CN113632398A

CN113632398A - Channel state information feedback for higher rank extension

Info

Publication number: CN113632398A
Application number: CN201980094748.3A
Authority: CN
Inventors: 刘皓; M·玛索; F·托萨托
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2021-11-09
Anticipated expiration: 2039-03-29
Also published as: CN113632398B; WO2020199045A1

Abstract

Embodiments of the present disclosure relate to methods, devices, apparatuses, and computer-readable storage media for Channel State Information (CSI) feedback. The terminal device obtains a set of parameters from the network device, the set of parameters being used to configure an actual number of non-zero coefficients to a plurality of layers of the channel. The terminal device determines information on non-zero coefficients to be indicated in the first part of the CSI. The terminal device determines the actual number of non-zero coefficients based on the set of parameters and the information. The terminal device sends a first portion of the CSI indicative of the information to the network device and a second portion of the CSI to the network device based on the actual number of non-zero coefficients. Thus, the total payload for CSI feedback for higher ranks may remain comparable to the total payload for lower ranks.

Description

Channel state information feedback for higher rank extension

Technical Field

Embodiments of the present disclosure relate generally to the field of telecommunications, and, in particular, to methods, devices, apparatuses, and computer-readable storage media for Channel State Information (CSI) feedback.

Background

In the latest 3GPP specification (i.e., release 16), the following consensus has been reached: type II CSI feedback, which is designed for lower ranks, such as Rank Indication (RI) of 1 or 2, may be extended to higher ranks, such as RI of 3 or 4, to support more data streams per User Equipment (UE) for single user multiple input multiple output (SU-MIMO) or multi-user multiple input multiple output (MU-MIMO) transmission. The rank may indicate a number of independent transmission layers supported in the communication channel. That is, the overhead of CSI feedback will increase significantly as more layers are added for rank spreading. In this case, it is desirable to keep the total payload for CSI feedback for higher ranks (such as RI of 3 or 4) comparable to the total payload for CSI for lower ranks (such as RI of 2).

Disclosure of Invention

In general, example embodiments of the present disclosure provide a solution for CSI feedback.

In a first aspect, an apparatus is provided. The apparatus includes at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to: obtaining, at a terminal device, a set of parameters from a network device, the set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the terminal device and the network device; determining information about non-zero coefficients to be indicated in a first part of the channel state information; determining an actual number of non-zero coefficients based on the set of parameters and the information, the actual number of non-zero coefficients being associated with a second portion of the channel state information; transmitting a first portion of channel state information indicative of the information to a network device; and transmitting a second portion of the channel state information to the network device based on the actual number of non-zero coefficients.

In a second aspect, an apparatus is provided. The apparatus includes at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to: indicating, from the network device to the terminal device, a set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the network device and the terminal device; receiving a first portion of channel state information from a terminal device, the first portion of channel state information indicating information about non-zero coefficients to be used across a plurality of layers; determining an actual number of non-zero coefficients based on the information and the set of parameters; and receiving a second portion of the channel state information from the terminal device based on the actual number of non-zero coefficients.

In a third aspect, a method is provided. The method comprises the following steps: obtaining, at a terminal device, a set of parameters from a network device, the set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the terminal device and the network device; determining information about non-zero coefficients to be indicated in a first part of the channel state information; determining an actual number of non-zero coefficients based on the set of parameters and the information, the actual number of non-zero coefficients being associated with a second portion of the channel state information; transmitting a first portion of channel state information indicative of the information to a network device; and transmitting a second portion of the channel state information to the network device based on the actual number of non-zero coefficients.

In a fourth aspect, a method is provided. The method comprises the following steps: indicating, from the network device to the terminal device, a set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the network device and the terminal device; receiving a first portion of channel state information from a terminal device, the first portion of channel state information indicating information about non-zero coefficients to be used across a plurality of layers; determining an actual number of non-zero coefficients based on the information and the set of parameters; and receiving a second portion of the channel state information from the terminal device based on the actual number of non-zero coefficients.

In a fifth aspect, there is provided an apparatus comprising: means for obtaining, at a terminal device, a set of parameters from a network device, the set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the terminal device and the network device; means for determining information about non-zero coefficients to be indicated in a first portion of channel state information; means for determining an actual number of non-zero coefficients based on the set of parameters and the information, the actual number of non-zero coefficients being associated with a second portion of the channel state information; means for transmitting a first portion of channel state information indicative of the information to a network device; and means for transmitting a second portion of the channel state information to the network device based on the actual number of non-zero coefficients.

