WO2011020426A1

WO2011020426A1 - Method and system for uplink signal synchronization

Info

Publication number: WO2011020426A1
Application number: PCT/CN2010/076065
Authority: WO
Inventors: 戴谦; 喻斌; 张银成; 张健
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-08-17
Filing date: 2010-08-17
Publication date: 2011-02-24
Also published as: CN101998614B; CN101998614A

Abstract

A method for uplink signal synchronization is disclosed in the present invention. The method includes the following steps: adopting the synchronization information of the uplink carriers for which uplink synchronization has already been achieved by the user terminal to assist the target uplink carriers to implement uplink synchronization. A system for uplink signal synchronization is also disclosed in the present invention. The system includes an uplink synchronization implementation unit, which is used for adopting the synchronization information of the uplink carriers for which uplink synchronization has already been achieved by the user terminal to assist the target uplink carriers to realize uplink synchronization. Applying the method and system of the present invention can implement uplink signal synchronization of multiple carrier systems, and improve the system performance.

Description

Method and system for uplink signal synchronization

The present invention relates to the field of wireless communication technologies, and in particular, to a method and system for uplink signal synchronization in a wireless network. Background technique

In the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) of the third generation mobile communication Long Term Evolution (LTE) system, the uplink data passes through the physical uplink shared channel. (PUSCH, Physical Uplink Shared Channel) transmission. An uplink radio resource is allocated to each user terminal by an evolved base station (eNB, Evolved NodeB). Here, the user terminal in the LTE system is represented by User Equipment, abbreviated as UE. The access technology used by E-UTRAN is Orthogonal Frequency Division Multiplexing (OFDM) technology. The radio resource management of E-UTRAN system has large bandwidth and multiple time compared with the second generation mobile communication system. The characteristics of the process, its wireless resources appear in two dimensions of time and frequency, and the number of users that can be carried is greatly enhanced.

In the LTE system, the frame boundaries of the uplink signals of all users are required to be aligned when they reach the receiving end of the base station, so as to avoid mutual interference between the received signals. However, since the distances of the UEs from the base station are different, that is, the airborne propagation distances of the uplink signals of the UEs are different, which may result in the frame boundary of the uplink signal of each UE not reaching the receiving end of the base station. Align. In the LTE system, in order to solve this technical problem, the uplink synchronization technology is used.

The method for obtaining the synchronization of the uplink signal of the LTE system belongs to the uplink synchronization method controlled by the base station, that is, the dynamic timing advance amount of the base station is given to the UE, where the timing advance amount in the LTE system is According to Timing Advance, the abbreviation is TA, and the UE adjusts the timing of the uplink signal transmission timing according to the TA. The signal will generate a propagation delay from the transmitting end to the receiving end, and the TA just cancels the propagation delay, so that the UE After the sent uplink signal arrives at the receiving end of the base station side, it can be aligned with the frame boundary of the downlink transmitting signal of the base station, thereby achieving synchronization, as shown in FIG. With this technique, the frame boundaries of all the UEs connected to the base station and the base station side are aligned by the control of the base station.

The method of uplink signal synchronization of the LTE system is roughly divided into an initial synchronization phase and a synchronization maintenance phase. The initial synchronization phase is completed by a random access process, and the function is to implement large-scale synchronization of the uplink signal; the synchronization and hold phase is completed by the base station by measuring the reference signal in the uplink signal after completing the random access procedure, It is a small-scale synchronization that implements uplink signals. The uplink reference signal includes a pilot reference signal and a demodulation reference signal.

For the initial synchronization phase, as shown in FIG. 2, the process of completing the initial synchronization phase by the UE through the random access procedure includes the following contents:

First, the UE measures the downlink synchronization signal sent by the base station, and measures the time position of the downlink synchronization signal, so that the frame boundary of the received downlink signal can be derived, and the frame boundary is used as the downlink synchronization timing.

The UE downlink synchronization timing is used as the uplink signal transmission frame boundary, that is, the boundary A shown in Fig. 2; the random access prefix is transmitted.

After receiving the random access prefix, the base station measures the difference between the timing of the random access prefix and the boundary of the downlink signal frame to obtain the initial synchronization TA. The base station sends the TA to the UE through the random access response message. Here, for the difference, it is apparent from Fig. 2 that the difference includes the sum of the uplink propagation delay and the downlink propagation delay.

The UE performs timing advance adjustment according to the TA on the uplink signal transmission time boundary, that is, performs advance adjustment according to the TA on the basis of the original transmission boundary A, thereby canceling the uplink propagation delay, so that the uplink signal arrives at the base station side and the base station downlink. The signal frame boundaries are aligned. That is, uplink synchronization is achieved.

This TA is used as the initial TA of the uplink synchronization of the UE. When a small-scale TA is subsequently received, it is accumulated on the initial TA, and so on. It should be noted here that when the UE performs uplink signal transmission, the TA used is the accumulated TA.

After the UE successfully completes the random access, the UE and the base station establish an RRC link through a RRC (Radio Resource Control) layer link establishment process. During the establishment of the RRC link, the base station sends configuration information related to the physical channel resource to the UE through the RRC signaling, and the UE configures the corresponding physical channel resource according to the configuration information. The configuration information includes configuration information of the pilot reference signal, and the UE transmits the uplink pilot reference signal according to the configuration information.

For the synchronization hold phase, the process of the synchronization hold phase of the uplink carrier includes the following:

The base station obtains a small-scale TA measurement result according to the measurement of the reference signal in the uplink signal, and sends the TA value to the UE through a MAC Control Element (MAC CE, Media Access Control Control Element). The reference signal in the uplink signal includes a pilot reference signal and a demodulation reference signal.

The UE accumulates the TA value on the previously adjusted TA value, that is, TA ( n+1 ) = TA ( n ) + the measured TA at the current time, and the UE performs the uplink signal transmission frame boundary according to the accumulated TA. Timing adjustment in advance.

The UE needs to know system information such as frequency point information, bandwidth information, and random access channel resource configuration information of the target uplink carrier during the completion of the uplink synchronization process, and the system information is sent by the base station through the broadcast channel broadcast or through the radio resource control signaling. UE.

