WO2011026377A1

WO2011026377A1 - Method and user equipment (ue) for obtaining timing advance command (ta)

Info

Publication number: WO2011026377A1
Application number: PCT/CN2010/074807
Authority: WO
Inventors: 朱鹏; 郝鹏; 喻斌; 王瑜新; 张戎
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-09-01
Filing date: 2010-06-30
Publication date: 2011-03-10
Also published as: CN101646234A

Abstract

A method and a User Equipment (UE) for obtaining a Timing Advance Command (TA) are disclosed. The method is applied in the system of Carrier Aggregation and includes: the UE obtains a TA through an initial access and reads the System Information (SI) broadcasted by a cell site; when the UE is scheduled by a Base Station (BS) to transmit an uplink signal on a new Component Carrier, the UE decides whether it is required to obtain a new TA according to the configuration information of the TA of each Component Carrier in the SI and/or the indication information of the TA transmitted by the BS; if required, the UE then initiates a random access on the new Component Carrier to obtain a new TA. Through the method, the flexible configuration which adopts the same or different TAs on different Component Carriers which are based on cells or UEs can be realized, and the cost for establishing and maintaining uplink synchronization such as random access can be reduced as well.

Description

Method for acquiring timing advance amount and user terminal

Technical field

The present invention relates to the field of mobile communications, and in particular, to a method for acquiring timing advance and a user terminal.

Background technique

The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system uses SC-FDMA (Single-Carrier Frequency Division Multiple Access) transmission technology to meet user terminals (User Equipment) For example, the orthogonality between the uplink signals of the UE must ensure that the uplink signals of the UEs arrive at the receiving end of the base station at the same time, that is, uplink synchronization. Uplink synchronization can be implemented by the base station controlling the UE to use different Timing Advance Command (TA), that is, the UE that is far away from the base station and has a large propagation delay is transmitted earlier, and is closer to the base station and has a propagation delay. The smaller UEs are sent later, so that the uplink signals of the respective UEs arrive at the base station receiving end substantially simultaneously. The base station instructs the UE to use the appropriate timing advance TA by Medium Access Control (MAC) layer signaling.

The UE may obtain a timing advance from a random access response of the base station by initiating random access (Random Access), or a MAC layer signaling timing advance amount MAC control unit (Tiing Advance Command) sent by the base station. MAC control element ) Gets an update of the timing advance. The timing advance in the random access response is 1 lbits, indicating a new uplink timing. The timing advance in the Timing Advance Command MAC control element is 6 bits, indicating the adjustment of the current uplink timing.

The following describes the acquisition method of the timing advance amount in the random access response.

First, the user terminal establishes downlink time synchronization and frequency synchronization with the cell base station through cell search, and obtains downlink timing. Then, the system information (System Information) on the Physical Broadcast Channel (PBCH) and the Physical Downlink Shared Channel (PDSCH) is read.

The system information of the LTE system is divided into a Master Information Block (MIB). And a series of System Information Blocks (SIBs). The main information block (MIB) contains some basic system information, including downlink system bandwidth, physical downlink HARQ (Hybrid Automatic Retransmission) indicator channel (PHICH) configuration information, system frame number, and so on. The Master Information Block (MIB) is periodically transmitted on the Physical Broadcast Channel (PBCH). System Information Blocks (SIBs) are classified into 11 categories (System Information Block Types 1-11) according to the content, and are transmitted on the physical downlink shared channel. The SystemInformationBlockType2 (SIB-2) includes radio resource configuration information of the cell, including carrier frequency information of the uplink carrier, uplink system bandwidth, and random access configuration parameters.

After completing downlink synchronization and acquiring system information, the user terminal initiates random access. Through random access, the user terminal establishes uplink time synchronization with the cell base station to obtain a timing advance. According to different ways of occupying resources, the random access process is further divided into contention based random access and non-contention based random access.

As shown in Figure 1, the contention-based random access process is divided into four steps:

(1) The UE selects a physical random access channel (Physical Random Access Channel, PRACH for short) to send a random connection to the base station eNB (evolved Node B, evolved Node B) according to the random access configuration parameter in the system information block SIB-2. The Random Access Preamble (also known as Message 1 , abbreviated as Msg. 1).

The so-called contention-based random access, that is, the random access preamble optional set configured by the base station is shared by multiple user terminals in the cell.

The random access preamble is transmitted based on the subframe synchronization (subframe) position (assuming that the timing advance is 0). Specifically, for the Frequency Division Duplex (FDD) mode, the random access preamble starts to be transmitted at the start position of the downlink synchronization subframe; for the Time Division Duplex (TDD) mode, the random access The preamble format 0~3 (reamble format 0~3) starts to be transmitted at the start position of the downlink synchronization subframe, and the random access preamble format 4 (reamble format 4) is in the downlink synchronization time slot UpPTS (uplink pilot time slot). The end of the 5158 Ts starts to send. Where Ts = l / (15000 x 2048) seconds.

(2) After detecting the random access preamble, the base station calculates the timing advance by using the random access preamble sequence therein. As shown in Figure 2, the timing advance includes the uplink and downlink propagation delays. (ropagation delay) and multipath delay. The timing advance, along with some other signaling information, is sent over the physical downlink shared channel, called the random access response (also known as Message 2, abbreviated as Msg. 2).

(3) after receiving the random access response, the user terminal according to the timing advance amount corresponding to the random access preamble sent by the user in the random access response, on the basis of the start position of the downlink synchronized subframe, correspondingly in advance The first scheduled UL transmission (also called Message 3, abbreviated as Msg. 3) is sent for a period of time. Msg. 3 contains different information depending on the event that triggered the random access procedure.

(4) As described above, for a contention-based random access procedure, multiple user terminals may select the same random access preamble from the shared random access preamble selective set and select the same random access channel. . After receiving the Msg. 3, the base station also feeds the content resolution resolution (Contention Resolution, also known as Message 4, abbreviated as Msg. 4) to the user terminal to solve the possible conflict problem.

