CN105634697B - The configuration method and device of signal parameter in a kind of air interface synchronization - Google Patents

Abstract

The present invention provides a method and device for configuring signal parameters in air interface synchronization, wherein the method for configuring signal parameters in air interface synchronization includes: configuring a reference signal as an LRS for a source base station in the same layer, wherein the LRS of the source base station in the same layer is the same ; Configure the same subframe offset for the LRS sent by the source base station of the same layer, and configure different subframe offsets for the LRS sent by the source base station of different layers; control the subframe offset of each source base station based on the LRS configured by itself amount, the LRS is sent at the corresponding subframe position. In this solution, by configuring the same LRS as a reference signal for the source base station at the same layer, the LRS signals sent by the source base station at the same layer are additively enhanced to each other to obtain signal diversity gain, thereby solving the problem of the same LRS signal in the ultra-dense deployment scenario of small cells in the prior art. The synchronization reference signal (LRS, listening RS) sent by multiple source cells in the layer causes the problem of mutual interference caused by the conflict of RE resources, so as to improve the synchronization performance of the network air interface.

Description

Method and device for configuring signal parameters in air interface synchronization

technical field

The present invention relates to the field of wireless technologies, and in particular, to a method and device for configuring signal parameters in air interface synchronization.

Background technique

To suppress inter-station interference, TDD base stations deployed on the same frequency need to perform time-frequency synchronization between stations. 3GPP preferentially supports three inter-station time-frequency synchronization schemes: (1) based on GNSS (Global Navigation Satellite System) satellite synchronization, such as GPS synchronization; (2) based on ideal backhaul network synchronization, such as IEEE1588v2 synchronization; ( 3) Radio-interface based synchronization mechanism (RIBS for short). In typical LTE application scenarios such as indoor and high-rise hotspot coverage (such as Home eNodeB, Nano Cell, Small Cell), GPS signals are not easy to obtain, and ideal backhaul is difficult to guarantee. Therefore, it is necessary to study the air interface synchronization technology.

At present, 3GPP focuses on an air interface synchronization technology called network listening (NW: network listening). A synchronization reference signal (LRS: listening reference signal) of a base station, or a source cell, adjusts the local clock accordingly to maintain time-frequency synchronization between stations.

In the early days of 3GPP, RIBS technology (Radiointerface based synchronization) was studied for Home eNB scenarios. The basic points are as follows:

(1) A new listening RS is not defined, and an existing reference signal (such as a cell common reference signal CRS) is used as the listening RS, so the listening RS sequences sent by different source cells are different (scrambled by the cell ID);

(2) An eNB (called a target cell) newly accessing the synchronization network selects a certain base station (called a source cell) as its own synchronization source, that is, a target cell only listens to the listening RS of one source cell;

(3) Considering the multi-hop synchronization scenario, it is possible to set target cell T1 (synchronization level n) to listen to the CRS of source cell S1 (synchronization level n-1) at subframe M for synchronization tracking. T1 may hear signals other than the LRS sent by S1 (including LRS or service data sent by other base stations) on the Mth subframe, which affects the network listening performance. There are two main types of interference:

a) The interference of the downlink signal of the base station of the n+1th layer to the nth layer of listening subframes;

b) The interference to the LRS of S1 by the downlink signal (possibly also the LRS) sent by other base stations in the n-1th layer except S1;

(4) For the first type of interference, 3GPP proposes a cross-subframe muting (silence) mechanism to solve it;

(5) 3GPP does not discuss the second type of interference. Reviewing the 3GPP manuscripts of other companies, a potential tendency is: multiple source cells at the same layer send their respective LRSs in the same downlink subframe. These LRSs are legacyRSs (such as CRS, positioning reference signal PRS), so these The sequence of LRS is different. Obviously, when the number of nodes in the source cell of the same layer is small, these LRSs can be staggered in the frequency domain (eg, by frequency shift technology) to avoid mutual interference of LRS signals of the same layer.

In particular, in the Home eNB and current small cell deployment scenarios, the total number of eNB nodes in a cluster is limited, typically 8. If a total of 3 hops are supported, there are 2 to 3 base stations on average in each hop (layer). These base stations on the same layer send LRS signals (such as CRS or PRS sequences) scrambled by their respective cell IDs on the same subframe, and these LRS signals can be staggered on RE resources through cell planning.

However, for the more dense deployment scenarios of small cells (micro stations) in the future (such as 5G UDN: ultra dense network), there may be more than 60 small cells in a cluster (cluster), and there may be more than 7 small cells per hop (layer). small cells. According to the existing RIBS technology, that is, the base stations on the same layer send LRS signals scrambled by their respective cell IDs in the same subframe, the number of source cells on the same layer exceeds the multiplexing degree of the LRS signals (such as the CRS signal with 2 ports). The multiplexing degree of the LRS signal is 3, and the multiplexing degree of the PRS signal is 6). These LRS signals are difficult to be completely staggered on the RE resources even through cell planning, so they will interfere with each other and reduce the network air interface synchronization performance.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a method and device for configuring signal parameters in air interface synchronization, so as to solve the synchronization reference signal (LRS, listening RS) The problem of mutual interference caused by the conflict of RE resources.

In order to solve the above technical problem, an embodiment of the present invention provides a method for configuring signal parameters in air interface synchronization, including:

Configure the reference signal as the LRS for the source base station in the same layer, wherein the LRS of the source base station in the same layer is the same;

Configure the same subframe offset for the LRS sent by the source base station in the same layer, and configure different subframe offsets for the LRS sent by the source base station in different layers;

Each source base station is controlled to send the LRS at the corresponding subframe position based on the subframe offset of the LRS configured by itself.

In the above configuration method, wherein the reference signal configured as the LRS for the source base station in the same layer includes:

Any one of the CRS, PRS and CSI-RS reference signals is configured as the reference signal of the LRS of the source base station in the same layer, and the same initial phase is configured for the any one of the reference signals.

In the above configuration method, wherein configuring the same initial phase for any one of the reference signals includes:

Use the radio frame number to replace the base station-related parameters in the initial phase calculation formula to generate the same initial phase.

The present invention also provides a method for configuring signal parameters in air interface synchronization, including:

Receive the same LRS from multiple source base stations in the same layer;

Obtaining respective corresponding source base station sending times from a plurality of the LRSs, where the source base station sending time is based on the source base station clock;

Obtain the respective local reception times corresponding to the arrival of a plurality of the LRSs, and the local reception times are based on the local clock;

The estimated value of the average timing deviation is obtained by performing operations by using the transmission time and local reception time of the source base station corresponding to each of the plurality of LRSs.

The above configuration method, wherein, before using the respective corresponding source base station transmission time and local reception time of the plurality of LRSs to obtain the average timing deviation estimate value, further comprising:

obtaining path propagation delay times corresponding to each of the plurality of LRSs;

The average timing deviation value obtained by the calculation using the respective corresponding source base station transmission time and local reception time of the plurality of LRSs is as follows:

The average timing deviation value is obtained by performing operations on the source base station transmission time, local reception time and path propagation delay time corresponding to each of the plurality of LRSs.

The present invention also provides a method for configuring signal parameters in air interface synchronization, including:

Configure an LRS mode for the base station, so that the LRS sent by the base station is orthogonal to the LRS sent by other base stations in the same layer;

The cell-scrambled LRS is transmitted according to the LRS pattern.

In the above configuration method, the LRS sent by the base station and the LRS sent by other base stations in the same layer are respectively located in the GPs of different special subframes in the TDD system.