The above-mentioned uplink signal synchronization process is only applicable to a single-carrier system. In order to meet the needs of various wireless services that are currently growing rapidly in the future, the next-generation wireless communication evolution standard has also begun to enter the formulation process, taking the next generation evolution of LTE as an example. Is advanced LTE (LTE-Advanced) standard.

LTE-Advanced is the 3GPP (the 3rd Generation Partner Project) organization to meet the requirements of the International Telecommunication Union (ITU, International Telecommunication Union). The standard LTE-Advanced system introduced is an evolved version based on the LTE release 8 system. It introduces many new technologies to meet the basic needs of IMT-Advanced. One of the most important technologies is carrier aggregation.

Due to the current shortage of wireless spectrum resources, the spectrum resources owned by mobile operators in the world tend to be scattered, and IMT-Advanced requires higher peak rate indicators, namely: 100Mbps for high mobility and 1Gbps for low mobility. The maximum 20MHz bandwidth of the current LTE standard cannot meet the requirements of IMT-Advanced, so it needs to be expanded to higher bandwidth, such as 40MHz, 60MHz, or even higher. One way to increase the bandwidth and peak rate is to expand the frequency domain by bundling several 20MHz-based LTE bands and performing bandwidth expansion by carrier aggregation. This is the essence of carrier aggregation technology.

In the LTE-Advanced system to which the carrier aggregation technology is applied, the carrier participating in the aggregation is called a component carrier (CC). The UE can transmit and receive in multiple frequency bands and eNBs at the same time. In a single frequency band, LTE is still maintained. The feature of release8 means that the LTE-Advanced system can be seen as a bundle of multiple LTE systems.

Similar to LTE-Advanced, the current evolution standards of various future communication systems use similar multi-carrier technology.

Taking the LTE-Advanced system as an example, when a UE of an LTE-Advanced system establishes a link with an LTE-Advanced base station, instead of establishing a link together on multiple uplink carriers, the UE first establishes a link on the uplink carrier. The base station establishes a link, and then the base station decides whether to allow the UE to establish a service link on more uplink carriers according to factors such as service conditions and radio resource conditions. In order for a UE to establish a service link between an uplink carrier and a base station, uplink synchronization must be obtained. However, there are still technical problems in how the LTE-Advanced system completes uplink synchronization on multiple uplink carriers, due to different uplink carriers. The frequency of the radio transmission is different. When the frequency interval of different uplink carriers is large, the radio propagation path may be different. In addition, different uplink carriers may correspond to different base stations or different radio remote units. RRU, Radio Remote United), for the same UE, these factors will cause it to maintain different uplink synchronization TAs for different uplink carriers.

If the original single carrier system is used, that is, the UE uses the random access method on the target uplink carrier, that is, the uplink carrier that wants to establish a service link, the uplink synchronization can be completed, but the method brings Delay, signaling overhead, and UE power consumption are large. If the UE wants to implement uplink synchronization on N uplink carriers, it needs to initiate N random access procedures, which is a big burden for the system.

In addition, since the UE maintains service links of multiple uplink carriers, the power consumption and signaling overhead are large. When the uplink service demand is small, the base station usually reduces the number of uplink carriers linked by the UE, and when the uplink service demand increases. The base station will increase the number of uplink carriers of the UE link again. Due to the diversity and complexity of the current communication service, this behavior will be more frequent, which leads to frequent initiation of random access if the uplink synchronization method is used. The process of entering further increases the burden on the UE and the system.

Moreover, when the UE loses uplink synchronization on a certain uplink carrier, or the UE needs to perform handover, it needs to perform uplink synchronization on the original uplink carrier or the new target uplink carrier, so the problem of solving the uplink synchronization process is improved. The meaning of system performance is quite large. The uplink carrier loses the uplink synchronization index. In the LTE system, the UE maintains a TA timer for the uplink carrier. When the UE receives the TA command sent by the base station, the timer is re-counted; When the timer expires after the TA command, the UE considers that the uplink carrier loses uplink synchronization. In summary, the above technical problems exist not only in the LTE-Advanced system, but also in other multi-carrier systems that use similar carrier management methods in the LTE-Advanced system. That is to say, in view of the above technical problems, a solution under the multi-carrier system has not been proposed yet, and if the current single-carrier uplink synchronization technology is still used, the system performance is greatly reduced. Summary of the invention

In view of this, the main purpose of the present invention is to provide a method and system for uplink signal synchronization, which can implement uplink signal synchronization in a multi-carrier system, so as to reduce the complexity, power consumption, and signaling overhead of the UE acquiring synchronization on the uplink carrier. And the above technical problems, thereby improving system performance.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

A method for synchronizing uplink signals, the method comprising: using the synchronization information of the uplink carrier that the user terminal has obtained the uplink synchronization, to assist the target uplink carrier to implement uplink synchronization.

The scenario of implementing uplink synchronization includes: performing, by the user terminal, uplink synchronization on a new uplink carrier, recovering uplink synchronization on an uplink carrier that loses uplink synchronization, or re-implementing uplink synchronization on an uplink carrier.

Wherein, the uplink synchronization is implemented by using any one or at least one combination of the following manners; mode 1: the user terminal uses the value of the timing advance of the specified uplink carrier as the initial synchronization timing advance of the target uplink carrier. The user terminal receives the timing advance command sent by the base station to complete the synchronization hold;

Method 2: The user terminal measures downlink synchronization timing of the downlink carrier corresponding to the target uplink carrier, and calculates a difference between the downlink synchronization timing and the downlink synchronization timing of the downlink carrier corresponding to the designated uplink carrier; The accumulated value obtained by adding twice the difference value to the timing advance amount of the specified uplink carrier is used as the value of the initial synchronization timing advance amount of the target uplink carrier; the user terminal receives the timing advance amount command sent by the base station to complete Keep it in sync.

