CN104080174B - Cell reference signals interference processing method, system and the device of minizone - Google Patents

Abstract

The invention discloses a CRS interference processing method, system and device between cells: for any two adjacent cells in the network where CRS positions conflict, when the DwPTS time slot in the special subframe used by one of the cells is configured as a long DwPTS Configure the DwPTS time slot in the special subframe used by another cell as a short DwPTS time slot; determine the CRS position conflict with the adjacent cell and configure the long DwPTS time slot among the terminals of the cell that meets the requirements For the terminal, the compliance includes: being located at the edge of the cell to which it belongs and adjacent to a neighboring cell where the CRS position conflicts with the cell to which it belongs; scheduling the determined terminal to the DwPTS time slot in the special subframe used by the cell to which it belongs for data transmission. Applying the scheme of the present invention can improve the downlink performance of the system.

Description

Inter-cell cell reference signal interference processing method, system and device

technical field

The present invention relates to wireless technology, in particular to a method, system and device for processing cell reference signal interference between cells.

Background technique

In a Time Division Long Term Evolution (TD-LTE, Time Division Long Term Evolution) system, a Cell-specific Reference Signal (CRS, Cell-specific Reference Signal) is an important reference signal for a terminal to perform channel estimation and data demodulation.

For the currently commonly used two-antenna port system, under the normal cyclic prefix (CP, Cyclic Prefix) configuration, the CRS is located in the 1st, 5th, 8th, and 12th orthogonals of each 1ms subframe in the time domain On frequency division multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) symbols (the number of OFDM symbols starts from 1), in the frequency domain, every 3 subcarriers appear once, that is, there are 4 CRS positions in every 12 subcarriers.

For the terminal, if the CRS is interfered by the CRS of the adjacent cell, it will seriously affect the signal estimation and data reception performance of the terminal, thereby degrading the downlink performance of the system. Therefore, in the prior art, the CRS frequency domain shift between cells is usually used bit solution.

However, due to the high density of CRS in the frequency domain in the TD-LTE system, there are only three CRS positions that can be staggered from each other at most, while in wireless networks, especially in dense urban areas, it is easy to have four or even more The phenomenon that multiple cells are adjacent, at this time, the CRS positions of two cells must not be staggered, that is, CRS position conflicts occur. As shown in Figure 1, Figure 1 is a schematic diagram of CRS position conflicts among existing cells. The CRS positions of Cell 2, Cell 3, and Cell 4 can be staggered from each other, but the CRS positions of Cell 1 and Cell 2 cannot be staggered, so that A CRS location conflict occurs, which in turn leads to CRS interference between cells.

It can be seen that there are still defects in the existing method, which will lead to a decrease in the downlink performance of the system.

Contents of the invention

In view of this, the present invention provides a method, system and device for processing cell reference signal interference between cells, which can improve the downlink performance of the system.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

A method for processing CRS interference between cells, comprising:

For any two adjacent cells in the network where CRS positions conflict, configure the downlink pilot time slot DwPTS in the special subframe used by one cell as a long DwPTS time slot, and configure the DwPTS time slot in the special subframe used by the other cell as a long DwPTS time slot. The DwPTS slot is configured as a short DwPTS slot;

Determine the terminals that meet the requirements among the terminals of the cell subordinate to the cell that has a CRS position conflict with the adjacent cell and is configured with a long DwPTS time slot. Neighboring cell: scheduling the determined terminal to the DwPTS time slot in the special subframe used by the cell to perform data transmission.

A CRS interference processing system between cells, comprising:

The time slot configuration device is used to configure the downlink pilot time slot DwPTS in the special subframe used by one of the cells as a long DwPTS time slot for any two adjacent cells in the network where the CRS position conflict occurs, and configure the DwPTS time slot of the other cell The DwPTS slot in the special subframe used is configured as a short DwPTS slot;

The resource allocation device is used to determine a terminal that meets the requirements among the terminals of the cell subordinate to the cell that has a CRS position conflict with the adjacent cell and is configured with a long DwPTS time slot. Adjacent cells where the CRS positions of the cells collide; the determined terminal is scheduled to the DwPTS time slot in the special subframe used by the cell for data transmission.

