CN104811288A - Coordinated multiple point (CoMP) transmission method - Google Patents

Abstract

The invention relates to a CoMP transmission method. The CoMP transmission method in one embodiment comprises that a central node sends a CoMP configuration message to a base station/cell, to which the central node belongs, via X2 interface signaling. The method can meet new requirements and facilitate CoMP transmission.

Description

Method for Coordinated Multipoint Transmission

technical field

The present invention relates generally to mobile communication technology, and more particularly to coordinated multipoint transmission.

Background technique

In modern mobile communication systems such as Long Term Evolution (LTE), the base station determines the used transport format, transport block size, modulation for the downlink (DL) and uplink (UL) And coding scheme, multiple input multiple output (Multiple Input Multiple Output, MIMO) transmission mode, etc. To be able to make such a determination for the downlink, the base station needs information from the User Equipment (UE) about the performance of the current downlink channel, usually referred to as Channel State Information (CSI).

Frequency division duplex (FDD) downlink Coordinated Multiple Point (CoMP) transmission technology has the potential to improve cell edge user throughput and even improve cell average throughput. However, the support for the coordinated multipoint transmission technology in the prior art is still insufficient.

Contents of the invention

A main purpose of the present invention is to realize coordinated multi-point transmission and overcome the above-mentioned defects in the prior art.

One embodiment of the present invention provides a method suitable for CoMP transmission. The method includes the following steps: the central node sends a coordinated multi-point configuration message to the base station/cell under its jurisdiction via X2 interface signaling.

In one embodiment, the CoMP configuration message sent via the X2 interface signaling includes a desired channel state information mode (CSI process) and a zero-power channel state information reference signal resource (ZP CSI-RS) configuration.

In one embodiment, the expected channel state information mode (CSI process) includes: non-zero power channel state information reference signal resource (NZP CSI-RS) configuration, channel state information interference measurement resource (CSI-IM) configuration, periodic Or aperiodic channel state information reporting configuration.

In one embodiment, the non-zero power channel state information reference signal resource (NZP CSI-RS) configuration includes: the ID of the NZP CSI RS configuration; qcl-CRS-Info includes qcl-ScramblingIdentity, the number of CRS ports, and the MBSFN subframe configuration.

In one embodiment, channel state information interference measurement resource (CSI-IM) configuration includes: ID of CSI IM configuration; resource configuration list; subframe configuration.

In one embodiment, the channel state information interference measurement resource (CSI-IM) configuration includes: an indication of a cooperating set for interference measurement.

In one embodiment, the zero-power channel state information reference signal resource (ZP CSI-RS) configuration includes some or all of the following: a specific cell ZP CSI RS configuration request, a rejection/acceptance message about the ZP CSI RS request Feedback indication, request indication of the same ZP CSI RS configuration as the specific cell, request indication of ZPCSI RS configuration different from the specific cell, active broadcast of its own ZP CSI RS configuration indication, feedback ZP CSI RS configuration request indication.

In one embodiment, the Channel State Information Mode (CSI process) configuration includes some or all of the following: ID of CSI process configuration; ID of NZP CSI RS configuration; ID of CSI IM configuration; power control and codebook subclasses One or more sets of set restriction configurations; ID of RI-reference-CSI-process configuration; pmi-RI-Report configuration; ID of periodic CSI report configuration; ID of aperiodic CSI report configuration; cell center user or cell Indication of edge user; indication of user equipment interference type.

In one embodiment, the CoMP configuration message sent via X2 interface signaling further includes RSRP report configuration and triggering.

In one embodiment, the CoMP configuration message sent via the X2 interface signaling also includes power information exchange.

In one embodiment, the CoMP configuration message sent via the X2 interface signaling further includes a transmission mode exchange.

The above summarizes the technical features and advantages of the present invention to make the following detailed description of the present invention easier to understand. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. Those skilled in the art should also understand that such equivalent constructions do not depart from the spirit and scope of the appended claims.

Description of drawings

The following detailed description of preferred embodiments of the present invention will be easier to understand with reference to the accompanying drawings. The present invention is illustrated by way of example and not limited by the accompanying drawings, in which like reference numerals indicate like elements.

FIG. 1 shows a CoMP transmission system architecture according to an embodiment of the present invention;

Fig. 2 shows a schematic diagram of signaling transfer between a central node and a base station according to an embodiment of the present invention.

Detailed ways

The detailed description of the drawings is intended as a description of presently preferred embodiments of the invention and is not intended to represent the only forms in which the invention can be embodied. It is to be understood that the same or equivalent function may be performed by different embodiments, which are intended to be encompassed within the spirit and scope of the invention.

