Patent Description:
A high frequency carrier is introduced in a new radio (New Radio, NR for short) technology. Therefore, during NR deployment, because of factors such as a high frequency and an uplink-downlink configuration, NR uplink coverage and downlink coverage differ greatly. In this case, if a low frequency carrier is used for uplink transmission and a high frequency carrier is used for downlink transmission, the difference between the NR uplink coverage and downlink coverage can be reduced. This technology is referred to as uplink and downlink decoupling.

In a Long Term Evolution (Long Term Evolution, LTE for short) technology, because frequencies of an uplink carrier and a downlink carrier are the same or similar, after a downlink path loss is obtained through downlink measurement, the downlink path loss may be used as an uplink path loss, and uplink transmit power of a terminal is obtained based on the uplink path loss. If a low frequency resource is obtained in NR by sharing with another network, for example, the low frequency resource may be obtained through LTE-NR uplink sharing, to form a supplementary uplink (Supplemental Uplink, SUL for short) cell, because there is no corresponding intra-frequency downlink cell, in an NR uplink and downlink decoupling scenario, user equipment (User Equipment, UE for short) cannot implement uplink power control by means of downlink measurement. To be specific, in an NR uplink and downlink decoupling scenario, a frequency difference between a carrier used for downlink transmission and a carrier used for uplink transmission is very large (for example, a downlink frequency is <NUM>, and an uplink frequency is <NUM>). The uplink and downlink path losses differ greatly. Therefore, the downlink path loss cannot be used as the uplink path loss to obtain the uplink transmit power of the terminal.

Currently, an uplink control method is urgently required to obtain uplink transmit power of a terminal in an uplink and downlink decoupling scenario.

3GPP document, 3GPP TSG RAN WG1 Meeting #88bis, R1-<NUM>, discloses aspects of co-existence of LTE uplink and NR UL within the bandwidth of an LTE component carrier.

<CIT> discloses a method for estimating a path loss estimation on a downlink of a component carrier in a component carrier list, so that an uplink transmission for other component carriers in the list may be controlled. Moreover, a path-loss difference parameter is sent to a UE.

This application provides an uplink control method, an apparatus, and a system, to obtain uplink transmit power of a terminal in an uplink and downlink decoupling scenario.

It is noted that embodiments in <FIG>, <FIG>, and <FIG> are not part of the invention, but illustrative examples helpful for understanding the invention.

First, an uplink and downlink decoupling technology is briefly described.

The uplink and downlink decoupling technology means that carriers used for uplink transmission and downlink transmission respectively do not belong to a same frequency band. For example, when a low frequency carrier such as a carrier in a <NUM> frequency band is used for the uplink transmission, and a high frequency carrier such as a carrier in a <NUM> frequency band is used for the downlink transmission, the uplink and downlink decoupling is implemented.

All scenarios in embodiments of this application are uplink and downlink decoupling scenarios. In the uplink and downlink decoupling scenarios, a corresponding terminal may be referred to as a decoupling terminal, for example, a terminal that performs uplink transmission on a low frequency carrier and performs downlink receiving on an air interface resource corresponding to a high frequency carrier. Correspondingly, in a non-decoupling scenario, frequencies of carriers corresponding to uplink transmission and downlink transmission are on a same frequency band, and a corresponding terminal may be referred to as a non-decoupling terminal.

In uplink control in an uplink and downlink decoupling scenario, the embodiments of this application relate to three aspects: obtaining an uplink transmit power of a decoupling terminal, determining a cell that is initially accessed, and identifying the decoupling terminal by a base station in an initial access process.

<FIG> is a possible application scenario diagram according to an embodiment of this application. Referring to <FIG>, a system architecture includes a base station <NUM> and a terminal <NUM>. Both a base station corresponding to downlink transmission (a high frequency carrier) and a base station corresponding to uplink transmission (a low frequency carrier) are deployed in the base station <NUM>.

<FIG> is another possible application scenario diagram according to an embodiment of this application. Referring to <FIG>, a system architecture includes a low frequency base station <NUM>, a high frequency base station <NUM>, and a terminal <NUM>. The low frequency base station <NUM> is a base station corresponding to uplink transmission (a low frequency carrier), and the high frequency base station <NUM> is a base station corresponding to downlink transmission (a high frequency carrier).

Uplink control methods in the foregoing two application scenarios are described in detail below by using specific embodiments.

An applicable premise of the method for obtaining an uplink transmit power of a terminal and the method for determining a cell initially accessed by a terminal in this application is as follows: A first network (for example, an NR network) corresponding to an uplink and downlink decoupling scenario obtains a low frequency resource by sharing a resource with an existing network, that is, no low frequency resource is allocated to the first network. On the premise of standalone networking of the first network, uplink and downlink transmission may be performed on a high frequency carrier (for example, a carrier in a <NUM> frequency band), and uplink transmission may be performed on a low frequency carrier (for example, a carrier in a <NUM> frequency band). The uplink transmit power of the terminal in this embodiment of this application is an uplink transmit power of the terminal in the first network, and the cell that is initially accessed by the terminal and to be determined is a cell initially accessed by the terminal to the first network.

First, the method for obtaining an uplink transmit power of a terminal is described in detail.

