sharing the same TA value set.

 The receiving unit 191 can be an interface. The determining unit 192 can be a processor.

 In this way, by means of the CSI-RS group sharing the same TA value, the UE does not have to perform uplink synchronization every time to determine the TA value, which saves signaling resources and improves system efficiency.

 An example of the terminal device 190 is the UE described above, and the various processes involved in the terminal in the method described in FIG. 14 can be performed. To avoid repetition, details are not described in detail.

 For example, when the configured or activated CSI-RS belongs to the same CSI-RS group as one CSI-RS currently used, the determining unit 192 determines that the TA value corresponding to the configured or activated CSI-RS is the CSI-RS. The TA value of the group. Alternatively, when the configured or activated CSI-RS does not belong to the same CSI-RS group as the currently used CSI-RS, the determining unit 192 determines to perform uplink synchronization to acquire the TA corresponding to the configured or activated CSI-RS. value. At this time, the determining unit 192 can initiate uplink synchronization to obtain the TA value in the manner described in FIG. 4, FIG. 6-10, and the like.

Figure 20 is a schematic block diagram of a network side device in accordance with one embodiment of the present invention. The network side device 200 of FIG. 20 includes a transmitting unit 201, a receiving unit 202, and a determining unit 203. The sending unit 201 is configured to send a channel state information reference signal CSI-RS configuration or activation message to the terminal device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS;

 The receiving unit 202 is configured to receive a synchronization signal sent by the terminal device according to a CSI-RS configuration or an activation message.

 The determining unit 203 is for determining the TA value based on the synchronization signal.

 The sending unit 201 is further configured to send a TA adjustment message to the terminal device, where the TA adjustment message carries the determined TA value.

 The receiving unit 202 and the transmitting unit 201 may be interfaces and may be combined into one unit. The determining unit 203 can be a processor.

 Therefore, the embodiment of the present invention causes the terminal to send a synchronization signal to the network side according to the CSI-RS configuration or activation message on the network side, and the network side calculates a corresponding TA value according to the synchronization signal and returns the terminal, so that the terminal can know the TA value and the CSI. The correspondence relationship of -RS improves the accuracy of the uplink timing and realizes uplink synchronization.

 An example of the network side device 200 is the foregoing eNB or RRH, and various processes related to the network side in FIG. 5-10 can be performed. To avoid repetition, details are not described in detail.

 21 is a schematic block diagram of a network side device according to another embodiment of the present invention. The network side device 210 of Fig. 21 includes a generating unit 211 and a transmitting unit 212.

 The generating unit 211 is configured to generate a channel state information reference signal CSI-RS configuration or activation message, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS and includes indication information, where the indication information is used to indicate whether the terminal device needs to perform uplink Synchronize.

 The sending unit 212 is configured to send the indication information to the terminal device to indicate the TA value to the terminal device by using the indication information.

 Transmitting unit 212 can be an interface. The generating unit 211 may be a processor.

In this way, the terminal can determine whether it is necessary to perform uplink synchronization according to the indication on the network side, and obtain corresponding TA values in different manners. An example of the network side device 210 is the foregoing eNB or RRH, and various processes related to the network side in FIG. 13 can be performed. To avoid repetition, details are not described in detail.

 Figure 22 is a schematic block diagram of a network side device in accordance with another embodiment of the present invention. The network side device 220 of Fig. 22 includes a transmitting unit 221.

 The transmitting unit 221 is configured to send information of a channel state information reference signal CSI-RS group to the terminal device, where the CSI-RS group refers to a set of one or more CSI-RSs that share the same TA value.

 The sending unit 221 is further configured to send a CSI-RS configuration or activation message to the terminal device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS, so that the terminal device configures or activates the message and the group information according to the CSI-RS. The TA value corresponding to the configured or activated CSI-RS is determined.

 The transmitting unit 221 can be an interface.

 In this way, by means of the CSI-RS group sharing the same TA value, the UE does not have to perform uplink synchronization every time to determine the TA value, which saves signaling resources and improves system efficiency.

 An example of the network side device 220 is the foregoing eNB or RRH, and various processes related to the network side in FIG. 15 can be performed. To avoid repetition, details are not described in detail.