In the above configuration method, the configuring an LRS mode for the base station includes:

Sending a signaling requesting feedback of the LRS mode used to the neighboring base stations of the same layer;

receiving the response information fed back by the neighboring base station according to the signaling;

According to the response information, an LRS pattern that is different from the LRS patterns of all neighboring base stations is acquired in the local LRS pattern database.

In the above configuration method, the configuring an LRS mode for the base station includes:

Determine a candidate subframe for LRS to be sent;

listening to the LRS sent by other neighboring cells on the candidate subframe;

If the listening result is that there are LRS configuration resources in the candidate subframe that are not occupied by the LRSs of the other neighboring cells, determine an unoccupied LRS configuration resource;

An LRS mode is determined according to the determined LRS configuration resources.

The above configuration method, wherein, also includes:

If the listening result is that all available LRS configuration resources of the candidate subframe are occupied by the LRSs of the other neighboring cells, then continue to perform the determining of a candidate subframe for which LRS is to be sent.

The above configuration method, wherein, in the same cluster, the transmission period of all LRSs is the same; if the micro-station has a switch conversion function, even if it is in a dormant state, the LRS is also sent; the LRS has different characteristic points from other signals, and can be recognized by other neighboring cells.

The present invention also provides a device for configuring signal parameters in air interface synchronization, including:

a first configuration module, configured to configure a reference signal used as an LRS for the source base station at the same layer, wherein the LRS of the source base station at the same layer is the same;

The second configuration module is configured to configure the same subframe offset for the LRS sent by the source base station of the same layer, and configure different subframe offsets for the LRS sent by the source base station of different layers;

The control module is configured to control each source base station to send the LRS at the corresponding subframe position based on the subframe offset of the LRS configured by itself.

The above configuration device, wherein the first configuration module includes:

a first configuration unit, configured to configure any one of the reference signals in the CRS, PRS and CSI-RS as the reference signal of the LRS of the source base station in the same layer;

The second configuration unit is configured to configure the same initial phase for any one of the reference signals.

The above configuration device, wherein the second configuration unit includes:

The replacement component is used to replace the base station-related parameters in the initial phase calculation formula with the radio frame number, so as to generate the same initial phase.

The present invention also provides a device for configuring signal parameters in air interface synchronization, including:

a receiving module for receiving the same LRS from multiple source base stations on the same layer;

a first obtaining module, configured to obtain respective corresponding source base station sending times from a plurality of the LRSs, where the source base station sending time is based on the source base station clock;

A second acquisition module, configured to acquire respective local reception times corresponding to the arrival of a plurality of the LRSs, and the local reception times are based on a local clock;

an operation module, configured to perform an operation by using the transmission time and the local reception time of the source base station corresponding to the plurality of LRSs to obtain an estimated value of the average timing deviation.

The above configuration device, wherein, also includes:

a third obtaining module, used for obtaining the path propagation delay times corresponding to the plurality of LRSs before the operation module module performs the operation;

The operation module is specifically used for:

The average timing deviation value is obtained by performing operations on the source base station transmission time, local reception time and path propagation delay time corresponding to each of the plurality of LRSs.

The present invention also provides a device for configuring signal parameters in air interface synchronization, including:

The third configuration module is configured to configure an LRS mode for the base station, so that the LRS sent by the base station is orthogonal to the LRS sent by other base stations in the same layer;

A sending module, configured to send the LRS scrambled by the cell according to the LRS mode.

In the above configuration device, the LRS sent by the base station and the LRS sent by other base stations in the same layer are respectively located in the GPs of different special subframes in the TDD system.

The above configuration device, wherein the third configuration module includes:

a first sending unit, configured to send a signaling requesting feedback of the LRS mode used to the neighboring base stations of the same layer;

a receiving unit, configured to receive the response information fed back by the neighboring base station according to the signaling;

an obtaining unit, configured to obtain an LRS mode that is different from the LRS modes of all adjacent base stations from the local LRS mode database according to the response information.

The above configuration device, wherein the third configuration module includes:

a first determining unit, configured to determine a candidate subframe of the LRS to be sent;

a second sending unit, configured to listen to the LRS sent by other neighboring cells on the candidate subframe;

a second determining unit, configured to determine an unoccupied LRS configuration resource if the listening result is that there is an LRS configuration resource that is not occupied by the LRS of the other neighboring cells in the candidate subframe;

The third determining unit is configured to determine an LRS mode according to the determined LRS configuration resource.

The above configuration device, wherein, also includes:

The loop module is configured to continue to perform the determining of a candidate subframe for which LRS to be sent if the listening result is that all available LRS configuration resources of the candidate subframe have been occupied by LRSs of the other neighboring cells.

The above configuration device, wherein, in the same cluster, the transmission period of all LRSs is the same; if the micro-station has a switch conversion function, even if it is in a dormant state, the LRS is also sent; the LRS has different characteristic points from other signals, and can be recognized by other neighboring cells.

The beneficial effects of the above-mentioned technical solutions of the present invention are as follows:

In the above solution, the method for configuring signal parameters in the air interface synchronization is to configure the same LRS as a reference signal for the same-layer source base station, so that the LRS signals sent by the same-layer source base station are additively enhanced with each other to obtain signal diversity gain, or the same-layer source base station. The source base station is configured with different LRS modes, so that the LRSs sent by each other are orthogonal, thereby solving the problem of the synchronization reference signal (LRS, listening RS) sent by multiple source cells on the same layer in the ultra-dense deployment scenario of small cells in the prior art. The problem of mutual interference caused by the conflict of RE resources can improve the synchronization performance of the network air interface.

Description of drawings

FIG. 1 is a schematic diagram 1 of steps of a method for configuring signal parameters in air interface synchronization according to an embodiment of the present invention;

FIG. 2 is a second schematic diagram of steps of a method for configuring signal parameters in air interface synchronization according to an embodiment of the present invention;

FIG. 3 is a schematic diagram 3 of steps of a method for configuring signal parameters in air interface synchronization according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram 1 of an apparatus for configuring signal parameters in air interface synchronization according to an embodiment of the present invention;

FIG. 5 is a second structural schematic diagram of an apparatus for configuring signal parameters in air interface synchronization according to an embodiment of the present invention;

FIG. 6 is a third structural schematic diagram of an apparatus for configuring signal parameters in air interface synchronization according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of multi-hop synchronization according to an embodiment of the present invention;

8 is a schematic diagram of the principle of Method A according to an embodiment of the present invention;

9 is a schematic diagram 1 of Method B according to an embodiment of the present invention;

10 is a schematic diagram 2 of Method B according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of an air interface synchronization principle applied in an embodiment of the present invention;

FIG. 12 is a schematic diagram of the principle of Method C according to an embodiment of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

Aiming at the problem of mutual interference between synchronization reference signals (LRS, listening RS) sent by multiple source cells at the same layer due to the conflict of RE resources in the prior art in the scenario of ultra-dense deployment of small cells, the present invention provides an air interface The configuration method of signal parameters in synchronization, as shown in Figure 1, includes:

Step 11: Configure the reference signal as the LRS for the source base station in the same layer, wherein the LRS of the source base station in the same layer is the same;

Step 12: configure the same subframe offset for the LRS sent by the source base station in the same layer, and configure different subframe offsets for the LRS sent by the source base station in different layers;

Step 13: Control each source base station to send the LRS at the corresponding subframe position based on the subframe offset of the LRS configured by itself.

