CN105591993B - A kind of up-link interference coordination method and device for OFDMA system - Google Patents

Abstract

The present invention relates to the technical field of wireless communication, in particular to an uplink interference coordination method and device for an OFDMA system. An uplink interference coordination method and device for an OFDMA system provided by the present invention evaluates and classifies UEs from two perspectives, namely the sensitivity of UEs to interference and the degree of interference caused by UEs to neighboring cells, which ensures that they are easily interfered The edge UEs on the edge of the cell are scheduled to the frequency band resources with the least interference, and at the same time, it can ensure that the UEs with strong interference to the adjacent cells can avoid the pre-planned frequency bands of the adjacent cells, so as to more effectively stagger the strong interference between the cells and greatly improve the security of the cell edge users. Performance, and through reasonable interference avoidance and management, the system performance loss is small, and even significantly improved.

Description

A kind of uplink interference coordination method and device for OFDMA system

technical field

The present invention relates to the technical field of wireless communication, in particular to an uplink interference coordination method and device for an OFDMA system.

Background technique

Cellular wireless communication systems based on OFDMA (Orthogonal Frequency Division Multiple Access) technology, such as LTE (Long Term Evolution, long-term evolution), WIMAX (Worldwide Interoperability for Microwave Access, global microwave interconnection access) system, cell Intra-users realize signal orthogonality through frequency division, which better solves the problem of intra-cell interference. But as a price, the same-frequency networking will bring strong inter-cell interference. Cell-edge users are far away from the serving base station, and the received power of useful signals is low, which is easily affected by interference. At the same time, cell-edge users are closer to neighboring cells, and are more likely to cause interference to neighboring cells during uplink data transmission. Based on these two reasons, the performance of cell edge users becomes the key to investigate whether the inter-cell interference is serious or not. Therefore, how to suppress inter-cell interference and improve the performance of edge users has become an important research topic.

For the uplink based on the OFDMA system, the interference comes from different users in neighboring cells, the magnitude of the interference depends on the location and transmission power of the users, and the interference characteristics are more complicated. Due to the influence of the uplink power control technology, the uplink transmission power of each user is related to the fading of the user channel, and the received power reaching the serving base station is often different, which leads to different anti-interference capabilities between users, and at the same time causes great interference to neighboring cells. difference. Especially under the sectorized cell topology, both users at the edge of the cell and users near the center of the cell may cause strong uplink interference to neighboring cells.

Therefore, only by judging the user's location information or the interference situation to determine the edge user, and by scheduling different frequency bands for the edge user of the adjacent cell interference coordination method, can not effectively avoid the strong interference between the cells, because some distance The central users near the base station may also cause strong interference to the edge users in the co-located neighboring cells, so the existing uplink interference coordination methods have limited performance improvement for the edge users.

Contents of the invention

Aiming at the defect that the existing detection technology cannot overcome the defect that some central users closer to the base station may cause strong interference to edge users in co-located adjacent cells, the present invention provides an uplink interference coordination method for OFDMA systems and devices.

In one aspect, the present invention provides an uplink interference coordination method for an OFDMA system, including:

The base station receives the received power RSRP of the uplink pilot signal sent by the user equipment UE;

judging whether the RSRP is smaller than a first preset threshold;

If the RSRP is smaller than the first preset threshold, scheduling edge frequency band resources of the cell to which the UE belongs for the UE;

If the RSRP is greater than or equal to a first preset threshold, then judging whether the RSRP is smaller than a second preset threshold;

If the RSRP is greater than or equal to a first preset threshold and less than a second preset threshold, scheduling edge frequency band resources or high interference sensitivity frequency band resources of the cell to which the UE belongs for the UE;

If the RSRP is greater than or equal to a second preset threshold, sequentially determine whether the received interference power from the UE to each neighboring cell of the cell to which the UE belongs is greater than a third preset threshold;

If the RSRP is greater than or equal to the second preset threshold, and the interference received power is greater than the third preset threshold, schedule the high interference sensitivity frequency band and all related Frequency band resources other than the edge frequency bands of adjacent cells;

If the RSRP is greater than or equal to a second preset threshold, and the interference received power is less than or equal to a third preset threshold, scheduling frequency band resources for the UE except edge frequency bands of all neighboring cells;

The first preset threshold is smaller than the second preset threshold, and the fringe frequency band and the high interference sensitivity frequency band are frequency bands pre-allocated by the base station for each cell.