A time slot configuration device, comprising:

The time slot configuration module is used to configure the downlink pilot time slot DwPTS in the special subframe used by one of the cells as a long DwPTS time slot for any two adjacent cells where the cell reference signal CRS position conflict occurs in the network. The DwPTS slot in the special subframe used by another cell is configured as a short DwPTS slot.

A resource allocation device, comprising:

A determination module, configured to determine a terminal that meets the requirements among the terminals of the cell subordinate to the cell that has a cell reference signal CRS position conflict with an adjacent cell and is configured with a long downlink pilot time slot DwPTS, and the compliance includes: being located at the edge of the cell to which it belongs , and is adjacent to a neighboring cell whose CRS position conflicts with the cell to which it belongs; notifying the scheduling module of the determined terminal;

The scheduling module is configured to schedule the determined terminal to the DwPTS time slot in the special subframe used by the cell to which it belongs for data transmission.

It can be seen that, by adopting the scheme of the present invention, a long DwPTS time slot and a short DwPTS time slot are respectively configured for two adjacent cells where CRS position conflicts occur, and the terminals of the cell with the long DwPTS time slot configured are located at the edge of the cell and Terminals in adjacent cells that are close to CRS position conflicts are scheduled to long DwPTS time slots for data transmission, and terminals that are severely interfered by adjacent cell CRS are scheduled to long DwPTS time slots for data transmission, thereby reducing or even avoiding CRS interference, and then The downlink performance of the system is improved.

Description of drawings

FIG. 1 is a schematic diagram of a CRS location conflict occurring between existing cells.

Fig. 2 is a flowchart of an embodiment of a method for processing CRS interference between cells according to the present invention.

Fig. 3 is a schematic diagram of configuring special subframes used by two cells according to the method of the present invention.

Fig. 4 is a schematic diagram of a terminal that needs to be scheduled to a long DwPTS time slot for data transmission according to the method of the present invention.

detailed description

Aiming at the problems existing in the prior art, the present invention proposes an inter-cell CRS interference processing scheme, which can improve the downlink performance of the system.

In order to make the technical solution of the present invention more clear and understandable, the solution of the present invention will be further described in detail below with reference to the accompanying drawings and examples.

Fig. 2 is a flowchart of an embodiment of a method for processing CRS interference between cells according to the present invention. As shown in Figure 2, it includes the following steps:

Step 21: For any two adjacent cells in the network where CRS positions conflict, configure the downlink pilot time slot (DwPTS, Downlink Pilot Time Slot) in the special subframe used by one of the cells as a long DwPTS time slot, and set The DwPTS slot in the special subframe used by another cell is configured as a short DwPTS slot.

In the TD-LTE system, in each 10ms long wireless frame, there are 1~2 special subframes with a length of 1ms. The special subframe consists of a DwPTS time slot, a guard interval (GP, Guard Period) time slot and an uplink pilot Time slot (UpPTS, Uplink PilotTime Slot) composition.

Among them, the DwPTS time slot is used for the transmission of downlink control signals and data signals, the GP time slot is the guard time slot for uplink and downlink transmission, and there is no signal transmission, and the UpPTS time slot is used for uplink sounding reference signal (SRS, Sounding Reference Signal) and random access. transmission of incoming signals.

Under the normal CP configuration, the TD-LTE standard specifies 9 special subframe configurations, each of which corresponds to a combination of the number of OFDM symbols occupied by each special time slot, as shown in Table 1.