The method for configuring signal parameters in the air interface synchronization provided by the embodiment of the present invention configures the same LRS as a reference signal for the source base station on the same layer, so that the LRS signals sent by the source base station on the same layer are additively enhanced with each other to obtain signal diversity gain, thereby solving the problem of The problem of mutual interference caused by conflicting RE resources between synchronization reference signals (LRS, listening RS) sent by multiple source cells at the same layer in the prior art in the ultra-dense deployment scenario of small cells is solved, so as to improve the network air interface synchronization performance.

Specifically, a preferred method for configuring the reference signal of the LRS for the source base station in the same layer is to combine CRS (Cell-specific reference signal), PRS (Positioning reference signal) and CSI-RS (CSI-RS) reference signals, and CSI is the abbreviation of Channel-State Information) any one of the reference signals is configured as the reference signal of the LRS of the source base station in the same layer, and the same initial phase is configured for any one of the reference signals.

It is not excluded to design a new reference signal. When the new reference signal is configured as the reference signal of the LRS of the source base station in the same layer, the sequence generation manner and the initial phase are exactly the same.

The configuring the same initial phase for any one of the reference signals includes: using the radio frame number to replace the base station-related parameters in the initial phase calculation formula, so as to generate the same initial phase.

Preferably, for CRS and PRS, the Cell-ID parameter is replaced by the radio frame number For CSI-RS, replace the parameter configured by the higher layer with the radio frame number

In order to solve the above technical problem, an embodiment of the present invention also provides a method for configuring signal parameters in air interface synchronization, as shown in FIG. 2 , including:

Step 21: Receive the same LRS from multiple source base stations at the same layer;

Step 22: Acquire respective corresponding source base station transmission times from a plurality of the LRSs, and the source base station transmission time is based on the source base station clock;

Step 23: Obtain the respective local reception times corresponding to the arrival of a plurality of the LRSs, and the local reception times are based on the local clock;

Step 24: Obtain an average timing offset estimate value by performing an operation on the source base station transmission time and local reception time corresponding to each of the plurality of LRSs. Among them, the estimated value contains the measurement error value.

The method for configuring signal parameters in the air interface synchronization provided by the embodiment of the present invention obtains an estimated average timing deviation by processing LRSs sent by multiple source base stations in the same layer, which further solves the problem of the ultra-dense deployment scenario of small cells in the prior art The synchronization reference signal (LRS, listening RS) sent by multiple source cells in the same layer below is a problem of mutual interference caused by the conflict of RE resources, so as to improve the network air interface synchronization performance.

Wherein, before using the source base station transmission time and local reception time corresponding to the plurality of LRSs to obtain the average timing deviation estimate value, the method further includes: acquiring the path propagation delay times corresponding to the plurality of LRSs; Described using the source base station sending time and local receiving time corresponding to each of a plurality of described LRSs, the average timing deviation value obtained by calculation is specifically: using the source base station sending time, local receiving time corresponding to each of the plurality of described LRSs, and The path propagation delay time is calculated to obtain the average timing deviation value.

In order to solve the above technical problem, an embodiment of the present invention also provides a method for configuring signal parameters in air interface synchronization, as shown in FIG. 3 , including:

Step 31: Configure an LRS mode for the base station, so that the LRS sent by the base station is orthogonal to the LRS sent by other base stations in the same layer;

Step 32: Send the LRS scrambled by the cell according to the LRS pattern.

The method for configuring signal parameters in the air interface synchronization provided by the embodiment of the present invention makes the LRS sent to each other orthogonal by configuring different LRS modes for the source base stations of the same layer, which solves the problem of the same problem in the ultra-dense deployment scenario of small cells in the prior art. The synchronization reference signal (LRS, listening RS) sent by multiple source cells in the layer causes the problem of mutual interference caused by the conflict of RE resources, so as to improve the network air interface synchronization performance.

Wherein, the LRS sent by the base station and the LRS sent by other base stations in the same layer are respectively located in the GPs of different special subframes in the TDD system.

The present invention preferentially adopts the distributed LRS mode scheduling mechanism, and there are two specific implementation forms. The first one: the configuring an LRS mode for the base station includes: sending a signaling requesting feedback of the LRS mode used by the adjacent base stations at the same layer ; Receive the response information fed back by the neighboring base station according to the signaling; obtain an LRS mode that is different from the LRS modes of all neighboring base stations in the local LRS mode database according to the response information.

The second type: in the configuration method provided by the embodiment of the present invention, configuring an LRS mode for the base station includes: determining a candidate subframe for LRS to be sent; LRS; if the listening result is that there is an LRS configuration resource in the candidate subframe that is not occupied by the LRS of the other neighboring cells, then determine an unoccupied LRS configuration resource; according to the determined LRS configuration resource Identify an LRS mode.

Further, if the listening result is that all available LRS configuration resources of the candidate subframe are occupied by the LRSs of the other neighboring cells, then continue to perform the determining of a candidate subframe for which LRS is to be sent.

Among them, in the same cluster, the transmission period of all LRSs is the same; if the micro-station has the switching function, it will also send the LRS even in the dormant state; the LRS has different characteristic points from other signals, and can be used by other adjacent cells. identified.

In order to solve the above technical problems, an embodiment of the present invention also provides a device for configuring signal parameters in air interface synchronization, as shown in FIG. 4 , including:

a first configuration module, configured to configure a reference signal used as an LRS for the source base station at the same layer, wherein the LRS of the source base station at the same layer is the same;

The second configuration module is configured to configure the same subframe offset for the LRS sent by the source base station of the same layer, and configure different subframe offsets for the LRS sent by the source base station of different layers;

The control module is configured to control each source base station to send the LRS at the corresponding subframe position based on the subframe offset of the LRS configured by itself.

The apparatus for configuring signal parameters in the air interface synchronization provided by the embodiment of the present invention configures the same LRS as a reference signal for the source base station on the same layer, so that the LRS signals sent by the source base station on the same layer are additively enhanced with each other to obtain signal diversity gain, thereby solving the problem of The problem of mutual interference caused by conflicting RE resources between synchronization reference signals (LRS, listening RS) sent by multiple source cells at the same layer in the prior art in the ultra-dense deployment scenario of small cells is solved, so as to improve the network air interface synchronization performance.

Specifically, the first configuration module includes: a first configuration unit, configured to combine CRS (Cell-specific reference signals), PRS (Positioning reference signals) and CSI-RS (CSI reference signals), and CSI is the abbreviation of Channel-StateInformation, and RS is the abbreviation of reference signal (reference signal), which is configured as the reference signal of the LRS of the source base station in the same layer; the second configuration unit is used for this arbitrary reference signal. A reference signal is configured with the same initial phase.

It is not excluded to design a new reference signal. When the new reference signal is configured as the reference signal of the LRS of the source base station in the same layer, the sequence generation manner and the initial phase are exactly the same.

Wherein, the second configuration unit includes: a replacement component, configured to replace the base station related parameters in the initial phase calculation formula with the radio frame number, so as to generate the same initial phase.

Preferably, for CRS and PRS, the Cell-ID parameter is replaced by the radio frame number For CSI-RS, replace the parameter configured by the higher layer with the radio frame number

In order to solve the above technical problem, an embodiment of the present invention also provides a device for configuring signal parameters in air interface synchronization, as shown in FIG. 5 , including:

a receiving module for receiving the same LRS from multiple source base stations on the same layer;

a first obtaining module, configured to obtain respective corresponding source base station sending times from a plurality of the LRSs, where the source base station sending time is based on the source base station clock;

A second acquisition module, configured to acquire respective local reception times corresponding to the arrival of a plurality of the LRSs, and the local reception times are based on a local clock;

an operation module, configured to perform an operation by using the transmission time and the local reception time of the source base station corresponding to the plurality of LRSs to obtain an estimated value of the average timing deviation. Among them, the estimated value contains the measurement error value.