 A communication system according to an embodiment of the present invention may include the above-described terminal device or the above-described network side device. Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, for clarity of hardware and software. Interchangeability, the composition and steps of the various examples have been generally described in terms of function in the above description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

A person skilled in the art can clearly understand that, for the convenience and the cleaning of the description, the specific working process of the system, the device and the unit described above can be referred to the corresponding process in the foregoing method embodiment, and details are not described herein again. In the several embodiments provided herein, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form. The components displayed by the unit may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

 In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

 The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may contribute to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. , including a plurality of instructions for causing a computer device (which may be a personal computer, a server, a storage medium including: a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM, Random) A variety of media that can store program code, such as Access Memory, disk, or optical disk.

The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited Therefore, any person skilled in the art can easily conceive changes or substitutions within the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

Rights request

 A method for determining a timing advance TA value, comprising:

 Receiving a channel state information reference signal CSI-RS configuration or activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS;

 Sending a synchronization signal to the network side device according to the CSI-RS configuration or activation message; receiving a TA adjustment message sent by the network side device, where the TA adjustment message carries the network side device based on the synchronization signal Determined TA value;

 And determining a TA value corresponding to the configured or activated CSI-RS according to the TA value carried in the TA adjustment message.

 The method according to claim 1, wherein the CSI-RS configuration or activation message is radio resource control RRC signaling, media access control control element MAC CE or physical layer signaling.

 3. The method of claim 1 wherein:

 Sending the synchronization signal to the network side device includes:

 Transmitting a dedicated preamble or a sounding reference signal configured by the network side device as the synchronization signal, or

 A randomly selected preamble is transmitted as the synchronization signal.

 The method of claim 3, wherein receiving the TA adjustment message sent by the network side device comprises:

 Receiving the TA adjustment message, where the TA adjustment message carries a TA value determined by the network side device and a CSI-RS identifier, a CSI-RS port number, a TA identifier, or a CSI-RS corresponding to the determined TA value. Group ID, or,

 Receiving the TA adjustment message, where the TA adjustment message carries multiple TA values arranged in an order corresponding to multiple CRI-RSs configured or activated, or

Receiving the TA adjustment message, where the TA adjustment message carries a TA end value used to calculate the TA value, or a TA end value and a step value used to calculate the TA value, or a TA end value used to calculate the TA value. And the cutoff value.

 5. The method of claim 4, further comprising:

 The TA adjustment message includes a bitmap indication, where each indicator bit of the bitmap corresponds to one CSI-RS or CSI-RS group, and each indicator bit is used to indicate whether the TA adjustment message includes The TA value of the CSI-RS or CSI-RS group corresponding to each of the indication bits.

 6. The method of claim 1, further comprising:

 Selecting a corresponding TA value of the best CSI-RS to perform uplink data transmission; or receiving indication information sent by the network side device, where the indication information is used to specify a TA value used in uplink data transmission, and using the indication The TA value specified by the information is used for uplink data transmission; or, based on the corresponding TA value of the primary CSI-RS, for uplink data transmission; or

 Detecting a PDCCH channel to obtain a plurality of scheduled resource blocks, and performing uplink data transmission on the plurality of scheduled resource blocks in sequence according to a sequence of TA values; or

 Uplink data transmission is performed using TA values corresponding to different CSI-RSs through different antennas or different antenna ports.

 The method according to claim 6, wherein the indication information includes at least one of a CSI-RS identifier, a CSI-RS port number, a CSI-RS group identifier, and a TA identifier.

 8. The method of claim 1 wherein:

 Receiving the TA adjustment message sent by the network side device includes: receiving the TA adjustment message, where the TA adjustment message carries a final TA value determined by the network side device,

 Determining a TA value corresponding to the configured or activated CSI-RS according to the TA adjustment message includes: determining that the final TA value is a TA value corresponding to the configured or activated CSI-RS.

