CN103037403A - Measurement method in heterogeneous network - Google Patents

Abstract

Provided is a measurement method in a heterogeneous network. The measurement method includes measurement limit indicates through measurement information, measurement subframe collection is allocated, and user experience (UE) of users executes limit measurement to small cells to be measured according to measurement subframes. Reliability of measurement under an idle state of a regional resource center (RRC) is improved.

Description

A Measurement Method in Heterogeneous Network

technical field

The present invention relates to the technical field of communications, and more specifically, to a measurement method in a heterogeneous network.

Background technique

In the LTE-Advanced network, in order to provide hotspot coverage and expand cell coverage, a heterogeneous network structure is introduced. The heterogeneous network refers to the deployment of low-power nodes in the coverage area of the macro base station (macro eNB), thereby forming a heterogeneous network system including different node types. Low power nodes include pico base stations (pico eNB), home base stations (Home eNB) and relay base stations (Relay eNB).

The introduction of small cells in the heterogeneous network leads to more cell boundary areas, which causes serious interference. In addition, LTE R10 introduces Range expansion technology for pico cells. Range expansion refers to deliberately expanding the coverage of micro cells in order to reduce the load of macro cells (marco cells). Specifically, when the UE judges to access a macro cell or a micro cell, it will add a bias (bias) to the signal strength (RSRP) or signal quality (RSRQ) of the micro cell, where bias is a positive number, making the UE more Easy access to micro cells.

When the Range expansion technology is used, the user (UE) within the micro cell expansion area will suffer severe interference from the macro cell downlink, which greatly increases the possibility that the UE within the micro cell expansion area cannot correctly receive its transmitted data. How to effectively alleviate or even eliminate the interference problem caused by the introduction of micro cells is the key to improving the performance of the LTE-advanced system.

Almost empty subframes (ABS) were introduced in LTE R10 to solve the above problems. Specifically, when the severely interfered Pico UE located at the edge of the micro cell is receiving the downlink subframe of the micro base station, the macro base station will send the ABS subframe to reduce the downlink channel interference to the edge Pico UE. The ABS subframe does not transmit service data.

The introduction of the ABS mechanism will affect the measurement of the UE, because the RSRQ of the micro cell on the ABS and non-ABS will have a large difference. Since the macro base station does not use the ABS to transmit control signaling and service data related to the UE, the interference on the ABS of the micro cell is relatively small, while the interference on the non-ABS is relatively large. When the UE measures the ABS and non-ABS type subframes, the RSRQ measurement values of the two will be quite different. In order to solve this problem and increase the reliability of UE measurement, in R10, the measurement of UE in the RRC connection state is restricted as follows:

1) The macro eNB configures measurement restrictions on neighboring cells for the macro UE

Since the macro UE needs to measure multiple neighboring cells, which include not only pico cells, but also ordinary macro cells, and only the measurement of pico cells needs to use restricted measurements. Therefore, when the macro eNB configures measurement restrictions for the macro UE, in addition to configuring the measurement subframe set, it also needs to configure the cell list corresponding to the measurement subframe set, that is, the physical cell identity (PCI) list. After receiving the measurement restriction configuration, the UE will perform the corresponding restricted measurement on the neighboring cells belonging to the PCI range, and perform ordinary measurement on the neighboring cells not belonging to the PCI range.

2) pico eNB configures measurement restrictions on the serving cell for pico UE

For the pico UE located on the edge of the pico cell to measure the pico cell, limit its measurement on the ABS. After receiving the measurement restriction configuration, the UE will perform restricted measurement on its own serving cell.

However, in the RRC idle state, the UE also needs to measure the serving cell and neighboring cells, so as to perform a cell reselection process. In a heterogeneous network with ABS technology introduced, the UE in the RRC idle state still needs to perform restricted measurements, otherwise the measurement results will be unreliable. How to instruct UE to perform restricted measurements in RRC idle state is an unsolved problem.

Contents of the invention

An embodiment of the present invention proposes a measurement method in a heterogeneous network to improve measurement reliability in an RRC idle state.

The technical scheme of the embodiment of the present invention is as follows:

A measurement method in a heterogeneous network, the method comprising:

Measurement limits are indicated by measurement messages;

Configure a set of measurement subframes;

The user UE performs restricted measurement on the cell to be measured according to the set of measurement subframes.