In a sixth aspect, there is provided an apparatus comprising: means for indicating, from the network device to the terminal device, a set of parameters for configuring an actual number of non-zero coefficients for a plurality of layers of a channel between the network device and the terminal device; means for receiving a first portion of channel state information from a terminal device, the first portion of channel state information indicating information about non-zero coefficients to be used across a plurality of layers; means for determining an actual number of non-zero coefficients based on the information and the set of parameters; and means for receiving a second portion of the channel state information from the terminal device based on the actual number of non-zero coefficients.

In a seventh aspect, a non-transitory computer readable medium is provided, comprising program instructions for causing an apparatus to perform at least a method according to the third or fourth aspect.

It should be understood that the summary is not intended to identify key or essential features of embodiments of the disclosure, nor is it intended to be used to limit the scope of the disclosure. Other features of the present disclosure will become readily apparent from the following description.

Drawings

Some example embodiments will now be described with reference to the accompanying drawings, in which:

FIG. 1 illustrates an example communication network in which example embodiments of the present disclosure may be implemented;

fig. 2 shows a schematic diagram illustrating a process for CSI feedback according to an example embodiment of the present disclosure;

fig. 3 shows a flow diagram of a method implemented at a terminal device according to an example embodiment of the present disclosure;

fig. 4 shows a flow diagram of a method implemented at a network device, according to an example embodiment of the present disclosure;

FIG. 5 shows a simplified block diagram of an apparatus suitable for implementing an example embodiment of the present disclosure; and

FIG. 6 illustrates a block diagram of an example computer-readable medium, according to an example embodiment of the present disclosure.

Throughout the drawings, the same or similar reference numbers refer to the same or similar elements.

Detailed Description

The principles of the present disclosure will now be described with reference to a few exemplary embodiments. It is understood that these embodiments are described only for the purpose of illustration and to aid those skilled in the art in understanding and practicing the present disclosure, and do not set forth any limitations on the scope of the present disclosure. The disclosure described herein may be implemented in various other ways than those described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

References in the present disclosure to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term "and/or" includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," "having," "has," "having," "includes" and/or "including" when used herein, specify the presence of stated features, elements, and/or components, etc., but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof.

As used herein, the term "circuitry" may refer to one or more or all of the following:

(a) a purely hardware circuit implementation (such as an implementation in analog and/or digital circuitry only), and

(b) a combination of hardware circuitry and software, such as (as applicable):

(i) combinations of analog and/or digital hardware circuitry and software/firmware, and

(ii) a hardware processor with software (including a digital signal processor), software and any portion of memory that work together to cause a device (such as a mobile phone or server) to perform various functions, and

(c) a hardware circuit and/or a processor, such as a microprocessor or a portion of a microprocessor, that requires software (e.g., firmware) for operation, but may not be present when operation is not required.

The definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also encompasses implementations in hardware circuitry only or a processor (or multiple processors) or a portion of a hardware circuitry or a processor and its (or their) accompanying software and/or firmware. The term circuitry also encompasses (e.g., and if applicable to a particular claim element) a baseband integrated circuit or processor integrated circuit of a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as Long Term Evolution (LTE), LTE-advanced (LTE-a), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), narrowband internet of things (NB-IoT), and so forth. Further, communication between the terminal device and the network device in the communication network may be performed according to any suitable generation communication protocol, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols, and/or any other protocol now known or later developed. Embodiments of the present disclosure may be applied to various communication systems. Given the rapid development of communications, there will, of course, also be future types of communication technologies and systems that may be used to embody the present disclosure. The scope of the present disclosure should not be limited to the above-described systems.

As used herein, the term "network device" refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. A network device may refer to a Base Station (BS) or an Access Point (AP), e.g., a NodeB (NodeB or NB), evolved NodeB (eNodeB or eNB), NR NB (also known as gNB), Remote Radio Unit (RRU), Radio Head (RH), Remote Radio Head (RRH), relay, low power node (such as femto, pico), etc., depending on the terminology and technology applied.

