CN107154841A

CN107154841A - CSI back method, acquisition methods and relevant device

Info

Publication number: CN107154841A
Application number: CN201610125494.5A
Authority: CN
Inventors: 陈润华; 李辉; 高秋彬; 拉盖施; 陈文洪
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT
Priority date: 2016-03-04
Filing date: 2016-03-04
Publication date: 2017-09-12

Abstract

The invention discloses a kind of CSI back method, acquisition methods and relevant device, the feedback granularity to solve due to CSI is fixed, and is caused CSI feedback granularity and can not be applied to practical application scene, the problem of reducing systematic function.Feedback method is：Receiving terminal determines channel condition information CSI current feedback granularity, and the feedback granularity is used for the size for characterizing the resource corresponding to each CSI；The receiving terminal feeds back CSI according to the current feedback granularity.

Description

Channel State Information (CSI) feedback method, Channel State Information (CSI) acquisition method and related equipment

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a Channel State Information (CSI) feedback method, an acquisition method, and a related device.

Background

In order to meet the requirements of spectral efficiency and reliability, Multiple Input Multiple Output (MIMO) technology has become a key technology adopted in many commercial wireless communication systems. By equipping a plurality of antennas at a transmitting end and a receiving end, for example, the transmitting end is a base station (eNB) in Long Term Evolution (LTE), and the receiving end is a terminal (UE) in LTE, N data streams can be transmitted simultaneously on the same frequency resource, where N >1, thereby greatly improving spectrum efficiency. The maximum value of N is min { Nt, Nr }, where Nt represents the number of transmit antennas and Nr represents the number of receive antennas.

The transmitting end performs precoding to improve the spectrum efficiency, and needs to acquire CSI for precoding. The receiving end utilizes a downlink reference signal (such as pilot frequency) to measure the CSI and feeds the measured CSI back to the transmitter through an uplink channel.

For an Nt × Nr MIMO channel, the transmitting end needs to obtain Nt × Nr complex channel coefficients. Most commercial wireless communication systems adopt an implicit feedback mode, that is, the precoding at the transmitting end can only be selected from a group of candidate precoding matrixes (such as codebooks) with limited quantity. The receiving end reports the optimal Precoding Matrix Indication (PMI) to the transmitting end for the transmitting end to select a Precoding Matrix. While reporting the PMI, the receiving end may also report a Channel Quality Indication (CQI). The CQI is used to indicate channel quality that can be obtained by the receiving end when precoding with the fed-back PMI. The CQI may represent a signal-to-noise ratio, a supportable Modulation and Coding Scheme (MCS), or other parameters, and may also represent a function of the above listed parameters. When the reported PMI is adopted, the number of data streams (such as Rank Indication (RI)) that can be received by the receiving end may also be reported independently. For example, RI r, PMI k indicates that the receiving end UE proposes the transmitting end eNB to use the kth precoding matrix in the rank-r codebook. Wherein the rank-r codebook comprises a set of precoding matrices of Nt × r.

In commercial wireless systems, it is necessary to simultaneously support communication over a wide frequency band for a plurality of terminals. In order to effectively utilize the system bandwidth, multicarrier modulation is widely used as an air interface. The system bandwidth will be divided into a plurality of sub-carriers, for example, the system bandwidth of 5MHz in LTE is divided into a plurality of sub-carriers, each of which is 15 KHz. A group of adjacent subcarriers may be combined into a larger spectral unit, e.g. a Physical Resource Block (PRB) in LTE, where one PRB contains 12 subcarriers. It is generally assumed that the frequency characteristics of the channel are the same within one spectral unit (e.g., PRB), which may serve as the minimum frequency-domain granularity for measuring and quantizing CSI.

The LTE system defines multiple CSI feedback modes, and in each CSI feedback mode, the feedback granularity of PMI and CQI may be wideband or subband. In the case where the feedback granularity is wideband, only one PMI or CQI for the entire system bandwidth is fed back. And when the feedback granularity is sub-band, feeding back a PMI or CQI for each sub-band, wherein the size of the sub-band is uniquely determined by the system bandwidth. For example, when the system bandwidth is 5MHz, the subband size is 6 PRB.

In an actual application scenario, the variation of the channel in the frequency domain is not fixed, for example, an outdoor channel with a single main path may be relatively flat in the frequency domain, and a sub-band with a larger size is selected, which may ensure that CSI is matched with the time of transmitting PDSCH, and may reduce system overhead. For indoor office scenes, more scatterers and rich multipath fading exist, the channel changes obviously in the frequency domain, and the sub-band with a smaller size can ensure that the CSI is matched with the time for transmitting the PDSCH. However, the existing method for fixing the CSI feedback granularity cannot perform adaptive adjustment according to the change condition of the channel in the frequency domain, thereby reducing the system performance.

Disclosure of Invention

The embodiment of the invention provides a Channel State Information (CSI) feedback method, an acquisition method and related equipment, which are used for solving the problems that the CSI feedback granularity is not suitable for practical application scenes and the system performance is reduced due to the fixed CSI feedback granularity.

The embodiment of the invention provides the following specific technical scheme:

in a first aspect, an embodiment of the present invention provides a method for feeding back channel state information CSI, including:

a receiving end determines the current feedback granularity of Channel State Information (CSI), wherein the feedback granularity is used for representing the size of a resource corresponding to each CSI;

and the receiving end feeds back CSI according to the current feedback granularity.