Further, the received interference power from the UE to each neighboring cell of the cell to which the UE belongs is calculated using the following formula:

Further, the edge frequency band and the high interference sensitivity frequency band are frequency bands pre-divided by the base station for each cell according to the user load of the cell, and the edge frequency band of each cell is respectively related to the edge frequency band and high interference sensitivity frequency band of each adjacent cell. The interference sensitivity frequency bands are orthogonally staggered, and the high interference sensitivity frequency bands of each cell are orthogonally staggered with the high interference sensitivity frequency bands of each adjacent cell.

On the other hand, the present invention also provides an uplink interference coordination device for an OFDMA system, including:

The receiving module is used for the base station to receive the received power RSRP of the uplink pilot signal sent by the user equipment UE;

A first judging module, configured to judge whether the RSRP is smaller than a first preset threshold;

A first scheduling module, configured to schedule the edge frequency band resources of the cell to which the UE belongs if the RSRP is smaller than a first preset threshold;

A second judging module, configured to judge whether the RSRP is smaller than a second preset threshold if the RSRP is greater than or equal to a first preset threshold;

A second scheduling module, configured to, if the RSRP is greater than or equal to a first preset threshold and smaller than a second preset threshold, schedule edge frequency band resources or high interference sensitivity frequency band resources of a cell to which the UE belongs for the UE;

A third judging module, configured to, if the RSRP is greater than or equal to a second preset threshold, sequentially judge whether the interference receiving power from the UE to each neighboring cell of the cell to which the UE belongs is greater than a third preset threshold;

The third scheduling module is configured to: if the RSRP is greater than or equal to the second preset threshold, and the interference received power is greater than the third preset threshold, then schedule the high-level cell for the UE except the adjacent cell that the UE interferes with Frequency band resources other than the interference sensitivity frequency band and the edge frequency band of all adjacent cells;

A fourth scheduling module, configured to schedule the UE except the edge frequency bands of all adjacent cells if the RSRP is greater than or equal to a second preset threshold and the interference received power is less than or equal to a third preset threshold frequency band resources;

The first preset threshold is smaller than the second preset threshold, and the fringe frequency band and the high interference sensitivity frequency band are frequency bands pre-allocated by the base station for each cell.

Further, the received interference power from the UE to each neighboring cell of the cell to which the UE belongs is calculated using the following formula:

Further, the edge frequency band and the high interference sensitivity frequency band are frequency bands pre-divided by the base station for each cell according to the user load of the cell, and the edge frequency band of each cell is respectively related to the edge frequency band and high interference sensitivity frequency band of each adjacent cell. The interference sensitivity frequency bands are orthogonally staggered, and the high interference sensitivity frequency bands of each cell are orthogonally staggered with the high interference sensitivity frequency bands of each adjacent cell.

An uplink interference coordination method and device for an OFDMA system provided by the present invention evaluates and classifies UEs from two perspectives, namely the sensitivity of the UE to interference and the degree of interference generated by the UE to neighboring cells, which ensures easy The interfered edge UE is scheduled to the frequency band resource with the least interference, and at the same time, it can ensure that the UE with strong interference to the adjacent cell can avoid the pre-planned frequency band of the adjacent cell, so as to more effectively stagger the strong interference between cells and greatly improve the cell edge. The user's performance, and through reasonable interference avoidance and management, the system performance loss is small, and even significantly improved.