The term "terminal device" refers to any terminal device capable of wireless communication. By way of example, and not limitation, a terminal device may also be referred to as a communication device, User Equipment (UE), Subscriber Station (SS), portable subscriber station, Mobile Station (MS), or Access Terminal (AT). The end devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable end devices, Personal Digital Assistants (PDAs), portable computers, desktop computers, image capture end devices (such as digital cameras), gaming end devices, music storage and playback devices, in-vehicle wireless end devices, wireless terminals, mobile stations, laptop embedded devices (LEEs), laptop installation devices (LMEs), USB dongles, smart devices, wireless client devices (CPEs), internet of things (loT) devices, watches or other wearable devices, Head Mounted Displays (HMDs), vehicles, drones, medical devices and applications (e.g., tele-surgery), industrial devices and applications (e.g., robots and/or other wireless devices operating in industrial and/or automated processing chain environments), Consumer electronics devices, devices operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

As described above, in the latest 3GPP specification (i.e., release 16), consensus has been reached for: type II CSI feedback (which is designed for lower ranks, such as RI of 1 or 2) may be extended to higher ranks, such as RI of 3 or 4, to support more data streams per UE for SU-MIMO or MU-MIMO transmission. However, the overhead of CSI feedback will increase significantly as more layers are added for higher rank spreading. In this case, it is desirable to keep the total payload of CSI feedback for higher ranks comparable to the total payload of CSI feedback for lower ranks.

Some conventional solutions control and limit the payload of CSI feedback in different layers for different RIs. For example, for different RIs, the spatial domain parameters and the frequency domain base parameters may be configured for different layers. Furthermore, since the total number of non-zero coefficients between different layers may be linear combination coefficients for different RIsThe total payload of the (LCC) quantization has a significant impact, so some conventional solutions set the maximum number of non-zero coefficients (K)₀) To limit the maximum feedback overhead for higher rank extensions. However, these solutions cannot ensure that the total payload for CSI feedback for higher ranks is comparable to the total payload for CSI feedback for lower ranks.

Embodiments of the present disclosure provide a solution for CSI feedback to at least partially address the above and other potential problems. Some example embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the disclosure extends beyond these limited embodiments.

Fig. 1 illustrates an example communication network 100 in which implementations of the present disclosure may be implemented. Communication network 100 includes network device 110 and terminal devices 120-1, 120-2, … …, 120-N (which may be collectively referred to as "terminal devices" 120). Network 100 may provide one or more cells 102 to serve terminal devices 120. It should be understood that the number of network devices, terminal devices, and/or cells are given for illustrative purposes and do not set any limit to the present disclosure. Communication network 100 may include any suitable number of network devices, terminal devices, and/or cells suitable for implementing implementations of the present disclosure.

In communication network 100, network device 110 may communicate data and control information to terminal device 120, and terminal device 120 may also communicate data and control information to network device 110. The link from network device 110 to terminal device 120 is referred to as the Downlink (DL) and the link from terminal device 120 to network device 110 is referred to as the Uplink (UL).

Communications in network 100 may conform to any suitable standard including, but not limited to, global system for mobile communications (GSM), Long Term Evolution (LTE), LTE evolution, LTE advanced (LTE-a), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), and so forth. Further, the communication may be performed according to any generation of communication protocols currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, and fifth generation (5G) communication protocols.

To obtain CSI for the communication channel between network device 110 and terminal device 120, network device 110 may transmit a channel state information reference signal (CSI-RS) to terminal device 120. Terminal device 120 may receive the CSI-RS from network device 110 and obtain channel information by measuring the CSI-RS. Terminal device 120 may then determine the CSI for the communication channel based on the obtained channel information and the corresponding codebook. For example, the acquired channel information may be quantized into CSI based on the corresponding codebook. Terminal device 120 may report CSI to network device 110. The process for reporting CSI is also referred to as "CSI feedback". The CSI may ensure reliability of wireless communications between network device 110 and terminal device 120.

Fig. 2 shows a schematic diagram of a process 200 for CSI feedback according to an example embodiment of the present disclosure. For purposes of discussion, the process 200 will be described with reference to fig. 1. Flow 200 may involve terminal device 120 and network device 110 as shown in fig. 1.

As shown in fig. 2, a terminal device may obtain 210 a set of parameters (such as γ)₀、γ₁、α、β₃And/or beta₄As described below) that is used to configure the actual number of non-zero coefficients to the multiple layers of the channel between terminal device 120 and network device 110. In some embodiments, the set of parameters may be determined by network device 110 and indicated 210 to terminal device 120 via radio resource control signaling.

The terminal device 120 may determine 220 information about non-zero coefficients to be indicated in the first part of the CSI. In some embodiments, for example, terminal device 120 may measure channels and perform channel quantization from CSI-RSs sent from network device 110. Terminal device 120 may then determine the value of the RI, and information about the non-zero coefficients to be indicated in the first portion of the channel state information.

