CN110662255B

CN110662255B - Method, base station and storage medium for channel state indication reference signal allocation

Info

Publication number: CN110662255B
Application number: CN201810693104.3A
Authority: CN
Inventors: 田继宇
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2018-06-29
Filing date: 2018-06-29
Publication date: 2024-01-23
Anticipated expiration: 2038-06-29
Also published as: WO2020001501A1; CN110662255A

Abstract

The embodiment of the invention discloses a CSI-RS distribution method, a base station and a storage medium, and belongs to the field of communication. Wherein the method comprises the following steps: analyzing the frame structure, determining the working mode of each time slot of the new air interface NR, distributing CSI-RS transmission resources in the time slots with downlink symbols, and distributing CSI-RS feedback resources in the time slots with uplink symbols; initializing a CSI-RS resource according to preset parameters; after receiving a feedback result of a measurement event, acquiring UE with poor channel quality; and allocating resources for each UE with poor channel quality according to the initialized CSI-RS resources. According to the embodiment of the invention, the CSI-RS with non-conflicting resources is allocated to each accessed UE with poor channel quality in the RRC reconfiguration process, so that resource feedback of a plurality of UEs at the same moment is prevented from conflicting, the requirement of measuring the channel state of the UEs in real time is met, and the expenditure of a base station side is ensured to be as little as possible.

Description

Method, base station and storage medium for channel state indication reference signal allocation

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method, a base station, and a storage medium for allocating CSI-RS (Channel State Information Reference Signal, channel state indicator reference signals) in NR (New Radio) mobile communications.

Background

Due to popularization of the multi-antenna technology, CSI-RS is proposed in 4G, and the reference signal and the cell reference signal are used together to measure channel state information of UE (User Equipment). As the protocol evolves, CSI-RS replaces the cell reference signal entirely in NR, as the only reference signal for channel measurement, which can more accurately measure the channel quality to each UE. Because the frame structure of the NR is flexible in configuration, uplink and downlink resources can be combined in multiple ways, an accurate method is needed to reasonably allocate the feedback resources of the CSI-RS, ensure that the positions of all the UEs do not conflict, and simultaneously realize the transmission and the feedback of the resources.

Currently, CSI-RS can only be allocated to a UE in two procedures, the first procedure being allocation by the RRC (Radio Resource Control ) layer when the UE initially accesses the base station; the second procedure is allocated by the RRC layer upon base station radio resource reconfiguration. Since the initial access cannot acquire the capability information of the UE, the designated CSI-RS can be allocated to the UE only through the RRC reconfiguration procedure. In order to meet the condition that multiple UE can normally feed back channel state information under the condition of poor channel quality, and ensure that the cost of a base station side is as low as possible, the UE with poor channel quality must be allocated with a CSI-RS with non-conflicting resources, so that the allocated CSI-RS is distributed

The CSI-RS avoids the conflict of resource feedback of a plurality of UE at the same moment.

Disclosure of Invention

In view of the above, an object of an embodiment of the present invention is to provide a CSI-RS allocation method, a base station, and a storage medium. The technical problem that each accessed UE with poor channel quality allocates the CSI-RS with non-conflicting resources is solved.

The technical scheme adopted by the embodiment of the invention for solving the technical problems is as follows:

according to one aspect of the present invention, a CSI-RS allocation method is provided, comprising:

analyzing the frame structure, determining the working mode of each time slot of the new air interface NR, distributing CSI-RS transmission resources in the time slots with downlink symbols, and distributing CSI-RS feedback resources in the time slots with uplink symbols;

initializing a CSI-RS resource according to preset parameters;

after receiving a feedback result of a measurement event, acquiring UE with poor channel quality;

and allocating resources for each UE with poor channel quality according to the initialized CSI-RS resources.

According to another aspect of the present invention, there is provided a base station comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program implementing the steps of the CSI-RS allocation method described above when being executed by the processor.

According to still another aspect of the present invention, there is also provided a storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the CSI-RS allocation method described above.

According to the CSI-RS distribution method, the base station and the storage medium, a 5G protocol is used as an underlying basis, and resource feedback of a plurality of UE at the same moment can be prevented from conflicting by distributing the CSI-RS with non-conflicting resources to each accessed UE with poor channel quality, so that the condition that each UE can normally feed back channel state information under the condition that the channel quality of the plurality of UEs is poor is met, the requirement of measuring the channel state of the UE in real time is met, and the expenditure on the base station side is ensured to be as little as possible. The method not only enables the beam management and channel measurement functions of the 5G to be more widely exerted, but also can improve the switching speed in a switching scene, reduce the switching time delay and provide smoother experience and service for the UE. Meanwhile, the application of the CSI-RS can help the base station evaluate the UE signal, better bandwidth resources are allocated for the UE, and user experience is improved.