Those skilled in the art should understand that the means and functions described herein can be implemented using software functions in combination with a programmed microprocessor and a general-purpose computer, and/or implemented using an application-specific integrated circuit (ASIC). It should also be understood that although the invention has been described primarily in terms of methods and apparatus, the invention may also be embodied as computer program products and systems comprising a computer processor and memory coupled to the processor, wherein the memory is used to perform the Encode one or more procedures of the functions disclosed here.

Those skilled in the art should understand that base stations have different technical terms in different protocol standards. For example, a base station is called a Node B (Node B) or an evolved Node B (evolved NodeB, eNB) in an LTE system or an LTE-A system. The base station referred to in the present invention is, for example but not limited to, an eNB in an LTE-A system. The method and device provided in the present invention are suitable for example but not limited to LTE system.

Fig. 1 shows a CoMP transmission system architecture according to an embodiment of the present invention. Base stations 101 to 109, central node 100 are shown in the figure. The base stations 101 to 106 form a cooperating set 10, and all base stations in the cooperating set communicate with the central node 100 via the X2 interface. The radio resource management in the cooperating set 10 , especially the part related to CoMP transmission, is mainly undertaken by the central node 100 . Although the central node 100 is shown in FIG. 1 as being independent from the base stations 101-106, those skilled in the art should understand that the central node 100 may also be integrated in one of the base stations 101-106.

Fig. 2 shows a schematic diagram of signaling transfer between a central node and a base station according to an embodiment of the present invention. As shown in the figure, the central node 100 sends a coordinated multipoint (CoMP) configuration message to the base station 101/cell under its jurisdiction via X2 interface signaling.

The signaling configuration suitable for the CoMP mode is described in detail below.

1. Basic signaling

Basic Signaling for Signal Measurements

A base station can broadcast part or all of the following information to neighboring base stations (or, a node can send part or all of the following information of a base station to other base stations): Non-zero power channel state information reference signal (Non-Zero -Power Channel Status Information Reference Signal, NZP CSI RS) configuration, zero-power channel status information reference signal (Zero-Power Channel Status Information Reference Signal, ZP CSI RS) configuration.

Basic signaling for point selection

A node can send part or all of the following information of a base station to other base stations: demodulation reference signal (demodulation reference signal, DMRS) configuration, physical downlink shared channel mapping (PDSCH mapping) configuration.

Basic Signaling for Interference Measurements

In addition to the signal measurement protection of NZP CSI RS, ZP CSI RS can be configured for interference measurement by CSI Interference Measurement (CSI IM). In order to reduce the overhead of ZP CSI RS configuration, it is desired to be able to: One CSI IM configuration covers the interference measurements of several CoMP schemes in a cooperating set, and the CSI IM can be configured by the central node under several schemes.

Basic signaling for Channel State Information (CSI)/Reference Signal Receive Power (RSRP) report configuration

In single cell mode, the interference part of the channel quality information (CQI) from the user equipment (UE) is noise plus interference outside the serving cell. In CoMP mode, considering the overhead of ZP CSI RS and the stable interference information, the interference part of the CQI from the user equipment (UE) is noise plus interference outside the cooperating set (such as the cooperating set shown in Figure 1) . Therefore, more than one interference configuration is required, and it is desirable for the central node to know the type of CQI received. Therefore, some or all of the following information is required: CSI process configuration associated with NZP CSI RS configuration and CSI IM configuration, RSRP report indication for CQI reconstruction, and cooperation set indication.

2. Details of signaling enhancements

The X2 interface signaling discussed here includes: CSI process, ZP CSI RS, RSRP report configuration, power information, and transmission mode exchange. The CSI process includes: NZP CSI RS, CSI IM, aperiodic or periodic CSI report configuration.

2.1 NZP CSI RS configuration

NZP CSI RS configuration can also include the following information: ID of NZP CSI RS configuration; qcl-CRS-Info includes qcl-ScramblingIdentity, number of CRS ports, and MBSFN subframe configuration. The ID configured in NZP CSI RS can be used together with the cell ID number to distinguish NZP CSI RS. The MBSFN subframe configuration may include a radio subframe configuration period, a radio subframe configuration offset, and an MBSFN subframe configuration indication. The MBSFN subframe configuration indication is represented by a set of binary bitmaps. Each bit in the bitmap indicates whether the corresponding subframe is an MBSFN subframe. For example, 1 indicates that the corresponding subframe is an MBSFN subframe, and 0 indicates that the corresponding subframe is not MBSFN subframe.