In response to obtaining the set of parameters and determining the information to be indicated in the first portion of CSI, terminal device 120 may determine 230 an actual number of non-zero coefficients for the plurality of layers based on the information indicated in the first portion of CSI and the set of parameters.

In some embodiments, for different RIs (such as RIs 1, 2, 3, or 4), the information in the first portion of CSI may indicate a total number of non-zero coefficients to be used across multiple layers of the channel. For example, the total number of non-zero coefficients indicated in the first part of the CSI may be denoted as K_NZWherein 0 is<K_NZ≤2K₀，K₀Representing the maximum number of predefined non-zero coefficients per layer. That is, the number of bits used to report the first part of the CSI is always the same for different RIs

In some embodiments, for RI-3 (i.e., three independent layers are supported in one communication channel), the actual number of non-zero coefficients for the three layers may be expressed as

And

in some embodiments, the first and second electrodes may be, for example,

and

can be determined as follows:

wherein 1 > gamma₀≥γ₁> 0.5 and beta₃Not less than 1. Because of the fact that

That is, the sum of the actual number of non-zero coefficients for RI-3 is equal to or greater than the sum of the actual number of non-zero coefficients for RI-2.

In some embodiments, for RI-4 (i.e., four independent layers are supported in one communication channel), the actual number of non-zero coefficients for these four layers may be expressed as

And

in some embodiments, the first and second electrodes may be, for example,

and

can be determined as follows:

wherein 1 > gamma₀≥γ₁> 0.51 > alpha > 0.5 and_β4≥β₃not less than 1. Because of the fact that

That is, the sum of the actual number of non-zero coefficients for RI-4 is equal to or greater than the sum of the actual number of non-zero coefficients for RI-2.

In some embodiments, for RI-2 (i.e., two independent layers are supported in one communication channel), the actual number of non-zero coefficients for the two layers may be denoted as K, respectively_NZ，0And K_NZ，1. In some embodiments, for example, K_NZ，0And K_NZ，1Can be determined as follows:

in some embodiments, for RI ═ 1 (i.e., a single layer is supported in the communication channel), the actual number of non-zero coefficients for that single layer may be represented as K_NZ，0In which K is_NZ，0＝K_NZ′。

Alternatively, in some embodiments, the information in the first portion of the CSI may indicate two numbers, denoted respectively as K, for different RIs (such as 1, 2, 3, or 4 for RI)_NZ，0And K_NZ，1Wherein 0 < K_NZ，0≤K₀And 0 < K_NZ，1≤K₀In which K is₀Representing the maximum number of predefined non-zero coefficients per layer. That is, the number of bits used to report the first part of the CSI is always the same for different RIs

In some embodiments, K_NZ，0And K_NZ，1Can be determined by assuming RI 2. Assuming an RI of 2, two separate layers may be supported in the channel between terminal device 120 and network device 110. In some embodiments, K indicated in the first part of the CSI_NZ，0May represent a first number of non-zero coefficients to be used at a first of the two layers, and K is indicated in a first portion of CSI_NZ，1May represent a second number of non-zero coefficients to be used at a second of the two layers. For example, K_NZ，0And K_NZ，1May be common to different RIs (such as 2, 3 or 4), and when the RI is>2, they may correspond to the first two layers in the channel. In some embodiments, if RI is 1, then K_NZ，1Can be considered to be 0, although it can be reported as a different value.

And

in some embodiments, for example，

And

can be determined as follows:

wherein 1 > gamma₀≥γ₁> 0.5 and beta₃Not less than 1. As can be seen,

And

in some embodiments, the first and second electrodes may be, for example,

and

can be determined as follows:

wherein 1 > gamma₀≥γ₁> 0.5, 1 > alpha > 0.5 and beta₄≥β₃Not less than 1. It can be seen that

In some embodiments of the present invention, the,as described above, indication 210 that γ is included may be indicated 210 from network device 110 to terminal device 120 via RRC signaling₀、γ₁、α、β₃And/or beta₄The set of parameters of at least one of. With respect to the parameter gamma₀、γ₁And α, in some embodiments, three different values may be indicated via RRC signaling, such as { γ }₀，γ₁And alpha. Alternatively, in some embodiments, two different values may be indicated via RRC signaling, such as { γ, α }, where γ₀＝γ₁γ. Alternatively, in some embodiments, only a single value may be indicated via RRC signaling, such as { α }, where γ₀＝γ₁α. With respect to parameter beta₃And beta₄In some embodiments, two different values may be indicated via RRC signaling, such as { β [ ]₃，β₄}. Alternatively, in some embodiments, only a single value may be indicated via RRC signaling, such as { β }, where β₃＝β₄β. Alternatively, in some embodiments, the parameter β is indicated if not via RRC signaling₃And beta₄Then terminal device 120 may assume β₃And beta₄Are all equal to 1.