Table 1 Special subframe configuration under normal CP configuration

Among them, when a DwPTS time slot occupies 9, 10, 11 or 12 OFDM symbols, it can be used to transmit control signals or data signals, which is called a long DwPTS time slot; when a DwPTS time slot occupies 3 OFDM symbols When a symbol is used, only control signals can be transmitted, and data signals cannot be transmitted, which is called a short DwPTS time slot.

In this step, for two adjacent cells where CRS positions conflict, the DwPTS time slot in the special subframe used by one of the cells is configured as a long DwPTS time slot, and the DwPTS time slot in the special subframe used by the other cell is configured as a long DwPTS time slot. The slot is configured as a short DwPTS.

For a cell that does not have a CRS position conflict with an adjacent cell in the network, the DwPTS time slot in the special subframe used by it can be configured as a long DwPTS time slot to improve the downlink performance of the system.

In addition, the number of OFDM symbols occupied by the UpPTS time slots in the special subframes used by each cell in the network can be configured to be the same, for example, all are one, or both are two.

In practical application, this step can be realized by manual assistance or by automatic method.

Among them, the manual assistance method refers to manually analyzing the CRS positions of each cell in the network, and completing the configuration of long and short DwPTS time slots for different cells according to the analysis results.

The automatic mode does not require manual participation. For any cell, it can be determined whether the cell has a CRS position conflict with an adjacent cell according to the automatic neighbor relationship discovery function. If so, obtain the adjacent cell that has a CRS position conflict with the cell. , and compare the acquired identity with the identity of the cell, if the identity of the cell is larger, configure the DwPTS time slot in the special subframe used by the cell as a long DwPTS time slot, otherwise, configure the The DwPTS slot in the special subframe used by the cell is configured as a short DwPTS slot.

Step 22: Determine the qualified terminals among the terminals subordinate to the cell that has a CRS position conflict with the adjacent cell and is configured with a long DwPTS time slot. The compliance includes: being located at the edge of the cell to which it belongs, and close to the cell where CRS occurs Neighboring cells with conflicting positions; scheduling the determined terminal to the DwPTS time slot in the special subframe used by the cell to which it belongs for data transmission.

If a CRS location conflict occurs between a cell and an adjacent cell and a long DwPTS time slot is configured, then in this step, firstly determine the qualified terminal among the terminals subordinate to the cell, that is, the terminal located at the edge of the cell and close to the cell The terminal of the adjacent cell where the CRS position conflict occurs can then schedule the determined terminal to the DwPTS time slot in the special subframe used by the cell for data transmission.

To determine whether a terminal meets the requirements, the following methods can be used: obtain the Reference Signal Received Power (RSRP, Reference Signal Receiving Power) value of the adjacent cell that the terminal has measured and reported that conflicts with the CRS position of the cell it belongs to, and determine the obtained RSRP value and Whether the absolute value of the difference between the RSRP values of the cell to which the terminal belongs is within the interval {a, b}, if so, determine that the terminal is a qualified terminal; where a and b are both greater than or equal to 0, and b is greater than a . The specific values of a and b can be determined according to actual needs, preferably, a=0dB, b=3dB.

Steps 21-22 will be further described below in conjunction with the accompanying drawings.

Fig. 3 is a schematic diagram of configuring special subframes used by two cells according to the method of the present invention. As shown in Figure 3, a short DwPTS time slot is configured for cell 1, occupying 3 OFDM symbols, a long DwPTS time slot is configured for cell 2, occupying 10 OFDM symbols, and UpPTS time slots configured for cell 1 and cell 2 occupy 2 OFDM symbols; it can be seen that cell 1 has no signal transmission on the 4th to 12th downlink symbols, including CRS, and cell 2 can transmit data signals and CRS on the 4th to 10th downlink OFDM symbols. When cell 1 and cell 2 have a CRS location conflict as shown in FIG. 1 , cell 2 will not be interfered by the CRS of cell 1 in the time slot indicated in FIG. 3 .