 9. The method of claim 1 wherein:

 Receiving the TA adjustment message sent by the network side device includes: receiving the TA adjustment message, where the TA adjustment message carries multiple TA values determined by the network side device,

Determining a TA value packet corresponding to the configured or activated CSI-RS according to the TA adjustment message Comprising: obtaining a final TA value according to the plurality of TA values, determining that the final TA value is a TA value corresponding to the configured or activated CSI-RS.

 10. The method of claim 9, wherein obtaining the final TA value based on the plurality of TA values comprises:

 An average or weighted average of the plurality of TA values is calculated, and the average or weighted average is taken as the final TA value.

 The method according to claim 1, wherein the sending the synchronization signal to the network side device according to the CSI-RS configuration or activation message comprises:

 Determining a downlink timing offset value or a downlink path loss offset value of the configured or activated CSI-RS and the currently used CSI-RS;

 And when the downlink timing offset value or the downlink path loss offset value is greater than a predetermined threshold, sending a synchronization signal to the network side device.

 The method according to any one of claims 1 to 11, wherein receiving the channel state information reference signal of the network side device, the CSI-RS configuration or activation message comprises:

 Receiving the CSI-RS configuration or activation message, the CSI-RS configuration or activation message is also used to deactivate other CSI-RSs.

 The method according to any one of claims 1 to 11, further comprising: initiating retransmission of the synchronization signal when a TA value of at least one configured or activated CSI-RS is not successfully acquired , to get the TA value that was not successfully acquired.

 14. A method for determining a timing advance TA value, the method comprising:

 Transmitting, by the terminal device, a channel state information reference signal CSI-RS configuration or activation message, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS;

 Receiving a synchronization signal sent by the terminal device according to the CSI-RS configuration or activation message; determining a TA value based on the synchronization signal;

Sending a TA adjustment message to the terminal device, where the TA adjustment message carries the determined TA value.

 15. The method of claim 14 wherein:

 Transmitting the channel state information reference signal CSI-RS configuration or activation message to the terminal device includes: transmitting the CSI-RS configuration or activation message, where the CSI-RS configuration or activation message further includes a dedicated preamble configured for the terminal device Or explore the information of the reference signal,

 And receiving the synchronization signal sent by the terminal device according to the CSI-RS configuration or activation message, including: receiving the dedicated preamble or the sounding reference signal sent by the terminal device.

 The method according to claim 15, wherein the sending the TA adjustment message to the terminal device comprises:

 Sending the TA adjustment message, where the TA adjustment message carries a TA value determined by the network side device and a CSI-RS identifier, a CSI-RS port number, a TA identifier, or a CSI-RS group corresponding to the determined TA value. Logo, or,

 And sending the TA adjustment message, where the TA adjustment message carries a TA value arranged in an order corresponding to multiple CRI-RSs configured or activated.

 The method according to any one of claims 14 to 16, wherein the receiving the synchronization signal sent by the terminal device according to the CSI-RS configuration or activation message comprises:

 Receiving a randomly selected preamble transmitted by the terminal device.

 The method according to claim 17, wherein the sending the TA adjustment message to the terminal device comprises:

 Transmitting the TA adjustment message, where the TA adjustment carries a TA value determined by the network side device and a CSI-RS identifier, a CSI-RS port number, a TA identifier, or a CSI-RS group corresponding to the determined TA value. Group identification, or,

Sending the TA adjustment message, where the TA adjustment message carries a TA end value used to calculate the TA value, or a TA end value and a step value used to calculate the TA value, or a TA end value used to calculate the TA value Cutoff value.

A method for determining a timing advance TA value, the method comprising: receiving a channel state information reference signal CSI-RS configuration or activation message of a network side device, where the CSI-RS configuration or activation message is used for configuration or Activating a CSI-RS and including indication information, where the indication information is used to indicate whether the terminal device needs to perform uplink synchronization;

 Obtaining a TA value according to the indication information.

 The method according to claim 19, wherein the acquiring the TA value according to the indication information comprises: when the indication information indicates that uplink synchronization is not required to be performed,

 Obtain the TA value carried in the CSI-RS configuration or activation message.