As shown in fig. 2, terminal device 120 may send 240 a first portion of CSI indicative of information about non-zero coefficients to network device 110. In response to receiving the first portion of CSI from terminal device 120, network device 110 may determine 250 an actual number of non-zero coefficients for the plurality of layers based on information indicated in the first portion of CSI and the set of parameters. In some embodiments, for example, network device 110 may determine the actual number of non-zero coefficients of the multiple layers in the same manner as terminal device 120 described above, which will not be described herein again.

Network device 110 may then determine a payload size of the second portion of CSI based on the actual number of non-zero coefficients for the plurality of layers. In response to determining the payload size of the second portion of CSI, network device 110 may suitably receive 260 the second portion of CSI from terminal device 120.

In some embodiments, if in the first part of the CSIThe total number K of non-zero coefficients is indicated in the score_NZThen the total payload size for different RIs (such as 2, 3 or 4) according to the agreed LCC quantization method is as shown in table 1:

TABLE 1 payload sizes of two-part CSI for different RIs

In table 1, it is assumed that the number of Spatial Domain (SD) beams is 2L and the number of Frequency Domain (FD) beams is M. As can be seen from Table 1, if β₃1, then the linear sum of the quantization bit lengths for the non-zero coefficients with RI 3 (i.e., 7 × β₃K_NZ) Linear sum with quantization bit length for non-zero coefficients with RI 2 (i.e., 7 × K_NZ) The same is true. If beta is₃>1, the linear sum of the quantization bit lengths for the non-zero coefficients with RI-3 is still comparable to the linear sum of the quantization bit lengths for the non-zero coefficients with RI-2. If beta is₄1, then the linear sum of the quantization bit lengths for the non-zero coefficients with RI 4 (i.e., 7 × β₄K_NZ) Linear sum of quantization bit lengths of non-zero coefficients with RI 2 (i.e., 7 × K_NZ) The same is true. If beta is₄>1, the linear sum of the quantization bit lengths for the non-zero coefficients with RI-4 is still comparable to the linear sum of the quantization bit lengths for the non-zero coefficients with RI-2. Although the log-domain sum of the number of non-zero coefficients, and the product of the number of SD beams and the number of FD beams are different for different RIs, their impact on the total CSI payload of the LCC quantization is limited compared to the linear sum. That is, embodiments of the present disclosure enable the total payload for CSI feedback for higher ranks to be comparable to the total payload for CSI feedback for RI-2.

In some embodiments, if K is indicated in the first part of the CSI_NZ，0And K_NZ，1These two numbers, then, according to the agreed upon LCC quantization method, the total payload size for different RIs (such as an RI of 2, 3, or 4) is shown in table 2:

TABLE 2 payload sizes of two-part CSI for different RIs

In table 2, it is also assumed that the number of SD beams is 2L and the number of FD beams is M. As can be seen from Table 2, if β₃1, then the linear sum of the quantization bit lengths for the non-zero coefficients with RI 3 (i.e., 7 × β₃(K_NZ，0+K_NZ，1) Linear sum with quantization bit length for non-zero coefficients with RI 2 (i.e., 7 × (K)_NZ,0+K_NZ，1) Are identical). If beta is₃>1, the linear sum of the quantization bit lengths for the non-zero coefficients with RI-3 is still comparable to the linear sum of the quantization bit lengths for the non-zero coefficients with RI-2. If beta is₄1, then the linear sum of the quantization bit lengths for the non-zero coefficients with RI 4 (i.e., 7 × β₄(K_NZ，0+K_NZ，1) Linear sum with quantization bit length for non-zero coefficients with RI 2 (i.e., 7 xk)_NZ) The same is true. If beta is₄>1, the linear sum of the quantization bit lengths for the non-zero coefficients with RI-4 is still comparable to the linear sum of the quantization bit lengths for the non-zero coefficients with RI-2. Although the log domain sum of the number of non-zero coefficients, and the product of the number of SD beams and the number of FD beams, differ for different RIs, their impact on the total CSI payload of the LCC quantization is limited compared to the linear sum. That is, embodiments of the present disclosure enable the total payload for CSI feedback for higher ranks to be comparable to the total payload for CSI feedback for RI-2.