Description of drawings

The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the accompanying drawings:

FIG. 1 is a schematic flow diagram of an uplink interference coordination method for an OFDMA system in an embodiment of the present invention;

FIG. 2 is a schematic diagram of a cell frequency band resource planning in an embodiment of the present invention;

Fig. 3 is a schematic diagram of a cell structure in an embodiment of the present invention;

Fig. 4 is a schematic structural diagram of an uplink interference coordination device for an OFDMA system in an embodiment of the present invention.

Detailed ways

The technical solution of the present invention will be further described in detail in conjunction with the accompanying drawings and embodiments.

Fig. 1 shows a schematic flow chart of an uplink interference coordination method applicable to an OFDMA system in this embodiment. As shown in Fig. 1, a kind of uplink interference coordination method for an OFDMA system provided in this embodiment includes:

S1, the base station receives the received power RSRP of the uplink pilot signal sent by the user equipment UE;

S2, judging whether the RSRP is smaller than a first preset threshold;

S3, if the RSRP in step S2 is smaller than the first preset threshold, scheduling edge frequency band resources of the cell to which the UE belongs for the UE;

S4, if the RSRP in step S2 is greater than or equal to a first preset threshold, then judging whether the RSRP is smaller than a second preset threshold;

S5, if the RSRP in step S4 is smaller than the second preset threshold, scheduling edge frequency band resources or high interference sensitivity frequency band resources of the cell to which the UE belongs for the UE;

S6, if the RSRP in step S4 is greater than or equal to the second preset threshold, sequentially judge whether the interference receiving power from the UE to each neighboring cell of the cell to which the UE belongs is greater than the third preset threshold;

S7, if the RSRP in step S6 is greater than or equal to the second preset threshold, and the interference received power is greater than the third preset threshold, then schedule the high interference sensitivity of adjacent cells other than the cell to which the UE belongs for the UE Frequency bands and frequency band resources other than the edge frequency bands of all adjacent cells;

S8, if the RSRP in step S6 is greater than or equal to the second preset threshold, and the interference received power is less than or equal to the third preset threshold, scheduling frequency band resources for the UE except the edge frequency bands of all neighboring cells ;

The first preset threshold is smaller than the second preset threshold, and the fringe frequency band and the high interference sensitivity frequency band are frequency bands pre-allocated by the base station for each cell.

Further, the received interference power from the UE to each neighboring cell of the cell to which the UE belongs is calculated using the following formula:

Further, the edge frequency band and the high interference sensitivity frequency band are frequency bands pre-divided by the base station for each cell according to the user load of the cell, and the edge frequency band of each cell is respectively related to the edge frequency band and high interference sensitivity frequency band of each adjacent cell. The interference sensitivity frequency bands are orthogonally staggered, and the high interference sensitivity frequency bands of each cell are orthogonally staggered with the high interference sensitivity frequency bands of each adjacent cell.

For example, the base station evaluates the interference sensitivity of the UEs in each cell according to the received uplink pilot signal received power RSRP of the UEs, and classifies the UEs.

For each UEi, it is judged whether the uplink pilot signal received power P _{UL_Rx_ServingCell} (i) of the UE received by the base station is less than the first preset threshold P _{th_1} , if so, the UE is a user with level I interference sensitivity, otherwise it is further judged that P _{UL_Rx_ServingCell} ( i) Whether it is smaller than the second preset threshold P _{th_2} , if so, the UE is a user with level II interference sensitivity, otherwise, the UE is a user with level III interference sensitivity. For the above parameters P _{th_1} and P _{th_2} , it is required that P _{th_1} <P _{th_2} , and they are specifically set according to the distribution of the received power of the pilot signal and the distribution of the uplink interference power of the UE in the OFDMA system in the cell to which it belongs. It can be seen that the higher the user's interference sensitivity level, the less sensitive to interference and the better the anti-interference ability.

