CN111436064B

CN111436064B - Method and device for cooperative transmission of control channels

Info

Publication number: CN111436064B
Application number: CN201910028829.5A
Authority: CN
Inventors: 金婧; 刘光毅; 郑毅; 王启星; 李岩; 王飞
Original assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Current assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Priority date: 2019-01-11
Filing date: 2019-01-11
Publication date: 2023-05-09
Anticipated expiration: 2039-01-11
Also published as: CN111436064A

Abstract

The invention provides a method and a device for cooperative transmission of a control channel, and belongs to the technical field of wireless communication. A method of control channel cooperative transmission, comprising: and transmitting PDCCH by adopting orthogonal DMRS with other cooperative network elements serving the same terminal, wherein the cooperative network elements are base stations and/or transmission points and/or cells cooperatively transmitted for the same terminal in a multi-point transmission system. By the technical scheme, the DMRS interference when the multiple PDCCH resource positions are overlapped can be reduced, and the channel estimation performance is improved.

Description

Method and device for cooperative transmission of control channels

Technical Field

The present invention relates to the field of wireless communications technologies, and in particular, to a method and an apparatus for cooperative transmission of a control channel.

Background

The central user rate within the coverage area of the 5G network is high, and the edge user experience still needs to be improved in order to provide a consistent user experience. Especially for high frequency bands, edge coverage is urgently needed to be enhanced.

As shown in fig. 1, multi-TRP (Multi-transmission reception point) is to simultaneously provide services to an edge user using a plurality of TRP (transmission reception point), and enhance coverage of the edge user while increasing a rate, wherein PDSCH (Physical Downlink Shared Channel) is a physical downlink shared channel and PDCCH (Physical Downlink Control Channel) is a physical downlink control channel. In Multi-TRP transmission, a scheme of Multi-PDCCH transmission tends to be adopted, each PDCCH is independently scheduled, and dependency of cooperative transmission on backhaul can be reduced.

In NR (New Radio, new air interface), the DMRS (Demodulation Reference Signal ) of the PDCCH is fixed in position, and only single-port transmission is adopted, as shown in fig. 2, and the positions are fixed in 1 st, 5 th, and 9 th REs (Resource elements). In the Multi-TRP scenario, when multiple PDCCHs are independently scheduled, if multiple PDCCH resource positions of a cooperative base station to a current UE (User Equipment) overlap, DMRS estimation performance of the PDCCH is necessarily affected, and demodulation performance of the PDCCH is further affected.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method and a device for controlling channel cooperative transmission, which can reduce the interference among DMRS when multiple PDCCH resource positions overlap and improve the channel estimation performance.

In order to solve the technical problems, the embodiment of the invention provides the following technical scheme:

the embodiment of the invention provides a method for cooperative transmission of a control channel, which comprises the following steps:

and transmitting PDCCH by adopting orthogonal DMRS with other cooperative network elements serving the same terminal, wherein the cooperative network elements are base stations and/or transmission points and/or cells cooperatively transmitted for the same terminal in a multi-point transmission system.

Further, the orthogonality includes code domain orthogonality and/or frequency domain orthogonality.

Further, the code domain orthogonality is an orthogonal code mask OCC or a cyclic shift (cyclic shift) mode.

Further, the cooperative network element is a neighboring cell base station with the RSRP difference from the primary serving cell smaller than a preset threshold value, or a neighboring cell base station determined according to a neighboring cell relation list.

Further, the DMRS includes a plurality of ports, and the transmitting the PDCCH with the other cooperative network elements serving the same terminal by using the orthogonal DMRS includes at least one of the following manners:

transmitting PDCCH by using DMRS of the corresponding port, wherein the numbers of the ports are in one-to-one correspondence with the numbers of the cooperative network elements; or (b)

The terminal is informed of the port used by the DMRS for the PDCCH using higher layer signaling.

Further, the higher layer signaling is indication information added in the control resource set, and is used for indicating a port number used for DMRS of the PDCCH.

Further, the DMRS for the PDCCH is 2 or 4 ports.

Further, the DMRS for PDCCH uses a frequency domain OCC2 or frequency domain OCC4 or cyclic shift scheme.

Further, the DMRS includes a plurality of frequency domain locations, and the transmitting the PDCCH with the other cooperative network elements serving the same terminal by using the orthogonal DMRS includes at least one of the following manners:

transmitting PDCCH by using DMRS corresponding to the frequency domain positions, wherein the frequency domain positions are in one-to-one correspondence with the cooperative network elements; or (b)

The terminal is informed of the frequency domain location used by the DMRS for the PDCCH using higher layer signaling.