Drawings

Fig. 1 is a flowchart of a CSI-RS allocation method according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a next frame structure of an NR system according to an embodiment of the present invention;

fig. 3 is a flowchart of a method for initializing CSI-RS according to an embodiment of the present invention.

Fig. 4 is a flowchart of a resource allocation method according to an embodiment of the present invention.

Fig. 5 is a flowchart of another CSI-RS allocation method according to an embodiment of the present invention.

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear and obvious, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the particular embodiments described herein are illustrative only and are not limiting upon the invention.

The parameter meanings related to the embodiment of the invention are as follows:

CSI-RS parameter description

Parameter abbreviations	Chinese paraphrasing
		T1	CSI-RS transmission period
T2	CSI-RS feedback period
		M	Number of symbols for transmitting CSI-RS in transmission period
N	Symbol number for feeding back CSI-RS in feedback period
		B1	Total bandwidth for transmitting CSI-RS
B2	Total bandwidth for feedback CSI-RS
		P1	Frequency domain resource number for transmitting CSI-RS
P2	Frequency domain resource number for feedback CSI-RS
		ρ	Density of CSI-RS
Q	Frequency domain resource supported by each resource blockNumber of sources
		R1	Number of sets of transmission resources
R2	Feedback resource set number

Example 1

As shown in fig. 1, an embodiment of the present invention proposes a CSI-RS allocation method, which includes:

s101, analyzing a frame structure, determining the working mode of each time slot of NR, and distributing CSI-RS transmission resources in the time slots with downlink symbols and CSI-RS feedback resources in the time slots with uplink symbols.

Specifically, according to the frame structure configuration of the cell, the working mode of each time slot of the NR system is determined, which may be full downlink (all symbols are used for downlink), full uplink (all symbols are used for uplink), downlink self-contained (a plurality of symbols are used for downlink, a small number of symbols are used for uplink), and uplink self-contained (a plurality of symbols are used for uplink, and a small number of symbols are used for downlink). The base station analyzes the structure, allocates the CSI-RS transmission resource in the time slot with the downlink symbol, and allocates the feedback resource in the time slot with the uplink symbol.

Please refer to the next frame structure diagram of the NR system shown in fig. 2, wherein the abscissa is the time domain and the ordinate is the frequency domain. One slot (e.g., slot x) has 14 symbols. And analyzing the frame structure to obtain the transmission time t1 and the feedback time t2 of the CSI-RS. According to the preset transmission period T1 and feedback period T2, the transmission time T1 and feedback time T2 in the whole period can be determined.

S102, initializing the CSI-RS resources according to preset parameters.

Specifically, as the total resources of the air interface of the NR cell are limited, the number of the CSI-RS resources is not unlimited, the number of the resources needs to be reasonably controlled according to the actual scene, the total number of the CSI-RS transmission resources of one cell is determined by a CSI-RS transmission period T1, a symbol number M used for transmitting the CSI-RS in the transmission period T1, a total bandwidth B1 used for transmitting the CSI-RS and the density rho of the CSI-RS, and meanwhile, the total number of the feedback resources is determined by a CSI-RS feedback period T2, a symbol number N used for feeding back the CSI-RS in the feedback period T2 and a total bandwidth B2 used for feeding back the CSI-RS. In practical application, the parameters can be preset according to the scenes, but the base station can flexibly adjust the seven parameters to meet different scenes.

Referring to fig. 3, the present step further includes:

s1021, determining the number M of time domain symbols used for transmitting the CSI-RS in the transmission period T1 and the number N of time domain symbols used for feeding back the CSI-RS in the feedback period T2 according to a preset CSI-RS transmission period T1 and a preset CSI-RS feedback period T2.

S1022, determining the frequency domain resource number P1 for transmitting the CSI-RS and the frequency domain resource number P2 for feeding back the CSI-RS according to the preset total bandwidth B1 for transmitting the CSI-RS, the preset total bandwidth B2 for feeding back the CSI-RS and the preset bandwidth segment BWP.

S1023, determining the number of the resources supported by each resource block in the transmission resources according to the preset density rho of the CSI-RS.

S103, after receiving a feedback result of the measurement event, obtaining the UE with poor channel quality.

Specifically, the base station firstly transmits a measurement event, and confirms the UE with poor channel quality according to the feedback result of the measurement event.

Specifically, when the signal quality of the UE is lower than a set threshold, the signal quality is reported to the base station through a measurement event. And after receiving the measurement event, the base station acquires the UE with poor signal quality from the a2 measurement event. Since only the UE with poor signal quality will report, the base station can determine that the UE has poor signal quality after receiving the a2 measurement event of a certain UE.