<FIG> is a signaling flowchart <NUM> of a method for obtaining an uplink transmit power of a terminal according to an embodiment of this application. <FIG> is a schematic diagram of an actual scenario corresponding to <FIG> according to an embodiment of this application. <FIG> is a signaling flowchart <NUM> of a method for obtaining an uplink transmit power of a terminal according to an embodiment of this application. <FIG> is a schematic diagram of an actual scenario corresponding to <FIG> according to an embodiment of this application. <FIG> is a signaling flowchart <NUM> of a method for obtaining an uplink transmit power of a terminal according to an embodiment of this application. <FIG> is a signaling flowchart <NUM> of a method for obtaining an uplink transmit power of a terminal according to an embodiment of this application. <FIG> is a schematic diagram of an actual scenario corresponding to <FIG> according to an embodiment of this application.

The method for obtaining an uplink transmit power of a terminal may be implemented in the following possible implementations.

Referring to <FIG>, a first possible implementation of obtaining the uplink transmit power of the terminal is as follows:.

Specifically, the method for obtaining the uplink transmit power of the terminal in this embodiment may be applicable to the application scenario shown in <FIG>, and is also applicable to an application scenario in which the first network adopts standalone networking and an application scenario in which the first network and a second network adopt non-standalone networking. The first network may be an NR network, and the second network may be an LTE network. In this case, the method for obtaining the uplink transmit power of the terminal in this embodiment is applicable to both an application scenario of NR standalone networking and an application scenario of NR and LTE non-standalone networking, and the base station in this embodiment is an NR base station. The first reference signal in this embodiment may be a cell-specific reference signal C-RS.

The uplink transmit power of the terminal in this embodiment includes a transmit power of a random access preamble and/or a control information transmit power on a physical uplink control channel (Physical Uplink Control Channel, PUCCH for short) and/or a data transmit power on a physical uplink shared channel (Physical Uplink Shared Channel, PUSCH for short). In an uplink and downlink decoupling scenario, the uplink transmit power of the terminal in this embodiment is a transmit power used when the terminal performs uplink transmission on a low frequency carrier.

The method in this embodiment is described below by using an example in which the first network is an NR network, the second network is an LTE network, and the first reference signal is a C-RS.

For step S101, when NR adopts standalone networking, the base station sends the C-RS to the terminal on a high frequency carrier (for example, a carrier in a <NUM> frequency band). For an actual scenario, refer to <FIG>. When NR and LTE adopt non-standalone networking, the base station sends the C-RS to the terminal on a high frequency carrier (for example, a carrier in a <NUM> frequency band).

For step S102, when NR adopts standalone networking, the base station sends a C-RS transmit power, the first transmit power, and the second transmit power to the terminal on a high frequency carrier (for example, a carrier in a <NUM> frequency band). The C-RS transmit power, the first transmit power, and the second transmit power may be carried in a system message. The first transmit power includes the uplink transmit power of the terminal expected by the base station and the path loss offset, and the second transmit power includes the uplink transmit power of the terminal expected by the base station, the path loss offset, and the penetration loss offset. For an actual scenario, refer to <FIG>. When NR and LTE adopt non-standalone networking, the base station may send the C-RS transmit power, the first transmit power, and the second transmit power to the terminal by using an LTE base station. In this case, the C-RS transmit power, the first transmit power, and the second transmit power may be carried in a radio resource control (Radio Resource Control, RRC for short) reconfiguration message.

If the uplink transmit power of the terminal is a transmit power of a random access preamble, the uplink transmit power of the terminal expected by the base station is the transmit power that is of the random access preamble of the terminal that is expected by the base station; if the uplink transmit power of the terminal is a control information transmit power on a PUCCH, the uplink transmit power of the terminal expected by the base station is the control information transmit power that the base station expects the terminal to have on the PUCCH; or if the uplink transmit power of the terminal is a data transmit power on a PUSCH, the uplink transmit power of the terminal expected by the base station is the data transmit power that the base station expects the terminal to have on the PUSCH.

The path loss offset and the penetration loss offset by the base station may be obtained by using a method in the prior art. Details are not described in this embodiment again. For step S103, after receiving the C-RS, the terminal obtains a C-RS receive power of the serving cell through measurement, and obtains the downlink path loss based on the C-RS receive power and the C-RS transmit power, where downlink path loss = C-RS transmit power - C-RS receive power.

A person skilled in the art may understand that, when NR and LTE adopt non-standalone networking, the serving cell is a cell in LTE.

For step S104, when the terminal determines that the C-RS receive power is greater than or equal to the preset threshold, it may be considered that the terminal is located outdoors, and the terminal obtains the uplink transmit power of the terminal based on the downlink path loss, the first transmit power, and the maximum transmit power of the terminal; or when the terminal determines that the C-RS receive power is less than the preset threshold, it may be considered that the terminal is located indoors, and the terminal obtains the uplink transmit power of the terminal based on the downlink path loss, the second transmit power, and the maximum transmit power of the terminal. For an actual scenario, refer to <FIG>.

Specifically, a process of obtaining the uplink transmit power of the terminal is described by using the transmit power of the random access preamble as an example. In this case, the base station further sends, to the terminal, a power offset of a preamble currently configured in a preamble format <NUM>. That "the terminal obtains the uplink transmit power of the terminal based on the downlink path loss, the first transmit power, and the maximum transmit power of the terminal" includes: the terminal obtains an initial transmit power of the random access preamble of the terminal based on the downlink path loss, a sum of the first transmit power and the power offset, and the maximum transmit power of the terminal. Alternatively, that "the terminal obtains the uplink transmit power of the terminal based on the downlink path loss, the second transmit power, and the maximum transmit power of the terminal" includes: the terminal obtains an initial transmit power of the random access preamble of the terminal based on the downlink path loss, a sum of the second transmit power and the power offset, and the maximum transmit power of the terminal.