The cell to be measured is a neighboring cell, and the configuration further includes: configuring a physical cell identity (PCI) range of the corresponding neighboring cell;

The performing the restrictive measurement on the cell to be measured by the UE according to the measurement subframe set includes: performing the restricted measurement on the cell to be measured by the UE according to the measurement subframe set and the PCI range.

The measurement message includes system information, the cell to be measured includes a serving cell, and the indication includes: indication in a system information block SIB2 or SIB3.

The measurement message includes system information, the cell to be measured includes an intra-frequency cell, and the indication includes: indication in SIB4.

The measurement message includes system information, the cell to be measured includes an inter-frequency cell, and the indication includes: indicating in SIB5.

The measurement message includes system information, the cell to be measured includes a serving cell and a neighboring cell, and the indication includes: indication in SIB2 or SIB3.

The measurement message includes a paging message, the cell to be measured includes a serving cell and a neighboring cell, and the indication includes: indicating in the paging message.

The set of measurement subframes is respectively configured for different adjacent cell PCI ranges.

The set of measurement subframes is configured in the information of neighboring cells that need to perform restricted measurement.

It can be seen from the above technical solution that in the embodiment of the present invention, the measurement restriction is indicated through the measurement message; the measurement subframe set is configured, so that the UE can perform restricted measurement on the cell to be measured according to the measurement subframe set. Therefore, in the heterogeneous network configured with the ABS, the UE can also perform restricted measurements in the RRC idle state, thereby improving the reliability of the measurements.

Description of drawings

FIG. 1 is a schematic flowchart of a measurement method in a heterogeneous network according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clearly, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

In the embodiment of the present invention, the measurement restriction in the connected state is notified to the UE through RRC dedicated signaling, but in the idle state, the UE cannot receive the RRC dedicated signaling, so the UE can only be notified through a measurement message. Specifically, the measurement restriction is indicated by a measurement message, and a measurement subframe set is configured, so that the UE can perform restricted measurement on the cell to be measured according to the measurement subframe set. Therefore, in the heterogeneous network configured with the ABS, the UE can also perform restricted measurements in the RRC idle state, thereby improving the reliability of the measurements.

The following is a detailed description in conjunction with the schematic flow chart of the measurement method in the heterogeneous network of Figure 1, which specifically includes the following steps:

In step 101, the measurement restriction is indicated through a measurement message.

In the RRC idle state, the measurement restriction is indicated by a measurement message. Wherein, the measurement message includes system information and paging message. Different cells to be measured are indicated in different system information blocks (SIBs) or paging messages. The system information refers to the system information in the LTE system, and the paging message refers to the paging message in the LTE system.

Option One

The measurement restriction in the RRC idle state is indicated through system information, and for different cell types, the measurement restriction is indicated in different SIBs.

(1) The measurement restriction on the serving cell is indicated in SIB2 or SIB3.

In the existing system, the information related to the serving cell is included in SIB2 or SIB3, so the measurement restriction on the serving cell can be indicated in SIB2 or SIB3.

(2) The measurement restriction on intra-frequency neighboring cells is indicated in SIB4.

In the existing system, the relevant information of the intra-frequency neighboring cells is included in the SIB4, so the measurement restriction for the intra-frequency neighboring cells can be indicated in the SIB4.

(3) The measurement restriction on inter-frequency neighboring cells is indicated in SIB5.

In the existing system, the relevant information of inter-frequency neighboring cells is included in SIB5, so the measurement restriction for inter-frequency neighboring cells can be indicated in SIB5.

After receiving these SIBs, the UE in the RRC idle state will perform restricted measurements on the serving cell or some neighboring cells according to the measurement restriction indication therein.

Option II

The measurement restriction in the RRC idle state is indicated through system information, and the measurement restriction on the serving cell and the neighbor cell is indicated in SIB2 or SIB3. In this solution, it is not possible to distinguish whether the neighboring cell is an intra-frequency cell or an inter-frequency cell.

After receiving these SIBs, the UE in the RRC idle state will perform restricted measurements on the serving cell or some neighboring cells according to the measurement restriction indication therein.

third solution

The measurement restriction in the RRC idle state is indicated through the paging message, and the measurement restriction on the serving cell and the neighboring cell is indicated in the paging message. In this solution, it is not possible to distinguish whether the neighboring cell is an intra-frequency cell or an inter-frequency cell.

After receiving the paging message, the UE in the RRC idle state will perform restrictive measurements on the serving cell or some neighboring cells according to the measurement restriction indication therein.

Step 102, configuring a measurement subframe set.