At the same time, for a UE determined to be a user with level III interference sensitivity, the base station further evaluates whether the UE is an interference source user in the adjacent area according to the degree of interference to each adjacent area. The specific process is as follows:

First, calculate the interference received power from the UE to each neighboring cell:

The interference received power from the UE to each neighboring cell of the cell to which the UE belongs is calculated using the following formula:

Then, determine the UE's Whether it is greater than the third preset threshold I _Threshold , if so, the UE is a class I interferer user and has strong interference to neighboring cells; otherwise, the UE is a class II interferer user and has little interference to neighboring cells. I _Threshold can be specifically set according to the interference power distribution in the system.

Based on the above classification of UEs, the base station will pre-plan the frequency band resources of the cell according to the load of UEs in each cell. The base station allocates an edge frequency band and a high interference sensitivity frequency band for each cell. In addition, the edge frequency band of each cell is orthogonally staggered with the edge frequency band and the high interference sensitivity frequency band of each adjacent cell, and the high interference sensitivity frequency band of each cell is orthogonally staggered with the high interference sensitivity frequency band of each adjacent cell.

Taking the cell structure shown in FIG. 3 as an example, the frequency band resources allocated by the base station to the cells cell0, cell1, cell2, cell3, and cell4 are shown in FIG. 2 . Of course, Fig. 2 is only an example to illustrate the division of one of the frequency band resources. In the specific implementation process, there may be other different division results according to the specific situation. The division results shown in Fig. 2 do not limit the claims of this application in any way. .

As shown in Figure 2, F01, F11, F21, F31, and F41 correspond to the edge frequency bands of cells cell0, cell1, cell2, cell3, and cell4 respectively; F02, F12, F22, F32, and F42 correspond to cells cell0, cell1, cell2, and cell3, respectively. , the high interference sensitivity frequency band of cell4; the black frequency band area is the edge frequency band scheduled by the base station for adjacent cells. When the base station schedules the frequency band for the UE, this part of the area is prohibited from being used by the UE in this cell.

The edge frequency bands of each cell are respectively staggered with the edge frequency bands and high interference sensitivity frequency bands of each adjacent cell. Orthogonal stagger with F11, F12, F21, F22, F41, F42.

The method for scheduling frequency band resources for UEs in each cell is as follows:

If the UE is a user with level I interference sensitivity, it can only use the edge frequency band of the cell;

If the UE is a level II interference sensitive user, it can only use the high interference sensitivity frequency band and the edge frequency band of the cell;

If the UE is a level III interference sensitive user and is a level I interferer user in a neighboring cell, the UE is scheduled to use all frequency bands except the high interference sensitivity frequency band of the neighboring cell and the edge frequency bands of all neighboring cells . For example, UE1 in cell0 is the interference source user of cell1, then UE1 disables the high interference sensitivity frequency band F12 of cell1, and the available frequency bands are all frequency bands except F11, F21, F41 and F12.

If the UE is a level III interference sensitive user and is a level II interference source user of all adjacent cells, the UE can use all available frequency bands except edge frequency bands of all adjacent cells. For example, if UE2 in cell2 is a level III interference sensitive user and is a level II interference source user of all adjacent cells, then UE2 can use all frequency bands except F01, F11 and F31.

An uplink interference coordination method for an OFDMA system provided in this embodiment evaluates and classifies UEs from two perspectives, namely the sensitivity of UEs to interference and the degree of interference caused by UEs to neighboring cells, so as to ensure that they are easy to be detected Interfering edge UEs are scheduled to the frequency band resources with the least interference, and at the same time, it can ensure that UEs with strong interference to neighboring cells can avoid the pre-planned frequency bands of neighboring cells, so as to more effectively stagger the strong interference between cells and greatly improve the efficiency of cell edge users. performance, and through reasonable interference avoidance and management, the system performance loss is small, and even significantly improved.