The non-contention based random access procedure can be divided into two steps, similar to the first two steps of the contention based random access procedure. However, in the step (1), the user terminal selects the physical random access channel to send the random access preamble according to the random access configuration parameter in the system information block SIB-2 and the configuration of the high layer signaling. Specifically, the high layer signaling explicitly gives a dedicated random access preamble and a physical random access channel mask (PRACH Mask index). The user terminal selects a physical random access channel on a certain physical random access channel or a set of defined physical random access channels according to the mask, and sends a dedicated random access preamble.

The transmission timing of the random access preamble is the same as the contention based random access procedure, which is based on the downlink synchronization start position of the subframe (assuming the timing advance is 0).

After confirming that the random access is successful, the user terminal can determine the uplink timing according to the downlink timing and the timing advance, and further send the uplink signal. In this way, although different user terminals may be located at different locations in the cell, the path propagation delay and the multipath delay are different, and the time when the uplink signal sent by the user terminal arrives at the receiving end of the base station is the same.

As the user terminal moves or the scatterer moves in the propagation environment, the distance between the user terminal and the cell site changes, the propagation environment changes, and the propagation delay and multipath delay also change. The base station passes the MAC layer letter. Update the transmission timing advance amount to the user terminal, for the current uplink Adjust it regularly to keep the uplink synchronized.

The Long Term Evolution-Advanced (LTE-A system) is the next-generation evolution system of the LTE system. As shown in FIG. 3, the LTE-A system uses Carrier Aggregation (Carrier Aggregation) technology to extend the transmission bandwidth to obtain a higher data rate. Each aggregated carrier is called a "Component Carrier". The component carriers may be contiguous or non-contiguous in the spectrum; they may be in the same frequency band or in different frequency bands.

The uplink/downlink propagation delay and multipath delay on different component carriers may be the same or different. The factors affecting include: the frequency spacing between component carriers. If the interval is large, even in different frequency bands, different component carriers. The channel propagation characteristics may be different; and the transceiver position of the component carrier. If different component carriers use different antennas, and the spacing between antennas is large, the propagation delay and multipath delay may also be different.

Therefore, in a carrier aggregation system different from the prior art single carrier system, how does the user terminal acquire the timing advance on different component carriers to maintain uplink synchronization and reduce the overhead of establishing uplink synchronization through random access; , become an urgent problem to be solved.

Summary of the invention

The technical problem to be solved by the present invention is to provide a method for acquiring timing advance and a user terminal, which can be applied to a carrier aggregation system, so that the user terminal can acquire timing advances on different component carriers to maintain uplink synchronization.

In order to solve the above problem, the present invention provides a method for acquiring a timing advance amount, including: a user terminal acquires a timing advance amount through initial access, and reads system information broadcasted by the base station;

When the base station schedules the user terminal to send an uplink signal on a new component carrier, the user terminal sends, according to configuration information of a timing advance amount of each component carrier in the system information, and/or the base station sends The indication of the timing advance amount determines whether a new timing advance amount needs to be acquired; if a new timing advance amount needs to be acquired, random access is initiated on the new component carrier to acquire a new timing advance amount. Preferably, the configuration information of the timing advance of each component carrier includes information about whether the component carriers of the cell use the same timing advance amount;

In the step of determining, by the user terminal, whether it is necessary to acquire a new timing advance according to the configuration information,

If the configuration information indicates that each component carrier of the cell uses the same timing advance, the user terminal determines that it is not necessary to acquire a new timing advance, and if the configuration information indicates that each component carrier of the cell uses a different timing advance, Then the user terminal determines that it is necessary to acquire a new timing advance amount;

In the step of the user terminal transmitting an uplink signal on a new component carrier, determining, on the new component carrier, an uplink timing by using a timing advance on a component carrier that is initially connected to the uplink synchronization, and transmitting the uplink Signaling; or determining, on the new component carrier, the uplink timing using the new timing advance and transmitting an uplink signal.

Preferably, the configuration information of the timing advance of each component carrier includes configuration information of a carrier group of the current cell, and component carriers that use the same timing advance belong to the same component carrier group; according to the configuration of the user terminal The information determines whether a step of acquiring a new timing advance is required,

And the user terminal marks, according to the configuration information, a component carrier group to which the initially accessed component carrier belongs as uplink synchronization, and uses the acquired timing advance amount as a timing advance amount of the component carrier group;

Determining whether the new component carrier belongs to a component carrier group that has been uplink-synchronized, and if the new component carrier belongs to a component carrier group that has been uplink-synchronized, the user terminal determines that it is not necessary to acquire a new timing advance amount, if If the new component carrier does not belong to any one of the component carrier groups that have been uplink synchronized, the user terminal determines that it is necessary to acquire a new timing advance amount;

In the step of the user terminal transmitting an uplink signal on a new component carrier, determining, on the new component carrier, an uplink timing by using a timing advance of the component carrier group to which it belongs, and transmitting an uplink signal; or On the new component carrier, the uplink timing is determined by using the new timing advance, and an uplink signal is sent.

Preferably, the user terminal initiates random access on the new component carrier to acquire new After the step of timing advance, the method further includes:

In the configuration information of the component carrier group, the component carrier group to which the new component carrier belongs is marked as uplink synchronization, and the acquired new timing advance amount is used as the timing advance amount of the component carrier group.

Preferably, the configuration information of the timing advance is included in a system information block including cell radio resource configuration information or cell carrier aggregation configuration information, and the system information block is sent on a physical downlink shared channel.