The apparatus for configuring signal parameters in the air interface synchronization provided by the embodiment of the present invention obtains an estimated average timing deviation by processing LRSs sent by multiple source base stations in the same layer, which further solves the problem of the ultra-dense deployment scenario of small cells in the prior art The synchronization reference signal (LRS, listening RS) sent by multiple source cells in the same layer below is a problem of mutual interference caused by the conflict of RE resources, so as to improve the network air interface synchronization performance.

The method further includes: a third obtaining module, configured to obtain the path propagation delay times corresponding to the plurality of LRSs before the operation module performs the operation;

The operation module is specifically configured to: obtain an average timing deviation value by performing operation on the source base station transmission time, local reception time and path propagation delay time corresponding to each of the plurality of LRSs.

In order to solve the above technical problem, an embodiment of the present invention also provides a device for configuring signal parameters in air interface synchronization, as shown in FIG. 6 , including:

The third configuration module is configured to configure an LRS mode for the base station, so that the LRS sent by the base station is orthogonal to the LRS sent by other base stations in the same layer;

A sending module, configured to send the LRS scrambled by the cell according to the LRS mode.

The apparatus for configuring signal parameters in the air interface synchronization provided by the embodiment of the present invention configures different LRS modes for the source base stations of the same layer, so that the LRSs sent to each other are orthogonal to solve the problem of the same problem in the ultra-dense deployment scenario of small cells in the prior art. The synchronization reference signal (LRS, listening RS) sent by multiple source cells in the layer causes the problem of mutual interference caused by the conflict of RE resources, so as to improve the synchronization performance of the network air interface.

Wherein, the LRS sent by the base station and the LRS sent by other base stations in the same layer are respectively located in the GPs of different special subframes in the TDD system.

The present invention preferentially adopts the distributed LRS mode scheduling mechanism, and there are two specific implementation forms. The first one: the third configuration module includes: a first sending unit, which is used for sending request feedback to adjacent base stations on the same layer. LRS mode signaling; a receiving unit, configured to receive the response information fed back by the neighboring base station according to the signaling; an acquisition unit, configured to obtain a connection with all neighboring base stations from the local LRS mode database according to the response information The LRS patterns are not the same as the LRS patterns.

Second, the third configuration module in the configuration device provided by the embodiment of the present invention includes: a first determination unit, configured to determine a candidate subframe for an LRS to be sent; a second sending unit, configured to Listening to the LRS sent by other neighboring cells on the candidate subframe; the second determining unit is configured to, if the listening result is that there are LRS configuration resources in the candidate subframe that are not occupied by the LRS of the other neighboring cells, then Determine an unoccupied LRS configuration resource; the third determination unit is configured to determine an LRS mode according to the determined LRS configuration resource.

Further, it also includes: a loop module, configured to continue to perform the process of determining a pending transmission if all available LRS configuration resources of the candidate subframe have been occupied by the LRS of the other adjacent cells as a result of the listening Candidate subframes for LRS.

Among them, in the same cluster, the transmission period of all LRSs is the same; if the micro-station has the switching function, it will also send the LRS even in the dormant state; the LRS has different characteristic points from other signals, and can be used by other adjacent cells. identified.

The following specifically describes the method for configuring signal parameters in the air interface synchronization provided by the embodiment of the present invention.

Method A: Multiple source cells in the same layer transmit identical LRS signals in the same LRS transmission subframe, that is, the LRS signals of these cells in the same layer have the same pseudo-code sequence and occupy the same RE resources.

Fundamental:

Multiple source cells in the same layer transmit identical LRS signals in the same LRS transmission subframe, that is, the LRS signals of these cells in the same layer have the same pseudo-code sequence and occupy the same RE resources.

The target cell performs network listening in the above-mentioned LRS sending subframe, and the received signal is a superposition in the time domain of LRS signals (referred to as LRS components) sent by multiple source cells.

The target cell estimates the time-of-arrival (TOA) of all LRS components through time-domain correlation operations (or other similar operations), but since the pseudo-code sequences of all LRS components are the same, the target cell cannot correctly identify these components with different arrival times The source cell from which the LRS component of .

Pay attention to the node eNB 2-2 with stratum level (synchronization level) = 2 in Figure 7, it receives three source cells (respectively eNB1) of the previous hop (stratum level = 1) in the LRS transmission subframe of stratum level = 1 -1, LRS signal of eNB1-2, eNB1-3). These LRS signals have the same pseudo-code sequence, and time-frequency resources.

For brevity of description, the source cells eNB 1-1, eNB 1-2 and eNB 1-3 are respectively denoted as S1, S2 and S3, and the target cell eNB 2-2 is denoted as target cell T. As shown in FIG. 8 , source cells S1, S2 and S3 all transmit LRS signals at local time 0 (LRS transmission subframe). Due to the timing synchronization errors of S1, S2 and S3 themselves, the GNSS timing is used as the reference timing, and the actual transmission time of the LRS signal is t _TX1 =δ _S1 , t _TX2 =δ _S2 and t _TX3 =δ respectively _S3 . At the same time, it is assumed that the initial timing synchronization error of the target cell T itself is t _target =δ _T . Considering the path propagation delays τ _S1 , τ _S2 and τ _S3 from S1, S2 and S3 to the target cell T, the arrival times of the LRS signals sent by S1, S2 and S3 expressed in GNSS to the target cell T are respectively t _RX1 =δ _S1 +τ _S1 , t _RX2 =δ _S2 +τ _S2 and t _RX3 =δ _S3 +τ _S3 .

The signal received by the target cell T is actually a combination of the LRS signals sent by S1, S2 and S3 in the time domain. The arrival time of each LRS component expressed in GNSS time is shown in the image on the corresponding axis of receiver sig @T in Figure 8. are shown as t _RX1 =δ _S1 +τ _S1 , t _RX2 =δ _S2 +τ _S2 and t _RX3 =δ _S3 +τ _S3 , respectively.

As shown in FIG. 8 , the time of arrival (TOA) of each received signal component represented by the target cell local time is TOA _RX1 =t _RX1 -t _target =(δ _S1 -δ _T )+τ _S1 , TOA _RX2 =t _RX2 -t _target =(δ _S2 -δ _T )+τ _S2 and TOA _RX3 =t _RX3 -t _target =(δ _S3 -δ _T )+τ _S3 .

The target cell T first generates the replica of the local recurrence signal of the LRS, and then performs time-domain correlation processing (or other similar operations) on the replica and the received signal to obtain the composite correlation function combination ACF. The curve trend corresponds to combination ACF @T in Figure 8 The image on the axis is shown. The horizontal axis position corresponding to the peak value of the ACF function represents the signal propagation time expressed in the local time of the target cell. Through the position of the peak value of the ACF function, the estimator of the signal arrival time TOA expressed in the local time of the target cell can be estimated which is Among them ε _S1 , ε _S2 and ε _S3 represent TOA estimation errors (ie measurement errors). It can be assumed that ε _S1 , ε _S2 and ε _S3 are independently distributed with mean zero. That is, the original time difference measurement obtained by the target cell.

The target cell T finally generates an estimated value of the timing offset according to the TOA information of the above-mentioned LRS components and some other auxiliary information Make it approximately equal to the average timing deviation of the previous hop source base station. When obtaining timing bias estimates After that, the target cell is based on The local clock is calibrated so that it is approximately equal to the average timing deviation of the previous hop source base station, that is, the clock synchronization function of the adjacent 2-hop base station is realized.

