WO2022032451A1

WO2022032451A1 - Massive terminals grouping for channel state information overhead reduction

Info

Publication number: WO2022032451A1
Application number: PCT/CN2020/108261
Authority: WO
Inventors: Wenjian Wang
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2020-08-10
Filing date: 2020-08-10
Publication date: 2022-02-17
Also published as: CN116171617B; CN116171617A

Abstract

Embodiments of the present disclosure relate to device, method and computer readable storage media of massive terminals grouping for CSI overhead reduction. The method comprises receiving, from a second device, grouping information of the first device, the grouping information at least indicating a group index allocated for the first device; transmitting, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information; and in accordance with a determination of a reception of transmission path information between the first device and the second device associated with the receiving beam, determining channel state information, CSI, based on a CSI feedback indication associated with the group index. In this way, the overhead of CSI can be greatly reduced.

Description

MASSIVE TERMINALS GROUPING FOR CHANNEL STATE INFORMATION OVERHEAD REDUCTION

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular to devices, methods, apparatuses and computer readable storage media of massive terminals grouping for channel state information (CSI) overhead reduction.

BACKGROUND

Currently, there have been increasing studies involving the connectivity of huge number of user equipments (UEs) to network nodes. As evolved in wireless communications technology, the configuration of network devices has been standardized with directional searching for terminals accessing via beamforming or other functional usage. While at the same time, the commercial terminals today are likely equipped with the same facilities to either support multiple functional usage or enhance the power gain during transmission and reception.

During the transmission, the UEs first communicate with the network device through a series of sounding epochs, in which at a given epoch, the network device obtains the CSI for the data link afterwards from the UEs.

SUMMARY

In general, example embodiments of the present disclosure provide a solution of massive terminals grouping for channel state information (CSI) overhead reduction.

In a first aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device at least to receive, from a second device, grouping information of the first device, the grouping information at least indicating a group index allocated for the first device; transmit, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information; and in accordance with a determination of a reception of transmission path information between the first device and the second device associated with the receiving beam, determine CSI based on a CSI feedback indication associated with the group index.

In a second aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device at least to transmit grouping information of a first device to the first device, the grouping information at least indicating a group index allocated for the first device; in accordance with a determination of a reception of an indication of a receiving beam from the second device determined at the first device based on the grouping information, determine transmission path information between the first device and the second device based on the receiving beam; and transmit the transmission path information to the first device.

In a third aspect, there is provided a method. The method comprises receiving, from a second device, grouping information of a first device, the grouping information at least indicating a group index allocated for the first device; transmitting, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information; and in accordance with a determination of a reception of transmission path information between the first device and the second device associated with the receiving beam, determining CSI based on a CSI feedback indication associated with the group index.

In a fourth aspect, there is provided a method. The method comprises transmitting by a second device grouping information of a first device to the first device, the grouping information at least indicating a group index allocated for the first device; in accordance with a determination of a reception of an indication of a receiving beam from the second device determined at the first device based on the grouping information, determining transmission path information between the first device and the second device based on the receiving beam; and transmitting the transmission path information to the first device.

In a fifth aspect, there is provided an apparatus comprising means for receiving, from a second device, grouping information of a first device, the grouping information at least indicating a group index allocated for the first device; means for transmitting, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information; and means for in accordance with a determination of a reception of transmission path information between the first device and the second device associated with the receiving beam, determining CSI based on a CSI feedback indication associated with the group index.

In a sixth aspect, there is provided an apparatus comprising means for transmitting by a second device grouping information of a first device to the first device, the grouping information at least indicating a group index allocated for the first device; means for in accordance with a determination of a reception of an indication of a receiving beam from the second device determined at the first device based on the grouping information, determining transmission path information between the first device and the second device based on the receiving beam; and means for transmitting the transmission path information to the first device.

In a seventh aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the third aspect.

In an eighth aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the fourth aspect.