 The method of claim 19, wherein the acquiring the TA value according to the indication information comprises: when the indication information indicates that uplink synchronization needs to be performed,

 Sending a random access preamble to the network side device, and receiving a TA value calculated by the network side device according to the preamble; or

 And sending the sounding reference signal or the uplink data to the network side device, and receiving the TA value calculated by the network side device according to the sounding reference signal or the uplink data.

 22. A method for determining a timing advance TA value, the method comprising:

 Generating a channel state information reference signal CSI-RS configuration or an activation message, where the CSI-RS configuration or activation message is used to configure or activate a CSI-RS and includes indication information, where the indication information is used to indicate whether the terminal device needs to perform uplink synchronization. ;

 The CSI-RS configuration or activation message is sent to the terminal device to indicate a TA value to the terminal device by using the indication information.

The method of claim 22, wherein, when the indication information indicates that uplink synchronization is not required to be performed, the CSI-RS configuration or activation message carries the TA value, or When the information indicates that the uplink synchronization needs to be performed, the method further includes: receiving a random access preamble, a sounding reference signal, or uplink data sent by the terminal device, and calculating according to the random access preamble, the sounding reference signal, or the uplink data. The TA value.

24 . A method for determining a timing advance TA value, comprising: receiving a channel state information reference signal CSI-RS configuration or an activation message of a network side device, where the CSI-RS configuration or activation message is used for configuration or Activate CSI-RS;

 And determining a TA value of the configured or activated CSI-RS according to a downlink timing difference between the currently used CSI-RS and the configured or activated CSI-RS and a TA value of the currently used CSI-RS.

 The method according to claim 24, wherein: a downlink timing difference between the currently used CSI-RS and the configured or activated CSI-RS and a TA value of the currently used CSI-RS Determining the TA value of the configured or activated CSI-RS includes:

 If the downlink timing of the configured or activated CSI-RS is referenced, the configuration or activation

The TA value of the CSI-RS is the TA value of the currently used CSI-RS plus twice the downlink timing difference, or;

 If the downlink timing of the currently used CSI-RS is referenced, the TA value of the configured or activated CSI-RS is the TA value of the currently used CSI-RS plus the downlink timing difference.

 The method according to claim 24 or 25, further comprising:

 Transmitting the sounding reference signal to the network side device by using the TA value and the initial power of the configured or activated CSI-RS;

 And receiving, by the network side device, a TA adjustment message that is fed back by the sounding reference signal, where the TA adjustment message carries a TA value calculated by the network side device according to the sounding reference signal.

 27. A method for determining a timing advance TA value, the method comprising:

 Receiving a channel state information reference signal CSI-RS configuration or activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS;

Determining, according to the CSI-RS configuration or activation message and group information of the CSI-RS, performing uplink synchronization to obtain a TA value corresponding to the configured or activated CSI-RS, or configuring or activating according to the CSI-RS Message and CSI-RS group information, as determined by the configured or activated CSI-RS The value of TA,

 The CSI-RS group refers to a set of one or more CSI-RSs that share the same TA value.

 The method of claim 27, further comprising:

 Receiving group information of the CSI-RS sent by the network side device, or

 The group information of the CSI-RS is determined according to a timing deviation between the configured or activated CSI-RS and the currently used CSI-RS.

 The method according to claim 27 or 28, wherein, according to the CSI-RS configuration or activation message and group information of the CSI-RS, determining to perform uplink synchronization to obtain the configured or activated CSI-RS Corresponding TA values, or determining TA values corresponding to the configured or activated CSI-RSs according to the CSI-RS configuration or activation message and CSI-RS group information, include:

 When the configured or activated CSI-RS belongs to the same CSI-RS group as one CSI-RS currently used, determining that the TA value corresponding to the configured or activated CSI-RS is the TA of the CSI-RS group Value, or,

 When the configured or activated CSI-RS does not belong to the same CSI-RS group as the currently used CSI-RS, it is determined to perform uplink synchronization to acquire a TA value corresponding to the configured or activated CSI-RS.

 The method of claim 28, wherein receiving the group information of the CSI-RS sent by the network side device comprises:

 Receiving the group information carried by the network side device by using a broadcast message, a dedicated signaling, or a cell handover command.