In a possible embodiment, the determining, by the receiving end, the current feedback granularity of the CSI includes:

the receiving end receives a control signaling;

and the receiving end determines the current feedback granularity according to the indication information of the current feedback granularity carried in the control signaling.

In a possible embodiment, the control signaling is semi-static signaling or dynamic control signaling.

and the receiving end determines the current feedback granularity according to the current channel characteristics.

In a possible embodiment, the method further comprises:

and after determining the current feedback granularity according to the current channel characteristics, the receiving end sends the indication information of the current feedback granularity to the transmitting end.

In a possible embodiment, the feedback of CSI by the receiving end according to the current feedback granularity includes:

and the receiving end feeds back the CSI at one or a plurality of continuous CSI feedback moments according to the current feedback granularity.

the receiving end feeds back the CSI according to the current feedback granularity at a CSI feedback moment after receiving the control signaling; or,

the receiving end feeds back CSI according to the current feedback granularity at all CSI feedback moments in a window after receiving the control signaling; or,

the receiving end feeds back the CSI according to the current feedback granularity at continuous L CSI feedback moments after receiving the control signaling, wherein L is larger than 1; or,

and the receiving end feeds back the CSI according to the current feedback granularity at each CSI feedback time between the receiving of the control signaling and the receiving of the next control signaling for determining the feedback granularity of the CSI.

In a second aspect, an embodiment of the present invention provides a method for acquiring CSI, including:

a transmitting terminal receives Channel State Information (CSI);

and the transmitting end decodes the CSI according to the determined current feedback granularity of the CSI, wherein the feedback granularity is used for representing the size of the resource corresponding to each CSI.

In a possible embodiment, the method further comprises:

the transmitting end determines the current feedback granularity according to the current channel characteristics; or,

and the transmitting end receives the indication information of the current feedback granularity sent by the receiving end, and determines the current feedback granularity according to the indication information of the current feedback granularity.

In a possible embodiment, the method further comprises:

and after determining the current feedback granularity, the transmitting terminal sends the determined indication information of the current feedback granularity to a receiving terminal.

In a possible implementation manner, the sending, by the sending end, the determined indication information of the current feedback granularity to the receiving end includes:

and the transmitting end sends a control signaling to the receiving end, wherein the control signaling carries the indication information of the current feedback granularity.

In a possible embodiment, the decoding, by the transmitting end, the CSI according to the determined current feedback granularity of the CSI includes:

the transmitting end decodes the current feedback granularity indicated by the control signaling for the CSI after the control signaling is sent to the receiving end; or,

the transmitting end decodes all the CSI in a window after the control signaling is sent to the receiving end by adopting the current feedback granularity indicated by the control signaling; or,

the transmitting end decodes the continuous L CSI after the control signaling is sent to the receiving end by adopting the current feedback granularity indicated by the control signaling, wherein L is larger than 1; or,

and the transmitting end decodes each CSI between the control signaling sent to the receiving end and the next control signaling used for determining the feedback granularity of the CSI by adopting the current feedback granularity indicated by the control signaling.

In a third aspect, an embodiment of the present invention further provides a receiving end device, including:

the processing module is used for determining the current feedback granularity of the Channel State Information (CSI), and the feedback granularity is used for representing the size of a resource corresponding to each CSI;

and the sending module is used for feeding back CSI according to the current feedback granularity determined by the processing module.

In a possible implementation manner, the system further comprises a receiving module;

the receiving module is used for receiving a control signaling;

the processing module is configured to determine the current feedback granularity according to the indication information of the current feedback granularity carried in the control signaling received by the receiving module.

In a possible embodiment, the processing module is specifically configured to:

and determining the current feedback granularity according to the current channel characteristics.

In a possible implementation, the sending module is further configured to:

and after the processing module determines the current feedback granularity according to the current channel characteristic, sending the indication information of the current feedback granularity.

In a possible implementation, the sending module is specifically configured to:

and feeding back CSI at one or a plurality of continuous CSI feedback moments according to the current feedback granularity.

In a possible implementation, the sending module is specifically configured to:

feeding back CSI according to the current feedback granularity at a CSI feedback time after the receiving module receives the control signaling; or,

feeding back CSI according to the current feedback granularity at all CSI feedback moments in a window after the receiving module receives the control signaling; or,

feeding back CSI according to the current feedback granularity at continuous L CSI feedback moments after the receiving module receives the control signaling, wherein L is larger than 1; or,

and feeding back the CSI according to the current feedback granularity at each CSI feedback time between the time when the receiving module receives the control signaling and the time when the receiving module receives the next control signaling for determining the feedback granularity of the CSI.

In a fourth aspect, the present invention also provides a transmitting end device, including:

a receiving module, configured to receive channel state information CSI;

and the processing module is used for decoding the CSI according to the determined current feedback granularity of the CSI, and the feedback granularity is used for representing the size of the resource corresponding to each CSI.

In a possible embodiment, the processing module is further configured to: determining the current feedback granularity according to the current channel characteristics;

or,

the receiving module is further configured to: receiving the indication information of the current feedback granularity sent by the receiving end;

the processing module is specifically configured to: and determining the current feedback granularity according to the indication information of the current feedback granularity.