Other features and advantages of the embodiments of the present disclosure will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure are presented in the sense of examples and their advantages are explained in greater detail below, with reference to the accompanying drawings, where

FIG. 1 illustrates an example environment in which example embodiments of the present disclosure can be implemented;

FIG. 2 shows a signaling chart illustrating a process of massive terminals grouping for CSI overhead reduction according to some example embodiments of the present disclosure;

FIG. 3 shows an example application scenario according to some example embodiments of the present disclosure;

FIG. 4 shows a further example application scenario according to some example embodiments of the present disclosure;

FIG. 5 shows a flowchart of an example method of massive terminals grouping for CSI overhead reduction according to some example embodiments of the present disclosure;

FIG. 6 shows a flowchart of an example method of massive terminals grouping for CSI overhead reduction according to some example embodiments of the present disclosure;

FIG. 7 shows a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

FIG. 8 shows a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones 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 skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes 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 example 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 shall be understood that although the terms “first” and “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 functionalities of various elements. 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” , “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 combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

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

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

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

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as fifth generation (5G) systems, Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) new radio (NR) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

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. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR Next Generation NodeB (gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. A RAN split architecture comprises a gNB-CU (Centralized unit, hosting RRC, SDAP and PDCP) controlling a plurality of gNB-DUs (Distributed unit, hosting RLC, MAC and PHY) . A relay node may correspond to DU part of the IAB node.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a subscriber station (SS) , a portable subscriber station, a mobile station (MS) , or an access terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. The terminal device may also correspond to Mobile Termination (MT) part of the integrated access and backhaul (IAB) node (a.k.a. a relay node) . In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

Although functionalities described herein can be performed, in various example embodiments, in a fixed and/or a wireless network node, in other example embodiments, functionalities may be implemented in a user equipment apparatus (such as a cell phone or tablet computer or laptop computer or desktop computer or mobile IoT device or fixed IoT device) . This user equipment apparatus can, for example, be furnished with corresponding capabilities as described in connection with the fixed and/or the wireless network node (s) , as appropriate. The user equipment apparatus may be the user equipment and/or or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functionalities include the bootstrapping server function and/or the home subscriber server, which may be implemented in the user equipment apparatus by providing the user equipment apparatus with software configured to cause the user equipment apparatus to perform from the point of view of these functions/nodes.

As mentioned above, currently, there have been increasing studies involving the connectivity of huge number of user equipments (UEs) to network nodes. As evolved in wireless communications technology, the configuration of network devices has been standardized with directional searching for terminals accessing via beamforming or other functional usage. While at the same time, the commercial terminals today are likely equipped with the same facilities to either support multiple functional usage or enhance the power gain during transmission and reception.

FIG. 1 shows an example environment 100 in which embodiments of the present disclosure can be implemented. As shown in FIG. 1, the example environment 100 may comprise terminal devices 110-1 to 110-5 (hereinafter may also be referred to as UEs 110-1 to 110-5/first devices 110-1 to 110-5 individually or a UE 110/afirst device 110 collectively) . The example environment 100 may also comprise a network device 120, which may communicate with terminal devices 110-1 to 110-5. It is to be understood that the number of the network device and terminal devices shown in FIG. 1 is given for the purpose of illustration without suggesting any limitations. The example environment 100 100 may include any suitable number of network devices and terminal devices.

One of the major issues raised in the scenario with massive UEs is accompanied with the incremental changes in the quantity of UEs. Consequently, the amount of transmission resources allocated to CSI acquirement would be elevated as it is proportional to the number of UEs. Consequently, remaining uplink data transmission resources for UEs would be diminished. Therefore, alleviating this potential bottleneck is a major concern.

Similarly, in some other applications, such as those wherein a UE has to know the location of other UEs for certain tasks by an application layer, the cost on sounding other terminals occupies an increasing amount of resources as as the number of other UEs increases. Here, the technical concerns are similar as aforementioned to figure out a way to reduce the signalling overhead.

Therefore, the present disclosure provides solutions for reducing the overhead of the CSI feedback from massive numbers of UEs. In some embodiments, the gNB may determine the locations of UEs and allocate the UEs to different groups. The grouping information may indicate the position relationship between the UE and the gNB, which may cause the UE to determine a receiving beam from the gNB by performing a beam sweeping based on the grouping information. The UE may inform the determined receiving beam to the gNB, such that the gNB can determine a beam pair between the UE and the gNB. Based on the grouping procedure, the gNB may indicate selectively which UE in a same group needs to report short term CSI. In this way, the overhead of CSI feedback for the UEs can be reduced. By employing this proposed solution, the overhead can be reduced which can improve the amount of resources allocated to data transmission and meanwhile reduce latency in certain tasks.