Specifically, the transmit power P<NUM> of the random access preamble, that is, the initial transmit power of the random access preamble, may be obtained by using a formula <NUM>: <MAT> where
PCMAX is the maximum transmit power of the terminal, P<NUM>-pre is the first transmit power or the second transmit power, PL is the downlink path loss, and Δpreamble is the power offset.

The initial transmit power of the random access preamble is a power of a preamble sequence sent by the terminal to the base station for the first time. If the initial access fails, a subsequent transmit power of the random access preamble of the terminal may be obtained by using a formula <NUM>: <MAT> where
Npre is a quantity of times that the terminal sends the preamble sequence, and Δstep is a power ramp-up step.

In this embodiment, a difference between the uplink path loss and the downlink path loss is considered in use of the path loss offset and the penetration loss offset, so that the uplink transmit power of the terminal is obtained in the uplink and downlink decoupling scenario. In addition, in this embodiment, whether the terminal is located indoors or outdoors is considered, so that the obtained uplink transmit power of the terminal is relatively accurate.

Referring to <FIG>, a second possible implementation of obtaining the uplink transmit power of the terminal is as follows:.

Specifically, the method for obtaining the uplink transmit power of the terminal in this embodiment may be applicable to the application scenario shown in <FIG>, and is also applicable to an application scenario in which the first network adopts standalone networking and an application scenario in which the first network and the second network adopt non-standalone networking, where uplink-downlink spectrums are shared in the first network and the second network. The first network may be an NR network, and the second network may be an LTE network. In this case, the method for obtaining the uplink transmit power of the terminal in this embodiment is applicable to both an application scenario of NR standalone networking and an application scenario of NR and LTE non-standalone networking, and NR and LTE need to coexist in uplink and downlink. The base station in this embodiment is an NR base station. The second reference signal in this embodiment may be a synchronization reference signal/secondary synchronization reference signal (Primary Synchronization Signal/Secondary Synchronization Signal, PSS/SSS for short).

A meaning of the uplink transmit power of the terminal in this embodiment is the same as that in the foregoing embodiment. Details are not described in this embodiment again. The method in this embodiment is described below by using an example in which the first network is an NR network, the second network is an LTE network, and the second reference signal is a PSS/SSS.

For step S201, when NR adopts standalone networking or non-standalone networking, the base station sends the PSS/SSS to the terminal by using an LTE air interface resource (for example, a carrier in a <NUM> frequency band or a carrier in a <NUM> frequency band). A time domain resource corresponding to the LTE air interface resource used to send the PSS/SSS may be a multicast/broadcast over single frequency network (Multicast/Broadcast over Single Frequency Network, MBSFN for short) subframe. In this case, the frequency band to which the carrier used by the terminal for uplink transmission in the NR network belongs is the same as a frequency band to which the LTE air interface resource belongs.

For step S202, when NR adopts standalone networking, the base station sends, to the terminal on a high frequency carrier (for example, a carrier in a <NUM> frequency band), a PSS/SSS transmit power and the uplink transmit power of the terminal that is expected by the base station, and the PSS/SSS transmit power and the uplink transmit power of the terminal that is expected by the base station may be carried in a system message. When NR and LTE adopt non-standalone networking, the base station may send the PSS/SSS transmit power and the uplink transmit power of the terminal that is expected by the base station to the terminal by using an LTE base station. The NR base station sends an identifier of a virtual hyper cell to the LTE base station through an LTE core network device. In this case, the PSS/SSS transmit power and the uplink transmit power of the terminal that is expected by the base station may be carried in an RRC reconfiguration message.

For step S203, after receiving the PSS/SSS, the terminal obtains a PSS/SSS receive power of the serving cell through measurement, and obtains the downlink path loss based on the PSS/SSS receive power and the PSS/SSS transmit power, where downlink path loss = PSS/SSS transmit power - PSS/SSS receive power.

For step S204, the terminal may obtain an uplink path loss based on the downlink path loss, that is, the terminal uses the downlink path loss as the uplink path loss. This is because the PSS/SSS is sent to the terminal by using the LTE air interface resource, and a frequency band to which a carrier used for uplink transmission belongs is the same as a frequency band to which a carrier corresponding to the LTE air interface resource belongs. Therefore, the downlink path loss is directly used as the uplink path loss, and an error is relatively small. In this case, the terminal may obtain the uplink transmit power of the terminal based on the downlink path loss, the uplink transmit power of the terminal expected by the base station, and the maximum transmit power of the terminal. Specifically, a process of obtaining the uplink transmit power of the terminal is described by still using the transmit power of the random access preamble as an example.

In this case, the base station further sends, to the terminal, a power offset of a preamble currently configured in a preamble format <NUM>. Specifically, the transmit power P<NUM> of the random access preamble, that is, an initial transmit power of the random access preamble, may be obtained by using a formula <NUM>: <MAT> where
PCMAX is the maximum transmit power of the terminal, P<NUM>-pre is the uplink transmit power of the terminal expected by the base station, PL is the downlink path loss, and Δpreamble is the power offset.

For an actual scenario of the NR standalone networking, refer to <FIG>.

In this embodiment, the base station sends the reference signal by using the LTE air interface resource, the frequency band of the carrier used by the terminal to perform uplink transmission is the same as the frequency band of the carrier corresponding to the LTE air interface resource, and the downlink path loss may be directly used as the uplink path loss, so that the uplink transmit power of the terminal may be obtained based on the downlink path loss.

Referring to <FIG>, a third possible implementation of obtaining the uplink transmit power of the terminal is as follows:.