In a possible implementation manner, the apparatus further includes a sending module, configured to send, after the processing module determines the current feedback granularity, the determined indication information of the current feedback granularity to a receiving end.

In a possible implementation, the sending module is specifically configured to:

and sending a control signaling to the receiving end, wherein the control signaling carries the indication information of the current feedback granularity.

In a possible embodiment, the processing module is specifically configured to:

decoding the CSI after the control signaling is sent to the receiving end by adopting the current feedback granularity indicated by the control signaling; or,

decoding all the CSI in a window after the control signaling is sent to the receiving end by adopting the current feedback granularity indicated by the control signaling; or,

decoding the continuous L CSI after the control signaling is sent to the receiving end by adopting the current feedback granularity indicated by the control signaling, wherein L is larger than 1; or,

and sending each CSI between the control signaling sent to the receiving end and the next control signaling used for determining the feedback granularity of the CSI to the receiving end, and decoding by adopting the current feedback granularity indicated by the control signaling.

In a fifth aspect, the present invention is a receiving end device, which mainly includes a processor, a memory and a transceiver, wherein the transceiver is configured to receive and transmit data under the control of the processor, the memory stores a preset program, the processor reads the program in the memory, and executes the following processes according to the program:

determining current feedback granularity of Channel State Information (CSI), wherein the feedback granularity is used for representing the size of a resource corresponding to each CSI; and feeding back CSI according to the determined current feedback granularity.

In a possible embodiment, the processor receives a control signaling through the transceiver, and determines the current feedback granularity according to the indication information of the current feedback granularity carried in the received control signaling.

In a possible embodiment, the processor determines said current feedback granularity from current channel characteristics.

In a possible embodiment, the processor sends, via the transceiver, an indication of the current feedback granularity to the transmitter after determining the current feedback granularity according to the current channel characteristics.

In a possible implementation manner, the processor feeds back the CSI at one or a plurality of consecutive CSI feedback time instants according to the current feedback granularity.

In a possible embodiment, the processor feeds back CSI according to the current feedback granularity at a CSI feedback time after receiving the control signaling through the transceiver; or,

the processor feeds back CSI according to the current feedback granularity at all CSI feedback moments in a window after the transceiver receives the control signaling; or,

the processor feeds back the CSI according to the current feedback granularity at continuous L CSI feedback moments after the transceiver receives the control signaling, wherein L is larger than 1; or,

and the processor feeds back the CSI according to the current feedback granularity at each CSI feedback time between the time when the transceiver receives the control signaling and the time when the transceiver receives the next control signaling for determining the feedback granularity of the CSI.

In a sixth aspect, the present invention further provides another transmitting-end device, where the transmitting-end device mainly includes a processor, a memory, and a transceiver, where the transceiver is used to receive and transmit data under the control of the processor, the memory stores a preset program, the processor reads the program in the memory, and executes the following processes according to the program:

receiving, by a transceiver, channel state information, CSI;

and decoding the CSI according to the determined current feedback granularity of the CSI, wherein the feedback granularity is used for representing the size of the resource corresponding to each CSI.

In a possible embodiment, the processor determines the current feedback granularity according to the current channel characteristics;

or,

the processor receives the current indication information of the feedback granularity sent by the receiving end through the transceiver; and determining the current feedback granularity according to the indication information of the current feedback granularity.

In a possible embodiment, after determining the current feedback granularity, the processor sends the determined indication information of the current feedback granularity to the receiving end through the transceiver.

In a possible implementation manner, the processor sends a control signaling to the receiving end through the transceiver, where the control signaling carries the indication information of the current feedback granularity.

In a possible embodiment, the processor decodes the CSI after the control signaling is sent to the receiving end through the transceiver by using the current feedback granularity indicated by the control signaling; or,

the processor decodes all the CSI in a window after the control signaling is sent to the receiving end through the transceiver by adopting the current feedback granularity indicated by the control signaling; or,

the processor decodes the continuous L CSI after the control signaling is sent to the receiving end through the transceiver by adopting the current feedback granularity indicated by the control signaling, wherein L is larger than 1; or,

and the processor decodes each CSI between the sending of the control signaling and the sending of the next control signaling for determining the feedback granularity of the CSI to the receiving end through the transceiver by adopting the current feedback granularity indicated by the control signaling.

Based on the technical scheme, in the embodiment of the invention, the receiving end determines the current feedback granularity of the CSI, the feedback granularity is used for representing the size of the resource corresponding to each CSI, the CSI is fed back according to the current feedback granularity of the CSI, the dynamic adjustment of the CSI feedback granularity is realized, and the problems that the feedback granularity of the CSI cannot be suitable for practical application scenes and the system performance is reduced due to the fact that the feedback granularity of the CSI is fixed are solved.

Drawings

Fig. 1 is a schematic flow chart of a CSI feedback method according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating a CSI feedback process according to an embodiment of the present invention;

fig. 3 is a diagram illustrating another CSI feedback process according to an embodiment of the present invention;

fig. 4 is a diagram illustrating another CSI feedback process according to an embodiment of the present invention;

FIG. 5 is a flow chart illustrating a CSI acquisition method according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a receiving end device in the embodiment of the present invention;

fig. 7 is a schematic structural diagram of a transmitting end device in an embodiment of the present invention;

fig. 8 is a schematic structural diagram of another receiving end device in the embodiment of the present invention;

fig. 9 is a schematic structural diagram of another transmitting-end device in the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In theory, CSI feedback may be in units of PRBs. But this results in a significant overhead. Most wireless communication channels have larger relevant bandwidth, especially outdoor channels with main path propagation, and the channel characteristics of adjacent PRBs are similar, so that one CSI feedback is adopted.