Wherein, when the method 1 is used, the user terminal uses the value of the specified timing advance amount as the value of the initial synchronization timing advance amount, and further includes: the base station is configured for the user terminal to be implemented. a physical parameter of the pilot reference signal of the target uplink carrier of the uplink synchronization, and transmitting the physical parameter of the pilot reference signal to the user terminal;

The value of the timing advance amount specified by the user terminal as the value of the initial synchronization timing advance includes: the user terminal selects one uplink carrier in the uplink carrier that has obtained the uplink synchronization, and takes the timing of the selected uplink carrier. The value of the advance amount is used as the value of the timing advance amount of the initial uplink phase of the target uplink carrier;

Before the user terminal receives the timing advance command to complete the synchronization, the method further includes: after the user terminal completes the initial synchronization, transmitting the pilot reference signal on the target uplink carrier according to the physical parameter of the pilot reference signal configured by the base station; Receiving, by the base station, a pilot reference signal or a demodulation reference signal sent by the user terminal on the target uplink carrier, measuring the reference signal, and calculating a value of a timing advance amount in the synchronization holding phase, and advancing the timing of the synchronization holding phase The value of the quantity is sent to the user terminal; the user terminal receives the value of the timing advance amount of the synchronization holding phase transmitted by the base station, and the value of the timing advance amount of the synchronization holding phase and the timing advance amount of the initial synchronization phase The value is accumulated.

Wherein, when the mode 2 is used, the user terminal uses the accumulated value obtained by adding twice the difference value and the timing advance amount of the specified uplink carrier as the value of the initial synchronization timing advance amount. The method further includes: the base station configuring, for the user terminal, a physical parameter of the pilot reference signal of the target uplink carrier to be uplink synchronized, and transmitting the physical parameter of the pilot reference signal to the user terminal;

And the accumulated value obtained by adding, by the user terminal, the value of the timing advance amount of the specified uplink carrier by the user terminal is used as the value of the initial synchronization timing advance amount: the user terminal measures the target uplink carrier a downlink synchronization timing of the corresponding downlink carrier; the user terminal selects an uplink carrier in the uplink carrier that has obtained uplink synchronization, and calculates a selected uplink carrier pair difference; the user terminal selects the selected uplink carrier The value of the timing advance is twice as large Adding the calculated difference values, and adding the accumulated value as the value of the timing advance amount of the initial synchronization phase;

The selecting, by the user terminal, one uplink carrier in the uplink carrier that has obtained the uplink synchronization includes: selecting, by the user terminal, the user terminal, by using the dedicated signaling, the user terminal, to select an uplink carrier that has obtained the uplink synchronization.

The principle of selecting the uplink carrier includes: arbitrarily selecting one of uplink carriers that have obtained uplink synchronization; or selecting an uplink carrier with a minimum frequency domain interval from the target uplink carrier.

The uplink carrier that has obtained the uplink synchronization includes: an uplink carrier that has completed at least the initial synchronization phase.

The dedicated signaling includes: downlink control channel signaling, media access control (MAC) control element, or radio resource control signaling.

In the uplink carrier that has obtained the uplink synchronization, the selected uplink carrier is: multiple different uplink carriers, or the same uplink carrier.

When the uplink synchronization is implemented by using the mode 1 and/or the mode 2, the base station or the user terminal selects the uplink synchronization mode of the mode 1 for the target uplink carrier, The uplink synchronization mode of the mode 2, and/or the other uplink synchronization mode, where the other uplink synchronization mode includes: the user terminal initiates a random access procedure on the target uplink carrier to complete uplink initial synchronization; The timing advance command sent by the base station completes the synchronization hold.

The method further includes: when the base station selects an uplink synchronization mode for the target uplink carrier, the method further includes: after determining, by the base station, the uplink synchronization mode used by the target uplink carrier, the information about the target uplink carrier And the information related to the uplink synchronization mode is sent to the user terminal; the user terminal uses the corresponding uplink synchronization mode according to the information received from the base station, and performs uplink synchronization on the target uplink carrier;

When the user terminal selects the uplink synchronization mode for the target uplink carrier, the method further includes: the base station transmitting, to the user terminal, information about the uplink carrier and the target uplink carrier that the user terminal has obtained the uplink synchronization; The terminal determines the uplink synchronization mode to be used in the target uplink carrier according to the information received from the base station, and performs uplink synchronization.

The information of the target uplink carrier and the information related to the uplink synchronization mode include one or more of the following: when the uplink synchronization mode used by the target uplink carrier is selected by the base station:

Frequency point information or carrier sequence number information of one or more target uplink carriers;

Identification information of the uplink synchronization method;

The frequency point information or carrier sequence number information of the selected uplink carrier among the uplink carriers that have obtained the uplink synchronization corresponding to the target uplink carrier used for uplink synchronization.

When the user terminal selects the uplink synchronization mode for the target uplink carrier, the content of the information that the user terminal has obtained the uplink synchronization uplink carrier and the target uplink carrier includes one or more of the following contents. :

Frequency point information or carrier sequence number information of one or more uplink carriers that have obtained uplink synchronization; frequency point information or carrier sequence number information of one or more target uplink carriers; Whether the target uplink carrier and the uplink carrier that has obtained the uplink synchronization respectively correspond to radio remote units of different geographical locations of different base stations or the same base station.

The principle that the base station or the user terminal determines that the uplink synchronization method used in the target uplink carrier includes one or more of the following contents:

Fixedly using the random access procedure to complete uplink synchronization;

Fixed uplink synchronization using the uplink synchronization mode of the mode 1 to complete uplink synchronization;

Fixed uplink synchronization by using the uplink synchronization mode of the mode 2;

When one of the target uplink carrier and the uplink carrier that has obtained the uplink synchronization belongs to the same frequency band, and the two do not correspond to different base stations or different radio remote units of the same base station, the uplink uplink carrier is not independently uplink synchronized. The user terminal configures the same timing advance value for both;

When the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, the uplink synchronization mode of the mode 1 is used to complete the uplink synchronization.