Measurement restriction indication for the serving cell: similar to the indication method in the RRC connection state, a set of measurement subframes can be configured, and then restricted measurement is performed on the serving cell.

Measurement restriction indication for adjacent cells: similar to the indication method in the RRC connection state, configure the measurement subframe set and the corresponding PCI range of adjacent cells. The UE needs to measure a plurality of neighboring cells, and among these neighboring cells, some cells will use the ABS technology, and some cells will not use the ABS technology. For a cell using the ABS technology, the UE needs to perform restricted measurement on it; while for a cell not using the ABS technology, the UE does not need to perform restricted measurement on it. Therefore, in the measurement restriction indication for neighboring cells, in addition to configuring the set of measurement subframes, the PCI range of the corresponding neighboring cells should also be configured. After receiving the measurement restriction indication, the UE will only perform restricted measurements on neighboring cells within the PCI range.

For the measurement restriction indication of neighboring cells, only one set of measurement subframes can be configured, so there will be the following problems. When the ABS subframes used by the multiple cells that need to perform restricted measurement have intersections, the intersection of ABS subframes is configured in the measurement subframe set. However, in an actual system, different adjacent cells may use completely different ABSs, and there is no intersection between these ABSs, and in this case the above configuration method is no longer applicable.

In order to solve the above problems, the following two solutions are proposed.

(a) Configuring measurement subframe sets for different PCI ranges of neighboring cells.

Indicates a measurement restriction list, in which multiple measurement subframe sets and respective corresponding neighbor cell PCI ranges can be configured.

Different sets of measurement subframes are configured for different PCI ranges of neighboring cells. When the UE performs the measurement on the neighboring cell, it will find the corresponding measurement subframe set according to the PCI of the neighboring cell, and perform the measurement on the subframe indicated by the measurement subframe set.

(b) Configuring a set of measurement subframes corresponding to the neighboring cell in the information of the neighboring cell that needs to perform restricted measurement.

A set of measurement subframes is determined for each neighbor cell that requires restricted measurement. In the SIB4 and SIB5 of the existing system, the relevant information of each neighboring cell is indicated, such as PCI and the offset used for cell reselection, etc. At this time, the measurement adopted for the cell can be configured in the cell information How to configure the subframe set is an existing technology.

In step 103, the UE performs restricted measurement on the cell to be measured according to the set of measurement subframes.

For the serving cell, the UE performs restricted measurement on the cell to be measured according to the set of measurement subframes. For neighboring cells, the UE performs restricted measurements on different cells to be measured according to the measurement subframe set and the corresponding PCI range.

The above descriptions 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 (9)

1. A measurement method in a heterogeneous network, characterized in that the method comprises: Measurement limits are indicated by measurement messages; Configure a set of measurement subframes; The user UE performs restricted measurement on the cell to be measured according to the set of measurement subframes. 2. according to the measurement method in the heterogeneous network of claim 1, it is characterized in that, described sub-district to be measured is adjacent sub-district, and described configuration further comprises: configuration corresponding adjacent sub-district Physical Cell Identity (PCI) scope; The performing the restrictive measurement on the cell to be measured by the UE according to the measurement subframe set includes: performing the restricted measurement on the cell to be measured by the UE according to the measurement subframe set and the PCI range. 3. The measurement method in a heterogeneous network according to claim 1, wherein the measurement message includes system information, the cell to be measured includes a serving cell, and the indication includes: indicating in a system information block SIB2 or SIB3. 4. The measurement method in a heterogeneous network according to claim 1, wherein the measurement message includes system information, the cell to be measured includes an intra-frequency cell, and the indication includes: indicating in SIB4. 5. The measurement method in a heterogeneous network according to claim 1, wherein the measurement message includes system information, the cell to be measured includes an inter-frequency cell, and the indication includes: indicating in SIB5. 6. The measurement method in a heterogeneous network according to claim 1, wherein the measurement message includes system information, the cell to be measured includes a serving cell and a neighboring cell, and the indication includes: indication in SIB2 or SIB3. 7. The measurement method in a heterogeneous network according to claim 1, wherein the measurement message includes a paging message, the cell to be measured includes a serving cell and a neighboring cell, and the indication includes: indicating in the paging message . 8. The measurement method in the heterogeneous network according to claim 2, wherein the measurement subframe sets are respectively configured for different adjacent cell PCI ranges. 9. The measurement method in the heterogeneous network according to claim 2, wherein the set of measurement subframes is configured in the information of neighboring cells that need to perform restricted measurement.