The CSI feedback comprises any one or combination of PMI, RI and CQI.

The feedback granularity of PMI or CQI may be larger than 1 PRB to enable significant reduction of feedback overhead with less loss of system performance. That is, reporting of PMI or CQI may be in units of a set of adjacent PRBs, rather than in units of one PRB. The set of contiguous PRBs is defined as a subband.

The RI may be reported with the same feedback granularity as the PMI or the CQI, or may only report one RI for the entire system bandwidth.

The LTE system defines a plurality of feedback modes, and in each feedback mode, feedback granularity of PMI and CQI may be either wideband or subband. For wideband feedback, only one PMI/CQI is reported for the entire system bandwidth. For subband feedback, each subband reports a PMI/CQI, and the size of the subband is uniquely determined by the system bandwidth. The subband size for a 5MHz system is 6PRB, for example.

The inventor finds that in the current system design, the size of the sub-band is only related to the system bandwidth, the feedback granularity of the CSI is fixed, and is completely unrelated to the actual channel, so that the feedback granularity of the CSI cannot adapt to the change of the environmental frequency domain, and the system performance is reduced. For example, an outdoor channel with a single main path is likely to be flat in the frequency domain, and the sub-bands may be selected to be larger in size. On the contrary, for an indoor office scene, the channel has more scatterers and rich multipath fading, and the channel may change obviously in the frequency domain, so that a smaller sub-band size needs to be selected.

The inventors have also found that in current system design, the size of the sub-band is fixed with the system bandwidth determined, i.e. the feedback granularity of CSI is fixed, and it is difficult to adapt to multiple terminals at different moving speeds. The wireless network needs to support a plurality of terminals at different moving speeds, such as low-speed terminals indoors or high-speed terminals on trains and automobiles. Because there is a time delay between the time of reporting the CSI and the time of actually acting on PDSCH transmission by the CSI, the time delay easily causes mismatching between CSI and PDSCH transmission, so MIMO precoding is very sensitive to the speed of the UE. The faster the UE moves, the more prominent the mismatch between CSI and PDSCH transmissions, and the more significant the system performance degradation. Because the wideband CSI changes slowly relative to the narrowband CSI, the wideband CSI feedback is more robust to a high-speed channel and is more suitable for CSI feedback of high-speed mobile UE.

However, in current LTE designs, no relevant scheme has been proposed for dynamically adjusting the feedback granularity of CSI.

Based on this, the embodiment of the present invention provides a CSI feedback method as shown in fig. 1, which includes the following specific steps:

step 101: and the receiving end determines the current feedback granularity of the CSI, wherein the feedback granularity is used for representing the size of the resource corresponding to each CSI.

In particular implementations, the feedback granularity of the CSI is determined based on current channel characteristics

In implementation, the feedback granularity of the CSI is used to determine the size of the subband corresponding to one CSI feedback.

In implementation, the method for the receiving end to determine the current feedback granularity of the CSI includes, but is not limited to, the following two ways:

firstly, a receiving end receives a control signaling, and determines the current feedback granularity of the CSI according to the control signaling.

Specifically, the receiving end receives a control signaling sent by the transmitting end, and determines the current feedback granularity of the CSI according to the indication information of the current feedback granularity of the CSI carried in the control signaling.

In implementation, the control signaling may be semi-static signaling or dynamic control signaling.

For example, the semi-static control signaling received by the receiving end is Radio Resource Control (RRC) signaling, and the RRC signaling carries indication information of current feedback granularity of CSI.

For another example, the dynamic Control signaling received by the receiving end is an uplink scheduling notification (UL grant), such as a Physical Downlink Control Channel (PDCCH), or other possible dynamic Control signaling, where the UL grant is used to schedule the receiving end to perform uplink data transmission, and may also carry indication information of the current feedback granularity of the CSI. Specifically, the PDCCH carrying the indication information of the current feedback granularity of the CSI may be the PDCCH triggering the UE to report the CSI, or may be another PDCCH different from the PDCCH triggering the UE to report the CSI.

Secondly, the receiving end determines the current feedback granularity of the CSI.

Specifically, the receiving end determines the current feedback granularity of the CSI according to the current channel characteristics.

For example, the receiving end determines the current feedback granularity of the CSI according to the current moving speed, the long-term characteristics of the current channel, and the like. Specifically, the receiving end determines that the current feedback granularity of the CSI is proportional to the current moving speed, that is, the faster the current moving speed is, the larger the current feedback granularity of the CSI is, and conversely, the slower the current moving speed is, the smaller the current feedback granularity of the CSI is. The channel long-term characteristics may include statistical correlation of the channel in frequency domain resources. If the current frequency domain correlation is low, the channel is more different in different frequency domain resources, and a smaller feedback granularity should be used. If the current frequency domain correlation is high, the channel is less different in different frequency domain resources, and a larger feedback granularity should be used.

Step 102: and the receiving end feeds back the CSI according to the current feedback granularity.