Further, the higher layer signaling is indication information added in the control resource for indicating the frequency domain location of PDCCH DMRS for the PDCCH.

Further, the frequency domain location is a predefined set of locations, at least comprising the following 2 sets:

a first set of: #0, #4, #8 frequency domain REs of each RB occupied by the control channel,

a second set of: #1, #5, #9 frequency domain REs of each RB occupied by the control channel,

third set: #2, #6, #10 frequency domain REs of each RB occupied by the control channel,

fourth set: #3, #7, #11 frequency domain REs of each RB occupied by the control channel.

Further, before the other cooperative network elements serving the same terminal transmit the PDCCH with the orthogonal DMRS, the method further includes:

and interacting the identification code NID parameters in the DMRS sequence of the PDCCH of the terminal with other cooperative network elements, and configuring the same NID parameters with the other cooperative network elements.

The embodiment of the invention also provides a device for controlling the channel cooperative transmission, which comprises a processor and a transceiver,

the transceiver is configured to transmit PDCCH with other cooperative network elements serving the same terminal by using orthogonal DMRS, where the cooperative network elements are base stations and/or transmission points and/or cells cooperatively transmitting for the same terminal in the multipoint transmission system.

Further, the transceiver is specifically configured to perform at least one of the following: the DMRS includes a plurality of ports and,

Further, the higher layer signaling is indication information added in the control resource set for indicating a port number used for PDCCH DMRS of the PDCCH.

Further, the DMRS for the PDCCH is 2 or 4 ports.

Further, the DMRS includes a plurality of frequency domain locations, and the transceiver is specifically configured to perform at least one of the following:

Further, before the other cooperative network elements serving the same terminal transmit the PDCCH with the orthogonal DMRS, the transceiver is further configured to interact with the other cooperative network elements with the NID parameters in the DMRS sequence of the PDCCH of the terminal, and configure the same NID parameters with the other cooperative network elements.

The embodiment of the invention also provides a network element, which comprises: a memory, a processor and a computer program stored on the memory and executable on the processor, which when executed by the processor performs the steps in the method of control channel cooperative transmission as described above.

Embodiments of the present invention also provide a computer readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps in a method of control channel cooperative transmission as described above.

The embodiment of the invention has the following beneficial effects:

in the above scheme, orthogonal DMRS is introduced for control channel cooperative transmission, and the network element and other cooperative network elements serving the same terminal adopt orthogonal DMRS to transmit PDCCH, which can be multiport DMRS or DMRS with frequency domain shift.

Drawings

FIG. 1 is a schematic diagram of simultaneously providing services to an edge user using a plurality of TRPs;

fig. 2 is a schematic diagram of DMRS position fixing of PDCCH;

fig. 3 is a flow chart of a method for controlling channel cooperative transmission according to an embodiment of the present invention;

FIG. 4 is a schematic view of 4 positions of embodiment PDCCH DMRS of the present invention;

fig. 5 is a schematic structural diagram of an apparatus for controlling channel cooperative transmission according to an embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved by the embodiments of the present invention more apparent, the following detailed description will be given with reference to the accompanying drawings and the specific embodiments.

The names and abbreviations of the terms involved in the present invention change correspondingly, and the technical scheme of the present invention is still applicable when the abbreviations change.

An embodiment of the present invention provides a method for cooperative transmission of control channels, as shown in fig. 3, including:

step 101: and transmitting PDCCH by adopting orthogonal DMRS with other cooperative network elements serving the same terminal, wherein the cooperative network elements are base stations and/or transmission points and/or cells cooperatively transmitted for the same terminal in a multi-point transmission system.

In this embodiment, an orthogonal DMRS is introduced for control channel cooperative transmission, and the network element and other cooperative network elements serving the same terminal adopt the orthogonal DMRS to transmit PDCCH, which may be multiport DMRS or DMRS shifted in frequency domain.

Further, the DMRS for the PDCCH is 2 or 4 ports.

The scheme of the control channel cooperative transmission of the present invention is further described below with reference to the accompanying drawings and specific embodiments:

in this embodiment, orthogonal DMRS is introduced for control channel cooperative transmission, which may be a multiport DMRS or a DMRS shifted in the frequency domain.

In a specific example, when a PDCCH is transmitted using a multi-port DMRS, a PDCCH DMRS port number may be bound to a co-base station number when the DMRS port information does not need to be dynamically adjusted, for example: serving cell (current serving base station) uses port0, and cooperative base station 1 uses port1, so that UE can determine PDCCH DMRS port number through cooperative base station number; alternatively, the UE may be notified of the PDCCH DMRS port number by higher layer signaling, for example, in the control resource, adding a piece of information to indicate the port number used at PDCCH DMRS.