Specifically, the method for obtaining the uplink transmit power of the terminal in this embodiment may be applicable to an application scenario shown in <FIG>, and is also applicable to the application scenario in which the first network and the second network adopt non-standalone networking. The first network may be an NR network, and the second network may be an LTE network. In this case, the method for obtaining the uplink transmit power of the terminal in this embodiment is applicable to an application scenario of NR and LTE non-standalone networking, and the base station in this embodiment is an LTE base station. When the terminal in this embodiment is a terminal in an idle state, the third reference signal may be a cell-specific reference signal C-RS. When the terminal in this embodiment is a terminal in a connected state, the third reference signal may be a demodulation reference signal (Demodulation Reference Signal, DMRS for short).

A meaning of the uplink transmit power of the terminal in this embodiment is the same as that in the foregoing embodiment. Details are not described in this embodiment again. The method in this embodiment is described below by using an example in which the first network is an NR network, the second network is an LTE network, and the third reference signal is a DMRS.

For step S301, the base station sends the DMRS to the terminal. The base station is an LTE base station, that is, the DMRS is an LTE signal. In this case, a frequency band to which a carrier used by the terminal for uplink transmission in the first network belongs is the same as a frequency band to which an LTE air interface resource belongs, for example, a <NUM> frequency band or a <NUM> frequency band.

For step S302, the LTE base station sends a DMRS transmit power and the uplink transmit power of the terminal that is expected by the NR base station to the terminal. In this case, the DMRS transmit power may be carried in a system message sent by the LTE base station, and the uplink transmit power of the terminal that is expected by the NR base station may be carried in an RRC reconfiguration message. The uplink transmit power of the terminal that is expected by the NR base station is sent by the NR base station to the LTE base station by using an LTE core network device, and then is sent by the LTE base station to the terminal.

For step S303, after receiving the DMRS, the terminal obtains a DMRS receive power of the serving cell through measurement, and obtains the downlink path loss based on the DMRS receive power and the DMRS transmit power, where downlink path loss = DMRS transmit power - DMRS receive power.

A person skilled in the art may understand that the serving cell is a cell in LTE.

For step S304, the terminal may obtain an uplink path loss based on the downlink path loss, that is, the terminal uses the downlink path loss as the uplink path loss. This is because the DMRS is an LTE signal, and a frequency band to which a carrier used for uplink transmission belongs is the same as a frequency band to which a carrier corresponding to an air interface resource of the DMRS belongs. Therefore, the downlink path loss is directly used as the uplink path loss, and an error is relatively small. In this case, the terminal may obtain the uplink transmit power of the terminal based on the downlink path loss, the uplink transmit power of the terminal expected by the base station, and the maximum transmit power of the terminal.

Specifically, a process of obtaining the uplink transmit power of the terminal is described by still using the transmit power of the random access preamble as an example.

In this case, the base station further sends, to the terminal, a power offset of a preamble currently configured in a preamble format <NUM>. Specifically, the transmit power P<NUM> of the random access preamble, that is, an initial transmit power of the random access preamble, may be obtained by using a formula <NUM>: <MAT> where
PCMAX is the maximum transmit power of the terminal, P<NUM>-pre is the uplink transmit power of the terminal expected by the NR base station, PL is the downlink path loss, and Δpreamble is the power offset.

When the third reference signal is a C-RS, for a specific implementation method, refer to the method in which the third reference signal is the DMRS. Details are not described in this embodiment again.

In this embodiment, when the frequency band to which the carrier used by the terminal for uplink transmission belongs is the same as the frequency band to which the carrier corresponding to the air interface resource of the second network belongs, the downlink path loss of the signal of the second network is directly measured, so that the downlink path loss may be directly used as the uplink path loss, an error is relatively small, and the uplink transmit power of the terminal is obtained.

Referring to <FIG>, a fourth possible implementation of obtaining the uplink transmit power of the terminal is as follows:.

Specifically, the method for obtaining the uplink transmit power of the terminal in this embodiment may be applicable to the application scenario shown in <FIG>, and is also applicable to an application scenario in which the first network adopts standalone networking and an application scenario in which the first network and the second network adopt non-standalone networking. The first network may be an NR network, and the second network may be an LTE network. In this case, the method for obtaining the uplink transmit power of the terminal in this embodiment is applicable to both an application scenario of NR standalone networking and an application scenario of NR and LTE non-standalone networking, and the base station in this embodiment is an NR base station. The fourth reference signal may be a sounding reference signal (Sounding Reference Signal, SRS for short).

In addition, the terminal in this embodiment is a terminal in a connected state, and is not applicable to obtaining the uplink transmit power of the terminal during initial access.

A meaning of the uplink transmit power of the terminal in this embodiment is the same as that in the foregoing embodiment. Details are not described in this embodiment again. The method in this embodiment is described below by using an example in which the first network is an NR network, the second network is an LTE network, and the fourth reference signal is an SRS.

For step S401, when NR adopts standalone networking or non-standalone networking, during the period in which there is no data transmission or the inactive timer, the terminal sends the SRS to the NR base station corresponding to the serving cell in which the terminal is located. Because the terminal is a decoupling terminal, the terminal sends, on a low frequency carrier (for example, a carrier on a <NUM> frequency band, that is, a carrier on which the decoupling terminal performs uplink transmission), the SRS to the NR base station corresponding to the serving cell in which the terminal is located. In non-standalone networking, the serving cell is an LTE cell.