2.2ZP CSI RS configuration

In dense/ultra-dense small cell arrangements, the interference between cells may be very strong. When a base station detects strong interference from its neighboring base stations, and such strong interference may affect the signal detection on the user equipment side, the base station may: configure NZP CSI RS on the resources corresponding to the ZP CSI RS resources of the interfering cell, Or request the ZP CSI RS of the neighboring cell.

With respect to interference measurements, a central node and/or a base station can: request ZP CSI RS configuration for a specific cell, and/or feed back rejection/acceptance messages on ZP CSI RS request, and/or request the same ZP CSI RS configuration as for a specific cell , and/or request a ZP CSI RS configuration different from that of a specific cell, each transmission point (TP) can actively broadcast its own ZP CSI RS configuration, and each transmission point can be requested to feed back its ZP CSI RS configuration.

2.3 CSI IM Configuration

In order to obtain the expected CQI information, in addition to the ZP CSI RS configuration, the central node can adopt the following schemes.

Solution 1, configure CSI IM for the considered cell, which includes: ID of CSI IM configuration; resource configuration list, similar to resourceConfigList in TS36.331, the value is an integer between 0 and 31; subframe configuration, type Same as subframConfig in TS36.331, the value is an integer between 0 and 254.

Solution 2, configure a cooperation set for interference measurement. The cooperating set indicates the IDs of all the cells in it. Knowing such a configuration as well as the ZP CSI RS configuration with respect to neighboring cells and/or the central node, the base station is able to select a suitable interference assumption for interference measurements at the user equipment side.

With regard to CSI IM configuration, the central node and/or the base station may: request CSI IM configuration for a specific cell, and/or feed back a rejection/acceptance message regarding the CSI IM request.

2.4CSI process configuration

In order to obtain the expected CSI information, the central node should configure the CSI process configuration for the considered cell and/or UE in addition to the NZP CSI RS configuration and the CSI IM configuration. CSI process configuration includes some or all of the following information: ID of CSI process configuration; ID of NZP CSI RS configuration; ID of CSI IM configuration; one or more sets of power control and codebook subset limit configuration; RI-reference - ID of CSI-process configuration; configuration of pmi-RI-Report; ID of periodic CSI report configuration; ID of aperiodic CSI report configuration; indication of cell center user or cell edge user; indication of user equipment interference type, interference The type may be information of an interfering cell.

With regard to CSI reporting, the central node and/or the base station may: request CSI reporting configuration of a specific cell, and indicate reporting period and subframe; and/or feed back a rejection/reception message of the CSI reporting configuration request.

2.5 Periodic CSI report configuration and triggering

The periodic CSI report configuration message may include part or all of the following information: periodic CSI report configuration ID; cqi-pmi-ConfigIndex, an integer between 0 and 1023; CQI information indication, wideband CQI report mode 1 Or mode 2, the subband CQI reports an integer between 1 and 4, and a periodic factor with a value of 2 or 4; ri-ConfigIndex, an integer between 0 and 1023; csi-ConfigIndex includes : cqi-pmi-ConfigIndex, the value is an integer between 0 and 1023, ri-ConfigIndex, the value is an integer between 0 and 1023; filter factor for long-term CSI information; activate CQI, PMI and/or RI reporting report instructions.

2.6 Aperiodic CSI report configuration and triggering

The aperiodic CSI report configuration message may include: trigger mode, which indicates which set of CSI to report, or which aperiodic report mode, which subframe CSI report information, and the filter factor of long-term CSI information, as well as activated CQI , PMI and/or RI report reporting indications.

2.7 RSRP report configuration and triggering

The RSRP report configuration may include some or all of the following information: filter factor for RSRP measurement configuration; threshold for triggering RSRP report, for example, if the RSRP of the neighboring cell in the cooperating set is not lower than the RSRP of the serving cell minus the threshold, Then the serving cell should report the RSRP information associated with the neighbor cell ID and/or user equipment ID; the maximum number of reports, such as the maximum number of RSRP reports from configured cells, to reduce/manage the complexity of CoMP operations; the cooperating set Configuration, the node can indicate the cooperating set, using the cooperating set and the threshold information of the RSRP report, the base station can know which RSRP should be reported; periodic RSRP report configuration; aperiodic RSRP report configuration.

The periodic RSRP reporting configuration may include a reporting subframe pattern indicating the subframes used for RSRP reporting. RSRP in RSRP reporting configuration can be replaced by reference signal receive quality (RSRQ)/interference level (for RSRQ/interference level reporting configuration).

2.8 Power Information

If RSRP is used for CQI reconstruction, the node reconstructing CQI should know the Physical Downlink Shared Channel (PDSCH) and CRS (and/or CSI-RS).