Fig. 3 illustrates a flowchart of an example method 300 implemented at a terminal device, in accordance with some embodiments of the present disclosure. For purposes of discussion, the method 300 will be described with reference to fig. 1 from the perspective of the terminal device 120. It should be understood that method 300 may also include additional blocks not shown and/or omit some of the blocks shown, and the scope of the present disclosure is not so limited.

At block 310, terminal device 120 obtains a set of parameters from the network device that is used to configure an actual number of non-zero coefficients to multiple layers of a channel between the terminal device and the network device.

In some embodiments, terminal device 120 may obtain the set of parameters by: receiving a configuration for the set of parameters from a network device via radio resource control signaling; and determining the set of parameters based on the configuration.

In some embodiments, the set of parameters may include a single parameter.

In some embodiments, the set of parameters may include two or more different parameters.

At block 320, terminal device 120 determines information about non-zero coefficients to be indicated in the first portion of the channel state information.

At block 330, terminal device 120 determines an actual number of non-zero coefficients based on the set of parameters and the information, the actual number of non-zero coefficients being associated with the second portion of channel state information.

In some embodiments, the information may indicate a total number of non-zero coefficients to be used across multiple layers of the channel.

In some embodiments, terminal device 120 may determine the actual number of non-zero coefficients such that the sum of the actual number of non-zero coefficients has a correspondence with the total number of non-zero coefficients indicated by the information.

In some embodiments, terminal device 120 may determine the actual number of non-zero coefficients such that the sum of the actual number of non-zero coefficients equals the total number of non-zero coefficients indicated by the information.

In some embodiments, the plurality of layers may include more than two layers. The information may indicate a first number of non-zero coefficients to be used at a first layer of the plurality of layers and a second number of non-zero coefficients to be used at a second layer of the plurality of layers.

In some embodiments, the terminal device 120 may determine the actual number of non-zero coefficients such that the sum of the actual number of non-zero coefficients has a correspondence with the sum of the first number and the second number.

In some embodiments, terminal device 120 may determine the actual number of non-zero coefficients such that the sum of the actual number of non-zero coefficients is equal to the sum of the first number and the second number.

At block 340, terminal device 120 transmits a first portion of channel state information to the network device indicating the information.

At block 350, terminal device 120 sends a second portion of the channel state information to the network device based on the actual number of non-zero coefficients.

Fig. 4 illustrates a flow diagram of an example method 400 implemented at a network device in accordance with some embodiments of the present disclosure. For purposes of discussion, the method 400 will be described with reference to fig. 1 from the perspective of the network device 110. It should be understood that method 400 may also include additional blocks not shown and/or omit some of the blocks shown, and the scope of the present disclosure is not so limited.

At block 410, network device 110 indicates to the terminal device a set of parameters for configuring an actual number of non-zero coefficients for a plurality of layers of a channel between the network device and the terminal device.

In some embodiments, network device 110 may send the configuration for the set of parameters to the terminal device via radio resource control signaling.

At block 420, network device 110 receives a first portion of channel state information from a terminal device, the first portion of channel state information indicating information about non-zero coefficients to be used across multiple layers.

At block 430, network device 110 determines the actual number of non-zero coefficients based on the information and the set of parameters.

In some embodiments, network device 110 may determine the actual number of non-zero coefficients such that the sum of the actual number of non-zero coefficients has a correspondence with the total number of non-zero coefficients indicated by the information.

In some embodiments, network device 110 may determine the actual number of non-zero coefficients such that the sum of the actual number of non-zero coefficients is equal to the total number of non-zero coefficients indicated by the information.

In some embodiments, network device 110 may determine the actual number of non-zero coefficients such that the sum of the actual number of non-zero coefficients has a correspondence with the sum of the first number and the second number.

In some embodiments, network device 110 may determine the actual number of non-zero coefficients such that the sum of the actual number of non-zero coefficients is equal to the sum of the first number and the second number.

At block 440, network device 110 receives a second portion of the channel state information from the terminal device based on the actual number of non-zero coefficients.

In some embodiments, network device 110 may determine the size of the second portion of channel state information based on the actual number of non-zero coefficients. Network device 110 may receive a second portion of the channel state information from the terminal device based on the determined size.