 31. A method for determining a timing advance TA value, comprising:

 Transmitting, by the terminal device, information of a channel state information reference signal CSI-RS group, where the CSI-RS group refers to a set of one or more CSI-RSs sharing the same TA value;

Sending a CSI-RS configuration or activation message to the terminal device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS, so that the terminal device configures or activates according to the CSI-RS. The information and the group information determine a TA value corresponding to the configured or activated CSI-RS.

 The method according to claim 31, wherein the transmitting the information of the channel state information reference signal to the terminal device, the CSI-RS group includes:

 The group information carried by the broadcast system message, the dedicated signaling, or the cell handover command is transmitted.

33. A terminal device, comprising:

 a receiving unit, configured to receive a channel state information reference signal CSI-RS configuration or activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS;

 a sending unit, configured to send a synchronization signal to the network side device according to the CSI-RS configuration or activation message;

 The receiving unit is further configured to receive a TA adjustment message sent by the network side device, where the TA adjustment message carries a TA value determined by the network side device based on the synchronization signal;

 And a determining unit, configured to determine, according to the TA value carried in the TA adjustment message, a TA value corresponding to the configured or activated CSI-RS.

 The terminal device according to claim 33, wherein the transmitting unit transmits a dedicated preamble or a sounding reference signal configured by the network side device as the synchronization signal, or transmits a randomly selected preamble As the synchronization signal.

 35. A terminal device, comprising:

 a receiving unit, configured to receive a channel state information reference signal CSI-RS configuration or an activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS and include indication information, where the indication information is used by Instructing the terminal device whether to perform uplink synchronization;

 And an obtaining unit, configured to acquire a TA value according to the indication information.

 The terminal device according to claim 35, wherein the acquiring unit acquires a TA value carried in the CSI-RS configuration or activation message when the indication information indicates that uplink synchronization is not required to be performed.

37. A terminal device, comprising: a receiving unit, configured to receive a channel state information reference signal CSI-RS configuration or activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS;

 a determining unit, configured to determine the configured or activated CSI according to a downlink timing difference between the currently used CSI-RS and the configured or activated CSI-RS and a TA value of the currently used CSI-RS The TA value of the RS.

 38. A terminal device, comprising:

 a receiving unit, configured to receive a channel state information reference signal CSI-RS configuration or activation message of the network side device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS;

 a determining unit, configured to determine, according to the CSI-RS configuration or activation message and group information of the CSI-RS, performing uplink synchronization to obtain a TA value corresponding to the configured or activated CSI-RS, or according to the CSI - RS configuration or activation message and CSI-RS group information, determining the TA value corresponding to the configured or activated CSI-RS,

 The CSI-RS group refers to a set of one or more CSI-RSs that share the same TA value.

 39. A network side device, comprising:

 a sending unit, configured to send a channel state information reference signal CSI-RS configuration or an activation message to the terminal device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS;

 a receiving unit, configured to receive a synchronization signal that is sent by the terminal device according to the CSI-RS configuration or activation message;

 a determining unit, configured to determine a TA value based on the synchronization signal;

 The sending unit is further configured to send a TA adjustment message to the terminal device, where the TA adjustment message carries the determined TA value.

 40. A network side device, comprising:

a generating unit, configured to generate a channel state information reference signal CSI-RS configuration or an activation message, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS and include indication information, where the The indication information is used to indicate whether the terminal device needs to perform uplink synchronization;

 And a sending unit, configured to send the indication information to the terminal device, to indicate, by using the indication information, a TA value to the terminal device.

 41. A network side device, comprising:

 a sending unit, configured to send, to the terminal device, information of a channel state information reference signal CSI-RS group, where the CSI-RS group refers to a set of one or more CSI-RSs that share the same TA value; The sending unit is further configured to send a CSI-RS configuration or an activation message to the terminal device, where the CSI-RS configuration or activation message is used to configure or activate the CSI-RS, so that the terminal device is configured according to the CSI-RS or The activation message and the group information determine a TA value corresponding to the configured or activated CSI-RS.

 42. A communication system, comprising:

 A terminal device according to any one of claims 33 to 36; or

 A network side device according to any one of claims 37-41.