Fig. 4 is a schematic diagram of a terminal that needs to be scheduled to a long DwPTS time slot for data transmission according to the method of the present invention. As shown in Figure 4, assuming that the CRS positions of cell 2, cell 3, and cell 4 are staggered, that is, there will be no CRS position conflict and no CRS interference between them, and the CRS positions of cell 1 and cell 2 cannot be staggered, and terminal 1 is located in the cell 2 and adjacent to cell 1, in order to avoid CRS interference in cell 1, terminal 1 needs to be scheduled to the long DwPTS time slot in the special subframe used by cell 2 for data transmission.

So far, the introduction about the method embodiment of the present invention is completed.

Based on the above introduction, the present invention simultaneously discloses an inter-cell CRS interference processing system, a time slot configuration device and a resource allocation device.

The system includes:

The time slot configuration device is used for configuring the DwPTS time slot in the special subframe used by one cell as a long DwPTS time slot for any two adjacent cells in the network where CRS position conflict occurs, and configuring the special subframe used by the other cell as a long DwPTS time slot. The DwPTS slot in the subframe is configured as a short DwPTS slot;

The resource allocation device is used to determine a terminal that meets the requirements among the terminals of the cell subordinate to the cell that has a CRS position conflict with the adjacent cell and is configured with a long DwPTS time slot. Adjacent cells where the CRS positions of the cells collide; the determined terminal is scheduled to the DwPTS time slot in the special subframe used by the cell for data transmission.

The time slot configuration device includes:

The time slot configuration module is used to configure the DwPTS time slot in the special subframe used by one cell as a long DwPTS time slot for any two adjacent cells in the network where CRS position conflict occurs, and configure the special subframe used by the other cell to be a long DwPTS time slot. The DwPTS slots in the subframe are configured as short DwPTS slots.

The time slot configuration module may specifically include:

The first processing unit is used to obtain the CRS position analysis results of each cell in the network, wherein the CRS position analysis results of each cell include: whether the cell has a CRS position conflict with an adjacent cell and when the DwPTS required to be configured by the cell gap type;

Among them, for any two adjacent cells where the CRS position conflict occurs, the DwPTS time slot in the special subframe used by one of the cells needs to be configured as a long DwPTS time slot, and the DwPTS time slot in the special subframe used by the other cell needs to be configured as a long DwPTS time slot. The type of configuration required for the time slot is short DwPTS time slot;

completing the time slot configuration for the cell according to the analysis result;

or,

The second processing unit is used to perform the following processing for each cell in the network: according to the automatic neighbor cell relationship discovery function, determine whether the cell has a CRS position conflict with an adjacent cell, and if so, obtain the CRS position conflict with the cell. The identity of the adjacent cell whose CRS position conflicts, and compares the obtained identity with the identity of the cell. If the identity of the cell is larger, configure the DwPTS time slot in the special subframe used by the cell as a long DwPTS Otherwise, configure the DwPTS slot in the special subframe used by the cell as a short DwPTS slot.

The first processing unit and the second processing unit may be further configured to configure the number of OFDM symbols occupied by the UpPTS time slots in the special subframes used by each cell in the network to be the same.

Preferably,

The number of OFDM symbols occupied by the long DwPTS time slot is: 9, 10, 11 or 12;

The number of OFDM symbols occupied by the short DwPTS slot is: 3;

The number of OFDM symbols occupied by the UpPTS time slot is: 1 or 2.

The resource allocation device includes:

A determining module, configured to determine a terminal that meets the requirements among the terminals of the cell subordinate to the cell that has a CRS position conflict with an adjacent cell and is configured with a long DwPTS time slot. Adjacent cells where the CRS position conflict occurs; the determined terminal is notified to the scheduling module;

The scheduling module is configured to schedule the determined terminal to the DwPTS time slot in the special subframe used by the cell to which it belongs for data transmission.

specifically,

The determination module performs the following processing for each terminal subordinate to the cell that has a CRS position conflict with a neighboring cell and is configured with a long DwPTS time slot: Obtain the neighboring cell measured and reported by the terminal that has a CRS position conflict with the cell to which it belongs Determine whether the absolute value of the difference between the acquired RSRP value and the RSRP value of the cell to which the terminal belongs is within the interval {a, b}, and if so, determine that the terminal is a qualified terminal; Wherein, both a and b are greater than or equal to 0, and b is greater than a.