In implementation, for the second way of determining the current feedback granularity of the CSI, after determining the current feedback granularity of the CSI according to the channel characteristics, the receiving end sends the indication information of the current feedback granularity of the CSI to the transmitting end. Specifically, the receiving end feeds back the CSI according to the current feedback granularity of the CSI, and sends the indication information of the current feedback granularity of the CSI to the transmitting end.

Specifically, the receiving end sends the indication information of the current feedback granularity of the CSI to the transmitting end, which includes but is not limited to the following ways:

firstly, each time the receiving end sends the indication information of the current feedback granularity of the CSI, the current feedback granularity of the CSI which is fed back is only used for one CSI feedback corresponding to the indication information.

Secondly, the receiving end uses the fed-back current feedback granularity of the CSI for all CSI feedbacks in a window corresponding to the indication information every time the receiving end sends the indication information of the current feedback granularity of the CSI.

The length of the window may be defined by the receiving end and the transmitting end, and the specific implementation manner defined by the receiving end and the transmitting end is not limited herein, and only the transmitting end and the receiving end need to keep the same understanding of the length of the window.

Thirdly, each time the receiving end sends the indication information of the current feedback granularity of the CSI, the fed back current feedback granularity of the CSI is used for continuous L CSI feedbacks corresponding to the indication information, wherein L is larger than 1.

In a specific implementation, in the implementation, the specific value of L may be mutually agreed by the receiving end and the transmitting end, and here, the mutually agreed specific implementation is not limited, and it is only necessary to keep the values of L identical for the transmitting end and the receiving end.

Fourthly, the receiving end uses the fed-back current feedback granularity of the CSI for each CSI feedback between the indication information and the indication information of the current feedback granularity of the CSI sent next time every time the receiving end sends the indication information of the current feedback granularity of the CSI.

In implementation, the receiving end feeds back the CSI at one or a plurality of consecutive CSI feedback moments according to the current feedback granularity of the CSI.

Specifically, for the above first way of determining the current feedback granularity of the CSI, the receiving end feeds back the CSI according to the current feedback granularity of the CSI, which includes but is not limited to the following ways:

in a first implementation manner, the receiving end feeds back the CSI at a CSI feedback time after receiving the control signaling for indicating the current feedback granularity of the CSI according to the current feedback granularity of the CSI.

For example, as shown in fig. 2, one UL grant may dynamically adjust the feedback granularity of one aperiodic CSI, where CSI feedback 1 is fed back by using the feedback granularity of CSI indicated by UL grant 1, and CSI feedback 2 is fed back by using the feedback granularity of CSI indicated by UL grant 2. Note that, the UL grant 1 may be a UL grant that triggers CSI feedback 1, and may be a UL grant different from the UL grant that triggers CSI feedback 1. Likewise, UL grant 2 may be a UL grant triggering CSI feedback 2, and may be a different UL grant from the UL grant triggering CSI feedback 2.

In a second implementation manner, the receiving end feeds back the CSI according to the current feedback granularity of the CSI at all CSI feedback times in one window after receiving the control signaling for indicating the current feedback granularity of the CSI.

In this implementation, the length of the window may be agreed by the receiving end and the transmitting end, and the specific agreed implementation is not limited herein, and it is only necessary to keep the transmitting end and the receiving end understanding the length of the window the same.

In a specific implementation, in this implementation, one UL grant may dynamically adjust the feedback granularity of the CSI in a Window (Window) located after the UL grant, where the UL grant may be different from a UL grant triggering Physical Downlink Shared Channel (PDSCH) transmission, and may be a dedicated UL grant for dynamically adjusting the feedback granularity of the CSI.

In a specific embodiment, in this implementation, one UL grant may dynamically instruct the receiving end to set the feedback granularity of the CSI to a subband with a specific size in a window with a length of N subframes, and after the window with the length of N subframes passes through, the receiving end uses the predefined feedback granularity of the CSI, where the predefined feedback granularity of the CSI may be a wideband or a size of the predefined subband.

For example, as shown in fig. 3, if the receiving end determines that the feedback granularity of the CSI indicated by the UL grant 1 is K, that is, a subband corresponding to one CSI feedback is composed of K PRBs, after receiving the UL grant 1, L consecutive CSI feedbacks located in a window with a length of N subframes all use the UL grant 1 to indicate the feedback granularity of the CSI.

In a third implementation manner, the receiving end feeds back the CSI according to the current feedback granularity of the CSI at L consecutive CSI feedback times after receiving the control signaling for indicating the current feedback granularity of the CSI, where L is greater than 1.

Specifically, in this implementation, after receiving the control signaling for indicating the current feedback granularity of the CSI, the receiving end continuously feeds back L pieces of CSI using the indicated current feedback granularity of the CSI, and then uses the predefined feedback granularity of the CSI, where the predefined feedback granularity of the CSI may be a wideband or a predefined size of a subband.

In a fourth implementation manner, the receiving end feeds back the CSI at each CSI feedback time between receiving the control signaling for indicating the current feedback granularity of the CSI and the next control signaling for determining the current feedback granularity of the CSI according to the feedback granularity of the CSI.