Correspondingly, as shown in FIG. 4, this embodiment also provides an uplink interference coordination device for an OFDMA system, including:

The receiving module is used for the base station to receive the received power RSRP of the uplink pilot signal sent by the user equipment UE;

A first judging module, configured to judge whether the RSRP is smaller than a first preset threshold;

A first scheduling module, configured to schedule the edge frequency band resources of the cell to which the UE belongs if the RSRP is smaller than a first preset threshold;

A second judging module, configured to judge whether the RSRP is smaller than a second preset threshold if the RSRP is greater than or equal to a first preset threshold;

A second scheduling module, configured to, if the RSRP is greater than or equal to a first preset threshold and smaller than a second preset threshold, schedule edge frequency band resources or high interference sensitivity frequency band resources of a cell to which the UE belongs for the UE;

A third judging module, configured to, if the RSRP is greater than or equal to a second preset threshold, sequentially judge whether the interference receiving power from the UE to each neighboring cell of the cell to which the UE belongs is greater than a third preset threshold;

The third scheduling module is configured to: if the RSRP is greater than or equal to the second preset threshold, and the interference received power is greater than the third preset threshold, then schedule the high-level cell for the UE except the adjacent cell that the UE interferes with Frequency band resources other than the interference sensitivity frequency band and the edge frequency band of all adjacent cells;

A fourth scheduling module, configured to schedule the UE except the edge frequency bands of all adjacent cells if the RSRP is greater than or equal to a second preset threshold and the interference received power is less than or equal to a third preset threshold frequency band resources;

The first preset threshold is smaller than the second preset threshold, and the fringe frequency band and the high interference sensitivity frequency band are frequency bands pre-allocated by the base station for each cell.

Further, the received interference power from the UE to each neighboring cell of the cell to which the UE belongs is calculated using the following formula:

Further, the edge frequency band and the high interference sensitivity frequency band are frequency bands pre-divided by the base station for each cell according to the user load of the cell, and the edge frequency band of each cell is respectively related to the edge frequency band and high interference sensitivity frequency band of each adjacent cell. The interference sensitivity frequency bands are orthogonally staggered, and the high interference sensitivity frequency bands of each cell are orthogonally staggered with the high interference sensitivity frequency bands of each adjacent cell.

An uplink interference coordination device for an OFDMA system provided in this embodiment evaluates and classifies UEs from two perspectives, namely the sensitivity of UEs to interference and the degree of interference caused by UEs to neighboring cells, so as to ensure that they are easily Interfering edge UEs are scheduled to the frequency band resources with the least interference, and at the same time, it can ensure that UEs with strong interference to neighboring cells can avoid the pre-planned frequency bands of neighboring cells, so as to more effectively stagger the strong interference between cells and greatly improve the efficiency of cell edge users. performance, and through reasonable interference avoidance and management, the system performance loss is small, and even significantly improved.

Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention. within the bounds of the requirements.

Claims (4)