When the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, the uplink synchronization mode of the mode 2 is used to complete the uplink synchronization;

When the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, the random access procedure is used to complete the uplink synchronization;

When the target uplink carrier and any one of the uplink carriers that have obtained uplink synchronization do not belong to the same frequency band, but the frequency domain interval of one of the carriers is less than a preset threshold, the uplink synchronization mode of the mode 1 is used. To complete the uplink synchronization;

When the target uplink carrier and any one of the uplink carriers that have obtained uplink synchronization do not belong to the same frequency band, but the frequency domain interval of one of the carriers is less than a preset threshold, the uplink synchronization mode of the mode 2 is used. Complete uplink synchronization;

When the target uplink carrier and any one of the uplink carriers that have obtained uplink synchronization do not belong to the same frequency band, and the minimum frequency domain interval between the target uplink carrier and the uplink carrier that has obtained uplink synchronization is greater than When the preset threshold is used, the uplink synchronization mode of the mode 2 is used to complete the uplink synchronization; when the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, and the target uplink carrier and the obtained target are obtained. When the minimum frequency domain interval of the uplink carrier of the uplink synchronization is greater than a preset threshold, the random access procedure is used to complete the uplink synchronization;

When the target uplink carrier and the uplink carrier that has obtained the uplink synchronization respectively correspond to the radio remote units of different geographical locations of different base stations or the same base station, the uplink synchronization mode of the mode 2 is used to complete the uplink synchronization;

When the target uplink carrier and the uplink carrier that has obtained uplink synchronization respectively correspond to radio remote units of different geographical locations of different base stations or the same base station, the random access procedure is used to complete uplink synchronization.

The preset threshold value is further preset in the user terminal, or is sent by the base station to the user terminal by using broadcast or dedicated signaling.

The method further includes: when one of the plurality of uplink carriers of the user terminal loses the uplink synchronization, and the uplink synchronization needs to be resumed on the uplink carrier that loses the uplink synchronization, the method further includes:

The user terminal sends a message to notify the base station that the uplink carrier loses uplink synchronization, and the base station determines whether to resume uplink synchronization on the uplink carrier that loses uplink synchronization;

Alternatively, the user terminal resumes uplink synchronization on the uplink carrier that loses uplink synchronization. If the uplink carrier still loses uplink synchronization, the user terminal sends a message to notify the base station that the uplink carrier loses uplink synchronization.

A system for uplink signal synchronization, the system comprising: an uplink synchronization implementation unit, configured to use the synchronization information of the uplink carrier that the user terminal has obtained uplink synchronization to assist the target uplink carrier to implement uplink synchronization.

The uplink synchronization implementation unit is further configured to: implement, by the user terminal, uplink synchronization on a new uplink carrier, and resume uplink synchronization on an uplink carrier that loses uplink synchronization, or Uplink synchronization is re-implemented on the uplink carrier.

The uplink synchronization implementation unit further includes a first uplink synchronization implementation module and a second uplink synchronization implementation module, where the combination of any one or at least one of the uplink synchronization mode 1 and the mode 2 is implemented; ,

a first uplink synchronization implementation module, configured to: when the mode 1 is used, the value of the timing advance of the specified uplink carrier is used by the user terminal as a value of the initial synchronization timing advance of the target uplink carrier; Timing advance command to complete synchronization maintenance;

a second uplink synchronization implementation module, configured to: when the mode 2 is used, the user terminal measures downlink synchronization timing of the downlink carrier corresponding to the target uplink carrier, and calculates the downlink synchronization timing and the designated uplink carrier a difference value of the downlink synchronization timing corresponding to the downlink carrier; an accumulated value obtained by adding the difference between the difference value and the timing advance amount of the specified uplink carrier as the initial synchronization timing advance amount of the target uplink carrier The user terminal receives the timing advance command sent by the base station to complete the synchronization hold.

In the case that the uplink synchronization is implemented by using the mode 1 and/or the mode 2, the system further includes: an uplink synchronization mode selection unit, configured to select, by the base station or the user terminal, the target uplink carrier The uplink synchronization mode of the mode 1, the uplink synchronization mode of the mode 2, and/or other uplink synchronization modes;

The other uplink synchronization mode includes: the user terminal initiates a random access procedure on the target uplink carrier to complete the uplink initial synchronization; and the user terminal receives the timing advance command sent by the base station to complete the synchronization hold.

The user terminal of the present invention has obtained the synchronization information of the uplink carrier of the uplink synchronization, and assists the target uplink carrier to implement uplink synchronization.

According to the present invention, the uplink synchronization of the uplink carrier is obtained by the user terminal, and the uplink synchronization of the target uplink carrier is assisted, so that the uplink synchronization process of the target uplink carrier is simple and fast, the UE power consumption is small, and the signal is reduced. Make the cost. DRAWINGS

FIG. 1 is a schematic diagram of a prior art UE achieving uplink synchronization by transmitting an uplink signal in advance; FIG. 2 is a schematic diagram of a process of completing an uplink initial synchronization phase by a UE in the prior art;

3 is a schematic diagram of an implementation flow of an example 1 of the present invention;

4 is a schematic diagram of an implementation flow of an example 2 of the present invention;

FIG. 5 is a schematic diagram of an implementation flow of Example 3 of the present invention. detailed description

The basic idea of the present invention is: The user terminal has obtained synchronization information of the uplink carrier of the uplink synchronization to assist the target uplink carrier to implement uplink synchronization.

The implementation of the technical solution will be further described in detail below with reference to the accompanying drawings.

It should be noted that the user terminal of the present invention does not specifically refer to the UE in the LTE system, and the UE relates to the UE in the LTE system; the timing advance of the present invention does not specifically refer to the TA in the LTE system. The TA involved specifically refers to the TA in the LTE system; the following does not make a comment.

Here, the scenario for implementing uplink synchronization specifically includes: the user terminal implements uplink synchronization on the new uplink carrier, or restores uplink synchronization on the uplink carrier that loses uplink synchronization, or re-implements uplink synchronization on the uplink carrier. That is, the main application scenario of the present invention is: if the user terminal has obtained uplink synchronization on one or more uplink carriers, when the user terminal needs to complete uplink synchronization on a certain new uplink carrier, or needs to be in some The technical solution of the present invention can be applied when an uplink carrier that loses uplink synchronization resumes uplink synchronization, or when an uplink carrier needs to be re-synchronized.