Preferably, the indication information of the timing advance amount includes information indicating that the user terminal uses the obtained timing advance amount, or cannot use any one of the timing advance amounts that have been obtained;

In the step of determining, by the user terminal, whether it is necessary to acquire a new timing advance according to the indication information,

If the indication information indicates that the user terminal uses the obtained timing advance amount, the user terminal determines that it is not necessary to acquire a new timing advance amount, if the indication information indicates that the user terminal cannot use any one of the obtained timings In advance, the user terminal determines that random access needs to be initiated on the new component carrier to obtain a new timing advance;

In the step of the user terminal transmitting an uplink signal on a new component carrier, determining, on the new component carrier, the uplink timing using the obtained timing advance, and transmitting an uplink signal; or in the new On the component carrier, the new timing advance is used to determine the uplink timing and the uplink signal is transmitted.

Preferably, the indication information of the timing advance amount is included in the radio resource control signaling that the base station schedules a new component carrier for the user terminal.

Preferably, the user terminal determines whether it is necessary to acquire a new timing advance according to configuration information of a timing advance amount of each component carrier in the system information and/or indication information of a timing advance amount sent by the base station. In the step, when the system information includes the configuration information of the timing advance amount, and the base station also sends the indication information of the timing advance amount, the user terminal preferentially according to the indication information of the timing advance amount. Decide if you need to get a new timing advance.

Preferably, in the step that the user terminal determines that it is necessary to acquire a new timing advance, and then initiates random access on the new component carrier to acquire a new timing advance, Initiating random access on the new component carrier using a contention-based or non-contention based random access method;

In the step of the user terminal initiating random access on the new component carrier by using a non-contention based random access method,

The base station indicates a dedicated random access preamble and a physical random access channel mask by scheduling radio resource control signaling of the new component carrier for the user terminal, where the user terminal is based on the random access preamble and physical randomness Accessing the channel mask, and combining the random access configuration parameters on the new component carrier, selecting a physical random access channel to send a dedicated random access preamble.

Preferably, in the step of the user terminal initiating random access on the new component carrier, based on a new component carrier in a time division duplex mode, or based on a new uplink in a frequency division duplex mode Transmitting a random access preamble at a downlink start position of the downlink component of the downlink component carrier corresponding to the component carrier, and assuming that the timing advance is 0;

In the step of the user terminal transmitting an uplink signal on the new component carrier, determining an uplink timing according to a downlink timing of the new component carrier and the new timing advance amount.

Preferably, in the step of the user terminal initiating random access on the new component carrier, the random access preamble is sent based on the start position of the subframe in which the initial access is downlink synchronization, and the timing advance is assumed to be 0. ;

In the step of the user terminal transmitting an uplink signal on the new component carrier, the uplink timing is determined according to the downlink timing of the initial access and the new timing advance.

In order to solve the above technical problem, the present invention also discloses a user terminal, where the user terminal is configured to acquire a timing advance amount through initial access, and read system information broadcasted by the base station; after receiving the scheduling signal of the base station, according to The configuration information of the timing advance amount of each component carrier in the system information and/or the indication information of the timing advance amount sent by the base station determines whether a new timing advance amount needs to be acquired; if a new timing advance amount needs to be acquired, Then, random access is initiated on the new component carrier to acquire a new timing advance; and an uplink signal is sent on a new component carrier.

Preferably, the configuration information of the timing advance of each component carrier includes information on whether the component carriers of the cell use the same timing advance amount;

The user terminal is configured to: if the configuration information indicates use of each component carrier in the local cell If the same timing advance amount is determined, it is determined that it is not necessary to acquire a new timing advance quantity, and on the new component carrier, the uplink timing is determined by using the timing advance on the component carrier of the uplink synchronization that is initially accessed, and the uplink signal is sent; The configuration information indicates that each component carrier of the cell uses a different timing advance quantity, and then determines that a new timing advance quantity needs to be acquired, and on the new component carrier, the new timing advance quantity is used to determine an uplink timing, and the uplink timing is determined. Uplink signal.

Preferably, the configuration information of the timing advance of each component carrier includes configuration information of a component carrier group of the current cell, and component carriers that use the same timing advance amount belong to the same component carrier group; the user terminal is set to, according to The configuration information indicates that the component carrier group to which the initially accessed component carrier belongs is marked as uplink synchronization, and the acquired timing advance amount is used as the timing advance amount of the component carrier group; determining whether the new component carrier belongs to a component carrier group that has been uplink-synchronized, if the new component carrier belongs to a component carrier group that has been uplink-synchronized, the user terminal determines that it is not necessary to acquire a new timing advance amount, and uses the same on the new component carrier. The timing advance of the component carrier group determines the uplink timing, and transmits an uplink signal; if the new component carrier does not belong to any one of the component carriers that have been uplink synchronized, the user terminal determines that it is necessary to acquire a new timing advance amount; Determining using the new timing advance on the new component carrier Horizontal timing, and transmits the uplink signal.

Preferably, the user terminal is configured to preferentially indicate the information according to the timing advance amount when the system information includes the timing advance amount configuration information and the base station also sends the timing advance amount indication information. Decide if you need to get a new timing advance.

The method for acquiring timing advance on different component carriers in the carrier aggregation system provided by the present invention and the user terminal can implement cell-specific or UE-specific different component carriers on the same or Flexible configuration of different timing advances, while reducing the overhead of uplink synchronization establishment and maintenance such as random access. BRIEF abstract

1 is a schematic diagram of a contention-based random access procedure of an LTE system;

Figure 2 is a schematic diagram of timing advance;

FIG. 3 is a schematic diagram of carrier aggregation of an LTE-A system. Preferred embodiment of the invention

The method for obtaining the timing advance on different component carriers in the carrier aggregation system provided by the present invention may be as follows:

(1) The base station carries configuration information of the timing advance amount of each component carrier in the system information, for example, whether the component timing carriers of the same cell use the same timing advance amount information.

The system information for indicating whether each component carrier uses the same timing advance amount is 1 bit, and the bit information is 0 (or 1), indicating that each component carrier uses the same timing advance amount, and 1 (or 0) indicates use. Different timing advances.

The configuration information of the timing advance may be carried in a system information block SIB including cell radio resource configuration information or cell carrier aggregation configuration information, and the SIB is sent on a physical downlink shared channel.