In practical applications, where the above-mentioned time slot configuration device and resource allocation device are deployed in the network may be determined according to actual needs, for example, the time slot configuration device may be located in an Operations Maintenance Center (OMC, Operations Maintenance Center), and The device may be located in a base station. The time slot configuration device can perform its own functions after the network planning and deployment are completed. Considering that the network conditions may change, such as the increase or decrease of cells, the time slot configuration device can repeatedly perform its own functions periodically or eventually. Similarly, considering that the location of the terminal may move, etc., the resource allocation device may also perform its own function repeatedly periodically or event-wise. The specific implementations are well known in the art and will not be repeated here.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (12)

1. A method for processing inter-Cell Reference Signal (CRS) interference, comprising:

for any two adjacent cells in the network with CRS position conflict, configuring a downlink pilot time slot (DwPTS) in a special subframe used by one cell as a long DwPTS time slot, and configuring a DwPTS time slot in a special subframe used by the other cell as a short DwPTS time slot; wherein, the number of OFDM symbols occupied by the long DwPTS time slot is: 9. 10, 11 or 12; the number of OFDM symbols occupied by the short DwPTS time slot is as follows: 3;

determining a terminal meeting requirements in terminals which collide with CRS positions of adjacent cells and belong to a cell configured with a long DwPTS time slot, wherein the meeting requirements comprise: the adjacent cell is positioned at the edge of the cell and is close to the adjacent cell which generates CRS position conflict with the cell; and scheduling the determined terminal to a DwPTS time slot in a special subframe used by the cell to which the terminal belongs for data transmission.

2. The method of claim 1,

the method further comprises the following steps: and for a cell which does not conflict with the adjacent cell in CRS position in the network, configuring the DwPTS time slot in the special subframe used by the cell as a long DwPTS time slot.

3. The method of claim 2,

the method further comprises the following steps: and configuring the number of OFDM symbols occupied by UpPTS in the special sub-frame used by each cell in the network to be the same.

4. The method of claim 3,

the number of OFDM symbols occupied by the UpPTS time slot is as follows: 1 or 2.

5. A method according to claim 1, 2 or 3, wherein said determining a satisfactory terminal comprises:

aiming at each terminal which has CRS position conflict with adjacent cells and belongs to the cell with the long DwPTS time slot, the following processing is respectively carried out:

acquiring a Reference Signal Received Power (RSRP) value of an adjacent cell which is measured and reported by the terminal and has CRS position conflict with a cell to which the terminal belongs, determining whether an absolute value of a difference between the acquired RSRP value and the RSRP value of the cell to which the terminal belongs is located in an interval { a, b }, and if so, determining that the terminal is a terminal meeting requirements; wherein a and b are both greater than or equal to 0, and b is greater than a.

6. An inter-Cell Reference Signal (CRS) interference handling system, comprising:

a time slot configuration device, configured to configure a downlink pilot time slot DwPTS in a special subframe used by one cell as a long DwPTS time slot and configure a DwPTS time slot in a special subframe used by another cell as a short DwPTS time slot for any two adjacent cells in the network where CRS position conflicts occur; wherein, the number of OFDM symbols occupied by the long DwPTS time slot is: 9. 10, 11 or 12; the number of OFDM symbols occupied by the short DwPTS time slot is as follows: 3;

a resource allocation device, configured to determine a terminal that meets requirements among terminals that collide with CRS positions of neighboring cells and belong to a cell configured with a long DwPTS, where the meeting requirements include: the adjacent cell is positioned at the edge of the cell and is close to the adjacent cell which generates CRS position conflict with the cell; and scheduling the determined terminal to a DwPTS time slot in a special subframe used by the cell to which the terminal belongs for data transmission.