Here, achieving uplink synchronization is at least one of two ways. The uplink synchronization mode of the mode 1 specifically includes: a value of a timing advance amount of the specified uplink carrier used by the user terminal as a value of the initial synchronization timing advance amount of the target uplink carrier; and a timing advance of the user terminal receiving the base station transmission The quantity command is used to complete the synchronization hold. It is the following scheme one. The uplink synchronization mode of the mode 2 specifically includes: the user terminal measures downlink synchronization timing of the downlink carrier corresponding to the target uplink carrier, and calculates downlink synchronization timing of the downlink carrier corresponding to the downlink carrier corresponding to the specified uplink carrier. a difference value obtained by adding twice the difference value to the value of the timing advance amount of the specified uplink carrier as the value of the initial synchronization timing advance amount of the target uplink carrier; the user terminal receiving the timing advance command transmitted by the base station To complete the synchronization hold. This is the second option below. The present invention may also include other uplink synchronization modes, for example, the user terminal initiates a random access procedure on the target uplink carrier to complete the uplink initial synchronization; and the user terminal receives the timing advance command sent by the base station to complete the synchronization hold. This is the following scheme three.

It should be noted here that the present invention supports the following three uplink synchronization schemes, and the technical schemes of the present invention are described below.

Solution 1: The target user terminal uses the value of the specified timing advance as the value of the initial synchronization timing advance of the target uplink carrier, and the user terminal receives the timing advance command sent by the base station to complete the synchronization hold. Option 1 includes the following aspects:

The base station configures a physical configuration parameter of the pilot reference signal of the target uplink carrier to complete the uplink synchronization for the user terminal, and sends the configuration parameter to the user terminal.

2. The user terminal selects one uplink carrier in the uplink carrier that has obtained the uplink synchronization, and takes the value of the timing advance amount as the value of the timing advance amount of the initial synchronization phase of the target uplink carrier.

After the user terminal completes the initial synchronization, the pilot reference signal is transmitted on the target uplink carrier according to the physical parameter of the pilot reference signal configured by the base station.

4. If the base station receives the pilot reference signal or the demodulation reference signal sent by the user terminal on the target uplink carrier, the base station measures the reference signal and calculates a value of the timing advance amount in the synchronization holding phase, and the timing is The value of the advance amount is sent to the user terminal.

5. The user terminal receives the synchronization hold sequence of the target uplink carrier sent by the base station. The value of the timing advance amount of the segment accumulates the value of the timing advance amount of the synchronization holding phase and the value of the timing advance amount of the initial synchronization phase of the target uplink carrier.

Solution 2: The user terminal measures downlink synchronization timing of the downlink carrier corresponding to the target uplink carrier, and calculates a difference between the downlink synchronization timing and a downlink synchronization timing of the downlink carrier corresponding to the specified uplink carrier, The value of 2 times the difference is added to the value of the timing advance of the specified uplink carrier. As the value of the initial synchronization timing advance of the target uplink carrier, the user terminal receives the timing advance command sent by the base station to complete the synchronization hold. The program includes the following aspects:

The user terminal measures the downlink synchronization timing of the downlink carrier corresponding to the target uplink carrier; the user terminal selects an uplink carrier in the uplink carrier that has obtained the uplink synchronization, and calculates the uplink. And a value of a timing advance amount of the downlink selected uplink carrier of the downlink carrier corresponding to the link carrier is added to the calculated difference value by 2 times, and the calculation result is used as the target uplink. The value of the timing advance of the initial synchronization phase of the carrier.

5. The user terminal receives the timing advance amount of the synchronization holding phase of the target uplink carrier sent by the base station, and advances the timing of the initial synchronization phase with the target uplink carrier. The value is accumulated.

Solution 3: The user terminal initiates a random access procedure on the target uplink carrier to complete the initial uplink Synchronization, the user terminal receives the timing advance command sent by the base station to complete the synchronization hold.

For the first and second embodiments, the method for selecting one uplink carrier in the uplink carrier that has obtained uplink synchronization is as follows: the user terminal selects itself; the base station specifies by using dedicated signaling. The user terminal selects which uplink carrier has obtained uplink synchronization.

Further, the selection principle of selecting one uplink carrier in an uplink carrier that has obtained uplink synchronization currently includes: arbitrarily selecting one of uplink carriers that have obtained uplink synchronization; or selecting and the target The uplink carrier with the smallest frequency domain interval of the uplink carrier.

Further, the uplink carrier that has obtained the uplink synchronization may also be an uplink carrier that only completes the initial synchronization phase.

Further, the dedicated signaling sent by the base station may be: downlink control channel signaling, MAC control element, or radio resource control signaling.

Further, if there are multiple target uplink carriers, the uplink carriers selected in the uplink carriers that have obtained uplink synchronization may be multiple, or may be the same.

Preferably, the uplink synchronization of the wireless system may use one of the methods of the first scheme and the second scheme, or both may be used, or more schemes may be used at the same time.

Further, if the wireless system uses two or more uplink synchronization schemes, the base station may select which uplink synchronization scheme to use for the target uplink carrier, or the user terminal may select to use the target uplink carrier. Which uplink synchronization scheme.

Preferably, if the base station selects an uplink synchronization method for the target uplink carrier, the base station determines the uplink synchronization method used by the target uplink carrier, and then uses the target uplink carrier information and The information related to the uplink synchronization method is sent to the user terminal for uplink synchronization. Further, the information of the target uplink carrier and the content of the information related to the uplink synchronization method include one or more of the following:

Identification information of the uplink synchronization method;

The frequency point information or carrier sequence number information of the selected uplink carrier of the obtained uplink synchronization uplink carrier corresponding to the target uplink carrier used for uplink synchronization.

Preferably, if the user terminal selects which uplink synchronization scheme to use for the target uplink carrier, the base station sends information about the uplink carrier and the target uplink carrier that the user terminal has obtained the uplink synchronization to the user terminal, The user terminal determines which uplink synchronization scheme should be used in the target uplink carrier, and performs uplink synchronization.

Further, the content of the information that the user terminal has obtained the uplink synchronization uplink carrier and the target uplink carrier includes one or more of the following:

Frequency point information or carrier sequence number information of one or more uplink carriers that have obtained uplink synchronization; frequency point information or carrier sequence number information of one or more target uplink carriers;

Whether the target uplink carrier and the uplink carrier that has obtained uplink synchronization respectively correspond to different base stations or radio remote units of different geographical locations of the same base station.

Preferably, the principle that the base station or the user terminal determines which uplink synchronization method should be used in the target uplink carrier includes one or more of the following:

Fixed use of scheme 3 to complete uplink synchronization;

Fixed use scheme 1 to complete uplink synchronization;

Fixed use scheme 2 to complete uplink synchronization;

If the target uplink carrier and one of the uplink carriers that have obtained the uplink synchronization belong to the same frequency band and the two do not correspond to different base stations or different radio remote units of the same base station, the target uplink carrier is not performed. Independent uplink synchronization, the user terminal configures the same timing advance value for both; If the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, use the scheme 1 to complete the uplink synchronization;

If the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, the scheme 2 is used to complete the uplink synchronization;

If the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, the third method is used to complete the uplink synchronization;

If the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, but the frequency domain interval of one of the carriers is less than the preset threshold, the solution 1 is used to complete the uplink. Synchronize;

If the target uplink carrier and any one of the uplink carriers that have obtained uplink synchronization do not belong to the same frequency band, but the frequency domain interval of one of the carriers is less than a preset threshold, the method described in the second scheme is used. Method to complete uplink synchronization;

If the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, and the minimum frequency domain interval between the target uplink carrier and the uplink carrier that has obtained the uplink synchronization is greater than the preset gate. Limit, then use scheme 2 to complete uplink synchronization;

If the target uplink carrier and any one of the uplink carriers that have obtained the uplink synchronization do not belong to the same frequency band, and the minimum frequency domain interval between the target uplink carrier and the uplink carrier that has obtained the uplink synchronization is greater than the preset gate. Limit, then use scheme 3 to complete uplink synchronization;

If the target uplink carrier and the uplink carrier that has obtained uplink synchronization respectively correspond to radio remote units of different geographical locations of different base stations or the same base station, the uplink synchronization is implemented by using the second method;

If the target uplink carrier and the uplink carrier that has obtained uplink synchronization respectively correspond to radio remote units of different geographical locations of different base stations or the same base station, scheme 3 is used to complete uplink synchronization.

Further, the preset threshold may be preset in the user terminal, or may be based on The station transmits to the user terminal through broadcast or dedicated signaling.

Preferably, if one of the plurality of uplink carriers of the user terminal loses uplink synchronization, the processing method of the user terminal may select one of the following:

The user terminal sends a message to notify the base station that the uplink carrier loses uplink synchronization, and the base station determines whether to perform uplink synchronization on the uplink carrier.

The user terminal re-synchronizes the uplink carrier that has lost uplink synchronization. If the uplink carrier still loses uplink synchronization, the user terminal sends a message to notify the base station that the uplink carrier loses uplink synchronization.

The present invention is specifically illustrated in the following examples. The eNB and UE of the following examples belong to the LTE-Advanced system, support carrier aggregation technology, and adopt Frequency Division Duplex (FDD) mode.

Example 1 :

The scenario of this example is an LTE-Advanced system, and the eNB configures one uplink component carrier for the UE. Here, the uplink is represented by Uplink, hereinafter referred to as UL. The uplink component carrier configured is UL-CC1, and its frequency is 1930MHz. The UE has obtained uplink synchronization in UL-CC1, and the TA maintained by UE-UL1 is TA1.

Let the eNB configure a new UL component carrier for the UE, and set it to UL-CC2, and its frequency point is 1900MHz. The process of the UE performing uplink synchronization on the UL component carrier is as shown in FIG. 3, and the steps are as follows:

Step 301: The eNB sends the dedicated signaling to determine whether uplink synchronization needs to be implemented. Here, since UL-CC1 and UL-CC2 do not belong to the same frequency band, the division and definition of frequency points and frequency bands refer to the LTE protocol 3Gpp TS36.101, so the UE should perform independent uplink synchronization on UL-CC2, that is, the UE should be UL-CC2 maintains an independent TA. The eNB will activate the UL-CC2 activation indication; the system information including the frequency and bandwidth of the UL-CC2; the pilot reference signal configuration; the uplink synchronization method indication, that is: whether the UL-CC2 maintains an independent TA; And the UL CC1, which is the uplink carrier sequence number as the synchronization corresponding reference, is sent to the UE through dedicated signaling. Step 302: After receiving the signaling of the eNB, the UE takes the TA of the UL-CCl as the initial synchronization TA value of the UL-CC2.

Step 303: The UE sends a pilot reference signal (SRS) in the UL-CC2 according to the configuration of the dedicated signaling.

Step 304: The eNB measures the SRS of the UL-CC2, and obtains the TA of the UL-CC2 in the synchronous hold phase.

Step 305: The eNB sends a TA command on the downlink carrier corresponding to the UL-CC2.

Step 306: The UE performs uplink synchronization maintenance of the UL-CC2 according to the received TA command. Example 2:

The scenario of the present example is an LTE-Advanced system, and the eNB configures two UL component carriers for the UE, which are UL-CC1 and UL-CC2, and the frequency points are 1930 MHz and 1900 MHz, respectively, and the UE is UL-CC1 and UL- CC2 maintains TATA1 and TA2 respectively.

Let UL-CC2 have an uplink out-of-synchronization. The process of the UE re-upgrading the uplink synchronization on the UL-CC2 is as shown in FIG. 4, and the steps are as follows:

Step 401: The UE determines that uplink-synchronization occurs in the UL-CC2.

Step 402: The UE measures the downlink synchronization timing (DL_Timing2) of the downlink carrier corresponding to the UL-CC2, and the UE takes the downlink synchronization timing (DL Timingl) of the downlink carrier corresponding to the UL-CCl, and calculates the DeltaT=DL-Timing2-DL_ Timing 1 The UE uses TA1+2 X DeltaT as the initial synchronization TA value of UL-CC2.

Step 403: The UE continues to send in the UL-CC2 according to the original SRS configuration of the UL-CC2.

SRS.

Step 404: The eNB measures the SRS of the UL-CC2, and obtains the TA of the UL-CC2 in the synchronous hold phase.

Step 405: The eNB sends a TA command on the downlink carrier corresponding to the UL-CC2.

Step 406: The UE performs uplink synchronization maintenance of the UL-CC2 according to the received TA command. In step 402 of the example scenario, the UE has another processing method, specifically: the UE sends a dedicated signaling to the eNB in the UL CC 1 to: the UL CC2 uplink out-of-synchronization, and the eNB determines whether it needs to re-upgrade in the UL-CC2. Synchronization, if necessary, the UE signals the UE with dedicated signaling.

Example 3:

The Instance of the present example is an LTE-Advanced system, and the eNB configures two UL component carriers for the UE, which are respectively UL CC1 and UL-CC2, and the frequency points are 1930 MHz and 1860 MHz, respectively, belonging to different frequency bands, regarding frequency points and The division and definition of the frequency band refer to the LTE protocol 3Gpp TS36.101. The UE has obtained uplink synchronization in UL-CCl and UL-CC2, and the UE maintains different TAs for UL CC1 and UL-CC2, respectively, and is set to TA1 and TA2, respectively. The eNB configures an uplink synchronization method determination threshold for the UE, and the threshold is 100 MHz.

Let the eNB configure three new UL component carriers for the UE, which are respectively UL-CC3, UL-CC4, and UL-CC5, and their frequencies are 1780MHz, 835MHz, and 2510MHz, respectively. The 2510MHz corresponds to the radio remote unit of another geographical location of the base station. The process of the UE performing uplink synchronization on the three UL component carriers is as shown in FIG. 5, and the steps are as follows:

Step 501: The eNB determines, according to UL-CC3, UL-CC4, UL CC5, and system information of UL-CC1 and UL-CC2 that the UE has obtained uplink synchronization, that the UE should be in UL-CC3, UL-CC4, UL-CC5, respectively. Which uplink synchronization scheme is used.

Here, the frequency of UL-CC3 is 1780MHz, and neither UL-CCl nor UL-CC2 belong to one frequency band, and its frequency interval with UL-CC2 is 80MHz, which is smaller than the preset uplink synchronization method judgment threshold, so UL-CC3 The uplink synchronization uses the foregoing scheme 1. The uplink synchronous reference carrier is the UL-CC2 with the closest frequency interval.

The frequency of UL CC4 is 835MHz, and neither UL-CC1 nor UL-CC2 belong to one frequency band. The minimum frequency interval between it and UL-CC1 and UL-CC2 is 1025MHz, which is greater than the preset uplink synchronization method judgment threshold, so UL The uplink synchronization of CC4 uses the aforementioned scheme 2, The uplink synchronous reference carrier is the UL-CC2 with the closest frequency interval.

The frequency of UL CC5 is 2510MHz, and UL-CC1 and UL-CC2 do not belong to the same geographical location of the remote radio unit, so the UL-CC5 uplink synchronization uses the aforementioned scheme 3.

Step 502: The eNB sends the dedicated signaling to the UE.

Here, the signaling content includes activation indications of UL-CC3, UL-CC4, UL-CC5; system information including physical parameters such as frequency and bandwidth; pilot reference signal configuration information, such as UL-CC3, UL- SRS configuration information of CC4, UL-CC5; indication of uplink synchronization method, such as UL-CC3, UL-CC4, UL-CC5, which uplink synchronization scheme is used respectively; synchronization reference carrier indication, such as UL-CC3, UL-CC4, Which of the uplink-synchronized reference carriers of UL-CC5 is respectively, where UL-CC5 does not require a reference carrier.

Step 503: The UE performs the uplink synchronization method in the UL-CC3 scheme 1 according to the indication of the dedicated signaling, and performs the uplink synchronization on the uplink synchronization method in the UL-CC4 scheme 2; The uplink synchronization method is used to complete the uplink initial synchronization.

Step 504: The UE sends the SRS according to the pilot reference signal configuration information of the dedicated signaling, and sends the SRS in the UL-CC3 and the UL CC4; the UE initiates the random access in the UL-CC5.

Here, the random access procedure belongs to the prior art, and the random access procedure of the LTE can refer to the background technology and the 3GPP protocols TS36.211, TS36.213, TS36.300, TS36.321, which are not described in detail in this example.

Step 505: The eNB separately measures the SRS of the UL-CC3 and the UL-CC4, and obtains the TA of the UL-CC3 and the UL-CC4 in the synchronous hold phase.

Step 506: The eNB sends a TA command on the downlink carriers corresponding to UL-CC3 and UL-CC4, respectively.

Step 507: The UE performs uplink synchronization maintenance of UL CC3 and UL-CC4 according to the received TA commands of UL-CC3 and UL-CC4, respectively.

A system for uplink signal synchronization, the system comprising: an uplink synchronization implementation unit, The uplink information of the uplink carrier that the UE has obtained uplink synchronization is used to assist the target uplink carrier to implement uplink synchronization.

Here, the uplink synchronization implementation unit is further configured to implement uplink synchronization on the new uplink carrier, resume uplink synchronization on the uplink carrier that loses uplink synchronization, or re-implement uplink synchronization on the uplink carrier.

The uplink synchronization implementation unit further includes a first uplink synchronization implementation module and a second uplink synchronization implementation module. The uplink synchronization implementation unit further includes a combination of any one or at least one of the uplink synchronization mode. The first uplink synchronization implementation module is configured to: when the mode 1 is used, the UE uses the TA value of the specified uplink carrier as the initial synchronization TA value of the target uplink carrier; and the UE receives the TA command sent by the base station to complete the synchronization and hold. . a second uplink synchronization implementation module, configured to: when the method 2 is used, the UE measures downlink synchronization timing of a downlink carrier corresponding to the target uplink carrier, and calculates that the downlink synchronization timing is corresponding to the specified uplink carrier The difference of the downlink synchronization timing of the downlink carrier; the accumulated value obtained by adding twice the difference value to the TA value of the specified uplink carrier, as the initial synchronization TA value of the target uplink carrier; The TA command is used to complete the synchronization hold.

In the case that the uplink synchronization is implemented by using the mode 1 and/or the mode 2, the system further includes: an uplink synchronization mode selection unit, configured to select, by the base station or the UE, the target uplink carrier. The uplink synchronization mode of the mode 1, the uplink synchronization mode of the mode 2, and/or other uplink synchronization modes are used. The other uplink synchronization mode includes: the UE initiates a random access procedure on the target uplink carrier to complete the uplink initial synchronization; and the UE receives the TA command sent by the base station to complete the synchronization hold.

Here, the random access prefix mentioned above is represented by Preamble; in the above examples, in the LTE-Advanced system, the pilot reference signal is SRS, represented by Sounding Reference Signal; the demodulation reference signal is DMRS, represented by DeModulation Reference Signal .

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Scope

Claims

Claim

A method for synchronizing uplink signals, the method comprising: ???using synchronization information of uplink carriers that have been obtained by the user terminal for uplink synchronization, to assist the uplink uplink carrier to achieve uplink synchronization.

The method according to claim 1, wherein the implementing the uplink synchronization scenario comprises: the user terminal implementing uplink synchronization on a new uplink carrier, recovering uplink synchronization on an uplink carrier that loses uplink synchronization, or Uplink synchronization is re-implemented on the uplink carrier.

3. The method according to claim 1, wherein the uplink synchronization is implemented in any one or a combination of at least one of the following manners;

Method 1: The user terminal uses the value of the timing advance of the specified uplink carrier as the value of the initial synchronization timing advance of the target uplink carrier; the user terminal receives the timing advance command sent by the base station to complete the synchronization hold;

The method according to claim 3, wherein, when the mode 1 is used, the value of the specified timing advance amount used by the user terminal as the value of the initial synchronization timing advance includes: One uplink carrier is selected among the uplink carriers that have obtained uplink synchronization, and the value of the timing advance amount of the selected uplink carrier is taken as the value of the timing advance amount of the initial uplink phase of the target uplink carrier.

The method according to claim 3, wherein, when the mode 2 is used, the user terminal uses the value of twice the difference and the value of the timing advance of the specified uplink carrier to add up. a value, the value of the initial synchronization timing advance amount includes: the user terminal measures the target a downlink synchronization timing of the downlink carrier corresponding to the uplink carrier; the user terminal selects one uplink carrier in the uplink carrier that has obtained the uplink synchronization, and calculates that the selected user terminal corresponding to the uplink carrier selects the uplink uplink The value of the timing advance amount of the path carrier is added to twice the calculated difference value, and the added accumulated value is used as the value of the timing advance amount of the initial synchronization phase.

The method according to claim 4 or 5, wherein the selecting, by the user terminal, one uplink carrier in the uplink carrier that has obtained the uplink synchronization includes: selecting by the user terminal; or Let the designated user terminal select an uplink carrier that has obtained uplink synchronization.

The method according to claim 6, wherein the principle of selecting the uplink carrier comprises: arbitrarily selecting one of uplink carriers that have obtained uplink synchronization; or selecting a frequency domain between the uplink carrier and the target uplink carrier The smallest upstream carrier.

The method according to claim 6, wherein the uplink carrier that has obtained uplink synchronization comprises: at least an uplink carrier that has completed the initial synchronization phase.

The method according to claim 6, wherein the dedicated signaling comprises: downlink control channel signaling, media access control (MAC) control element, or radio resource control signaling.

The method according to claim 6, wherein, when there are multiple target uplink carriers, in the uplink carrier that has obtained uplink synchronization, the selected uplink carrier is: The uplink carrier, or the same uplink carrier.

The method according to claim 3, wherein, when the uplink synchronization is implemented by using the mode 1 and/or the mode 2, the base station or the user terminal selects to use the target uplink carrier. The uplink synchronization mode of the mode 1, the uplink synchronization mode of the mode 2, and/or other uplink synchronization modes;

The other uplink synchronization manner includes: the user terminal initiates random on the target uplink carrier The access process is performed to complete the uplink initial synchronization; the user terminal receives the timing advance command sent by the base station to complete the synchronization hold.

The method according to claim 11, wherein when the base station selects an uplink synchronization mode for the target uplink carrier, the method further includes: determining, by the base station, the target uplink carrier After the uplink synchronization mode, the information about the target uplink carrier and the information related to the uplink synchronization mode are sent to the user terminal; the user terminal uses the corresponding uplink synchronization mode according to the information received from the base station, and uplinks on the target. Uplink synchronization on the carrier;

The method according to claim 12, wherein when the uplink synchronization mode used by the target uplink carrier is selected by the base station, the information of the target uplink carrier and the information related to the uplink synchronization mode The content includes one or more of the following:

Identification information of the uplink synchronization method;

The method according to claim 12, wherein when the user terminal selects an uplink synchronization mode for the target uplink carrier, the user terminal obtains an uplink carrier and a target uplink carrier that are uplink synchronized. The content of the information includes one or more of the following: frequency point information or carrier sequence number information of one or more uplink carriers that have obtained uplink synchronization; frequency point information or carrier sequence number information of one or more target uplink carriers;

Whether the target uplink carrier and the uplink carrier that has obtained uplink synchronization respectively correspond to different base stations or Radio remote unit of different geographical locations of the same base station.

The method according to claim 11, wherein the base station or the user has one or more of:

Fixedly using the random access procedure to complete uplink synchronization;

The method according to claim 15, wherein the preset threshold value is further preset in the user terminal, or is sent to the user terminal by the base station through broadcast or dedicated signaling.

The method according to claim 2, wherein when one of the plurality of uplink carriers of the user terminal loses uplink synchronization and needs to resume uplink synchronization on the uplink carrier that loses uplink synchronization, the method further Includes:

A system for uplink signal synchronization, characterized in that the system comprises: an uplink synchronization implementation unit, configured to use the synchronization information of the uplink carrier that the user terminal has obtained uplink synchronization, to assist the target uplink carrier to implement uplink synchronization.

The system according to claim 18, wherein the uplink synchronization implementation form The element is further used for implementing uplink synchronization on the new uplink carrier, restoring uplink synchronization on the uplink carrier that loses uplink synchronization, or re-implementing uplink synchronization on the uplink carrier.

The system according to claim 19, wherein a combination of any one or at least one of the uplink synchronization mode 1 and the mode 2 is implemented; the uplink synchronization implementation unit further includes a first An uplink synchronization implementation module and a second uplink synchronization implementation module; wherein,

The system according to claim 20, wherein, in the case that the uplink synchronization is implemented by using the mode 1 and/or the mode 2, the system further includes: an uplink synchronization mode selection unit, configured to: Selecting, by the base station or the user terminal, the uplink synchronization mode, the uplink synchronization mode of the mode 2, and/or other uplink synchronization modes of the mode 1 for the target uplink carrier;