For step S402 and step S403, after receiving the SRS, the base station obtains an SRS receive power through measurement, and obtains the uplink path loss based on the SRS receive power and an SRS transmit power, where uplink path loss = SRS transmit power - SRS receive power. In standalone networking, the base station sends the uplink path loss and the uplink transmit power of the terminal that is expected by the base station to the terminal on a high frequency carrier (for example, a carrier on a <NUM> <NUM> frequency band). The uplink path loss may be carried in a downlink control message, and the uplink transmit power of the terminal expected by the base station is carried in a system message. In non-standalone networking, the base station may send the uplink path loss and the uplink transmit power of the terminal that is expected by the base station to the terminal by using the LTE base station.

For step S404, the terminal obtains the uplink transmit power of the terminal in the first network based on the uplink transmit power of the terminal expected by the base station, the uplink path loss, and the maximum transmit power of the terminal that are sent by the base station.

For a specific implementation process of step S404, refer to the embodiment corresponding to <FIG>. Details are not described in this embodiment again.

In this embodiment, the base station measures an uplink path loss of a decoupling low frequency signal, and then sends the uplink path loss to the terminal, so that the uplink transmit power of the terminal in the first network is obtained.

Second, the method for determining an initial access cell of a terminal is described in detail.

<FIG> is a signaling flowchart <NUM> of a method for determining an initial access cell of a terminal according to an embodiment of this application. <FIG> is a signaling flowchart <NUM> of a method for determining an initial access cell of a terminal according to an embodiment of this application. <FIG> is a signaling flowchart <NUM> of a method for determining an initial access cell of a terminal according to an embodiment of this application.

The method for determining an initial access cell of a terminal may be implemented in the following possible implementations.

Referring to <FIG>, a first possible implementation is as follows:.

Specifically, the method for obtaining the uplink transmit power of the terminal in this embodiment may be applicable to the application scenario shown in <FIG>, and is also applicable to an application scenario in which the first network adopts standalone networking and an application scenario in which the first network and the second network adopt non-standalone networking. The first network may be an NR network, and the second network may be an LTE network. In this case, the method for determining an uplink transmit power of a terminal in this embodiment is applicable to both an application scenario of NR standalone networking and NR and LTE non-standalone networking, and the base station in this embodiment is an NR base station. The method in this embodiment is described below by using an example in which the first network is an NR network and the second network is an LTE network.

For step S501, the base station can establish a user-centric network by using the UCNC technology, so that the terminal is unaware of a cell edge. For example, a plurality of neighboring <NUM> uplink cells that belong to NR form a virtual hyper cell, and the terminal considers that there is only one NR <NUM> uplink cell. The plurality of cells that form the virtual hyper cell are preconfigured by an operator.

For step S502, in an NR standalone networking scenario, the NR base station may send the identifier of the virtual hyper cell to the terminal on a high frequency carrier (for example, a carrier in a <NUM> frequency band). In an NR and LTE non-standalone networking scenario, the NR base station may send the identifier of the virtual hyper cell to the terminal by using the LTE base station. To be specific, the NR base station first sends the identifier of the virtual hyper cell to the LTE base station through an LTE core network device.

In this embodiment, the base station establishes the virtual hyper cell by using the UCNC technology, and the terminal side does not need to select a cell for uplink access. Referring to <FIG>, a second possible implementation is as follows:.

Specifically, the method for determining an initial access cell of a terminal in this embodiment may be applicable to the application scenario shown in <FIG>, and is also applicable to an application scenario in which the first network adopts standalone networking and an application scenario in which the first network and the second network adopt non-standalone networking. The first network and the second network need to coexist in uplink and downlink. The first network may be an NR network, and the second network may be an LTE network. In this case, the method for obtaining the uplink transmit power of the terminal in this embodiment is applicable to both an application scenario of NR standalone networking and an application scenario of NR and LTE non-standalone networking, and NR and LTE need to coexist in uplink and downlink. The base station in this embodiment is an NR base station. The fifth reference signal may be a PSS/SSS.

The method in this embodiment is described below by using an example in which the first network is an NR network, the second network is an LTE network, and the fifth reference signal is a PSS/SSS.

For step S601, when NR adopts standalone networking or non-standalone networking, the base station sends the PSS/SSS to the terminal by using an LTE air interface resource (for example, a carrier in a <NUM> frequency band or a carrier in a <NUM> frequency band). A time domain resource corresponding to the LTE air interface resource used to send the PSS/SSS may be referred to as an MBSFN subframe for short.

In this case, the frequency band to which the carrier used by the terminal for uplink transmission in the NR network belongs is the same as a frequency band to which the LTE air interface resource belongs.

For step S602, after receiving the PSS/SSS, the terminal obtains, through measurement, a PSS/SSS receive power of at least one cell in which the terminal is located.

Specifically, the terminal may be simultaneously located in a plurality of cells corresponding to a plurality of NR base stations. For example, the terminal is located in a cell a corresponding to an NR base station (if in the application scenario in <FIG>, the NR base station herein is the high frequency base station <NUM> in <FIG>) A, and is also located in a cell b corresponding to an NR base station B, so that the terminal needs to measure respective PSS/SSS receive powers of the cell a and the cell b.

A person skilled in the art may understand that a PSS/SSS receive power of the cell a is measured according to a PSS/SSS sent by the NR base station A, and a PSS/SSS receive power of the cell b is measured according to a PSS/SSS sent by the NR base station B.

For step S603, the terminal selects, from the at least one cell, the target cell having the maximum PSS/SSS receive power, where the identifier of the target cell is used by the terminal to initially access the first network.