If 2 base station cooperation is supported at maximum, 2 DMRS ports are supported at maximum, and FD-OCC2 can be used for the orthogonalization mode between DMRS ports, such as Port 0: [ +1+1], port1: [+1-1]. If a maximum of 4 base station cooperation is supported, a maximum of 4 DMRS ports are supported, and FD-OCC4, such as Port0, can be used for the orthogonal manner between DMRS ports: [ +1+1+1+1], port1: [ +1-1+1+1], port2: [ +1+1+1-1], port3: [ +1-1+1-1], or: port 0: [ +1+1+1+1], port1: [ +1-1+1-1], port2: [ +1+1-1-1], port3: [+1-1-1+1]. The orthogonal manner between DMRS ports may also use a cyclic shift manner.

In another specific example, when transmitting the PDCCH using the DMRS shifted in the frequency domain, as shown by a-d in fig. 4, 4 sets of available positions of the DMRS may be defined. As shown in fig. 4a, the DMRS position is at X, X, X th RE, as shown in fig. 4b, the DMRS position is at X, X, X th RE, as shown in fig. 4b, the DMRS position is at X, X, X th RE, as shown in fig. 4b, and the DMRS position is at X, X, X th RE.

When the DMRS frequency domain position of the PDCCH does not need to be dynamically adjusted, the DMRS frequency domain position of the PDCCH may be bound to a cooperative base station number, for example: the serving cell uses the position 0, and the cooperative base station 1 uses the position 1, so that the UE can determine the position of the DMRS frequency domain through the number of the cooperative base station; alternatively, higher layer signaling may be used to inform the UE of DMRS frequency domain location, such as adding a piece of information indicating PDCCH DMRS frequency domain location in the controlresource.

Specifically, a piece of information can be added to the control resource set as follows:

pdcch-DMRS-port INTEGER(0…Nmax)OPTIONAL,

wherein, pdcch-DMRS-port represents PDCCH DMRS port number and Nmax represents the maximum port number.

Or adding a piece of information to the ControlResourceSet as follows:

pdcch-DMRS-position INTEGER(0…3)OPTIONAL,

wherein the pdcch-DMRS-position represents the frequency domain position of PDCCH DMRS.

The specific flow of the control channel cooperative transmission in this embodiment is:

1. the UE brings the cells with the neighbor cell RSRP difference of < TdB into a cooperative cell set and feeds back the cells to a main service cell, wherein T is a preset value, and the value of T can be set according to the requirement;

2. the method comprises the steps that a main service cell determines a cooperative cell set for UE;

3. the method comprises the steps of interacting NID parameters in a DMRS sequence of PDCCH of the current UE between coordinated cells;

4. the cooperative base station configures NID to be the same;

5. the cooperative base station transmits the PDCCH using a multi-port DMRS, or transmits the PDCCH using a plurality of frequency shift positions.

In this embodiment, orthogonal DMRS, which may be multiport DMRS or DMRS shifted in frequency domain, are introduced for control channel cooperative transmission, so that interference between DMRS when multiple PDCCH resource positions overlap can be reduced, and channel estimation performance is improved.

An embodiment of the present invention provides an apparatus for cooperative transmission of control channels, as shown in fig. 5, comprising a processor 21 and a transceiver 22,

the transceiver 22 is configured to transmit PDCCH with other cooperative network elements serving the same terminal using orthogonal DMRS, where the cooperative network elements are base stations and/or transmission points and/or cells cooperatively transmitting for the same terminal in the multipoint transmission system.

Further, the DMRS for the PDCCH is 2 or 4 ports.

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (Application Specific Integrated Circuits, ASIC), digital signal processors (Digital Signal Processing, DSP), digital signal processing devices (DSP devices, DSPD), programmable logic devices (Programmable Logic Device, PLD), field programmable gate arrays (Field-Programmable Gate Array, FPGA), general purpose processors, controllers, microcontrollers, microprocessors, other electronic units configured to perform the functions described herein, or a combination thereof.

For a software implementation, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in a memory and executed by a processor. The memory may be implemented within the processor or external to the processor.

In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described by differences from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.

It will be apparent to those skilled in the art that embodiments of the present invention may be provided as a method, apparatus, or computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the invention may take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

Embodiments of the present invention are described with reference to flowchart illustrations and/or block diagrams of methods, user equipment (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing user equipment to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing user equipment, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing user equipment to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing user equipment to cause a series of operational steps to be performed on the computer or other programmable user equipment to produce a computer implemented process such that the instructions which execute on the computer or other programmable user equipment provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiment and all such alterations and modifications as fall within the scope of the embodiments of the invention.