When the path propagation delay τ _Si of all source cells can be completely ignored, we have and At this time, the timing deviation of the target cell can be estimated on average by a simple formula, that is,

Timing relationship:

Timing bias estimator:

Among them, represents the definition, E{□} represents the mean value, and the mean value of the measurement noise E{ε _Si }=0. Therefore, the physical meaning of the above formula is that when the path propagation delay τ _Si can be ignored, the timing deviation estimate of the target cell can be defined as the negative number of the mean value of TOA, and the timing deviation estimate calculated according to this definition is approximately equal to The difference between the real timing offset _δT of the target cell and the mean value E{ _δSi } of the timing offsets of all source base stations in the previous hop. After obtaining, the target cell adjusts the local clock so that the calibrated local clock timing deviation is approximately equal to the mean value E{ _δSi } of the timing deviations of all source base stations in the previous hop, that is,

However, when the path propagation delay τ _Si of the source cell is large and cannot be ignored, the timing deviation estimator of the target cell cannot be estimated by a simple TOA averaging algorithm. However, in Method A, since the LRS sequences of all LRS components are the same, it is difficult for the target cell T to correspond the LRS components to a specific source cell, that is, it is difficult to use the prior information (such as the path propagation delay τ _Si ) for the LRS components. The TOA estimate is calibrated (meaning the influence of the propagation delay τ _Si of the calibration path on the TOA measurement). When the propagation delay τ _Si of some source cell paths is large, it may cause a large systematic deviation to the target cell T timing deviation estimation algorithm. The following will give different timing offset estimation methods according to three different application scenarios.

Source cell side processing:

Source cells of the same stratum level use the same LRS subframe offset, and different stratum levels use different LRS subframe offsets.

Source cells of the same stratum level send exactly the same LRS signal in the same LRS transmission subframe, that is, the LRS signals of these same-layer cells have the same pseudo-code sequence and occupy the same RE resources. Therefore, the LRS signal here has nothing to do with the cell ID.

One embodiment is to scramble the LRS by the radio frame number (SFN) instead of the cell ID (cell number).

[Embodiment 1] For example, when the LRS signal is CSI-RS (CSI reference signals, and CSI is the abbreviation of Channel-State Information, and RS is the abbreviation of reference signal reference signal), the initial phase of its pseudo code sequence (initial phase calculation formula) is

in,

Among them, _ns is the slot number within a radio frame (Slot number within a radio frame), l is the OFDM symbol number within the slot (OFDM symbol number within the slot), is the CSI number of the cell; N _CP is the cyclic prefix type parameter, when using normal cyclic prefix (normal CP), N _CP =1, otherwise, when using extended cyclic prefix (extended CP), N _CP =0; c _init is the initial phase of the pseudo-random sequence.

can be put here Configured as an SFN number through higher layer signaling. This embodiment does not require modification of existing standards.

[Embodiment 2] When the LRS signal is CRS (Cell-specific reference signal) or PRS (Positioning reference signal), the initial phase of the pseudo code sequence (the initial phase calculation formula) is

The main parameters are the same as above, the main difference is Represents the cell ID (cell ID). This embodiment requires modifying the initial phase cinit of the LRS generation sequence. parameters, will Modified to SFN number.

If the LRS uses other reference signals, it can be configured similarly.

Target cell side processing:

Depending on the small cell deployment scenario, the processing method on the target cell side will also be different. It can be divided into 3 main deployment scenarios:

The first type of deployment scenario: all target cells can always find a source cell that is very close to themselves, and the path propagation delay between them is negligible.

According to the assumption, the shortest path propagation delay τ _S1 from all source base stations at the n-1th hop to the nth hop target cell can be ignored, and the timing offset estimate of the nth hop target cell can be defined by two methods.

The first one: Set the received signal power threshold. Specifically, when the ACF peak power of the LRS component is lower than a certain threshold, the LRS component does not participate in the target cell T timing offset estimation. The received signal power threshold may be a certain absolute power value, or may be a certain relative power value with the received power of the first LRS component as a reference. The mathematical expression is:

Timing offset estimator for the target cell

Among them, mean indicates the arithmetic mean, and the text below mean indicates that the correlation power of the M LRS components participating in the mean operation is greater than or equal to a certain threshold. Since the propagation delay of the path is longer, the power attenuation of the received signal is also larger, resulting in the reduction of the relevant power. Therefore, by setting the above threshold, it can be ensured that the path propagation delay τ _Si of all source base stations participating in the averaging operation is relatively small, and thus can be ignored, that is, τ _Si ≈0.

Substitute the calculation formula of TOA into the above In the definition of , to analyze the above Definitional inner principles. A known but

That is, the estimated timing offset is approximately equal to the difference between the real timing offset _δT of the target cell and the mean value E{ _δSi } of the timing offsets of all source base stations in the previous hop. After obtaining, the target cell adjusts the local clock so that the calibrated local clock timing deviation is approximately equal to the mean value E{ _δSi } of the timing deviations of all source base stations in the previous hop, that is,

The second: received signal power weighting. Specifically, when estimating the target cell T timing offset, the TOA estimation amount TOA _RXi is weighted by the received power P _i of the LRS component. The greater the received power _Pi , the the greater the weight. A possible mathematical expression is

Timing offset of target cell

Among them, g(□) is some kind of increasing function.

Since the propagation delay of the path is longer, the power attenuation of the received signal is also larger, resulting in the reduction of the relevant power. Therefore, by setting the above threshold, it can be ensured that the source base station with a large path propagation delay τ _Si has a relatively small weighted contribution to the timing deviation estimate of the target cell, while the source base station with a relatively large weighted contribution has a relatively large path propagation delay τ _Si . is relatively small, and the effect of the final total path propagation delay can be ignored.

Substitute the calculation formula of TOA into the above In the definition of , to analyze the above Definitional inner principles. A known but

but

Based on the assumption, the weighted contribution g(P _i ) of the source base station with a large path propagation delay τ _Si to the timing offset estimate of the target cell is relatively small, while the path propagation delay τ _Si of the source base station with a relatively large weighted contribution is both relatively small, so

finally available timing bias estimator It is approximately equal to the difference between the real timing deviation δ _T of the target cell and the mean value E{δ _Si } of the timing deviations of all source base stations in the previous hop. get After the target cell adjusts the local clock Make the calibrated local clock timing skew It is approximately equal to the mean value E{ _δSi } of the timing deviations of all source base stations in the previous hop, namely

The second type of deployment scenario: only the path propagation delay from the 0th hop base station (such as macro station) to the 1st hop base station (small cell) is large and cannot be ignored; while the nth hop base station (n≥1) to the nth hop The path propagation delay of the first LRS component of the +1 hop base station (small cell) can be ignored.

In this application scenario, the timing offset of the first hop base station and the timing offset of the nth hop (n≥2) can be estimated respectively by different methods.

The method for estimating the timing offset of the first hop base station is first introduced below. In this application scenario, only one 0th hop base station (such as a macro station) can be required in a cluster through configuration, and then the first hop target cell can measure its path with the 0th hop base station in advance through the implementation class method Propagation delay τ _S1 , its TOA relation is: Therefore, the timing offset estimator of the target cell can be defined Defined as TOA calibrated with the path propagation delay τ _S1 , namely: Assuming that the timing deviation δ _S1 of the 0th hop base station (such as a macro station) is approximately 0, and the mean value of the timing measurement error ε _S1 is 0, we have That is, the target cell timing offset estimator approximately equal to the true timing offset.