In some embodiments, an apparatus (e.g., terminal device 120) capable of performing method 300 may include means for performing the respective steps of method 300. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules.

In some embodiments, the apparatus comprises: means for obtaining, at a terminal device, a set of parameters from a network device, the set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the terminal device and the network device; means for determining information about non-zero coefficients to be indicated in a first portion of channel state information; means for determining an actual number of non-zero coefficients based on the set of parameters and the information, the actual number of non-zero coefficients being associated with a second portion of the channel state information; means for transmitting a first portion of channel state information indicative of the information to a network device; and means for transmitting a second portion of the channel state information to the network device based on the actual number of non-zero coefficients.

In some embodiments, the apparatus also includes means for performing other steps in some embodiments of the method 300. In some embodiments, the component comprises at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause execution of the apparatus.

In some embodiments, an apparatus (e.g., network device 110) capable of performing method 400 may include means for performing the respective steps of method 400. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules.

In some embodiments, the apparatus comprises: means for indicating, from the network device to the terminal device, a set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the network device and the terminal device; means for receiving a first portion of channel state information from a terminal device, the first portion of channel state information indicating information about non-zero coefficients to be used across a plurality of layers; means for determining an actual number of non-zero coefficients based on the information and the set of parameters; and means for receiving a second portion of the channel state information from the terminal device based on the actual number of non-zero coefficients.

In some embodiments, the apparatus also includes means for performing other steps in some embodiments of the method 400. In some embodiments, the apparatus includes at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause execution of the apparatus.

Fig. 5 is a simplified block diagram of a device 500 suitable for implementing embodiments of the present disclosure. The device 500 may be provided to implement a communication device, such as the terminal device 120 or the network device 110 shown in fig. 1. As shown, the device 500 includes one or more processors 510, one or more memories 520 coupled to the processors 510, and one or more communication modules 540 (such as transmitters and/or receivers) coupled to the processors 510.

The communication module 540 is used for bidirectional communication. The communication module 540 has at least one antenna to facilitate communication. The communication interface may represent any interface required to communicate with other network elements.

Processor 510 may be of any type suitable for a local technology network, and may include, by way of non-limiting example, one or more of the following: general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs), and processors based on a multi-core processor architecture. The device 500 may have multiple processors, such as an application specific integrated circuit chip that is time dependent from a clock synchronized to the main processor.

Memory 520 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, Read Only Memory (ROM)524, Electrically Programmable Read Only Memory (EPROM), flash memory, a hard disk, a Compact Disc (CD), a Digital Video Disk (DVD), and other magnetic and/or optical storage devices. Examples of volatile memory include, but are not limited to, Random Access Memory (RAM)522 and other volatile memory that does not persist for the duration of the power down.

The computer programs 530 include computer-executable instructions that are executed by the associated processor 510. The program 530 may be stored in the ROM 524. Processor 510 may perform any suitable actions and processes by loading programs 530 into RAM 522.

Embodiments of the disclosure may be implemented by the program 530 such that the device 500 may perform any of the processes of the disclosure as discussed with reference to fig. 2-4. Embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

In some embodiments, program 530 may be tangibly embodied in a computer-readable medium, which may be included in device 500 (such as in memory 520) or other storage device accessible to device 500. Device 500 may load program 530 from the computer-readable medium into RAM 522 for execution. The computer readable medium may include any type of tangible, non-volatile memory, such as ROM, EPROM, flash memory, a hard disk, a CD, a DVD, etc. Fig. 6 shows an example of a computer-readable medium 600 in the form of a CD or DVD. The computer readable medium has a program 530 stored thereon.

In general, the various embodiments of the disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of the embodiments of the disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the block diagrams, apparatus, systems, techniques or methods described herein may be implemented in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that execute in a device on a target real or virtual processor to perform the method 300 described above with reference to fig. 3 and/or the method 400 described above with reference to fig. 4. Generally, program modules include routines, programs, libraries, objects, classes, components, data types, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Program code for performing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the execution of the program codes by the processor or controller causes the functions/operations specified in the flowchart and/or block diagram to be performed. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of a carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples of a computer-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Also, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to:

obtaining, at a terminal device, a set of parameters from a network device, the set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the terminal device and the network device;

determining information about non-zero coefficients to be indicated in a first part of the channel state information;

determining the actual number of non-zero coefficients based on the set of parameters and the information, the actual number of non-zero coefficients being associated with a second portion of the channel state information;

transmitting the first portion of the channel state information to the network device, the first portion of the channel state information indicating the information; and

transmitting the second portion of the channel state information to the network device based on the actual number of non-zero coefficients.