The component carriers refer to component carriers in TDD mode or uplink component carriers in FDD mode.

In the TDD mode, the system information is broadcast on all component carriers or partial component carriers; in the FDD mode, the system information is broadcast on all downlink component carriers or part of downlink component carriers.

The user terminal obtains a timing advance by initial access, and reads system information broadcast by the base station, where the system message includes information on whether the component carriers of the cell use the same timing advance amount.

The user terminal determines the uplink timing according to the timing advance amount on the component carrier that has been uplink synchronized, and transmits an uplink signal.

When the base station schedules the user terminal to send an uplink signal on a new component carrier, the user terminal determines, according to the configuration information of the timing advance amount of each component carrier in the system information, whether to acquire a new timing advance amount, if necessary, Random access is initiated on the new component carrier.

If the configuration information indicates that each component carrier of the cell uses the same timing advance, the user terminal does not need to initiate random access on the new component carrier. On the new component carrier, the user terminal determines the uplink timing by using the timing advance on the component carrier of the uplink synchronization that is initially accessed, and then transmits the uplink signal.

If the configuration information indicates that each component carrier of the cell uses a different timing advance, The subscriber terminal needs to initiate random access on the new component carrier to obtain a new timing advance. The user terminal determines the uplink timing on the new component carrier using a new timing advance, and then transmits the uplink signal.

(2) The base station carries the configuration information of the timing advance of each component carrier in the system information, for example, indicating which component carriers of the local cell use the same timing advance.

The system information for indicating which component carriers use the same timing advance amount is the configuration information of the component carrier group, and the component carriers of the same timing advance amount are used to form one component carrier group, and the component carriers using different timing advance amounts belong to different groups. Component carrier group. Each component carrier group has at least one component carrier.

The configuration of the timing advance may be carried in a system information block SIB including cell radio resource configuration information or cell carrier aggregation configuration information, and the SIB is transmitted on a physical downlink shared channel.

The component carrier refers to a component carrier in TDD mode, or an uplink component carrier in FDD mode.

The user terminal obtains a timing advance amount through initial access, and reads system information broadcasted by the base station, where the system information includes information on which component carriers of the cell use the same timing advance amount.

The user terminal transmits an uplink signal according to the uplink timing determined by the timing advance on the component carrier that has been uplink synchronized.

The user terminal marks the component carrier group to which the uplink-synchronized component carrier belongs as uplink synchronization according to the configuration information of the component carrier group, and uses the obtained timing advance amount as the timing advance amount of the component carrier group.

When the base station schedules the user terminal to send an uplink signal on a new component carrier, the user terminal determines the new component carrier according to the configuration information of the timing advance amount of each component carrier in the system information, that is, the configuration information of the component carrier group. Whether it belongs to a certain component carrier group that has been uplink synchronized, and determines whether random access needs to be initiated on the new component carrier.

If the new component carrier belongs to a certain component carrier group that has been uplink synchronized, the user terminal does not need to initiate random access on the new component carrier. The user terminal uses the new component carrier The timing advance of the component carrier group determines the uplink timing, and further transmits an uplink signal.

If the new component carrier does not belong to any of the component carrier groups that have been uplink synchronized, the user terminal needs to initiate random access on the new component carrier to obtain a new timing advance. After the random access procedure is completed, according to the configuration information of the component carrier group, the component carrier group to which the component carrier belongs is marked as uplink synchronization, and the obtained new timing advance amount is used as the timing advance amount of the component carrier group. The user terminal determines the uplink timing on the new component carrier using a new timing advance, and then transmits the uplink signal.

(3) The base station transmits the timing advance amount indication information to the user terminal, instructing the user terminal to use a certain timing advance amount that the user terminal has obtained, or cannot use any of the timing advance amounts that have been obtained.

The user terminal obtains a timing advance by initial access.

On the component carrier that has been uplinked, the user terminal sends an uplink signal according to the uplink timing determined by the timing advance.

When the base station schedules the user terminal to transmit an uplink signal on a new component carrier, it instructs the user terminal to use a certain timing advance amount that the user terminal has obtained, or cannot use any timing advance amount that has been obtained.

If the base station indicates that the user terminal uses a certain timing advance amount that has been obtained, the user terminal determines, according to the indication information, that no random access needs to be initiated on the new component carrier; and the user terminal uses the indication on the new component carrier. The timing advance amount indicated by the information determines the uplink timing, and further transmits an uplink signal.

If the base station indicates that the user terminal cannot use any of the timing advances that have been obtained, the user terminal needs to initiate random access on the new component carrier according to the indication information to obtain a new timing advance. The user terminal determines the uplink timing on the new component carrier using the new timing advance, and then transmits the uplink signal.

The foregoing indication information may be used by the base station to schedule a new component carrier RRC (Radio)

Resource Control, Radio Resource Control) signaling is sent to the user terminal.

In summary, method (1) and method (2) are cell-specific, and method (3) is based on user-terminal (UE-specific). Wherein, method (a) and method (c), or The method (2) and the method (3) may be used together, and for a certain component carrier, the indication information based on the timing advance amount of the user terminal has a higher priority than the configuration information of the timing advance amount based on the cell. For example, when the base station indicates configuration information of the timing advance amount based on the cell in the system information, such as whether each component carrier uses the same timing advance amount, or which component carriers of the local cell use the same timing advance amount, and in the RRC signaling In the case that a certain user terminal indicates the timing advance on a certain component carrier, the user terminal shall take the indication in the RRC signaling based on the user terminal as the standard.

When the base station schedules the user terminal to transmit an uplink signal on a new component carrier, and the user terminal needs to initiate random access on the new component carrier to obtain a new timing advance, the user terminal may use the contention based or based on Non-competitive random access method. When the user terminal uses the non-contention based random access, the base station indicates the dedicated random access preamble and the physical random access channel mask (PRACH Mask index) by scheduling the RRC signaling of the new component carrier to the user terminal. . The user terminal combines the random access configuration parameters on the new component carrier to select a physical random access channel to transmit a dedicated random access preamble.