Specifically, for example, the terminal performs initial access from a cell having a larger PSS/SSS receive power in the cell a and the cell b. For example, if the PSS/SSS receive power of the cell a is greater than the PSS/SSS receive power of the cell b, the cell a is a target cell, and the terminal initially accesses the first network by using the identifier of the target cell.

In this embodiment, when the frequency band to which the carrier corresponding to the air interface resource of the second network belongs is the same as the frequency band to which the carrier used by the terminal to perform the uplink transmission in the first network belongs, the reference signal of the first network is sent to the terminal by using the air interface resource of the second network, the cell in which the first network is initially accessed may be selected by comparing the cell having the maximum reference signal receive power of the at least one cell in which the terminal is located.

Referring to <FIG>, a third possible implementation is as follows:.

Specifically, the method for obtaining the uplink transmit power of the terminal in this embodiment may be applicable to the application scenario shown in <FIG>, and is also applicable to an application scenario in which the first network and the second network adopt non-standalone networking. The first network may be an NR network, and the second network may be an LTE network. In this case, the method for obtaining the uplink transmit power of the terminal in this embodiment is applicable to an application scenario of NR and LTE non-standalone networking, and the base station in this embodiment is an LTE base station. If the terminal in this embodiment is a terminal in a connected state, the sixth reference signal may be a DMRS; or if the terminal in this embodiment is a terminal in an idle state, the sixth reference signal may be a C-RS.

In a non-standalone scenario, the terminal establishes bearers to both the LTE and NR sides (that is, dual connectivity (Dual Connectivity), DC for short).

The method in this embodiment is described below by using an example in which the first network is an NR network, the second network is an LTE network, and the sixth reference signal may be a DMRS.

For step S701, the base station sends the DMRS to the terminal. The base station is an LTE base station, that is, the DMRS is an LTE signal. In this case, the frequency band to which the carrier used by the terminal for uplink transmission in the first network belongs is the same as a frequency band to which an LTE network carrier belongs, for example, a <NUM> frequency band.

For step S702, the terminal obtains, through measurement, a DMRS receive power of the at least one cell in which the terminal is located.

Specifically, the terminal may be simultaneously located in a plurality of cells corresponding to a plurality of LTE base stations. For example, the terminal is located in a cell a corresponding to an LTE base station A, and is also located in a cell b corresponding to an LTE base station B, so that the terminal needs to measure respective DMRS receive powers of the cell a and the cell b.

A person skilled in the art may understand that a DMRS receive power of the cell a is measured according to the DMRS sent by the LTE base station A, and a DMRS receive power of the cell b is measured according to the DMRS sent by the LTE base station B. In non-standalone networking, the cell corresponding to the LTE base station has the same coverage as the cell corresponding to the NR base station. The at least one cell is a cell in LTE.

For step S703, the terminal selects, from the at least one cell, the target cell having the maximum DMRS receive power, where the identifier of the target cell is used by the terminal to initially access the first network.

Specifically, for example, the terminal performs initial access from a cell having a larger DMRS receive power in the cell a and the cell b. For example, if the DMRS receive power of the cell a is greater than the DMRS receive power of the cell b, the cell a is a target cell, and the terminal initially accesses the first network by using the identifier of the target cell.

For a method for determining, when the terminal is a terminal in an idle state and the sixth reference signal is a C-RS, a cell in which the terminal initially accesses the first network, refer to a method in which the terminal is a terminal in a connected state and the sixth reference signal is a DMRS.

In this embodiment, by using the reference signal of the second network, a cell having a maximum reference signal receive power in the at least one cell in which the terminal is located may be selected as a cell in which the first network is initially accessed.

In addition, when a low frequency resource is allocated to the first network corresponding to the uplink and downlink decoupling scenario adopts standalone networking, for example, a low frequency resource is allocated to the NR network adopts standalone networking, a cell of the NR network has a low frequency uplink/downlink resource and a high frequency downlink resource. In this case, a decoupling terminal and a non-decoupling terminal coexist. To be specific, the terminal that performs the uplink transmission by using the low frequency carrier may be a decoupling terminal or a non-decoupling terminal, and the base station needs to identify the decoupling terminal.

The uplink control apparatus provided in this application is described below by using a specific embodiment.

<FIG> is a schematic structural diagram <NUM> of an uplink control apparatus according to an embodiment of this application. Referring to <FIG>, the apparatus in this embodiment may include a determining module <NUM>, a receiving module <NUM>, and a transmit power obtaining module <NUM>.

The determining module <NUM> is configured to: measure, based on a received first reference signal, a first reference signal receive power of a serving cell in which the terminal is located, and determine a downlink path loss based on the first reference signal receive power and a received first reference signal transmit power; and the first reference signal is sent by the first target base station of the first network to the terminal by using an air interface resource of the first network. The receiving module <NUM> is configured to receive a first transmit power and a second transmit power that are sent by a first target base station. The first transmit power includes: an uplink transmit power of the terminal expected by the first target base station and a path loss offset, and the second transmit power includes: the uplink transmit power of the terminal expected by the first target base station, the path loss offset, and a penetration loss offset. The transmit power obtaining module <NUM> is configured to: if the first reference signal receive power is greater than or equal to a preset threshold, obtain, by the terminal, an uplink transmit power of the terminal in the first network based on the downlink path loss, the first transmit power, and a maximum transmit power of the terminal; or if the first reference signal receive power is less than a preset threshold, obtain, by the terminal, an uplink transmit power of the terminal in the first network based on the downlink path loss, the second transmit power, and a maximum transmit power of the terminal.