The timing offset estimation method of the nth hop (n≥2) base station is the same as the first type of deployment scenario.

The third type of deployment scenario: except that the path propagation delay from the 0th hop base station (such as macro station) to the first hop base station (small cell) cannot be ignored, and the nth hop base station (n≥1) to the n+1th hop The path propagation delay of the first LRS component of the base station (small cell) cannot be ignored either.

In this application scenario, the synchronization method from the 0th hop to the 1st hop may refer to the second type of deployment scenario.

The following mainly describes the synchronization method from the nth hop base station (n≥1) to the n+1th hop base station (small cell). When the path propagation delay of the first LRS component is not negligible, it needs to be calibrated (that is, adding the path propagation delay of the first LRS component is equivalent to changing the influence of the path propagation delay of the first LRS component from the target excluded from the cell timing offset estimator).

The processing steps are as follows:

Step 1: The target cell measures the path propagation delay between it and all neighboring base stations in advance by implementing the class method, and makes a mapping table between the path propagation delay and the base station pair. The mapping table format can be < path propagation delay, fromcell ID , to cell ID>. This measurement work can be performed when the target cell restarts. It is possible to restart all base stations in the entire cluster in turn when the UE service is inactive in the middle of the night every day/week, and measure the path propagation delay between them;

Step 2: The target cell selects the synchronization source source cell. The specific selection method may refer to the existing 3GPP standard. Set the stratum level of the source cell to n-1, then the stratum level of the target cell is set to n;

Step 3: The target cell obtains the offset of the LRS subframe sent by the source cell. The target cell further obtains the cell ID set of the adjacent source cells with stratum level=n-1. The target cell can obtain the cell ID information of the above-mentioned adjacent source cells through blind detection of PSS/SSS signals in Step 2, or backhaul signaling (eg, through the X2/S1 interface). According to the obtained cell ID set of adjacent source cells, the target cell searches the mapping table <path propagation delay, from cell ID, to cell ID> between the path propagation delay determined in Step 1 and the base station pair, and obtains the target cell to stratum level= The shortest path τ _min of the adjacent source cells of n-1;

Step 4: Same as the first category, in order to suppress the influence of the LRS component with larger path propagation delay on the estimation of the target cell T timing offset, two technical means can be used:

Set the received signal power threshold, then define

Timing offset of target cell

Received signal power weighting, i.e. defined

Timing offset of target cell

Among them, g(□) is some kind of increasing function. For other function definitions, refer to the first type of deployment scenario. Wherein, τ _min is not necessarily equal to the path propagation delay of the first LRS component, but generally, better path propagation delay calibration and air interface synchronization performance can be obtained.

Method B: Multiple source cells at the same layer send cell-scrambled LRS signals in the same or different downlink subframes as needed, and use appropriate scheduling mechanisms to ensure that LRS signals from different source cells at the same layer are orthogonal to each other . When working normally (not out of sync), the target cell only listens to the LRS signal of one synchronization source at a time to maintain air interface synchronization.

The core idea of Method B in this embodiment of the present invention is that a stratum level is bound to an LRS subframeoffset range; in this way, interference between LRS signals of the same layer can be completely suppressed.

As shown in FIG. 9 and FIG. 10 , multiple source cells in the same layer transmit cell-scrambled LRS in the same or different downlink subframes. Wherein, the LRS signal scrambled by the cell may be a legacy (traditional) RS (reference signal), such as CRS, PRS, CSI-RS, etc., and the LRS signal may also be a newly designed reference signal.

In order to ensure that the LRS signals from multiple source cells in the same layer are orthogonal to each other, the LRS can be divided into the subframe dimension and/or the frequency dimension within the subframe and/or the OFDM (Orthogonal Frequency Division Multiplexing) symbol dimension within the subframe. The RE (resource element/resource element) resources corresponding to the signal are staggered. The offset includes time domain offset (subframe level offset and symbol offset-OFDM symbol offset) and frequency domain offset (ie frequency offset/subcarrier offset).

In particular, different LRS signals have different degrees of frequency dimension reuse (that is, the LRS signals are staggered by subcarrier offsets in the frequency domain). For example, the frequency dimension reuse degree of 2-port CRS is 3, and the frequency dimension reuse degree of PRS is 3. is 6. When there are too many sourcecells in the same layer so that their LRS signals cannot be transmitted orthogonally on the same subframe, a new multiplexing dimension—subframe offset dimension—can be introduced to ensure the orthogonality of LRS signals. The specific offset The method is shown in Figure 9 and Figure 10.

The muting mechanism between different stratum levels can ensure better synchronous listening performance. Figures 9 and 10 show two different muting mechanisms. Figure 9 (Opt1) shows all muting across layers, that is, no matter which subframe on which stratum level sends LRS signals, all base stations at other stratum levels are muted (not sending data) at the same subframe to avoid interfering with LRS signal listening performance. Figure 10 (Opt2) shows the adjacent layer listening muting, that is, when the nth layer base station transmits the LRS signal, the n+2th layer is silent to avoid interfering with the LRS signal listening performance of the n+1th layer.

Multiple base stations on the same layer coordinate each other's LRS transmission resources (including transmission subframes, subcarrier offsets and OFDM symbols within the transmission subframes) by exchanging backhaul signaling to ensure the RE resources corresponding to each other's LRS signals stagger.

The following examples illustrate several feasible scheduling mechanisms to ensure that LRS signals from different source cells of the same layer are sent in a staggered manner on different time-frequency resources.

Option 1: Adopt a centralized listening RS pattern (pattern) scheduling mechanism: there is a central controller that centrally manages the listening RS patterns of all eNB target base stations, and ensures their orthogonality. Specifically, the central controller maintains a LRS pattern database.

1. When a base station wants to determine where it sends the LRS signal, it first sends a request signaling to the central controller, requesting feedback of an LRS pattern that will not cause collision;

2. The central controller selects an LRS pattern that does not conflict with the LRS patterns of all existing base stations according to the maintained LRS pattern database, and feeds the information back to the requesting base station through signaling;

3. The central controller adds the feedback LRS pattern into the LRS pattern database to update and maintain the database;

4. Request the base station to send the LRS signal according to the LRS pattern fed back by the central controller;

5. The request and feedback signaling can be transmitted through backhaul (such as S1 interface, X2 interface);

6. The LRS pattern shall at least include information such as LRS subframe offset and LRS signal repetition period.

Option 2: Using the distributed listening RS pattern scheduling mechanism, there are two implementation mechanisms.