On the new component carrier, the user terminal may send a random access preamble based on the subframe start position of the downlink carrier (FDD mode) downlink synchronization corresponding to the component carrier (TDD mode) or the uplink component carrier (assuming timing advance) The amount is 0). The user terminal determines the uplink timing on each component carrier according to the respective downlink timing and timing advance on each new component carrier, and then transmits the uplink signal on each component carrier.

The so-called random access preamble based on the downlink synchronization start position (assuming the timing advance is 0) means that for the FDD mode, the random access preamble starts to be transmitted at the start position of the downlink synchronization subframe; for the TDD mode, The random access preamble format 0~3 starts to be transmitted at the start position of the downlink synchronization subframe, and the random access preamble format 4 starts to transmit at 5158 Ts before the end position of the downlink synchronization time slot UpPTS. Where Ts = l / (15000 x 2048) seconds.

On the new component carrier, the user terminal may also transmit a random access preamble based on the starting position of the subframe in which the initial access is downlinked (assuming that the timing advance is 0). The user terminal determines the uplink timing on each component carrier according to the downlink timing of the initial access and the timing advance on each new component carrier on each new component carrier, and further transmits an uplink signal.

The invention will be described in detail below with reference to the embodiments and the accompanying drawings.

Embodiment 1 Assume that a carrier-aggregated LTE-A system operates in TDD mode with five component carriers CC 1~5.

The base station uses 1 bit (the bit is 1) in the system information of each component carrier to indicate that each component carrier of the cell uses a different timing advance.

When the user terminal initially accesses, it performs downlink synchronization and random access on CC1, obtains downlink (DL) timing (1), and timing advance TA1, and reads system information on CC1, including system information. 1-bit configuration information of the timing advance of each component carrier.

The user terminal transmits an uplink signal on the component carrier CC1 that has been uplinked, according to the uplink timing determined by the downlink timing DL timing1 and the timing advance TA1.

When the base station schedules the user terminal to send an uplink signal on CC3, the user terminal determines that random access needs to be initiated on CC3 according to the configuration information of the timing advance of each component carrier in the system information.

The user terminal first performs downlink synchronization on CC3, obtains downlink timing DL timin _g 3 , and reads system information on CC3. Then, according to the random access configuration parameter in the system information, a contention-based random access procedure is initiated on CC3, and a new timing advance TA3 is obtained.

Alternatively, the base station configures a dedicated random access preamble and a physical random access channel mask (PRACH Mask index) in the RRC signaling when scheduling the CC3 to the user terminal. The user terminal initiates a non-contention based random access procedure on CC3 in conjunction with the random access configuration parameters on CC3, and obtains a new timing advance TA3.

The user terminal determines the uplink timing according to the downlink timing DL timin _g 3 and the new timing advance TA3 on the new component carrier, and then transmits the uplink signal.

Embodiment 2

Assume that a carrier-aggregated LTE-A system operates in FDD mode with two downlink component carriers D1 and D2 and two uplink component carriers U1 and U2.

The base station uses 1 bit (the bit is 0) in the system information of D1, D2 (or only D1) to indicate that each component carrier of the cell uses the same timing advance.

During initial access, the user terminal first performs downlink synchronization and random access on D1 and U1, obtains downlink timing DL timingl, and timing advance TA1, and reads system information on D1, including 1 bit configuration information of timing advance of each component carrier in the system information.

The user terminal transmits an uplink signal according to the uplink timing determined by the downlink timing DL timing1 and the timing advance TA1 on the U1 that has been uplink synchronized.

When the base station schedules the user terminal to send an uplink signal on the U2, the user terminal determines that the random access is not required to be initiated on the U2 according to the configuration information of the timing advance of each component carrier in the system information.

The user terminal first performs downlink synchronization on D2, obtains downlink timing DL timin _g 2, and reads system information on D2.

The user terminal transmits an uplink signal on U2 according to the uplink timing determined by the downlink timing DL timing2 and the timing advance TA1.

Alternatively, Dl, D2 and Ul, U2 are strictly time-frequency synchronized, and the user terminal transmits an uplink signal on U2 according to the uplink timing determined by the downlink timing DL timingl on D1 and the timing advance TA1 on U1.

Embodiment 3

Assume that a carrier-aggregated LTE-A system operates in TDD mode with four component carriers CC 0~3. Among them, CC0 and CC1 have the same timing advance amount, which is component carrier group 0; CC2 and CC3 have the same timing advance amount, which is component carrier group 1.

The base station indicates in the system information of each component carrier which component carriers of the cell use the same timing advance. Specifically, CC0 and CC1 may be indicated as component carrier group 0 in the cell radio resource configuration information or the cell carrier aggregation configuration information; CC2 and CC3 are component carrier group 1.

When the user terminal initially accesses, the downlink synchronization and random access are completed on the CC3, the downlink timing DL timing3 is obtained, and a timing advance amount TA3 is obtained, and the system information on the CC3 is read, including the component carriers in the system information. The configuration information of the timing advance amount, that is, the configuration information of the component carrier group.

The user terminal marks the component carrier group 1 to which the uplink synchronization CC3 belongs as uplink synchronization according to the configuration information of the component carrier group, and uses the obtained timing advance amount TA3 as the timing advance amount of the component carrier group.

The user terminal is on the CC3 that has been uplink synchronized, according to the downlink timing DL timin _g 3 , and timing The uplink timing determined by the preamble TA3 transmits an uplink signal.

When the base station schedules the user terminal to send an uplink signal on the CC2, the user terminal determines, according to the configuration information of the component carrier group, that the CC2 belongs to the component carrier group 1 that has been uplinked, and determines that the random access is not required to be initiated on the CC2.