If the uplink transmit power of the terminal is an initial transmit power of a random access preamble, the receiving module is specifically configured to receive the first transmit power, the second transmit power, and a power offset of a preamble currently configured in a preamble format <NUM> that are sent by the first target base station. The transmit power obtaining module is specifically configured to obtain the initial transmit power of the random access preamble of the terminal based on the downlink path loss, a sum of the first transmit power and the power offset, and the maximum transmit power of the terminal; and the transmit power obtaining module is specifically configured to obtain the initial transmit power of the random access preamble of the terminal based on the downlink path loss, a sum of the second transmit power and the power offset, and the maximum transmit power of the terminal.

The apparatus in this embodiment may be configured to perform the technical solutions of the foregoing method embodiments. Implementation principles and technical effects of the apparatus are similar to those of the foregoing method embodiments.

<FIG> is a schematic structural diagram <NUM> of an uplink control apparatus according to an embodiment of this application. As shown in <FIG>, based on the structure of the apparatus shown in <FIG>, the apparatus in this embodiment may further include a cell selection module <NUM>.

The cell selection module <NUM> is configured to: before obtaining the uplink transmit power of the terminal, measure a second reference signal receive power of at least one cell in which the terminal is located, where the second reference signal is sent by the first base station of the first network to the terminal by using an air interface resource of a second network; and a frequency band to which a carrier corresponding to the air interface resource of the second network belongs is the same as a frequency band to which a carrier used by the terminal to perform uplink transmission in the first network belongs; and select, from the at least one cell, a target cell having a maximum second reference signal receive power, where an identifier of the target cell is used by the terminal to initially access the first network.

Alternatively, the cell selection module <NUM> is configured to: before obtaining the uplink transmit power of the terminal, receive an identifier of a virtual hyper cell sent by a first target base station, where the identifier of the virtual hyper cell is used by the terminal to initially access the first network. The virtual hyper cell is obtained by combining, by the first target base station by using a user centric no cell radio access UCNC technology, a plurality of neighboring cells, and the first target base station is a base station of the first network.

Alternatively, the cell selection module <NUM> is configured to: before obtaining the uplink transit power of the terminal, obtain, through measurement based on a received third reference signal sent by a second base station of a second network, a third reference signal receive power of at least one cell in which the terminal is located, and select, from the at least one cell, a target cell having a maximum third reference signal receive power. An identifier of the target cell is used by the terminal to initially access the first network, the first network and the second network adopt non-standalone networking; and a frequency band to which a carrier used by the terminal to perform uplink transmission in the first network belongs is the same as a frequency band to which a carrier corresponding to an air interface resource of the second network belongs. The terminal in the connected state and the terminal in the idle state receive different third reference signals. The receiving module <NUM> is specifically configured to receive a first transmit power and a second transmit power that are sent by the first target base station corresponding to the serving cell by using the second target base station; and the second target base station is a base station of the second network.

<FIG> is a schematic structural diagram <NUM> of an uplink control apparatus according to an embodiment of this application. Referring to <FIG>, the apparatus in this embodiment may include a receiving module <NUM> and a selection module <NUM>.

The receiving module <NUM> is configured to: when a first network is initially accessed, receive preamble sequences that are in a plurality of formats and that are delivered by a base station. The selection module <NUM> is configured to: when a terminal is a decoupling terminal, select a first target preamble sequence from the preamble sequences in a plurality of formats, and send the first target preamble sequence to the base station. The format of the first target preamble sequence is used to instruct the base station of the first network to send a random access response message by using a first baseband processing unit BBU, and a frequency band corresponding to the first BBU is different from a frequency band to which a carrier used by the terminal for uplink transmission belongs.

The selection module <NUM> is further configured to: when the terminal is a non-decoupling terminal, select a second target preamble sequence from a plurality of preamble sequences in a second format, and send the second target preamble sequence to the base station. The format of the second target preamble sequence is used to instruct the base station of the first network to send a random access response message by using a second BBU, and a frequency band corresponding to the second BBU is the same as the frequency band to which the carrier used by the terminal for uplink transmission belongs.

<FIG> is a schematic structural diagram <NUM> of an uplink control apparatus according to an embodiment of this application. Referring to <FIG>, the apparatus in this embodiment may include a sending module <NUM>.

The sending module <NUM> is configured to send a first reference signal to a terminal by using an air interface resource of a first network. A base station is a base station of the first network. The first reference signal is used by the terminal to measure a first reference signal receive power of a serving cell in which the terminal is located. The sending module <NUM> is further configured to send a first reference signal transmit power, a first transmit power, and a second transmit power to the terminal. The first transmit power includes: an uplink transmit power of the terminal expected by the base station and a path loss offset, and the second transmit power includes: the uplink transmit power of the terminal expected by the base station, the path loss offset, and a penetration loss offset. The first reference signal receive power and the first reference signal transmit power are used by the terminal to determine a downlink path loss. When the first reference signal receive power is greater than or equal to a preset threshold, the first transmit power and the downlink path loss are used by the terminal to obtain an uplink transmit power in the first network; or when the first reference signal receive power is less than a preset threshold, the second transmit power and the downlink path loss are used by the terminal to obtain an uplink transmit power in the first network. The sending module <NUM> is further configured to send a second reference signal to the terminal by using an air interface resource of a second network. A frequency band to which a carrier used by the terminal to perform uplink transmission in the first network belongs is the same as a frequency band to which a carrier corresponding to the air interface resource of the second network belongs. The second reference signal is used by the terminal to measure a second reference signal receive power of a serving cell in which the terminal is located, and the first reference signal receive power is used by the terminal to determine an initial access cell.