In a specific implementation, in the implementation, after the receiving end receives the control signaling for indicating the current feedback granularity of the CSI, the receiving end always feeds back the CSI by using the current feedback granularity of the CSI indicated by the control signaling until the receiving end receives the next control signaling for indicating the current feedback granularity of the CSI, and changes the current feedback granularity of the CSI indicated by the newly received control signaling into the current feedback granularity of the CSI fed back by using the newly received control signaling.

For example, as shown in fig. 4, when receiving the UL grant 1, the receiving end determines that the feedback granularity of the CSI indicated by the UL grant 1 is K, that is, a subband corresponding to CSI feedback is composed of K PRBs, and at each CSI feedback time when receiving the UL grant 1, the receiving end performs CSI feedback by using the feedback granularity of the CSI indicated by the UL grant 1. After the L pieces of CSI are fed back, the receiving end receives the UL grant 2, determines that the feedback granularity of the CSI indicated by the UL grant 2 is different from K, or indicates that the default CSI feedback granularity is adopted, and feeds back the CSI by adopting the feedback granularity of the CSI indicated by the UL grant 2 at each CSI feedback time after the UL grant 2.

Based on the same inventive concept, the embodiment of the present invention further provides a CSI acquisition method as shown in fig. 5, which specifically includes the following steps:

step 501: the transmitting end receives the CSI.

Specifically, the transmitting end receives the CSI sent by the receiving end.

Step 502: and the transmitting end decodes the CSI according to the determined current feedback granularity of the CSI, wherein the feedback granularity is used for representing the size of the resource corresponding to each CSI feedback.

In a specific implementation, the current feedback granularity of the CSI is determined according to the current channel characteristics.

Specifically, the transmitting end determines the number of CSI feedbacks according to the current feedback granularity of the CSI, and acquires each received CSI according to the determined number of CSI feedbacks. For example, assuming a system bandwidth of 50PRB, if the current feedback granularity of CSI is 5, it may be determined that there are 10 received CSI feedbacks, and if the current feedback granularity of CSI is 10, it may be determined that there are 5 received CSI feedbacks, so the feedback granularity of CSI determines the number of CSI feedbacks, and the network device needs to know the number of CSI feedbacks to correctly receive CSI.

In implementation, before the transmitting end decodes the CSI according to the current feedback granularity of the CSI, it needs to determine the feedback granularity corresponding to the received CSI.

Specifically, the method for the transmitting end to determine the current feedback granularity of the CSI includes, but is not limited to, the following two methods:

first, the transmitting end itself determines the current feedback granularity of the CSI.

Specifically, the transmitting end determines the current feedback granularity of the CSI according to the current channel characteristics.

For example, the transmitting end determines the current feedback granularity of the CSI according to the current moving speed of the receiving end, the long-term characteristics of the current channel, and the like. Specifically, the transmitting end determines that the current feedback granularity of the CSI is directly proportional to the current moving speed of the receiving end, that is, the faster the current moving speed of the receiving end is, the larger the feedback granularity of the CSI is, and conversely, the slower the current moving speed of the receiving end is, the smaller the current feedback granularity of the CSI is. The channel long-term characteristics may include statistical correlation of the channel in frequency domain resources. If the current frequency domain correlation is low, the channel is more different in different frequency domain resources, and a smaller feedback granularity should be used. If the current frequency domain correlation is high, the channel is less different in different frequency domain resources, and a larger feedback granularity should be used.

In the method, after determining the current feedback granularity of the CSI according to the current channel characteristics, the transmitting end sends the indication information of the determined current feedback granularity of the CSI to the receiving end to notify the receiving end of the current feedback granularity of the CSI.

Specifically, the transmitting end sends a control signaling to the receiving end, where the control signaling carries indication information of the current feedback granularity of the CSI. For example, the sending end carries the indication information of the current feedback granularity of the CSI in the Comment field in the RRC signaling.

The control signaling may be semi-static signaling or dynamic control signaling.

Secondly, the receiving end determines the current feedback granularity of the CSI and then informs the transmitting end.

Specifically, the transmitting end receives the indication information of the current feedback granularity of the CSI sent by the receiving end, and determines the current feedback granularity of the CSI according to the indication information of the current feedback granularity of the CSI.

In an implementation, corresponding to the above first way of determining the current feedback granularity of the CSI, the ways of notifying, by the transmitting end, the current feedback granularity of the CSI include, but are not limited to, the following:

in a first implementation manner, a transmitting end sends a control signaling carrying indication information of current feedback granularity of CSI to a receiving end, where the indicated current feedback granularity of CSI is only used for CSI feedback after the control signaling.

In the implementation manner, the transmitting end decodes a CSI after sending the control signaling to the receiving end by using the current feedback granularity of the CSI indicated by the control signaling.

In a second implementation manner, the transmitting end sends a control signaling carrying indication information of current feedback granularity of the CSI to the receiving end, and the indicated current feedback granularity of the CSI is used for all CSI feedbacks in a window after the control signaling.

In the implementation mode, the transmitting end decodes all CSI in a window after the transmitting end transmits the control signaling to the receiving end by adopting the current feedback granularity of the CSI indicated by the control signaling.

In a third implementation manner, a transmitting end sends a control signaling carrying indication information of current feedback granularity of CSI to a receiving end, where the indicated current feedback granularity of CSI is used for continuous L CSI feedbacks after the control signaling, where L is greater than 1.

In the implementation mode, the transmitting end decodes the continuous L CSI after the control signaling is sent to the receiving end, and the current feedback granularity of the CSI indicated by the control signaling is adopted, wherein L is larger than 1.