The user terminal first completes downlink synchronization on CC2, obtains downlink timing DL timin _g 2, and reads

System information on CC2.

The user terminal transmits an uplink signal on the CC2 according to the uplink timing determined by the downlink timing DL timin _g 2 and the timing advance TA3.

Alternatively, CC3 and CC2 are strictly time-frequency synchronized, and the user terminal transmits an uplink signal on CC2 according to the uplink timing determined by the downlink timing DL timin _g 3 on CC3 and the timing advance TA3 on CC3.

When the base station schedules the user terminal to send an uplink signal on CC0 (or CC1), the user terminal determines, according to the configuration information of the component carrier group, that CC0 does not belong to the component carrier group 1 that has been uplinked, and determines that a random connection needs to be initiated on CC0. In.

The user terminal first completes downlink synchronization on CC0, obtains downlink timing DL timingO, and reads

System information on CC0. Then, according to the random access configuration parameter in the system information, a contention-based random access procedure is initiated on CC0, and a new timing advance TA0 is obtained.

Alternatively, when the base station schedules CC0 to the user terminal, the base station configures a dedicated random access preamble and a physical random access channel mask (PRACH Mask index) in the RRC signaling. The user terminal initiates a non-contention based random access procedure on CC0 in conjunction with the random access configuration parameters on CC0, and obtains a new timing advance TA0.

The user terminal marks the component carrier group 0 to which the uplink synchronization CC0 belongs as uplink synchronization according to the configuration information of the component carrier group, and uses the obtained timing advance TA0 as the timing advance of the component carrier group.

The user terminal transmits an uplink signal on CC0 according to the uplink timing determined by the downlink timing DL timingO and the timing advance TA0.

Embodiment 4 Assume that a carrier-aggregated LTE-A system operates in FDD mode with three downlink component carriers D0, D1, and D2, and three uplink component carriers U0, U1, and U2.

During initial access, the user terminal first performs downlink synchronization and random access on D1 and U1, obtains downlink timing DL timing1, and timing advance TA1, and reads system information on D1.

The user terminal determines the uplink timing and transmits the uplink signal according to the downlink timing DL timing1 and the timing advance TA1 on the U1 that has been uplink synchronized.

When the base station schedules the user terminal to send an uplink signal on U2, the RRC signaling indicates that the user terminal cannot use any timing advance amount that the user terminal has obtained on U2. The user terminal needs to initiate random access on U2.

The user terminal first performs downlink synchronization on D2, obtains DL timin _g 2, and reads system information on D2. Then, according to the random access configuration parameter in the system information, a contention-based random access procedure is initiated on U2, and a new timing advance amount TA2 is obtained.

Alternatively, when the base station schedules U2 to the user terminal, the base station configures a dedicated random access preamble and a physical random access channel mask (PRACH Mask index) in the RRC signaling. The user terminal initiates a non-contention based random access procedure on U2 in conjunction with the random access configuration parameters on D2, and obtains a new timing advance TA2.

The user terminal determines the uplink timing and transmits the uplink signal according to the downlink timing DL timing2 and the timing advance TA2 on U2.

When the base station schedules the user terminal to send an uplink signal on U0, the RRC signaling indicates that the user terminal uses the timing advance TA1 that the user terminal has obtained on U0. The user terminal does not need to initiate random access on U0.

The user terminal first performs downlink synchronization on the DO, obtains downlink timing DL timingO, and reads system information on the DO.

The user terminal is on U0, according to the downlink timing DL timingO, and the timing advance indicated by the signaling.

TA1 determines the uplink timing and sends an uplink signal.

Alternatively, D1 and DO are strictly time-frequency synchronized, and the user terminal determines the uplink timing according to the downlink timing DL timing1 on D1 and the TA1 indicated by the signaling on U0, and transmits an uplink signal. Embodiment 5

Assume that a carrier-aggregated LTE-A system operates in TDD mode with five component carriers CC 0~4. Among them, CC0 and CC1 have the same timing advance amount, which is component carrier group 0; CC2 is component carrier group 1; CC3 and CC4 have the same timing advance amount, which is component carrier group 2.

The base station indicates in the system information of each component carrier which component carriers of the cell use the same timing advance. Specifically, CC0 and CC1 are indicated as component carrier group 0 in the cell radio resource configuration information or cell carrier aggregation configuration information; CC2 is component carrier group 1; CC3 and CC4 are component carrier group 2.

When the user equipment initially accesses, it performs downlink synchronization and random access on CC0, obtains downlink timing DL timingO, and a timing advance TAO, and reads system information on the CCO, including component carriers in the system information. The configuration information of the timing advance amount, that is, the configuration information of the component carrier group.

The user terminal determines the uplink timing and transmits the uplink signal according to the downlink timing DL timingO and the timing advance amount TA0 on the CC0 that has been uplink synchronized.

When the base station schedules the user terminal to send an uplink signal on CC1, the user terminal determines, according to the configuration information of the component carrier group, that CC1 belongs to the component carrier group 0 that has been uplinked, and determines that random access is not required to be initiated on CC1.

The user terminal first performs downlink synchronization on CC1, obtains downlink timing DL timingl, and reads system information on CC1.

The user terminal determines the uplink timing and transmits the uplink signal according to the downlink timing DL timing1 and the timing advance TA0 on CC1.

Alternatively, if the CCO and CC1 are strictly time-frequency synchronized, the user terminal determines the uplink timing and sends the uplink signal according to the downlink timing DL timingO on CC0 and the timing advance TA0 on CC0 on CC1.

When the base station schedules the user terminal to send an uplink signal on the CC2, the user terminal determines, according to the configuration information of the component carrier group, that the CC2 does not belong to the component carrier group 0 that has been uplinked, and determines that it is required. Random access is initiated on CC3.

The user terminal first performs downlink synchronization on CC2, obtains downlink timing DL timin _g 2, and reads system information on CC2. Then, according to the random access configuration parameter in the system information, a contention-based random access procedure is initiated on CC2, and a new timing advance TA2 is obtained.