S104, allocating resources for each UE with poor channel quality according to the initialized CSI-RS resources.

Preferably, in order to better avoid interference between the signals of E, according to the feedback sequence of the measurement event to the UEs with poor channel quality, time domain resources are allocated preferentially, and then frequency domain resources are allocated, so that feedback resources are allocated to each accessed UE with poor channel quality in sequence.

Referring to fig. 4, the steps further include:

s1041, according to the preset transmission resource set number R1, allocating R1 set transmission resources for each accessed UE with poor channel quality.

S1042, according to the preset feedback resource set number R2, allocating R2 set of feedback resources for each accessed UE with poor channel quality.

S1043, associating the allocated transmission resource and feedback resource, and sending to the access UE through air interface redistribution.

Specifically, the CSI-RS has an irreplaceable role in channel measurement, beam management, etc. The base station may perform beam management based on feedback from the UE for each set of resources. The UE can also feed back different contents based on different feedback purposes of the R2 set. Each set of feedback resources may correspond to 1 or more sets of transmission resources, but the purpose of each set of feedback resources must be unique. The 1 or more sets of transmission resources may be used for measurements of different beams and may assist the base station in selecting an optimal beam.

In the embodiment of the invention, the 5G protocol is used as a basis, and the conflict of resource feedback of a plurality of UE at the same moment can be avoided by distributing the CSI-RS with non-conflicting resources for each accessed UE with poor channel quality, so that the condition that each UE can normally feed back channel state information under the scene of poor channel quality of the plurality of UEs is satisfied, the requirement of measuring the channel state of the UE in real time is satisfied, and the expenditure on the side of a base station is ensured to be as little as possible.

Example two

As shown in fig. 5, a method for initializing CSI-RS resources provided by an embodiment of the present invention includes:

s501, analyzing a frame structure, determining the working mode of each time slot of a new air interface NR, and distributing CSI-RS transmission resources in the time slots with downlink symbols and CSI-RS feedback resources in the time slots with uplink symbols.

S502, initializing CSI-RS resources according to preset parameters.

S503, after receiving a feedback result of the measurement event, obtaining the UE with poor channel quality.

S504, according to the initialized CSI-RS resources, resources are allocated for each UE with poor channel quality.

S505, after detecting the release of the UE, recovering the feedback resources allocated to the UE.

In the embodiment of the invention, on the basis of the first embodiment, after detecting that the UE is released, the feedback resource allocated to the UE is recovered, and the base station can continue to allocate the resource for the UE with poor new access channel quality, thereby improving the utilization rate of the resource.

Example III

The embodiment of the invention is described by taking a typical scene as an example: in an office building scenario, 400 UEs with poor channel quality are supported. The configuration parameters are as follows: the frame structure is 10ms in period, each frame uses 1 downlink symbol to measure the channel state, uses 5 uplink symbols to feed back information, the cell bandwidth is 272RB, the frequency domain supports 20 resources and feeds back CSI information at the same time, each CSI information occupies 2RB, and the number of feedback resource sets is 1 (only the channel quality is measured). The measurement period is configured to be 10ms, the feedback period is configured to be 40ms, and the allocation principle is that the time domain resource is allocated first and then the frequency domain resource is allocated according to the feedback sequence of the UE measurement event to the poor channel quality.

Typical scene parameter configuration table

Parameter list	Parameter configuration values
		T1	10ms
T2	40ms
		M	1
N	20
		B1	272RB
B2	40RB

According to the sequence of feedback of UE measurement events to poor channel quality, the feedback time domain position of the ith UE with poor channel quality is: (slot 0+ (i-1) ×slot)% N, where slot0 represents a slot position allocated to the CSI-RS feedback resource, slot represents a total number of slots of each frame structure, and feedback frequency domain positions of the i-th UE with poor channel quality are: (i×p2)% n+p0, where P0 represents an initial position of the frequency domain resource position.

According to the above rule, the following are specific to the scenario of the present embodiment:

the CSI-RS feedback time domain position is: the CSI of the 1 st UE is shifted to 3 in the configured CSI period,

the CSI of the second UE is offset by 7 during the configured CSI period,

the CSI of the ith UE is offset by 3+ (i-1) x 4 in the configured CSI period.

After 20 UEs are configured, the subsequent UE sends slots of CSI and so on,

the time domain position of the jth UE needing to issue the CSI-RS is consistent with the (j% 20) th UE.