Fourthly, the transmitting end transmits a control signaling carrying the indication information of the current feedback granularity of the CSI to the receiving end, wherein the indicated current feedback granularity of the CSI is used for all CSI feedback between the control signaling and the control signaling carrying the indication information of the next feedback granularity of the CSI.

In the implementation manner, the transmitting end decodes each CSI between the transmission of the control signaling and the transmission of the next control signaling for determining the feedback granularity of the CSI to the receiving end by using the current feedback granularity of the CSI indicated by the control signaling.

In implementation, corresponding to the above second method for determining the current feedback granularity of the CSI, the transmitter receives the indication information of the current feedback granularity of the CSI sent by the receiver, and the indicated current feedback granularity of the CSI has the following application methods:

firstly, the transmitting end receives indication information of current feedback granularity of the CSI sent by the receiving end, and only uses the indicated current feedback granularity of the CSI for corresponding one CSI feedback.

Secondly, the transmitting end receives the indication information of the current feedback granularity of the CSI sent by the receiving end, and uses the indicated current feedback granularity of the CSI for all CSI feedbacks in a window corresponding to the indication information.

Thirdly, the transmitting end receives the indication information of the current feedback granularity of the CSI sent by the receiving end, and uses the indicated current feedback granularity of the CSI for continuous L CSI feedbacks corresponding to the indication information, wherein L is larger than 1.

Fourthly, the transmitting end receives the indication information of the current feedback granularity of the CSI sent by the receiving end, and uses the indicated current feedback granularity of the CSI for each CSI feedback between the indication information and the indication information of the feedback granularity of the CSI sent by the receiving end next time.

In a specific implementation, the transmitting end is a network side device, and the receiving end is a UE.

In the embodiment of the present invention, the current feedback granularity of the CSI may be the feedback granularity of the CSI in the frequency domain, or the feedback granularity of the CSI in the time domain.

In the embodiment of the present invention, the feedback granularity of the CSI may be an absolute value, or may be a function of a specified feedback granularity of the CSI, for example, the feedback granularity of the CSI is indicated by a proportional value, and a product of the proportional value and the specified feedback granularity of the CSI is the feedback granularity of the actual CSI. For example, the UL grant indicates that the feedback granularity of the CSI at the receiving end is 10 PRBs, and may also indicate that the feedback granularity of the received CSI is increased or decreased by K1/K2 times as compared with the feedback granularity of the CSI before, where K1 and K2 may be positive integers greater than 1.

It should be noted that, in the embodiment of the present invention, the CSI may include any one or a combination of any plurality of RI, PMI, and CQI, and the feedback granularity of the CSI may be applied to any one or a combination of any plurality of RI, PMI, and CQI. The feedback granularity of the CSI provided by the embodiment of the present invention may also be extended and applied to other parameters that the UE can feed back, for example, for the feedback of 16/32 transmitting antenna codebook, the UE may apply the feedback granularity of the CSI to the reporting of any one or more of W11, W12, and W2.

Based on the same inventive concept, embodiments of the present invention provide a receiving end device, and specific implementation of the receiving end device may refer to the description of the foregoing method embodiment, and repeated details are not repeated, as shown in fig. 6, and mainly include:

the processing module 601 is configured to determine current feedback granularity of the CSI, where the feedback granularity is used to characterize the size of a resource corresponding to each CSI;

a sending module 602, configured to feed back CSI according to the current feedback granularity determined by the processing module.

In implementation, the system further comprises a receiving module 603;

the receiving module 603 is configured to receive a control signaling;

the processing module 602 is configured to determine the current feedback granularity according to the indication information of the current feedback granularity carried in the control signaling received by the receiving module.

In implementation, the control signaling is semi-static signaling or dynamic control signaling.

In implementation, the processing module is specifically configured to: and determining the current feedback granularity according to the current channel characteristics.

In an implementation, the sending module is further configured to: and after the processing module determines the current feedback granularity of the CSI according to the current channel characteristics, sending the indication information of the current feedback granularity.

In implementation, the sending module is specifically configured to:

Based on the same inventive concept, an embodiment of the present invention further provides a transmitting end device, and specific implementation of the transmitting end device may refer to the description of the foregoing method embodiment, and repeated details are not repeated, as shown in fig. 7, and the method mainly includes:

a receiving module 701, configured to receive channel state information CSI;

a processing module 702, configured to decode the CSI according to the determined current feedback granularity of the CSI, where the feedback granularity is used to characterize a size of a resource corresponding to each CSI.

In an implementation, the processing module is further configured to: determining the current feedback granularity according to the current channel characteristics;

or,

the receiving module is further configured to: receiving the indication information of the current feedback granularity sent by the receiving end; the processing module is specifically configured to: and determining the current feedback granularity according to the indication information of the current feedback granularity.

In an implementation, the apparatus further includes a sending module 703, configured to send, after the processing module determines the current feedback granularity, the determined indication information of the current feedback granularity to a receiving end.

In implementation, the sending module is specifically configured to:

Wherein the control signaling is semi-static signaling or dynamic control signaling.