Alt 1: Based on backhaul (backhaul) signaling. Each eNB consults the LRS configuration information of neighboring or all base stations through backhaul signaling to determine its own LRS configuration information to ensure that it is orthogonal to the LRS signals of other eNBs. The specific steps include:

1. When a base station wants to determine where it sends the LRS signal, it first sends a request signaling to the adjacent base station, requesting the other party to feed back the LRS pattern it uses;

2. The neighboring base station responds to the request and feeds back the LRS pattern used by itself to the requesting base station;

3. Request the base station to maintain a local LRS pattern database according to all the collected LRS pattern information of adjacent base stations, and then select an LRS pattern that does not conflict with the LRS patterns of all adjacent base stations according to the database;

4. Request the base station to send the LRS signal according to the currently selected LRS pattern.

Alt 2: Each eNB first listens (blindly detects) the LRS signals of other eNBs through the air interface, and then configures its own LRS configuration information based on the listening results to ensure that it is orthogonal to the LRS signals of other eNBs. Specific steps include:

1. When a base station (called the current base station) wants to determine where it is sending LRS signals, it first determines a candidate subframe to send LRS signals, and then listens to other adjacent cells on the candidate subframe. LRS signal (blind detection);

2. In order to avoid the influence of the listening process on the UE service of the current base station, the current base station may configure a measurement gap. Specifically, the measurement interval can be configured as an MBSFM (Multicast/Multicast Single Frequency Network) subframe;

3. If the current base station finds through blind detection that all available LRS configuration resources of the candidate subframe are occupied by LRS signals of other cells, the current base station reselects a candidate subframe to be sent LRS signals, and then re-executes step 1 ;

4. Otherwise, if it is found through blind detection that the candidate subframe is not occupied by LRS signals of other cells, the current base station will occupy the subframe and select an unoccupied LRS configuration resource to send LRS signals.

In addition, additional requirements In order to avoid missed listening, the following additional constraints need to be met:

Constraint 1: In the same cluster (cluster), the transmission period of all listening RSs is the same;

Constraint 2: If there is a small cell with on/off switching function, the off cell is required to also send listening RS;

Constraint 3: LRS needs to be able to be distinguished from non-LRS signals. For example, LRS signals are newly designed reference signals and can be blindly detected by other neighboring cells.

Method C: Multiple source cells at the same layer send cell-scrambled LRS signals in different downlink subframes as needed, and the LRS signals are only sent in special subframes of the TDD system, and use the same scheduling mechanism as Method B , to ensure that the LRS signals from different source cells in the same layer are orthogonal to each other. For the specific configuration of its LRS signal, please refer to the solution in the patent application 201410035839.9, as follows:

An air interface synchronization scheme that uses the GP (Guard Interval) of a TDD (Time Division Duplex) special subframe to send an LRS signal. As shown in Figure 11, the TDD source cell sends the LRS signal in the GP of the special subframe. A possible embodiment is: the ratio of uplink and downlink time slots of the special subframe is 9:3:2, wherein the downlink DwPTS (downlink pilot frequency slot) occupies 9 OFDM symbols, the GP occupies 3 OFDM symbols, and the uplink UpPTS (upstream pilot time slot) occupies 2 OFDM symbols. The source cell transmits the LRS signal using the first OFDM symbol of the GP. The LRS signal may be a tailored legacy RS (such as CRS, PRS, CSI-RS, etc.), and the so-called tailoring refers to sending legacy (legacy) RS (reference signal) signals only on the OFDM symbols sent by the LRS, and sending legacy (legacy) RS (reference signal) signals on other OFDM symbols. No data is sent on the symbol.

The solution shown in Fig. 11 cleverly utilizes the advantage of not transmitting data on the GP of the TDD special subframe, and can automatically realize the cross-layer overall mute function. Therefore, the scheme has better synchronous interception performance.

On the other hand, the scheme is completely transparent to the UE with ideal backward compatibility.

However, the scheme shown in Figure 11 has a certain system overhead, that is, all base stations are required to reserve (vacate) several (≥1) OFDM symbols in the GP for transmitting/listening LRS signals, which may cause certain resource overhead and waste. However, if the number of OFDM symbols occupied by the LRS signal is small (eg = 1), it will hardly affect the service rate, because the service rate is determined by the TBS (transmission block size), and the use of one OFDM symbol has a greater impact on the TBS. Small, for example, the ratio of uplink and downlink time slots is 9:3:2 (used by the scheme in the patent application 201410035839.9) and 10:2:2 (compared to the scheme, the LRS of 1 OFDM symbol is released for service communication) generally have The TBS of the system, so the service rate of the two is the same. Of course, although the TBS of the two are the same, the transmission bit size of the two is different, which will affect the encoding/decoding performance. Therefore, the system overhead of the solution in the patent application 201410035839.9 can be expressed as: on the premise that the TBS (reflected as service rate) remains basically unchanged, the encoding/decoding performance (reflected as robustness) slightly decreases.

Method C enhances the solution shown in Figure 11 from the perspective of stratum level and subframe offset mapping for the ultra-dense deployment scenario of small cells.

As shown in FIG. 12 , through an appropriate scheduling mechanism, a synchronization level is corresponding to a certain LRS subframe offset set to ensure that multiple source cells in the same layer send cell-scrambled LRS signals in different downlink subframes.

On the basis of Method B, the combination scheme can automatically realize the cross-layer muting mechanism, so there is no need to introduce additional system overhead, and further excellent results are achieved.

To sum up, in the case of more dense deployment of small cells in the future (such as 5G UDN: ultra dense network), there may be more than 60 small cells in a cluster, and there may be more than 7 small cells per hop (layer). , if according to the existing RIBS technology, that is, the base station of the same layer sends the LRS signals scrambled by their respective cell IDs in the same subframe, then because the number of source cells in the same layer exceeds the multiplexing degree of the LRS signals, these LRS signals even pass through It is also difficult for cell planning to be completely staggered on RE resources, which will interfere with each other and reduce network air interface synchronization performance.

However, the embodiment of the present invention proposes three RIBS parameter configuration schemes and embodiments for the problem of mutual interference between LRS signals sent by multiple source cells at the same layer in the air interface synchronization application in the ultra-dense deployment scenario of small cells:

Method A: Multiple source cells in the same layer transmit identical LRS signals in the same LRS transmission subframe, that is, the LRS signals of these cells in the same layer have the same sequence and occupy the same RE resources.

Method B: Multiple source cells at the same layer send cell-scrambled LRS signals in the same or different downlink subframes as needed, and use appropriate scheduling mechanisms to ensure that LRS signals from different source cells at the same layer are orthogonal to each other .

Method C: Combining Method B with the scheme in patent application 201410035839.9—that is, the RIBS scheme for transmitting LRS signals in the GP of TDD special subframes—defines a new synchronization level and LRS transmission subframe offset (LRS for short). subframe offset), that is, through an appropriate scheduling mechanism, a synchronization level corresponds to a certain LRS subframe offset range (LRS subframe offset range, and the number of offsets in the set ≥ 1) to ensure that the same layer Multiple source cells transmit cell-scrambled LRS signals in different downlink subframes.

The RIBS parameter configuration technology provided by the embodiments of the present invention can solve the problem of mutual interference caused by the conflict of RE resources between synchronization reference signals sent by multiple source cells on the same layer in the ultra-dense deployment scenario of small cells, thereby effectively guaranteeing small cells Inter-station air interface synchronization performance in ultra-dense deployment scenarios.

The above are the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as It is the protection scope of the present invention.

Claims (20)

1. a configuration method of signal parameters in air interface synchronization, is characterized in that, comprising: Configure the reference signal as the synchronization reference signal LRS for the source base station of the same layer, wherein the LRS of the source base station of the same layer is the same; Configure the same subframe offset for the LRS sent by the source base station in the same layer, and configure different subframe offsets for the LRS sent by the source base station in different layers; Each source base station is controlled to send the LRS at the corresponding subframe position based on the subframe offset of the LRS configured by itself. 2. The configuration method according to claim 1, wherein the reference signal configured as the synchronization reference signal LRS for the source base station in the same layer comprises: Configure any one of the cell common reference signal CRS, the positioning reference signal PRS, and the channel state information reference signal CSI-RS as the reference signal of the LRS of the source base station in the same layer, and configure the same for any one of the reference signals the initial phase. 3. The configuration method according to claim 2, wherein the configuring the same initial phase for any one of the reference signals comprises: Replace the base station-related parameters in the initial phase calculation formula with the radio frame number to generate the same initial phase. 4. A method for configuring signal parameters in air interface synchronization, comprising: Receive the same synchronization reference signal LRS from multiple source base stations on the same layer; Obtaining respective corresponding source base station sending times from a plurality of the LRSs, where the source base station sending time is based on the source base station clock; Obtain the respective local reception times corresponding to the arrival of a plurality of the LRSs, and the local reception times are based on the local clock; Using the source base station transmission time and local reception time corresponding to each of the plurality of LRSs to obtain an average timing deviation estimate value; Wherein, before using the transmission time and the local reception time of the source base station corresponding to the plurality of LRSs to obtain the average timing deviation estimate value, the method further includes: obtaining path propagation delay times corresponding to each of the plurality of LRSs; According to the path propagation delay time, the source base station is divided into three types of deployment scenarios; the deployment scenarios include the first type of deployment scenarios corresponding to the path propagation delay times of 0, and some of the path propagation scenarios. The second type of deployment scenario corresponding to the delay time of 0 and the third type of deployment scenario corresponding to the path propagation delay time not being 0; The average timing deviation value obtained by the calculation using the respective corresponding source base station transmission time and local reception time of the plurality of LRSs is as follows: According to the three types of deployment scenarios, the average timing deviation value is obtained by performing operations on the source base station sending time and local receiving time corresponding to the plurality of LRSs. 5. A method for configuring signal parameters in air interface synchronization, comprising: According to the synchronization reference signal LRS mode used by the adjacent base station, configure an LRS mode for the base station itself, so that the LRS sent by the base station is orthogonal to the LRS sent by other base stations in the same layer; The cell-scrambled LRS is transmitted according to the LRS pattern. 6 . The configuration method according to claim 5 , wherein the LRS sent by the base station and the LRS sent by other base stations in the same layer are respectively located in guard intervals GP of different special subframes in a time division duplex TDD system. 7 . 7. The configuration method according to claim 5, wherein the configuring an LRS mode for the base station itself comprises: Sending a signaling requesting feedback of the LRS mode used to the neighboring base stations of the same layer; receiving the response information fed back by the neighboring base station according to the signaling; According to the response information, an LRS pattern that is different from the LRS patterns of all neighboring base stations is acquired in the local LRS pattern database. 8. The configuration method according to claim 5, wherein the configuring an LRS mode for the base station itself comprises: Determine a candidate subframe for LRS to be sent; listening to the LRS sent by other neighboring cells on the candidate subframe; If the listening result is that there are LRS configuration resources in the candidate subframe that are not occupied by the LRSs of the other neighboring cells, determine an unoccupied LRS configuration resource; An LRS mode is determined according to the determined LRS configuration resources. 9. The configuration method of claim 8, further comprising: If the listening result is that all available LRS configuration resources of the candidate subframe are occupied by the LRSs of the other neighboring cells, then continue to perform the determining of a candidate subframe for which LRS is to be sent. 10. configuration method as claimed in claim 8, is characterized in that, in the same cluster, the transmission cycle of all LRS is identical; If micro-station has switch conversion function, then even in dormancy state also sends LRS equally; LRS has and Feature points that are different from other signals and can be identified by other neighboring cells. 11. A device for configuring signal parameters in air interface synchronization, comprising: a first configuration module, configured to configure a reference signal used as a synchronization reference signal LRS for the source base station at the same layer, wherein the LRS of the source base station at the same layer is the same; The second configuration module is configured to configure the same subframe offset for the LRS sent by the source base station of the same layer, and configure different subframe offsets for the LRS sent by the source base station of different layers; The control module is configured to control each source base station to send the LRS at the corresponding subframe position based on the subframe offset of the LRS configured by itself. 12. The configuration apparatus according to claim 11, wherein the first configuration module comprises: a first configuration unit, configured to configure any one of the cell common reference signal CRS, the positioning reference signal PRS and the channel state information reference signal CSI-RS as the reference signal of the LRS of the source base station in the same layer; The second configuration unit is configured to configure the same initial phase for any one of the reference signals. 13. The configuration device according to claim 12, wherein the second configuration unit comprises: The replacement component is used to replace the base station-related parameters in the initial phase calculation formula with the radio frame number, so as to generate the same initial phase. 14. A device for configuring signal parameters in air interface synchronization, characterized in that it comprises: a receiving module for receiving the same synchronization reference signal LRS from multiple source base stations on the same layer; a first obtaining module, configured to obtain respective corresponding source base station sending times from a plurality of the LRSs, where the source base station sending time is based on the source base station clock; A second acquisition module, configured to acquire respective local reception times corresponding to the arrival of a plurality of the LRSs, and the local reception times are based on a local clock; an operation module, configured to perform an operation using the respective corresponding source base station transmission times and local reception times of a plurality of the LRSs to obtain an estimated average timing deviation; Wherein, the configuration device further includes: a third obtaining module, configured to obtain the path propagation delay times corresponding to the plurality of LRSs before the operation module performs the operation; According to the path propagation delay time, the source base station is divided into three types of deployment scenarios; the deployment scenarios include the first type of deployment scenarios corresponding to the path propagation delay times of 0, and some of the path propagation scenarios. The second type of deployment scenario corresponding to the delay time of 0 and the third type of deployment scenario corresponding to the path propagation delay time not being 0; The operation module is specifically used for: According to the three types of deployment scenarios, the average timing deviation value is obtained by performing operations on the source base station sending time and local receiving time corresponding to the plurality of LRSs. 15. A device for configuring signal parameters in air interface synchronization, comprising: The third configuration module is configured to configure an LRS mode for the base station itself according to the LRS mode of the synchronization reference signal used by the adjacent base station, so that the LRS sent by the base station is orthogonal to the LRS sent by other base stations in the same layer; A sending module, configured to send the LRS scrambled by the cell according to the LRS mode. 16 . The configuration apparatus according to claim 15 , wherein the LRS sent by the base station and the LRS sent by other base stations in the same layer are respectively located in guard intervals GP of different special subframes in a time division duplex TDD system. 17 . 17. The configuration apparatus according to claim 15, wherein the third configuration module comprises: a first sending unit, configured to send a signaling requesting feedback of the LRS mode used to the neighboring base stations of the same layer; a receiving unit, configured to receive the response information fed back by the neighboring base station according to the signaling; an obtaining unit, configured to obtain an LRS mode that is different from the LRS modes of all adjacent base stations from the local LRS mode database according to the response information. 18. The configuration apparatus according to claim 15, wherein the third configuration module comprises: a first determining unit, configured to determine a candidate subframe of the LRS to be sent; a second sending unit, configured to listen to the LRS sent by other neighboring cells on the candidate subframe; a second determining unit, configured to determine an unoccupied LRS configuration resource if the listening result is that there is an LRS configuration resource that is not occupied by the LRS of the other neighboring cells in the candidate subframe; The third determining unit is configured to determine an LRS mode according to the determined LRS configuration resources. 19. The configuration device of claim 18, further comprising: The loop module is configured to continue to perform the determining of a candidate subframe for which LRS to be sent if the listening result is that all available LRS configuration resources of the candidate subframe have been occupied by LRSs of the other neighboring cells. 20. configuration device as claimed in claim 18 is characterized in that, in the same cluster, the transmission period of all LRS is identical; If micro-station has switch conversion function, then even in dormancy state also sends LRS equally; LRS has and Feature points that are different from other signals and can be identified by other neighboring cells.