The frequency domain position is: the 1 st UE frequency domain continuously occupies 2 RBs, the second UE occupies the same frequency domain position until the 20 th UE, and the occupied frequency domain position is unchanged. The frequency domain positions of the 20 th to 40 th UE needing to issue the CSI-RS are 2 continuous RBs behind the first 20 UEs, and so on, each 20 UEs are a group, and each group occupies 2 continuous RBs behind the former group of frequency domains. After 400 UEs are accessed, the time domain occupies 20 resources in total, and the frequency domain occupies 20 resources in total. The exemplary scenario is taken as an example in the embodiment of the present invention to intuitively illustrate the CSI-RS allocation method, which is not limited to practical application.

In addition, the embodiment of the invention also provides a base station, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the computer program realizes the steps of the CSI-RS allocation method when being executed by the processor.

In addition, the embodiment of the invention also provides a computer readable storage medium, and a computer program is stored on the computer readable storage medium, and when the computer program is executed by a processor, the steps of the CSI-RS allocation method are realized.

It should be noted that, the base station and the computer readable storage medium belong to the same concept as the CSI-RS allocation method embodiment, the specific implementation process of the base station and the computer readable storage medium are detailed in the method embodiment, and technical features in the method embodiment are correspondingly applicable to the base station and the computer readable storage medium, which are not repeated herein.

Those of ordinary skill in the art will appreciate that all or some of the steps, systems, functional modules/units in the apparatus, and methods disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof.

In a hardware implementation, the division between the functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed cooperatively by several physical components. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as known to those skilled in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Furthermore, as is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, and thus do not limit the scope of the claims of the present invention. Any modifications, equivalent substitutions and improvements made by those skilled in the art without departing from the scope and spirit of the present invention shall fall within the scope of the appended claims.

Claims

1. A channel state indication reference signal CSI-RS allocation method, the method comprising:

initializing a CSI-RS resource according to preset parameters;

according to initialized CSI-RS resources, allocating resources for each UE with poor channel quality according to the feedback sequence of measurement events to the UE with poor channel quality, and sequentially allocating according to the principle of firstly allocating time domain resources and then allocating frequency domain resources;

the feedback time domain position of the i-th UE with poor channel quality is: (slot 0+ (i-1) ×slot)% N, wherein slot0 represents a slot position allocated to the CSI-RS feedback resource, slot represents a total number of slots per frame structure, and N represents a number of time domain symbols for feeding back the CSI-RS;

the feedback frequency domain position of the i-th UE with poor channel quality is: (i×p2)% n+p0, where P0 represents an initial position of the frequency domain resource position and P2 represents the frequency domain resource number P2 for feeding back the CSI-RS.

2. The CSI-RS allocation method according to claim 1, wherein the preset parameters include: a CSI-RS transmission period T1, a CSI-RS feedback period T2, a bandwidth B1 for transmitting the CSI-RS, a bandwidth B2 for feeding back the CSI-RS, a density rho of the CSI-RS, a transmission resource cover number R1 and a feedback resource cover number R2.

3. The CSI-RS allocation method according to claim 2, comprising: the initializing the CSI-RS resource comprises:

determining the number M of time domain symbols used for transmitting the CSI-RS in the transmission period T1 and the number N of time domain symbols used for feeding back the CSI-RS in the feedback period T2 according to the preset CSI-RS transmission period T1 and the preset CSI-RS feedback period T2;

determining the frequency domain resource number P1 for transmitting the CSI-RS and the frequency domain resource number P2 for feeding back the CSI-RS according to a preset total bandwidth B1 for transmitting the CSI-RS, a preset total bandwidth B2 for feeding back the CSI-RS and a preset bandwidth segment BWP;

and determining the number of the resources supported by each resource block in the transmission resources according to the preset density rho of the CSI-RS.

4. The CSI-RS allocation method according to claim 2, wherein said allocating resources for each UE with poor channel quality comprises:

according to a preset transmission resource set number R1, allocating R1 set transmission resources for each accessed UE with poor channel quality;

according to the preset feedback resource set number R2, allocating R2 sets of feedback resources for each accessed UE with poor channel quality;

and associating the allocated transmission resources with the feedback resources, and transmitting the transmission resources and the feedback resources to the access UE through air interface redistribution.

5. The CSI-RS allocation method according to any of claims 1 to 4, characterized in that the method then comprises: and after detecting that the UE is released, recovering the CSI-RS feedback resource of the UE.

6. A base station comprising a memory, a processor and a computer program stored on the memory and executable on the processor, which when executed by the processor, implements the steps of the CSI-RS allocation method according to any of claims 1 to 5.

7. A computer readable storage medium, wherein a computer program is stored on the computer readable storage medium, which when executed by a processor, implements the steps of the CSI-RS allocation method according to any of claims 1 to 5.