Therefore, the power information exchange may include the following information:

Cell ID or virtual cell ID.

Power parameter used for RSRP adjustment (in CQI reconstruction). For example, in PDSCH resource elements in non-zero energy (energy per resource element, EPRE), for each OFDM symbol, the ratio of PDSCH energy per resource element (EPRE) to cell-specific reference signal EPRE is expressed as ρ _A or ρ _B , in addition, ρ _A and ρ _B are user-specific. For another example, in the case of CSI-RS used for RSRP reporting, the ratio of EPRE of PDSCH to EPRE of CSI-RS. It should be noted that the ratio of EPRE of PDSCH to EPRE of CSI-RS is used for CQI reconstruction on the network side, and the transmission power parameter Pc in CSI-process is used for CQI calculation on the user side.

2.9 Transmission Mode

The transmission mode indication here is sent from the central node to the base station. The transmission mode information may include part or all of the following information: the maximum number of users scheduled on the same time-frequency resource of the indicated cell; transmission mode 1 to transmission mode 10; the rank limit of each user equipment (which may be determined by RI instructions superseded).

2.10 Addition/release of configuration

The configuration information in subsections 2.1 to 2.9 can be added and/or released via the indication of the X2 interface signaling of the corresponding ID information.

While various embodiments of the invention have been illustrated and described, the invention is not limited to these embodiments. The ordinal numerals such as "first" and "second" appearing in the claims are only used for distinction, and do not imply any specific sequence or connection relationship between corresponding components. The technical features appearing only in certain claims or embodiments does not mean that they cannot be combined with other features in other claims or embodiments to achieve beneficial new technical solutions. Many modifications, changes, variations, substitutions and equivalents will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as described in the claims.

Claims (11)

1. be suitable for a method for collaborative multicast communication, comprise:

Central node sends the message of collaborative Multipoint weighting to administrative base station/cell via X2 interface signaling.

2. the method for claim 1, is characterized in that, the message of described collaborative Multipoint weighting comprises the channel condition information pattern of expectation (CSI process) and zero energy channel state information reference signals resource (ZP CSI-RS) configuration.

3. method as claimed in claim 2, it is characterized in that, the channel condition information pattern (CSI process) of described expectation comprises: non-zero power channel state information reference signals resource (NZP CSI-RS) configures, channel condition information interferometry resource (CSI-IM) configures, periodicity or the configuration of acyclic channel status information reports.

4. method as claimed in claim 3, is characterized in that, described non-zero power channel state information reference signals resource (NZP CSI-RS) configuration comprises: the ID that NZP CSI RS configures; Qcl-CRS-Info comprises qcl-ScramblingIdentity, CRS port number, MBSFN sub-frame configuration.

5. method as claimed in claim 3, is characterized in that, described channel condition information interferometry resource (CSI-IM) configuration comprises: the ID that CSI IM configures; Resource distribution list; Sub-frame configuration.

6. method as claimed in claim 3, is characterized in that, described channel condition information interferometry resource (CSI-IM) configuration comprises: the instruction of the collaboration set of interferometry.

7. method as claimed in claim 2, it is characterized in that, it is part or all of that the configuration of described zero energy channel state information reference signals resource (ZPCSI-RS) comprises in the following: specific cell ZP CSI RS configuring request, about the feedback instruction of refusal/the accept message that ZP CSIR S asks, the request instruction that the ZP CSI RS identical with specific cell configures, the request instruction that the ZP CSI RS different from specific cell configures, the instruction that active broadcast self ZP CSI RS configures, the request instruction of feedback ZP CSI RS configuration.

8. method as claimed in claim 2, is characterized in that, it is part or all of that described channel condition information pattern (CSI process) configuration comprises in the following: the ID that CSI process configures; The ID that NZP CSI RS configures; The ID that CSI IM configures; One or more collection of power control and codebook subset limitation arrangement; The ID of RI-reference-CSI-process configuration; Pmi-RI-Report configures; The periodically ID of CSI report configuration; The ID of aperiodicity CSI report configuration; The instruction of Cell Center User or Cell Edge User; The instruction of subscriber equipment interference type.

9. method as claimed in claim 2, is characterized in that, the message of described collaborative Multipoint weighting also comprises Reference Signal Received Power report configuration and triggers.

10. method as claimed in claim 2, is characterized in that, the message of described collaborative Multipoint weighting also comprises power information and exchanges.

11. methods as claimed in claim 2, is characterized in that, the message of described collaborative Multipoint weighting also comprises transmission mode and exchanges.