7. A timeslot configuring apparatus, comprising:

a time slot configuration module, configured to configure a downlink pilot time slot DwPTS in a special subframe used by one cell as a long DwPTS time slot and configure a DwPTS time slot in a special subframe used by another cell as a short DwPTS time slot for any two adjacent cells in the network where cell reference signal CRS position conflicts occur;

wherein, the number of OFDM symbols occupied by the long DwPTS time slot is: 9. 10, 11 or 12; the number of OFDM symbols occupied by the short DwPTS time slot is as follows: 3.

8. the apparatus of claim 7, wherein the timeslot configuration module comprises:

a first processing unit, configured to acquire a CRS location analysis result of each cell in a network, where the CRS location analysis result of each cell includes: whether CRS position conflict occurs between the cell and the adjacent cell and the DwPTS time slot type required to be configured by the cell;

for any two adjacent cells with CRS position conflict, the type required to be configured by the DwPTS time slot in the special subframe used by one cell is a long DwPTS time slot, and the type required to be configured by the DwPTS time slot in the special subframe used by the other cell is a short DwPTS time slot;

finishing the time slot configuration of the cell according to the analysis result;

or,

a second processing unit, configured to perform the following processing for each cell in the network: according to the automatic neighbor relation discovery function, whether the cell conflicts with the adjacent cell in the CRS position is determined, if yes, the identification of the adjacent cell which conflicts with the CRS position of the cell is obtained, the obtained identification is compared with the identification of the cell, if the identification of the cell is larger, the DwPTS time slot in the special subframe used by the cell is configured to be a long DwPTS time slot, and if not, the DwPTS time slot in the special subframe used by the cell is configured to be a short DwPTS time slot.

9. The apparatus of claim 8,

the first processing unit and the second processing unit are further configured to configure the number of OFDM symbols occupied by the UpPTS in the special subframe used by each cell in the network to be the same.

10. The apparatus of claim 9,

the number of OFDM symbols occupied by the UpPTS time slot is as follows: 1 or 2.

11. A resource allocation apparatus, comprising:

a determining module, configured to determine a terminal that meets requirements among terminals under a cell having a cell reference signal CRS position conflict with an adjacent cell and configured with a long downlink pilot time slot DwPTS, where the meeting requirements include: the adjacent cell is positioned at the edge of the cell and is close to the adjacent cell which generates CRS position conflict with the cell; informing the determined terminal to a scheduling module;

for any two adjacent cells in the network where CRS position conflict occurs, configuring a downlink pilot time slot (DwPTS) in a special subframe used by one cell as a long DwPTS time slot, and configuring a DwPTS time slot in a special subframe used by the other cell as a short DwPTS time slot; the number of OFDM symbols occupied by the long DwPTS time slot is as follows: 9. 10, 11 or 12; the number of OFDM symbols occupied by the short DwPTS time slot is as follows: 3;

and the scheduling module is used for scheduling the determined terminal to a DwPTS time slot in a special subframe used by the cell to which the terminal belongs for data transmission.

12. The apparatus of claim 11,

the determining module performs the following processing for each terminal under the cell which has the position conflict of CRS with the adjacent cell and is configured with the long DwPTS time slot: acquiring a Reference Signal Received Power (RSRP) value of an adjacent cell which is measured and reported by the terminal and has CRS position conflict with a cell to which the terminal belongs, determining whether an absolute value of a difference between the acquired RSRP value and the RSRP value of the cell to which the terminal belongs is located in an interval { a, b }, and if so, determining that the terminal is a terminal meeting requirements; wherein a and b are both greater than or equal to 0, and b is greater than a.