Alternatively, the base station configures a dedicated random access preamble and a physical random access channel mask (PRACH Mask index) in the RRC signaling when scheduling the CC2 to the user terminal. The user terminal initiates a non-contention based random access procedure on CC2 in conjunction with the random access configuration parameters on CC2, and obtains a new timing advance TA2.

The user terminal marks the component carrier group 1 to which the uplink synchronization CC2 belongs as uplink synchronization according to the configuration information of the component carrier group, and uses the obtained timing advance amount TA2 as the timing advance amount of the component carrier group.

The user terminal determines the uplink timing according to the downlink timing DL timin _g 2 and the timing advance amount TA2 on the CC2, and transmits an uplink signal.

When the base station schedules the user terminal to send an uplink signal on the CC3, the user terminal determines, according to the configuration information of the component carrier group, that the CC3 does not belong to the uplink-synchronized component carrier group 0 or the component carrier group 1, and determines that a randomization needs to be initiated on the CC3. Access.

The user terminal marks the component carrier group 2 to which the uplink synchronization CC3 belongs as uplink synchronization according to the configuration information of the component carrier group, and uses the obtained timing advance amount TA3 as the timing advance amount of the component carrier group.

The user terminal determines the uplink timing according to the downlink timing DL timin _g 3 and the timing advance amount TA3 on the CC3, and transmits an uplink signal.

When the base station schedules the user terminal to send an uplink signal on the CC4, it uses the RRC signaling indication. The subscriber terminal cannot use any timing advance (TA0, TA2, or TA3) that the user terminal has obtained on CC4. The user terminal needs to initiate random access on CC4.

The user terminal first performs downlink synchronization on CC4, obtains downlink timing DL timin _g 4, and reads system information on CC4. Then, according to the random access configuration parameter in the system information, a contention-based random access procedure is initiated on CC4, and a new timing advance amount TA4 is obtained.

Alternatively, the base station configures a dedicated random access preamble and a physical random access channel mask (PRACH Mask index) in the RRC signaling when scheduling the CC4 to the user terminal. The user terminal initiates a non-contention based random access procedure on CC4 in conjunction with the random access configuration parameters on CC4, and obtains a new timing advance TA4.

The user terminal determines the uplink timing according to the downlink timing DL timin _g 4 and the timing advance amount TA4 on the CC4, and transmits an uplink signal.

Embodiment 6

Assume that a carrier-aggregated LTE-A system operates in TDD mode with five component carriers CC 1~5.

When the user terminal initially accesses, the downlink synchronization and random access are completed on the CC1, the downlink timing DL timing1, and the timing advance amount TAl are obtained, and the system information on the CCl is read, including the timing advance of each component carrier in the system information. The amount of lbit configuration information.

The user terminal determines the uplink timing and transmits the uplink signal according to the downlink timing DL timing1 and the timing advance amount TA1 on the CC1 that has been uplink synchronized.

When the base station schedules the user terminal to send an uplink signal on the CC3, the user terminal determines that a random access needs to be initiated on the CC3 according to the system information.

The user terminal obtains the random access configuration parameter on the CC3 from the system information on the CC1, sends a random access preamble based on the DL timing1 on the CC3, initiates a random access procedure based on the competition, and obtains a new timing advance TA3. .

Alternatively, when scheduling the CC3 to the user terminal, the base station configures a random access configuration parameter, a dedicated random access preamble, and a physical random access channel mask (PRACH Mask index) on the CC3 in the RRC signaling. The user terminal sends a random access preamble based on DL timing1 on CC3, and initiates Based on the non-contention random access procedure, a new timing advance TA3 is obtained.

The user terminal determines the uplink timing and transmits the uplink signal according to the downlink timing DL timing1 at the initial access and the timing advance amount TA3 on the CC3.

The present invention also discloses a user terminal, the user terminal is configured to acquire a timing advance by initial access, and read system information broadcast by the base station; after receiving the scheduling signal of the base station, according to the system information The configuration information of the timing advance amount of each component carrier and/or the indication information of the timing advance amount transmitted by the base station determines whether it is necessary to acquire a new timing advance amount; if it is necessary to acquire a new timing advance amount, the new A random access is initiated on the component carrier to acquire a new timing advance; and an uplink signal is transmitted on a new component carrier.

The configuration information of the timing advance amount of each component carrier includes information about whether the same timing advance amount is used by each component carrier of the local cell;

The user terminal is configured to: if the configuration information indicates that each component carrier of the cell uses the same timing advance amount, determine that it is not necessary to acquire a new timing advance, and use the initial access station on the new component carrier. The timing advance on the component carrier of the uplink synchronization determines the uplink timing, and sends an uplink signal; if the configuration information indicates that each component carrier of the local cell uses a different timing advance amount, it is determined that a new timing advance amount needs to be acquired, where On the new component carrier, the new timing advance is used to determine the uplink timing and the uplink signal is transmitted.

The configuration information of the timing advance of each component carrier includes configuration information of a component carrier group of the current cell, and the component carriers that use the same timing advance amount belong to the same component carrier group; the user terminal is set to, according to the The configuration information indicates that the component carrier group to which the initially accessed component carrier belongs is marked as uplink synchronization, and the acquired timing advance amount is used as the timing advance amount of the component carrier group; determining whether the new component carrier belongs to An uplink-synchronized component carrier group, if the new component carrier belongs to an uplink-synchronized component carrier group, the user terminal determines that it is not necessary to acquire a new timing advance amount, and uses the associated component on the new component carrier The timing advance of the component carrier group determines an uplink timing, and transmits an uplink signal; if the new component carrier does not belong to any one of the component carriers that have been uplink synchronized, the user terminal determines that a new timing advance is required to be acquired; Determining on the new component carrier using the new timing advance Line timing and send an upstream signal.