If the uplink transmit power of the terminal is an initial transmit power of a random access preamble, the sending module <NUM> is specifically configured to send the first reference signal transmit power, the first transmit power, and the second transmit power to the terminal, and send a power offset of a preamble currently configured in a preamble format <NUM> to the terminal. When the first reference signal receive power is greater than or equal to the preset threshold, the first transmit power, the downlink path loss, and the power offset are used by the terminal to obtain the initial transmit power of the random access preamble in the first network; or when the first reference signal receive power is less than the preset threshold, the second transmit power, the downlink path loss, and the power offset are used by the terminal to obtain the initial transmit power of the random access preamble in the first network.

<FIG> is a schematic structural diagram <NUM> of an uplink control apparatus according to an embodiment of this application. As shown in <FIG>, based on the structure of the apparatus shown in <FIG>, the apparatus in this embodiment may further include a cell combination module <NUM>.

The cell combination module <NUM> is configured to combine, by using a user centric no cell radio access UCNC technology, a plurality of neighboring cells to obtain a virtual hyper cell.

The sending module is further configured to send, by the base station, an identifier of the virtual hyper cell to the terminal, where the identifier of the virtual hyper cell is used by the terminal to access the first network.

<FIG> is a schematic structural diagram <NUM> of an uplink control apparatus according to an embodiment of this application. As shown in <FIG>, the apparatus in this embodiment includes a sending module <NUM> and a receiving module <NUM>.

The sending module <NUM> is configured to send preamble sequences in a plurality of formats to a terminal. The receiving module <NUM> is configured to: when the terminal is a decoupling terminal, receive a first target preamble sequence sent by the terminal, and obtain a format of the first target preamble sequence, where the format of the first target preamble sequence is used to indicate that the terminal is a decoupling terminal, and the first target preamble sequence is selected by the terminal from preamble sequences in a plurality of formats.

The sending module <NUM> is further configured to send, by the base station, a random access response message to the terminal by using a first baseband processing unit BBU, where a frequency band corresponding to the first BBU is different from a frequency band to which a carrier used by the terminal for uplink transmission belongs.

The receiving module is further configured to: if the terminal is a decoupling terminal, receive a second target preamble sequence sent by the terminal, and obtain a format of the second target preamble sequence, where the format of the second target preamble sequence is used to indicate that the terminal is a non-decoupling terminal, and the second target preamble sequence is selected by the terminal from the preamble sequences in a plurality of formats.

The sending module is further configured to send a random access response message to the terminal by using a second BBU, where a frequency band corresponding to the second BBU is the same as the frequency band to which the carrier used by the terminal for uplink transmission belongs.

An embodiment of this application further provides an uplink control system, including a terminal and a base station. The terminal may use the structure shown in <FIG>, and the base station may use the structure shown in <FIG>.

<FIG> is a schematic structural diagram <NUM> of an uplink control system according to an embodiment of this application. Referring to <FIG>, an embodiment of this application includes a processor <NUM>, a memory <NUM>, and a communications bus <NUM>. The communications bus is configured to implement connection between components, the memory is configured to store a program instruction, and the processor is configured to: read the program instruction in the memory, and perform, based on the program instruction in the memory, the method corresponding to the terminal side in the foregoing method embodiment.

<FIG> is a schematic structural diagram <NUM> of an uplink control system according to an embodiment of this application. Referring to <FIG>, an embodiment of this application includes a processor <NUM>, a memory <NUM>, and a communications bus <NUM>. The communications bus is configured to implement connection between components, the memory is configured to store a program instruction, and the processor is configured to: read the program instruction in the memory, and perform, based on the program instruction in the memory, the method corresponding to the base station side of the first network in the foregoing method embodiment.

An embodiment of this application further provides a computer readable storage medium. The computer readable storage medium includes an instruction, and when the instruction is run on a computer, the computer is enabled to perform the method performed on a terminal side according to the foregoing method embodiment.

An embodiment of this application further provides a computer-readable storage medium. The computer-readable storage medium includes an instruction, and when the instruction is run on a computer, the computer is enabled to perform the method performed on a base station side of the first network according to the foregoing method embodiment.

Method or algorithm steps described in combination with the content disclosed in this application may be implemented by hardware, or may be implemented by a processor by executing a software instruction. The software instruction may include a corresponding software module. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable hard disk, a CD-ROM, or a storage medium of any other form well-known in the art. For example, a storage medium is coupled with the processor, so that the processor can read information from the storage medium or write information into the storage medium. Certainly, the storage medium may alternatively be a component of the processor.

Claim 1:
An uplink control method, comprising:
measuring, by a terminal based on a received first reference signal, a first reference signal receive power of a serving cell in which the terminal is located, and determining a downlink path loss based on the first reference signal receive power and a received first reference signal transmit power, wherein the first reference signal is sent by a first target base station of a first network to the terminal by using an air interface resource of the first network;
receiving, by the terminal, a first transmit power and a second transmit power that are sent by the first target base station, wherein the first transmit power comprises: an uplink transmit power of the terminal expected by the first target base station and a path loss offset, and the second transmit power comprises: the uplink transmit power of the terminal expected by the first target base station, the path loss offset, and a penetration loss offset; and
when the first reference signal receive power is greater than or equal to a preset threshold, obtaining, by the terminal, an uplink transmit power of the terminal in the first network based on the downlink path loss, the first transmit power, and a maximum transmit power of the terminal; or when
the first reference signal receive power is less than a preset threshold, obtaining, by the terminal, an uplink transmit power of the terminal in the first network based on the downlink path loss, the second transmit power, and a maximum transmit power of the terminal.