It is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or user device that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or user device. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or user device comprising the element.

While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various modifications and changes can be made without departing from the principles of the present invention, and such modifications and changes are intended to be within the scope of the present invention.

Claims

1. A method of controlling channel cooperative transmission, comprising:

transmitting PDCCH by adopting orthogonal DMRS with other cooperative network elements serving the same terminal, wherein the cooperative network elements are base stations and/or transmission points and/or cells cooperatively transmitted for the same terminal in a multi-point transmission system;

the DMRS includes a plurality of frequency domain positions, and the other cooperative network elements serving the same terminal transmit the PDCCH by using orthogonal DMRS includes at least one of the following modes:

2. The method of claim 1, wherein the orthogonal comprises code domain orthogonal and/or frequency domain orthogonal.

3. The method for cooperative transmission of control channel according to claim 2, wherein the code domain orthogonality is an orthogonal mask OCC or a cyclic shift pattern.

4. The method for cooperative transmission of control channels according to claim 1, wherein the cooperative network element is a neighboring cell base station having an RSRP difference from a primary serving cell less than a preset threshold, or a neighboring cell base station determined according to a neighboring cell relationship list.

5. The method of claim 1, wherein the DMRS includes a plurality of ports, and the transmitting the PDCCH with the DMRS orthogonal to other cooperative network elements serving the same terminal includes at least one of:

6. The method of claim 5, wherein the higher layer signaling is indication information added in a control resource set for indicating a port number used for DMRS of the PDCCH.

7. The method of claim 5 wherein the DMRS for the PDCCH is 2 or 4 port.

8. The method of claim 3 wherein the DMRS for the PDCCH uses a frequency domain OCC2 or frequency domain OCC4 or cyclic shift.

9. The method of claim 1, wherein the higher layer signaling is indication information added in a control resource set for indicating a frequency domain position of the DMRS for the PDCCH.

10. The method for cooperative transmission of control channels according to claim 1, wherein

The frequency domain position is a predefined position set, and at least comprises the following 2 sets:

11. The method of claim 1, wherein before the PDCCH is transmitted with the orthogonal DMRS by the other cooperative network element serving the same terminal, the method further comprises:

12. An apparatus for cooperative transmission of a control channel, comprising a processor and a transceiver,

the transceiver is used for transmitting PDCCH by adopting orthogonal DMRS with other cooperative network elements serving the same terminal, and the cooperative network elements are base stations and/or transmission points and/or cells cooperatively transmitted for the same terminal in a multi-point transmission system;

the DMRS includes a plurality of frequency domain locations, and the transceiver is specifically configured to perform at least one of the following:

13. The apparatus of claim 12, wherein the orthogonal comprises code domain orthogonal and/or frequency domain orthogonal.

14. The apparatus for cooperative transmission of control channel of claim 13, wherein the code domain orthogonality is an orthogonal mask OCC or a cyclic shift pattern.

15. The apparatus for cooperative transmission of control channels according to claim 12, wherein the cooperative network element is a neighboring cell base station having an RSRP difference from a primary serving cell less than a preset threshold, or a neighboring cell base station determined according to a neighbor relation list.

16. The apparatus of claim 12, wherein the DMRS comprises a plurality of ports, and wherein the transceiver is configured to perform at least one of:

17. The apparatus of claim 16, wherein the higher layer signaling is indication information added in a control resource for indicating a port number used for PDCCH DMRS use of the PDCCH.

18. The apparatus of claim 16 wherein the DMRS for the PDCCH is 2 or 4 port.

19. The apparatus of claim 14 wherein the DMRS for the PDCCH uses either frequency domain OCC2 or frequency domain OCC4 or cyclic shift.

20. The apparatus of claim 12, wherein the higher layer signaling is indication information added in a control resource for indicating a frequency domain location of PDCCH DMRS for the PDCCH.

21. The apparatus for cooperative transmission of control channels of claim 12, wherein

22. The apparatus for cooperative transmission of control channels of claim 12, wherein the transceiver is further configured to interact with other cooperative network elements with an identification code NID parameter in a DMRS sequence of a PDCCH of the terminal and configure the same NID parameter as the other cooperative network elements before the other cooperative network elements serving the same terminal transmit the PDCCH using orthogonal DMRS.

23. A network element, comprising: memory, a processor and a computer program stored on the memory and executable on the processor, which when executed by the processor performs the steps in the method of control channel cooperative transmission as claimed in any of claims 1 to 11.

24. A computer readable storage medium, characterized in that it has stored thereon a computer program which, when executed by a processor, implements the steps of the method of cooperative transmission of control channels according to any of claims 1 to 11.