In addition, the user terminal is configured to include, in the system information, the timing advance amount When the configuration information and the base station also transmit the indication information of the timing advance amount, it is preferred to determine whether it is necessary to acquire a new timing advance amount according to the indication information of the timing advance amount.

The functions of the user terminal are the same as those of the user terminal in the method embodiment, and are not described herein.

One of ordinary skill in the art will appreciate that all or a portion of the steps above may be accomplished by a program to instruct the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

It is a matter of course that the invention may be embodied in various other forms and modifications without departing from the spirit and scope of the invention.

INDUSTRIAL APPLICABILITY A method for acquiring timing advance amount and a user terminal provided by the present invention can be applied to a carrier aggregation system, so that a user terminal can acquire timing advance amounts on different component carriers, thereby maintaining uplink synchronization and reducing The overhead of establishing and maintaining uplink synchronization, such as random access.

Claims

Claim

1. A method for obtaining a timing advance amount, comprising:

The user terminal acquires a timing advance amount through initial access, and reads system information broadcast by the base station;

When the base station schedules the user terminal to send an uplink signal on a new component carrier, the user terminal is configured according to configuration information of a timing advance amount of each component carrier in the system information, and/or sent by the base station. The indication information of the timing advance amount determines whether a new timing advance amount needs to be acquired; if a new timing advance amount needs to be acquired, random access is initiated on the new component carrier to acquire a new timing advance amount.

2. The method of claim 1 wherein

The configuration information of the timing advance of each component carrier includes information about whether the same timing advance amount is used by each component carrier of the current cell;

3. The method of claim 1, wherein

The configuration information of the timing advance of each component carrier includes configuration information of a component carrier group of the current cell, and component carriers that use the same timing advance amount belong to the same component carrier group;

In the step of determining, by the user terminal, whether it is necessary to acquire a new timing advance according to the configuration information, The user terminal marks, according to the configuration information, a component carrier group to which the initially accessed component carrier belongs as uplink synchronization, and uses the acquired timing advance amount as a timing advance amount of the component carrier group;

4. The method of claim 3, wherein

After the step of the user terminal initiating a random access on the new component carrier to obtain a new timing advance amount, the method further includes:

5. The method of claim 2, 3 or 4, wherein

The configuration information of the timing advance is included in a system information block including cell radio resource configuration information or cell carrier aggregation configuration information, and the system information block is transmitted on a physical downlink shared channel.

6. The method of claim 1, wherein

The indication information of the timing advance amount includes information indicating that the user terminal uses the obtained timing advance amount, or cannot use any one of the timing advance amounts that have been obtained;

If the indication information indicates that the user terminal uses the obtained timing advance amount, the user terminal determines that it is not necessary to acquire a new timing advance amount, if the indication information indicates the user end The terminal cannot use any one of the timing advances that have been obtained, and the user terminal determines that random access needs to be initiated on the new component carrier to obtain a new timing advance amount;

7. The method of claim 6, wherein

The indication information of the timing advance amount is included in radio resource control signaling of a new component carrier scheduled by the base station for the user equipment.

8. The method according to claim 1, 2, 3, 4, 6 or 7, wherein: at the user terminal, according to configuration information of a timing advance amount of each component carrier in the system information, and/or the In the step of determining whether to acquire a new timing advance amount, the system information includes the timing advance amount configuration information, and the base station also sends the timing advance When the amount of indication information is obtained, the user terminal preferentially determines whether it is necessary to acquire a new timing advance amount according to the indication information of the timing advance amount.

9. The method of claim 8 wherein

In the step of the user terminal determining that a new timing advance is required to be acquired, and then performing random access on the new component carrier to acquire a new timing advance,

Generating random access on the new component carrier using a contention-based or non-contention based random access method;

10. The method of claim 8 wherein

In the step of the user terminal initiating random access on the new component carrier, based on The new component carrier in the time division duplex mode, or the random access preamble based on the downlink start position of the downlink component of the downlink component carrier corresponding to the new uplink component carrier in the frequency division duplex mode, and assumes timing advance The amount is 0;

11. The method of claim 8, wherein

In the step of the user terminal initiating random access on the new component carrier, the random access preamble is sent based on the start position of the subframe in which the downlink synchronization is initially accessed, and the timing advance is assumed to be 0;

12. A user terminal, the user terminal is configured to acquire a timing advance by initial access, and read system information broadcast by the base station; after receiving the scheduling signal of the base station, according to each component carrier in the system information The configuration information of the timing advance amount and/or the indication information of the timing advance amount sent by the base station determines whether a new timing advance amount needs to be acquired; if a new timing advance amount needs to be acquired, on the new component carrier Initiating random access to acquire a new timing advance; and transmitting an uplink signal on a new component carrier.

13. The user terminal according to claim 12, wherein

14. The user terminal according to claim 12, wherein

The configuration information of the timing advance of each component carrier includes the configuration of the component carrier group of the local cell. Information, component carriers using the same timing advance amount belong to the same component carrier group;

The user terminal is configured to mark, according to the configuration information, a component carrier group to which the initially accessed component carrier belongs as uplink synchronization, and use the acquired timing advance amount as a timing advance amount of the component carrier group; Determining whether the new component carrier belongs to a component carrier group that has been uplink-synchronized, and if the new component carrier belongs to a component carrier group that has been uplink-synchronized, the user terminal determines that it is not necessary to acquire a new timing advance amount, On the new component carrier, the uplink timing is determined by using the timing advance of the component carrier group to which it belongs, and the uplink signal is sent; if the new component carrier does not belong to any component carrier group that has been uplink synchronized, the user terminal Determining that a new timing advance is required; on the new component carrier, determining the uplink timing using the new timing advance and transmitting an uplink signal.

The user terminal according to claim 12, wherein the user terminal is configured to: when the system information includes configuration information of the timing advance amount and indication information that the base station also transmits a timing advance amount, Determining whether it is necessary to acquire a new timing advance amount according to the indication information of the timing advance amount.