Principle and implementations of the present disclosure will be described in detail below with reference to FIG. 2, which show a schematic process for the massive terminals grouping for CSI overhead reduction. For the purpose of discussion, the process 200 will be described with reference to FIG. 1. The process 200 may involve the UE 110 and the gNB 120 as illustrated in FIG. 1. It is to be understood that the UE 110 hereinafter described with the process 200 can be considered as any of UEs 110-1 to 110-5.

As shown in FIG. 1, the UE 110 may transmit 205 a sounding signal. The sounding signal may comprise a preamble specific to the UE 110. After the gNB 120 receives the sounding signal from the UE 110, the gNB 120 may obtain the preamble specific to the UE 110 and determine a location of the UE 110. The location may be a coarse location or a partial location, such as a relative angle of arrival at the gNB 120. The gNB 120 may determine the location by itself or in collaboration with other gNBs receiving the sounding signal or other sounding signals from the UE 110.

Based on the location of the UE 110, the gNB 120 can assign a group for the UE. In some example embodiments, the gNB 120 may generate 210 grouping information based on a group index of the group assigned to the UE 110 by the gNB 120. Furthermore, the grouping information may also comprise location information associated with the UE 110 and gNB 120. The location information can be referred to as the location of the UE 110 or the gNB 120. The location information can also be referred to as the location relationship between the UE 110 and the gNB 120. In some embodiments, UEs may be assigned to groups based on their coarse location such that UEs in each group are substantially scattered, for example such that UEs, whose coarse location information suggests them to be relatively closest together of all UEs in the groups, are assigned to different groups.

After the grouping information is generated, the gNB 120 may transmit 215 the grouping information to the UE 110. The UE 110 then may perform a beam sweeping procedure to determine a receiving beam from the gNB 120.

In some example embodiments, the UE 110 may perform the beam sweeping procedure on the beam around the spatial domain by several epochs. For example, the UE 110 may obtain the location relationship between the UE 110 and gNB 120 or the location of the UE 110 or the gNB 120. Based on the location information, the UE 110 may determine a direction for the beam sweeping and determine the receiving beam by performing the beam sweeping procedure on the direction.

In some example embodiments, the UE 110 may perform the beam sweeping procedurere with other UEs in the same group simultaneously at a given epoch. For example, the UE 110 may determine a time interval associated with the group index of the UE 110 for performing a beam sweeping procedure based on the grouping information. Then the UE 110 may determine the receiving beam from the gNB 120 by performing the beam sweeping procedure within the time interval.

Based on the beam sweeping procedure, the UE 110 may determine 220 a receiving beam from the gNB 120. Then the UE 110 may transmit 225 an indication of the receiving beam to the gNB 120, to inform which beam is chosen by the UE 110 for the transmission between the UE 110 and the gNB 120. Based on the receiving beam, the gNB 120 may determine 230 a transmission path between the UE 110 and the gNB 120.

In some example embodiments, the gNB 120 may determine a beamforming direction of the receiving beam and determine a corresponding transmitting beam based on the beamforming direction. Then the transmission path between the UE 110 and the gNB 120 can be determined based on the receiving beam and the corresponding transmitting beam.

The gNB 120 may further transmit 235 the transmission path information to the UE 110. After receiving the transmission path information, the UE 110 may determine in which group the UE 110 is located. Then the UE may obtain an indication of CSI feedback.

Two types of CSI are considered for the CSI feedback, namely a short term CSI and a long term CSI. For example in current cellular standards, the long-term CSI and short-term CSI can be reported by uplink channels Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH) . In these standards, the detailed types of reports are further divided into periodic report (PUCCH report) , non-periodic report (PUSCH report) , PUCCH semi-static report and PUSCH semi-static report. Normally, the UE may need to report both short and long term CSI.

In embodiments of the present invention, the indication of CSI feedback, which is obtained by the UE 110, may indicate which UE in a same group is required to report the short term CSI. In other word, only a specific UE in the same group has to report the short term CSI and other UE may be allowed or required to report only the long term CSI.