2. The apparatus of claim 1, wherein the apparatus is caused to obtain the set of parameters by:

receiving a configuration for the set of parameters from the network device via radio resource control signaling; and

determining the set of parameters based on the configuration.

3. The apparatus of claim 1, wherein the information indicates a total number of non-zero coefficients to be used across the plurality of layers of the channel, and wherein the apparatus is caused to:

determining the actual number of non-zero coefficients such that a sum of the actual number of non-zero coefficients has a correspondence with the total number of non-zero coefficients indicated by the information.

4. An apparatus of claim 3, wherein the apparatus is caused to:

determining the actual number of non-zero coefficients such that a sum of the actual number of non-zero coefficients is equal to the total number of non-zero coefficients indicated by the information.

5. The apparatus of claim 1, wherein the plurality of layers comprises more than two layers, the information indicating a first number of non-zero coefficients to be used at a first layer of the plurality of layers and a second number of non-zero coefficients to be used at a second layer of the plurality of layers, and wherein the apparatus is caused to:

determining the actual number of non-zero coefficients such that a sum of the actual number of non-zero coefficients has a correspondence with a sum of the first number and the second number.

6. The apparatus of claim 5, wherein the apparatus is caused to:

determining the actual number of non-zero coefficients such that a sum of the actual number of non-zero coefficients is equal to a sum of the first number and the second number.

7. The apparatus of claim 1, wherein the set of parameters comprises a single parameter.

8. The apparatus of claim 1, wherein the set of parameters comprises two or more different parameters.

9. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

indicating, from a network device to a terminal device, a set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the network device and the terminal device;

receiving a first portion of channel state information from the terminal device, the first portion of channel state information indicating information about non-zero coefficients to be used across the plurality of layers;

determining the actual number of non-zero coefficients based on the information and the set of parameters; and

receiving a second portion of the channel state information from the terminal device based on the actual number of non-zero coefficients.

10. The apparatus of claim 9, wherein the apparatus is caused to indicate the set of parameters by:

sending a configuration for the set of parameters to the terminal device via radio resource control signaling.

11. The apparatus of claim 9, wherein the apparatus is caused to receive the second portion of the channel state information by:

determining a size of the second portion of the channel state information based on the actual number of non-zero coefficients; and

receiving the second portion of the channel state information from the terminal device based on the determined size.

12. The apparatus of claim 9, wherein the information indicates a total number of non-zero coefficients to be used across the plurality of layers of the channel, and wherein the apparatus is caused to:

determining the actual number of non-zero coefficients such that a sum of the actual number of non-zero coefficients has a correspondence with a total number of the non-zero coefficients indicated by the information.

13. An apparatus of claim 12, wherein the apparatus is caused to:

14. The apparatus of claim 9, wherein the plurality of layers comprises more than two layers, the information indicating a first number of non-zero coefficients to be used at a first layer of the plurality of layers and a second number of non-zero coefficients to be used at a second layer of the plurality of layers, and wherein the apparatus is caused to:

15. The apparatus of claim 14, wherein the apparatus is caused to:

16. The apparatus of claim 9, wherein the set of parameters comprises a single parameter.

17. The apparatus of claim 9, wherein the set of parameters comprises two or more different parameters.

18. A method, comprising:

19. A method, comprising:

20. An apparatus, comprising:

means for obtaining, at a terminal device, a set of parameters from a network device, the set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the terminal device and the network device;

means for determining information about non-zero coefficients to be indicated in a first portion of channel state information;

means for determining the actual number of non-zero coefficients based on the set of parameters and the information, the actual number of non-zero coefficients being associated with a second portion of the channel state information;

means for transmitting the first portion of the channel state information to the network device, the first portion of the channel state information indicating the information; and

means for transmitting the second portion of the channel state information to the network device based on the actual number of non-zero coefficients.

21. An apparatus, comprising:

means for indicating, from a network device to a terminal device, a set of parameters for configuring an actual number of non-zero coefficients to a plurality of layers of a channel between the network device and the terminal device;

means for receiving a first portion of channel state information from the terminal device, the first portion of the channel state information indicating information about non-zero coefficients to be used across the plurality of layers;

means for determining the actual number of non-zero coefficients based on the information and the set of parameters; and

means for receiving a second portion of the channel state information from the terminal device based on the actual number of non-zero coefficients.

22. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of claim 18 or 19.