1. A kind of uplink interference coordination method for OFDMA system, it is characterized in that, described method comprises: The base station receives the received power RSRP of the uplink pilot signal sent by the user equipment UE; judging whether the RSRP is smaller than a first preset threshold; If the RSRP is smaller than the first preset threshold, scheduling edge frequency band resources of the cell to which the UE belongs for the UE; If the RSRP is greater than or equal to a first preset threshold, then judging whether the RSRP is smaller than a second preset threshold; If the RSRP is greater than or equal to a first preset threshold and less than a second preset threshold, scheduling edge frequency band resources or high interference sensitivity frequency band resources of the cell to which the UE belongs for the UE; If the RSRP is greater than or equal to a second preset threshold, sequentially determine whether the received interference power from the UE to each neighboring cell of the cell to which the UE belongs is greater than a third preset threshold; If the RSRP is greater than or equal to the second preset threshold, and the interference received power is greater than the third preset threshold, schedule the high interference sensitivity frequency band and all related Frequency band resources other than the edge frequency bands of adjacent cells; If the RSRP is greater than or equal to a second preset threshold, and the interference received power is less than or equal to a third preset threshold, scheduling frequency band resources for the UE except edge frequency bands of all neighboring cells; The first preset threshold is smaller than the second preset threshold, and the edge frequency band and the high interference sensitivity frequency band are frequency bands pre-divided by the base station for each cell: The edge frequency band and the high interference sensitivity frequency band are frequency bands pre-divided by the base station for each cell according to the user load of the cell, and the edge frequency band of each cell is respectively related to the edge frequency band and high interference sensitivity of each adjacent cell The frequency bands are orthogonally staggered, and the frequency bands with high interference sensitivity of each cell are orthogonally staggered with the frequency bands with high interference sensitivity of each adjacent cell. 2. The method according to claim 1, wherein the received interference power from the UE to each neighboring cell of the cell to which the UE belongs is calculated using the following formula: in, is the received power of interference from the i-th UE to the j-th neighboring cell of the cell to which the UE belongs, P _{UL_Rx_ServingCell} (i) is the received power of the uplink pilot signal of the i-th UE in the cell to which it belongs, PL _Serving (i) represents the path loss from the i-th UE to the cell to which it belongs, Indicates the path loss from the i-th UE to the j-th neighboring cell of the cell to which the UE belongs. 3. An uplink interference coordination device for an OFDMA system, characterized in that the device comprises: The receiving module is used for the base station to receive the received power RSRP of the uplink pilot signal sent by the user equipment UE; A first judging module, configured to judge whether the RSRP is smaller than a first preset threshold; A first scheduling module, configured to schedule the edge frequency band resources of the cell to which the UE belongs if the RSRP is smaller than a first preset threshold; A second judging module, configured to judge whether the RSRP is smaller than a second preset threshold if the RSRP is greater than or equal to a first preset threshold; A second scheduling module, configured to, if the RSRP is greater than or equal to a first preset threshold and smaller than a second preset threshold, schedule edge frequency band resources or high interference sensitivity frequency band resources of a cell to which the UE belongs for the UE; A third judging module, configured to, if the RSRP is greater than or equal to a second preset threshold, sequentially judge whether the interference receiving power from the UE to each neighboring cell of the cell to which the UE belongs is greater than a third preset threshold; The third scheduling module is configured to: if the RSRP is greater than or equal to the second preset threshold, and the interference received power is greater than the third preset threshold, then schedule the high-level cell for the UE except the adjacent cell that the UE interferes with Frequency band resources other than the interference sensitivity frequency band and the edge frequency band of all adjacent cells; A fourth scheduling module, configured to schedule the UE except the edge frequency bands of all adjacent cells if the RSRP is greater than or equal to a second preset threshold and the interference received power is less than or equal to a third preset threshold frequency band resources; The first preset threshold is smaller than the second preset threshold, and the edge frequency band and the high interference sensitivity frequency band are frequency bands pre-divided by the base station for each cell: The edge frequency band and the high interference sensitivity frequency band are frequency bands pre-divided by the base station for each cell according to the user load of the cell, and the edge frequency band of each cell is respectively related to the edge frequency band and high interference sensitivity of each adjacent cell The frequency bands are orthogonally staggered, and the frequency bands with high interference sensitivity of each cell are orthogonally staggered with the frequency bands with high interference sensitivity of each adjacent cell. 4. The device according to claim 3, wherein the received interference power from the UE to each neighboring cell of the cell to which the UE belongs is calculated using the following formula: in, is the received power of interference from the i-th UE to the j-th neighboring cell of the cell to which the UE belongs, P _{UL_Rx_ServingCell} (i) is the received power of the uplink pilot signal of the i-th UE in the cell to which it belongs, PL _Serving (i) represents the path loss from the i-th UE to the cell to which it belongs, Indicates the path loss from the i-th UE to the j-th neighboring cell of the cell to which the UE belongs.