Thus, if the UE 110 determines, based on the CSI feedback indication, the UE is responsible for CSI feedback in a group, the UE 110 may determine the CSI feedback information based on long term CSI and short term CSI. If the UE 110 determines the UE is not responsible for CSI feedback in a group, the UE 110 may determine the CSI feedback information only based on long term CSI.

Assuming that there are P bits to feedback long-term CSI and Q bits to feedback short-term CSI respectively, the overhead of conventional hybrid feedback scheme (C _a) and the reduced overhead (C _b) provided by embodiments of the invention are shown as followings:

where TTI _nums indicates a reporting ratio of long-term CSI over short-term CSI, which in current cellular standards may be expressed as a number of transmission time intervals (TTIs) ; where M is a number of gNBs, N is a number of UEs; where κ (t) may represent a group size coefficient.

It is to be understood that the long-term and short-term CSI require different feedback periods. For example, in LTE-A or NR system, the feedback period of long-term CSI can be 200-1000 (TTIs) , while the period of short-term CSI is one or several (TTIs) . As a result, it is beneficial to group the UEs such that the feedback overhead of short-term CSI is reduced.

For example, if P=6 for the long-term part W ₁, which includes the beam basis and the beam power information, and Q=12 for the short-term part W ₂, which includes the phase. N=10, M=3, TTI _num=200, κ (t) =6/10. The overheads with grouping and without grouping scheme are 43380bits and 72180bits respectively, which greatly reduce the overhead. This assumption is reasonable since both low-rank and high-rank codebook will share the same W ₁ part.

After the UE 110 is successful accessed to the gNB 120, the gNB 120 may further perform a fine grouping procedure for the UE 110, because the UE 110 can be moveable.

In some example embodiments, the UE 110 may report the channel gain to the gNB 120 based on the transmission path determined by the gNB 120, which is transmitted to the UE 110 at action 235 as shown in FIG. 2.

In a scenario with multiple gNBs, the mean channel gain associated with gNBs can be modelled as below:

where the antennas at each gNB and each UE are m _t and m _r, respectively, where M is the number of gNBs, PL ₀ is the intercept, d _i, j is the propagation distance between the ith UE and the jth gNb, n is the path loss exponent on the specific propagation environment. The shadow fading factor χ _σ is a zero-mean Gaussian variable with standard deviation of σ and E _{j=1, …, M} is an expectation operator. The variance of

can be calculated as the maximum of threshold λcapturing the degree of UE dispersion, here N is the number of UEs. It is noted that the channel gain may be approximated by other channel models without departing from the scope of the invention.

Based the channel gain, the gNB may further perform a fine grouping procedure for UEs. In an initialization phase, assuming Ω= {1, ..., N} ,

n=1.

Then UE precedence can be calculated as below:

where

is the mean value of long term CSI of the ith UE at the time slot t, which for throughput-maximization scheduling, can be approximated as

, by considering that the capacity is the linear function of channel gain. Thus, the proportional fairness among UEs are guaranteed.

Then the grouping criteria can be set as below:

where λ has impact on the group size and the feedback overhead of instantaneous CSI. If

R is the multi-antenna transmission rank, i.e., the group size is lower than that required, repeat n=n+1 in equation (4) , and then the group size coefficient could be defined as κ (t) =|ξ (t) |/N, then the scheduling complexity changes from O (F (N) to O (F (κ (t) ·N) . F is the function of UE numbers. n=n+1 means if

then change the UE index to n+1, namely

this value is the sub-optimal value (a little bit less than previous) of

and then recalculated whether

until satisfied.

In this way, the gNB may further determine optimized grouping information for the UEs. If the gNB 120 transmit the optimized grouping information to the UE 110, the UE 110 may update its grouping information.

Hereinbefore the process of massive terminals grouping for CSI overhead reduction has been described with FIG. 2. With reference to FIG. 3 and FIG. 4, two example application scenarios may be further explained as below.

FIG. 3 shows an example application scenario according to some example embodiments of the present disclosure.

In 3GPP 5G NR, the radio band is proposed to be operated around 60GHz, where some exemplary requirements of the spectrum are regulated from such as 57 GHz to 71 GHz in USA, 57GHz to 64GHz in Canada and 59GHz to 64GHz in China, etc. Due to the very strong path-loss in mmWave band, the gNB and the UE are likely to be configured with massive number of antennas to achieve sufficient beamforming gain against the power attenuation through propagation. As shown in FIG. 3, it is assumed that 10 UEs, namely, UEs 310-0 to 310-9, simultaneously access to three gNBs 320-0 to 320-2, where the UEs and gNBs employ 32 and 64 antennas, respectively.

Before cell selection, each of UEs 310-0 to 310-9 may modulate the identification information on a random access preamble during the contention based initial random access procedure and send the identification information to the gNBs 320-0 to 320-2. The gNBs 320-0 to 320-2 may estimate a rough location of the UEs 310-0 to 310-9, for example via the reduced power feature of the preamble signal. Afterwards, the gNBs 320-0 to 320-2 may collaboratively label the UEs 310-0 to 310-9 into 3 groups. For each of the UEs 310-0 to 310-9 and gNBs 320-0 to 320-2, the principle of the above mentioned process has been described with the

actions

205, 210 and 215 as shown in FIG. 2. After the coarse grouping procedure is completed, an exemplary grouping result can be found as below.

Table 1: exemplary grouping result

Group ID	UE ID
A

	1, 3, 8
B	2, 5, 6
C	0, 4, 7, 9

Then the gNBs 320-0 to 320-2 may send the grouping ID to UEs 310-0 to 310-9. Then UEs and gNB start the procedure in beam management operated at mmWave band, where the beam sweeping procedure in one group is synchronized and operating in the same way. Furthermore, the beam sweeping procedure across different groups are proposed to be consecutive in time as the first group hand over the sweeping right to the next when the former one completed. After the sweeping, the beam measurement and beam determination are conducted by gNBs. For each of the UEs 310-0 to 310-9 and gNBs 320-0 to 320-2, the details of the above mentioned process has been described with the actions 215 to 230 as shown in FIG. 2.

FIG. 4 shows a further example application scenario according to some example embodiments of the present disclosure.

Virtual reality (VR) and augmented reality (AR) are promising technologies to improve the way people interact with the environment. Recently, the standardization of VR has attracted lots of concerns. The example application scenario shown in FIG. 4 considers the technical way to guarantee a safety environment for VR operator as required by the environment safety division in IEEE 2048 standard. Since the VR game contents is far from the real vision around environment of the players, the players in the same room can physically hurt each other during the game. Therefore, the free body collision mechanism is usually deployed in the VR gaming, where the danger in playing can be removed by a feedback to players when it occurs in the real environment. Throughout an appropriate feedback design from the VR application layer, players can adjust his/her operation to avoid the potential physical hurt. To ensure this safety, the low latency in danger detection has the first priority in the system design. Hence, this example application scenario mainly concerns the communication signals framework to reduce the delay in danger detection

In the scenario shown in FIG. 4, assuming 6 players wearing wireless VR headset in a lounge room playing the VR game simultaneously and interactively, where the VR accessing nodes are distributed in the example application scenario as shown in FIG. 4. At the very beginning, the VR terminals 410-1 to 410-6 first send a series preamble to the network devices 420-1 to 420-4. Then the network devices 420-1 to 420-4 may estimate locations of these VR terminals 410-1 to 410-6 and partition the VR terminals 410-1 to 410-6, for example, into 2 groups by separating players in a same group as far as possible. Afterwards, the VR headsets sweep the obstacles around him/her via sending out an ultrasonic signal and collecting back the echoes to determine whether the dangers are around him/her. Moreover, the players in one group employ the ultrasonic signal at difference frequency.

It is to be noted that it does not require the synchronization in one group. Thus players can detect the change of environment very quickly. Meanwhile, through detection of the ultrasonic signals, the network devices 420-1 to 420-4 can assess the location of the players to avoid the collision to the playing area edge, e.g. building walls or windows. At the same time, in the VR gaming, the network devices 420-1 to 420-4 may transmit high rate data streams to the VR headset collaboratively through conventional communications strategy. For each of the VR terminals 410-1 to 410-6 and the network devices 420-1 to 420-4 in FIG. 4, the principle of the process as mentioned above may also be performed as the process 200 described with reference to FIG. 2, which is not repeated here.

FIG. 5 shows a flowchart of an example method 500 of massive terminals grouping for CSI overhead reduction according to some example embodiments of the present disclosure. The method 500 can be implemented at the first device 110 as shown in FIG. 1. For the purpose of discussion, the method 500 will be described with reference to FIG. 1.

At 510, the first device 110 receives, from a second device, grouping information of the first device, the grouping information at least indicating a group index allocated for the first device.

At 520, the first device 110 transmits, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information.

At 530, if the UE 110 determines a reception of, transmission path information between the first device and the second device associated with the receiving beam from the second device, the UE 110 determine CSI based on a CSI feedback indication associated with the group index.

In some example embodiments, the UE 110 may transmit a sounding signal to the second device, the sounding signal comprising a random access preamble specified to the first device.

In some example embodiments, the UE 110 may obtain a location relationship between the first device and the second device from the grouping information; determine a direction of a beam sweeping procedure based on the location relationship; and determine the receiving beam from the second device by performing the beam sweeping procedure on the direction.

In some example embodiments, the UE 110 may determine a time interval for performing a beam sweeping procedure based on the grouping information, the time interval being associated with the group index; and determine the receiving beam from the second device by performing the beam sweeping procedure within the time interval.

In some example embodiments, the UE 110 may determine the CSI feedback information based on long-term CSI and short-term CSI, if the UE 110 determines the CSI feedback indication that the first device is to be responsible for CSI feedback in a group having the group index.

In some example embodiments, the UE 110 may determine the CSI feedback information based on long term CSI, if the UE 110 determines the CSI feedback indication that the first device is not to be responsible for CSI feedback in a group having the group index.

In some example embodiments, the UE 110 may determine a channel gain associated with a transmission path between the first device and the second device based on the transmission path information; and transmit the channel gain to the second device.

FIG. 6 shows a flowchart of an example method 600 of massive terminals grouping for CSI overhead reduction according to some example embodiments of the present disclosure. The method 600 can be implemented at the second device 120 as shown in FIG. 1. For the purpose of discussion, the method 600 will be described with reference to FIG. 1.

At 610, the second device 120 transmits grouping information of a first device to the first device, the grouping information at least indicating a group index allocated for the first device.

At 620, the second device 120 determines transmission path information between the first device and the second device based on the receiving beam if the second device 120 determines a reception of an indication of a receiving beam from the second device determined at the first device based on the grouping information from the first device.

At 630, the second device 120 transmits the transmission path information to the first device.

In some example embodiments, the second device 120 may receive a sounding signal from the first device; obtain a random access preamble specified to the first device from the sounding signal; and determine the grouping information based on the random access preamble.

In some example embodiments, the second device 120 may determine a beamforming direction of the receiving beam; determine a transmitting beam of the second device based on the beamforming direction; and determine transmission path information based on the the receiving beam and the transmitting beam.

In some example embodiments, the second device 120 may receive a channel gain associated with the transmission path between the first device and the second device and determine, based on the channel gain, whether a further group index is to be allocated for the first device. If the second device 120 determines the further group index is to be allocated, the second device 120 may generate a further grouping information at least based on the further group index and transmit the further grouping information to the first device. transmit the further grouping information to the first device.

In some example embodiments, an apparatus capable of performing the method 500 (for example, implemented at the UE 110) may comprise means for performing the respective steps of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for receiving, from a second device, grouping information of the first device, the grouping information at least indicating a group index allocated for the first device; means for transmitting, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information; and means for in accordance with a determination of a reception of transmission path information between the first device and the second device associated with the receiving beam, determining CSI, based on a CSI feedback indication associated with the group index.

In some example embodiments, an apparatus capable of performing the method 600 (for example, implemented at the gNB 120) may comprise means for performing the respective steps of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for transmitting grouping information of a first device to the first device, the grouping information at least indicating a group index allocated for the first device; means for in accordance with a determination of a reception of an indication of a receiving beam from the second device determined at the first device based on the grouping information, determining transmission path information between the first device and the second device based on the receiving beam; and means for transmitting the transmission path information to the first device.

FIG. 7 is a simplified block diagram of a device 700 that is suitable for implementing embodiments of the present disclosure. The device 700 may be provided to implement the communication device, for example the UE 110 and the gNB 120 as shown in FIG. 1. As shown, the device 700 includes one or more processors 710, one or more memories 740 coupled to the processor 710, and one or more transmitters and/or receivers (TX/RX) 740 coupled to the processor 710.

The TX/RX 740 is for bidirectional communications. The TX/RX 740 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 710 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 700 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 724, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 722 and other volatile memories that will not last in the power-down duration.

A computer program 730 includes computer executable instructions that are executed by the associated processor 710. The program 730 may be stored in the ROM 720. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 720.

The embodiments of the present disclosure may be implemented by means of the program 730 so that the device 700 may perform any process of the disclosure as discussed with reference to FIGs. 2 to 6. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 730 may be tangibly contained in a computer readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer readable medium to the RAM 722 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. FIG. 8. shows an example of the computer readable medium 800 in form of CD or DVD. The computer readable medium has the program 730 stored thereon.

Generally, various embodiments of the present 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 embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, device, system, technique or method described herein may be implemented in, as non-limiting examples, 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, being executed in a device on a target real or virtual processor, to carry out the

methods

500 and 600 as described above with reference to FIGs. 5-6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like 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 a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out 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 device, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a 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, the computer program codes or related data may be carried by any suitable carrier to enable the device, device or processor to perform various processes and operations as described above. Examples of the 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 not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would 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 of the foregoing.

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 certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present 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 may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present 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

A first device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device at least to:

receive, from a second device, grouping information of the first device, the grouping information at least indicating a group index allocated for the first device;

transmit, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information; and

in accordance with a determination of a reception of transmission path information between the first device and the second device associated with the receiving beam, determine channel state information (CSI) based on a CSI feedback indication associated with the group index.
The first device of Claim 1, wherein the first device is further caused to:

transmit a sounding signal to the second device, the sounding signal comprising a random access preamble specified to the first device.
The first device of Claim 1, wherein the first device is further caused to:

obtain a location relationship between the first device and the second device from the grouping information;

determine a direction of a beam sweeping procedure based on the location relationship; and

determine the receiving beam from the second device by performing the beam sweeping procedure on the direction.
The first device of Claim 1, wherein the first device is further caused to:

determine a time interval for performing a beam sweeping procedure based on the grouping information, the time interval being associated with the group index; and

determine the receiving beam from the second device by performing the beam sweeping procedure within the time interval.
The first device of Claim 1, wherein the first device is caused to determine the CSI feedback information by:

in accordance with a determination that the CSI feedback indication that the first device is to be responsible for CSI feedback in a group having the group index, determining the CSI feedback information based on long term CSI and short term CSI.
The first device of Claim 1, wherein the first device is caused to determine the CSI feedback information by:

in accordance with a determination that the CSI feedback indication that the first device is not to be responsible for CSI feedback in a group having the group index, determining the CSI feedback information based on long term CSI.
The first device of Claim 1, wherein the first device is further caused to:

determine a channel gain associated with a transmission path between the first device and the second device based on the transmission path information; and

transmit the channel gain to the second device.
The first device of Claim 7, wherein the first device is further caused to:

in response to receiving a further grouping information from the second device, update the grouping information based on the further grouping information, the further grouping information being determined by the second device based on the channel gain.
The first device of Claim 1, wherein the first device comprises a terminal device and the second device comprises a network device.
A second device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device at least to:

transmit grouping information of a first device to the first device, the grouping information at least indicating a group index allocated for the first device;

in accordance with a determination of a reception of an indication of a receiving beam from the second device determined at the first device based on the grouping information, determine transmission path information between the first device and the second device based on the receiving beam; and

transmit the transmission path information to the first device.
The second device of Claim 10, wherein the second device is further caused to:

receive a sounding signal from the first device;

obtain a random access preamble specified to the first device from the sounding signal; and

determine the grouping information based on the random access preamble.
The second device of Claim 10, wherein the second device is caused to determine the transmission path information by:

determining a beamforming direction of the receiving beam;

determining a transmitting beam of the second device based on the beamforming direction; and

determining transmission path information based on the the receiving beam and the transmitting beam.
The second device of Claim 10, wherein the second device is further caused to:

receive a channel gain associated with the transmission path between the first device and the second device;

determine, based on the channel gain, whether a further group index is to be allocated for the first device;

in accordance with a determination that the further group index is to be allocated, generate a further grouping information at least based on the further group index; and

transmit the further grouping information to the first device.
The second device of Claim 10, wherein the first device comprises a terminal device and the second device comprises a network device.
A method comprising:

receiving, at a first device and from a second device, grouping information of the first device, the grouping information at least indicating a group index allocated for the first device;

transmitting, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information; and

in accordance with a determination of a reception of transmission path information between the first device and the second device associated with the receiving beam, determining channel state information (CSI) based on a CSI feedback indication associated with the group index.
The method of Claim 15, further comprising:

transmitting a sounding signal to the second device, the sounding signal comprising a random access preamble specified to the first device.
The method of Claim 15, further comprising:

obtaining a location relationship between the first device and the second device from the grouping information;

determining a direction of a beam sweeping procedure based on the location relationship; and

determining the receiving beam from the second device by performing the beam sweeping procedure on the direction.
The method of Claim 15, further comprising:

determining a time interval for performing a beam sweeping procedure based on the grouping information, the time interval being associated with the group index; and

determining the receiving beam from the second device by performing the beam sweeping procedure within the time interval.
The method of Claim 15, wherein determining the CSI feedback information comprises:

in accordance with a determination that the CSI feedback indication that the first device is to be responsible for CSI feedback in a group having the group index, determining the CSI feedback information based on long term CSI and short term CSI.
The method of Claim 15, wherein determining the CSI feedback information comprises:

in accordance with a determination that the CSI feedback indication that the first device is not to be responsible for CSI feedback in a group having the group index, determining the CSI feedback information based on long term CSI.
The method of Claim 15, further comprising:

determining a channel gain associated with a transmission path between the first device and the second device based on the transmission path information; and

transmitting the channel gain to the second device.
The method of Claim 21, further comprising:

in response to receiving a further grouping information from the second device, updating the grouping information based on the further grouping information, the further grouping information being determined by the second device based on the channel gain.
The method of Claim 15, wherein the first device comprises a terminal device and the second device comprises a network device.
A method comprising:

transmitting, from a second device, grouping information of a first device to the first device, the grouping information at least indicating a group index allocated for the first device;

in accordance with a determination of a reception of an indication of a receiving beam from the second device determined at the first device based on the grouping information, determining transmission path information between the first device and the second device based on the receiving beam; and

transmitting the transmission path information to the first device.
The method of Claim 24, further comprising:

receiving a sounding signal from the first device;

obtaining a random access preamble specified to the first device from the sounding signal; and

determining the grouping information based on the random access preamble.
The method of Claim 24, wherein determining the transmission path information comprises:

determining a beamforming direction of the receiving beam; and

determining a transmitting beam of the second device based on the beamforming direction; and

determining transmission path information based on the the receiving beam and the transmitting beam.
The method of Claim 24, further comprising:

receiving a channel gain associated with the transmission path between the first device and the second device;

determining, based on the channel gain, whether a further group index is to be allocated for the first device;

in accordance with a determination that the further group index is to be allocated, generating a further grouping information at least based on the further group index; and

transmitting the further grouping information to the first device.
The method of Claim 24, wherein the first device comprises a terminal device and the second device comprises a network device.
An apparatus comprising:

means for receiving, from a second device, grouping information of the first device, the grouping information at least indicating a group index allocated for the first device;

means for transmitting, to the second device, an indication of a receiving beam from the second device determined at the first device based on the grouping information; and

means for in accordance with a determination of a reception of transmission path information between the first device and the second device associated with the receiving beam, determining channel state information (CSI) based on a CSI feedback indication associated with the group index.
An apparatus comprising:

means for transmitting grouping information of a first device to the first device, the grouping information at least indicating a group index allocated for the first device;

means for in accordance with a determination of a reception of an indication of a receiving beam from the second device determined at the first device based on the grouping information, determining transmission path information between the first device and the second device based on the receiving beam; and

means for transmitting the transmission path information to the first device.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any of claims 15-23.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any of claims 24-28.