In implementation, the processing module is specifically configured to:

Based on the same inventive concept, an embodiment of the present invention further provides another receiving end device, and specific implementation of the receiving end device may refer to the description of the foregoing method embodiment, and repeated parts are not repeated, as shown in fig. 8, the receiving end device mainly includes a processor 801, a memory 802, and a transceiver 803, where the transceiver 803 is configured to receive and transmit data under the control of the processor 801, a preset program is stored in the memory 802, and the processor 801 reads the program in the memory 802, and executes the following processes according to the program:

In implementation, the processor receives a control signaling through the transceiver, and determines the current feedback granularity according to the indication information of the current feedback granularity carried in the received control signaling.

In practice, the processor determines the current feedback granularity from the current channel characteristics.

In an implementation, the processor sends, via the transceiver, an indication of the current feedback granularity after determining the current feedback granularity according to current channel characteristics.

In implementation, the processor feeds back the CSI at one or a plurality of consecutive CSI feedback time instants according to the current feedback granularity.

In implementation, the processor feeds back the CSI at a CSI feedback time after receiving the control signaling through the transceiver according to the current feedback granularity; or,

Where the processors, memory and transceivers are connected by a bus, the bus architecture may include any number of interconnected buses and bridges, with one or more processors represented by the processors and various circuits of the memory represented by the memory being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver may be a plurality of elements, i.e., including a transmitter and a transceiver, providing a means for communicating with various other apparatus over a transmission medium. The processor is responsible for managing the bus architecture and the usual processing, and the memory may store data used by the processor in performing operations.

Based on the same inventive concept, an embodiment of the present invention further provides another transmitting end device, and specific implementation of the transmitting end device may refer to the description of the foregoing method embodiment, and repeated parts are not repeated, as shown in fig. 9, the transmitting end device mainly includes a processor 901, a memory 902, and a transceiver 903, where the transceiver 903 is configured to receive and transmit data under the control of the processor 901, a preset program is stored in the memory 902, the processor 901 reads the program in the memory 902, and executes the following processes according to the program:

receiving, by a transceiver, channel state information, CSI;

In implementation, the processor determines the current feedback granularity according to the current channel characteristics;

or,

In implementation, after determining the current feedback granularity, the processor sends the determined indication information of the current feedback granularity to a receiving end through the transceiver.

In implementation, the processor sends a control signaling to the receiving end through the transceiver, where the control signaling carries the indication information of the current feedback granularity.

In implementation, the processor decodes the current feedback granularity indicated by the control signaling for one piece of CSI after the control signaling is sent to the receiving end through the transceiver; or,

Where the processors, memory and transceivers are connected by a bus, the bus architecture may include any number of interconnected buses and bridges, with one or more processors represented by the processors and various circuits of the memory represented by the memory being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver may be a plurality of elements, i.e., including a transmitter and a transceiver, providing a means for communicating with various other apparatus over a transmission medium. The processor is responsible for managing the bus architecture and general processing, and the memory may store data used by the processor 500 in performing operations.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, 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, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams 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 apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, 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 apparatus 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 apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for feeding back Channel State Information (CSI), comprising:

2. The method of claim 1, wherein the receiving end determines a current feedback granularity of the Channel State Information (CSI), comprising:

the receiving end receives a control signaling;

3. The method of claim 2, wherein the control signaling is semi-static signaling or dynamic control signaling.

4. The method of claim 1, wherein the receiving end determines a current feedback granularity of the Channel State Information (CSI), comprising:

5. The method of claim 4, wherein the method further comprises:

6. The method according to any of claims 1-5, wherein the receiving end feeds back CSI according to the current feedback granularity, comprising:

7. The method as claimed in claim 2 or 3, wherein the receiving end feeds back CSI according to the current feedback granularity, comprising:

8. A method for acquiring Channel State Information (CSI) is characterized by comprising the following steps:

a transmitting terminal receives Channel State Information (CSI);

9. The method of claim 8, wherein the method further comprises:

10. The method of claim 9, wherein the method further comprises:

11. The method as claimed in claim 10, wherein said transmitting end transmitting the determined indication information of the current feedback granularity to a receiving end, comprises:

12. The method of claim 11, wherein the control signaling is semi-static signaling or dynamic control signaling.

13. The method of claim 11, wherein the transmitting end decoding the CSI according to the determined current feedback granularity of the CSI comprises:

14. A receiving-end device, comprising:

15. The device of claim 14, further comprising a receiving module;

the receiving module is used for receiving a control signaling;

16. The apparatus of claim 15, wherein the control signaling is semi-static signaling or dynamic control signaling.

17. The device of claim 14, wherein the processing module is specifically configured to:

18. The device of claim 17, wherein the sending module is further to:

19. The device according to any one of claims 14 to 18, wherein the sending module is specifically configured to:

20. The device of claim 15 or 16, wherein the sending module is specifically configured to:

21. A transmitting-end device, comprising:

a receiving module, configured to receive channel state information CSI;

22. The device of claim 21, wherein the processing module is further to: determining the current feedback granularity according to the current channel characteristics;

or,

23. The apparatus of claim 22, further comprising a sending module, configured to send, to a receiving end, information indicating the determined current feedback granularity after the processing module determines the current feedback granularity.

24. The device of claim 23, wherein the sending module is specifically configured to:

25. The apparatus of claim 24, wherein the control signaling is semi-static signaling or dynamic control signaling.

26. The device of claim 24, wherein the processing module is specifically configured to: