Devices, methods, and apparatus for SRS enhancement

Abstract

The terminal device receives, from the network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, where the one or more OCC sequences have one or more lengths of 3 or 6. The terminal device further transmits, to the network device, an SRS signal using an OCC sequence from the one or more OCC sequences.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to the field of communications, and more particularly to devices, methods, apparatus, and computer-readable storage media for sounding reference signal (SRS) enhancement. [Background technology]

[0002] In the 3rd Generation Partnership Project (3GPP) Release 18 (Rel-18), adding uplink (UL) SRS antenna ports is defined as one of the multiple-input multiple-output (MIMO) topics. It is proposed to increase the number of UL SRS antenna ports without increasing the number of base sequences for SRS. It is also proposed to extend the number of cyclic shifts for SRS transmission.

[0003] However, increasing the number of cyclic shifts may degrade the channel estimation quality when the delay is long. Therefore, there is limited space for increasing the number of cyclic shifts for any comb pattern. Therefore, an improved solution for SRS extension is needed to support more UL SRS antenna ports. Summary of the Invention

[0004] Generally, exemplary embodiments of the present disclosure provide devices, methods, apparatus, and computer-readable storage media for SRS enhancement.

[0005] In a first aspect, a terminal device is provided, the terminal device including one or more transceivers and one or more processors communicatively coupled to the one or more transceivers, the one or more processors configured to cause the terminal device to: receive, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; and transmit, by the network device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0006] In a second aspect, a network device is provided, the network device comprising: one or more transceivers; and one or more processors communicatively coupled to the one or more transceivers, the one or more processors configured to cause the network device to: transmit, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; and receive, from the terminal device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0007] In a third aspect, a method implemented in a terminal device is provided. The method may include receiving, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; and transmitting, to the network device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0008] In a fourth aspect, a method implemented in a network device is provided. The method may include transmitting, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; and receiving, from the terminal device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0009] In a fifth aspect, an apparatus for a terminal device is provided, which may include: means for receiving, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; and means for transmitting, to the network device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0010] In a sixth aspect, an apparatus for network equipment is provided, which may include: means for transmitting, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; and means for receiving, from the terminal device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0011] In a seventh aspect, a terminal device is provided. The terminal device may include at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, by the at least one processor, to cause the terminal device to: receive, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, where the one or more OCC sequences have one or more lengths of length 3 or length 6; and transmit, by the network device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0012] In an eighth aspect, a network device is provided. The network device may include at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to cause the network device to: transmit, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, where the one or more OCC sequences have one or more lengths of length 3 or length 6; and receive, from the terminal device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0013] In a ninth aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform a method according to at least the third or fourth aspect.

[0014] In a tenth aspect, a computer program is provided that includes instructions that, when executed by an apparatus, cause the apparatus to at least receive, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, wherein the one or more OCC sequences have one or more of lengths 3 or 6; and transmit, from the network device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0015] In an eleventh aspect, a computer program is provided that includes instructions that, when executed by an apparatus, cause the apparatus to at least: transmit, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, wherein the one or more OCC sequences have one or more lengths of length 3 or length 6; and receive, from the terminal device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0016] In a twelfth aspect, a terminal device is provided. The terminal device may include: a receiving circuit configured to receive, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; and a transmitting circuit configured to transmit, to the network device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0017] In a thirteenth aspect, a network device is provided. The network device may include: a transmitting circuit configured to transmit, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; and a receiving circuit configured to receive, from the terminal device, an SRS signal using an OCC sequence from the one or more OCC sequences.

[0018] It should be understood that the Summary is not intended to identify key features or essential features of the embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily apparent through the following description. [Brief explanation of the drawings]

[0019] Exemplary embodiments will now be described with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 illustrates an exemplary network environment in which exemplary embodiments of the present disclosure may be implemented. [Figure 2] FIG. 2 illustrates an exemplary flowchart of a method implemented in a terminal device in an exemplary embodiment of the present disclosure. [Figure 3] FIG. 3 illustrates an exemplary flowchart of a method implemented in a network device in an exemplary embodiment of the present disclosure. [Figure 4] FIG. 4 illustrates an example signaling process for SRS enhancement in accordance with some embodiments of the present disclosure. [Figure 5A] FIG. 5A shows an example of the correlation of the baseline SRS sequence when a resource length of 306 is allocated. [Figure 5B] FIG. 5B shows an example of correlation of SRS sequences with OCC when a resource length of 306 is allocated. [Figure 6A]FIG. 6A is a diagram showing an example of cubic metrics (CM) of SRS symbols in a comparison between the conventional configuration and the proposed OCC sequence. [Figure 6B] FIG. 6B shows an example of the peak-to-average power ratio (PAPR) of the SRS symbols in a comparison between the prior art configuration and the proposed OCC sequence. [Figure 7] FIG. 7 shows an example of a simplified block diagram of an apparatus suitable for practicing exemplary embodiments of the present disclosure. [Figure 8] 8 illustrates a block diagram of an exemplary computer-readable medium in accordance with some exemplary embodiments of the present disclosure. Throughout the drawings, identical or similar reference numerals represent identical or similar elements. DETAILED DESCRIPTION OF THE INVENTION

[0020] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are set forth for illustrative purposes, without implying any limitation on the scope, and are intended to assist those skilled in the art in understanding and practicing the present disclosure. The present disclosure described herein may be embodied in various forms other than those described below.

[0021] In the following description and claims, unless otherwise defined, 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 pertains.

[0022] References in this disclosure to "one embodiment," "embodiment," "exemplary embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments need to include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly stated.

[0023] Although terms such as "first" and "second" may be used herein to describe various elements, it should be understood that these elements are not limited by these terms. These terms are merely used to distinguish one element from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0024] The terms used in the examples are for the purpose of describing particular embodiments and are not intended to limit the exemplary embodiments. In the examples, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly dictates otherwise. It will be further understood that the terms "comprises," "comprising," "has," "having," "includes," and / or "including" in the examples identify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. As used herein, similar expressions such as "at least one of, " and "at least one of, " mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements, when a list of two or more elements is joined by "and" or "or."

[0025] As used herein, the term "circuit" means (a) Hardware-only circuit implementations (e.g., analog and / or digital-only implementations, (b) a combination of hardware circuitry and software (if applicable); (i) a combination of analog and / or digital hardware circuitry and software / firmware; (ii) software (including digital signal processors), software, and hardware processor portions with memory that work together to cause a device, such as a mobile phone or server, to perform various functions; (c) A hardware circuit or processor, such as a microprocessor or part of a microprocessor, that requires software (e.g., firmware) to operate, but the software may be absent when not required for operation; It may refer to one or more, or all, of the following:

[0026] This definition of circuit applies to all uses of the term in this application, including the claims. As a further example, as used herein, the term circuit also covers simply a hardware circuit or processor (or processors), or a portion of a hardware circuit or processor, and its (or their) accompanying software and / or firmware implementations. The term circuit also covers, for example, a baseband or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network equipment, or other computing or network equipment, if applicable to particular claim elements.

[0027] As used herein, the term "communication network" refers to a network conforming 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), or Narrowband Internet of Things (NB-IoT). Furthermore, communications between terminal devices and network devices in a communication network may be based on, but not limited to, third-generation (3G), fourth-generation (4G), 4.5G, future fifth-generation (5G) communication protocols, and / or other protocols currently known or developed in the future. Embodiments of the present disclosure may be applied to various communications. Given the rapid development of communications, there are, of course, future communication technologies and systems that may embody the present disclosure. The scope of the present disclosure should not be considered limited to only the above-mentioned systems.

[0028] As used herein, the term "network equipment" refers to a node in a communication network through which terminal equipment accesses the network and receives services therefrom. Depending on the terminology and technology applied, network equipment may refer to a base station (BS) or access point (AP), e.g., a Node B (NodeB or NB), evolved Node B (eNodeB or eNB), new radio (NR) NB (also referred to as gNB), remote radio unit (RRU), radio header (RH), remote radio head (RRH), relay, femto, pico, or other low-power node.

[0029] The term "terminal equipment" refers to any end device capable of wireless communication. By way of example and not limitation, terminal equipment may also be referred to as communication equipment, user equipment (UE), subscriber station (SS), mobile subscriber station, mobile station (MS), or access terminal (AT). Terminal equipment includes, but is not limited to, mobile phones, cellular phones, smartphones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal equipment, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal equipment such as digital cameras, gaming terminal equipment, music storage and playback appliances, in-vehicle wireless terminal equipment, wireless endpoints, mobile stations, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, wearables such as watches, head-mounted displays (HMD), vehicles, drones, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless equipment operating in the context of industrial and / or automated processing chains), consumer electronics, equipment operating in commercial and / or industrial wireless networks, etc. In the following description, the terms "terminal equipment," "communications equipment," "terminal," "user equipment," and "UE" may be used interchangeably.

[0030] The 3GPP® MIMO topic targets SRS enhancements and has already proposed to consider or specify SRS enhancements to enable 8TX UL operation supporting more than four layers per UE, targeting UL for Customer Premises Equipment (CPE) / Fixed Wireless Access (FWA) / Automotive / Industrial equipment.

[0031] In 3GPP Specification 38.331 (-h10 June 2022), an SRS resource set is configured, where "srs-ResourceIdList" defines the SRS resource list, "resourceType" defines the trigger mechanism (aperiodic, semi-permanent, periodic), and "usage" is the configuration reason (beamManagement, codebook, non-Codebook antennaSwitching). "nrofSRS-Port" defines 1, 2, or 4 ports, "transmissionComb" is used to define combs 2 and 4 with a specific periodic shift, "transmissionComb-n8-r17" is used to define comb 8, "frequencyHopping" provides configuration information related to frequency hopping, "groupOrSequenceHopping" defines whether grouping is defined for SRS allocation, and "resourceType" defines the periodicity of the allocation.

[0032] As mentioned above, 3GPP (registered trademark) Rel-18 defines the addition of UL SRS antenna ports as one of the MIMO topics. Because the number of base sequences may be limited and channel estimation quality may deteriorate as the number of cyclic shifts of the SRS comb pattern increases, code division multiplexing TD OCC can be applied to increase the number of SRS antenna ports. Typically, the length of the TD OCC sequence is two or four. However, problems arise, such as increased SRS antenna port detection time and repetition of UL SRS symbols longer than the OCC length. Therefore, an improved solution for SRS enhancement is needed to support more SRS antenna ports.

[0033] According to an embodiment of the present disclosure, a scheme for SRS enhancement is provided. In this scheme, a terminal device receives sounding reference signal (SRS) configuration information from a network device. The SRS configuration information may indicate one or more orthogonal cover code (OCC) sequences in the frequency domain. The one or more OCC sequences may have one or more lengths of length 3 or length 6. Furthermore, the terminal device may transmit an SRS signal to the network device using an OCC sequence from the one or more OCC sequences.

[0034] This antenna port configuration information allows the use of FD OCCs with lengths of 3 or 6 to support more SRS antenna ports. For example, with an OCC length of 6 and a comb size of 2, the number of supported antenna ports increases by six times. This also allows for more SRS antenna ports with better performance.

[0035] To support more SRS antenna ports, it has been previously proposed to use a time-domain (TD) OCC with an OCC length of 2 or 4. However, this has the drawback of increasing the detection time of the SRS antenna ports due to the delay of SRS transmission over the OCC sequence. Furthermore, it requires repeating the UL SRS symbol over the TD OCC length. Furthermore, it imposes scheduling constraints on the network. However, in this disclosure, the OCC sequence is frequency-domain, so it does not increase the detection time of the SRS antenna ports. Furthermore, it does not impose scheduling constraints on the network because it does not require repeating the UL SRS symbol over the TD OCC length.

[0036] Furthermore, FD OCC sequences of length 3 and / or 6 are longer than conventional OCC sequences. Therefore, compared to conventional OCC sequences of length 2 or 4, the proposed OCC sequences can add more resources to a given resource, in this case, more antenna ports. Furthermore, a length 3 OCC sequence can add one port compared to a length 2 OCC sequence, and a length 6 OCC sequence can add two ports compared to a length 4 OCC sequence.

[0037] Furthermore, since there are already six resource elements per physical resource block (PRB), a length of six may fit into the SRS comb size of two. A length of four cannot support these six resources because the number of resource elements for SRS transmission per PRB is not a multiple of four. Furthermore, there are four fewer ports than the OCC sequence supported by a length of four because only OCC can be placed on two source elements (REs).

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principles and embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings, in which: Reference is first made to Figure 1, which illustrates an exemplary environment 100 in which exemplary embodiments of the present disclosure may be implemented.

[0039] The environment 100, which may be part of a communications network, includes terminal equipment 110 and network equipment 120 that communicate with each other or with other devices through each other. The communications environment 100 may include any suitable number of devices and cells. In the communications environment 100, the terminal equipment 110 and the network equipment 120 may communicate data and control information with each other. The link from the network equipment 120 to the terminal equipment 110 is referred to as the downlink (DL), and the link from the terminal equipment 110 to the network equipment 120 is referred to as the uplink (UL).

[0040] It should be understood that, without implying any limitation on the scope of the present disclosure, two devices are shown in environment 100 for illustrative purposes only. In some exemplary embodiments, environment 100 may include additional devices for communicating with terminal equipment 110 and network equipment 120.

[0041] Communications in environment 100 may follow any suitable communications standard or protocol, whether already in existence or developed in the future, such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), LTE-Advanced (LTE-A), 5th Generation (5G) New Radio (NR), Wireless Fidelity (Wi-Fi®), and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employ any suitable communications technology, including, for example, multiple-input multiple-output (MIMO), orthogonal frequency division multiplexing (OFDM), time division multiplexing (TDM), frequency division multiplexing (FDM), code division multiplexing (CDM), Bluetooth®, ZigBee®, etc., and machine type communications (MTC), enhanced mobile broadband (eMBB), massive machine type communications (mMTC), ultra-reliable low latency communications (URLLC), carrier aggregation (CA), dual connectivity (DC), new unlicensed radio (NR-U) technologies, etc.

[0042] 2 shows an example flowchart of a method 200 implemented in a terminal device according to an example embodiment of the present disclosure. For purposes of explanation, the method 200 will be described from the perspective of the terminal device 110 with reference to FIG.

[0043] 2, in block 210, terminal device 110 may receive sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain from network device 120. The one or more OCC sequences may have one or more lengths of length 3 or length 6.

[0044] At block 220, terminal device 110 may transmit an SRS signal to network device 120 using an OCC sequence from one or more OCC sequences.

[0045] In some exemplary embodiments, the SRS configuration information includes one or more of length information of one or more OCC sequences and OCC sequence start information of one or more OCC sequences. For example, the length information of one or more OCC sequences and the OCC sequence start information may be signaled together or separately from network equipment 112 to terminal equipment 110.

[0046] In some exemplary embodiments, the SRS configuration information is included in a field in the SRS resource list. This field may be a new field in the SRS resource list. For example, the SRS configuration information is included in a new field under the SRS resource list as follows: fdOcc-r18 SEQUENCE { occLength-r18 INTEGER (0..3), / / 0=3, 1=6, 2=12 length of OCC occStartingIndex-r18 INTEGER (0...15), / / OCC index } Here, occLength-r18 is 2 bits and indicates the length of the OCC sequence, and occStartingIndex-r18 is 4 bits and indicates the starting index of the OCC sequence information.

[0047] In some exemplary embodiments, the SRS configuration information may include offset information of one or more OCC sequences for a group of antenna ports. Terminal device 110 may determine an OCC sequence from one or more OCC sequences based on the offset information for the group of antenna ports. The offset information may also be included in a new field under the SRS-Resource List. For example, the offset information may be defined as follows: occOffset-n6-r18 INTEGER (0..5).

[0048] This parameter may indicate the offset of the assigned antenna port, for example, when the OCC length is 6. A similar parameter may also be defined when the OCC length is 3. As an example when the OCC length is 6, if four antenna ports are assigned with occOffset-n6-r18=2, the terminal device may use index 2+x, where x is, for example, as follows: For RE offset 0, x={0,1} (two antenna ports per comb), and for RE offset 1, x={0,1} (similar to RE offset 0).

[0049] In some embodiments, offset information (e.g., occOffset-n6-r18) can be configured for a group of terminal devices for the purpose of joint transmission via multiple transmitters. By reserving specific offset(s) for this type of use, the OCC can be used to allocate specific resources to a group of terminal devices.

[0050] In some exemplary embodiments, the terminal device may determine an index of an OCC sequence from one or more OCC sequences. The index may be rotated based on one or more of a time slot index for transmission of the SRS signal or a cell identity (cell ID). The term "rotated" or "rotation" refers to the act of rearranging the indexes. For example, indexes 1, 2, 3, and 4 become indexes 4, 3, 2, and 1 after rotation.

[0051] For example, the rotation index "occIndex" can be determined based on the following formula: occIndex=mod(occOffset-n6-r18+slotIndex,occSequenceLength) Here, the parameter "occOffset-n6-r18" indicates the offset information mentioned above, the parameter "slotIndex" indicates the index of the time slot, and the parameter "occSequenceLength" indicates the length of the OCC sequence, which may be 3 or 6.

[0052] In some exemplary embodiments, the length of the OCC sequence may be determined based on the size of the SRS transmit comb of the terminal device. For example, the rel18 SRS is signaled to the terminal device 110 by the network device 120 (e.g., gNB) in SRS configuration information. The length of the OCC sequence may be selected based on the configured SRS comb size. The SRS transmit comb size may indicate the density of subcarriers occupied by source elements of the SRS sequence.

[0053] In some exemplary embodiments, the length of the OCC sequence may be determined as 6 when the SRS transmit comb size is 2. In this case, the OCC sequence covers one PRB. In some exemplary embodiments, when the SRS transmit comb size is 4, the length of the OCC sequence may be determined as 3. In this case, the OCC sequence covers one PRB. In some exemplary embodiments, when the SRS transmit comb size is 8, the length of the OCC sequence may be determined as 3. In this case, the OCC sequence covers two PRBs.

[0054] An exemplary scheme for OCC sequence length selection is, for purposes of illustration, Comb 2: OCC length is 6 (covering one PRB), Comb 4: OCC length is 3 (covering one PRB), Comb 8: OCC length is 3 (covers two PRBs, currently Comb 8 is not used for SRS channel measurements, only for positioning measurements), It is provided as follows.

[0055] It can be seen that by extending the OCC from the first allocated PRB to two adjacent PRBs, the number of antenna ports can be increased up to a maximum of 12. If only eight antenna ports are required, it may be preferable to reserve the remaining four antenna ports (any subset of the given OCC sequence) for future use.

[0056] In some embodiments, the elements of one or more OCC sequences may have unit amplitude. In some embodiments, one or more OCC sequences may be multiplied by any scalar value that does not change the properties of the OCC sequence.

[0057] In some exemplary embodiments, the one or more OCC sequences having length 6 are: The first sequence is [1,1,1,1,1,1], a second sequence of [x1, x2, x3, x4, x5, x6], where x1, x2, x3, x4, x5, x6 represent six complex numbers corresponding to six equal points on the circumference of the unit circle; The third sequence is [x6,x5,x4,x3,x2,x1], The fourth sequence obtained by multiplying [x2,x3,x4,x5,x6,x1] by [1,-1,1,-1,1,-1], a fifth sequence that is an inverted version of the fourth sequence, and a sixth sequence of [x,-x,x,-x,x,-x], where x represents a complex number on the unit circle; may include one or more of:

[0058] In the length-6 sequence, the first sequence is an all-ones sequence and can be considered the baseline sequence. The baseline sequence may be used to detect and / or enable multiplexing between legacy UL SRS and Rel-18 UL SRS. The sixth sequence may be [1,-1,1,-1,1,-1], i.e., x=1.

[0059] The second sequence can be, for example, Exp(j*(2 / 6)*pi*i), i=0,1...5. Note that the third, fourth, and fifth sequences can be derived from the second sequence. For example, the third sequence is an inverted version of the second sequence. Another example: the fourth sequence can be obtained by multiplying a shifted version of the second sequence (cyclically shifted left by 1) by a predetermined sequence, for example, [1,-1,1,-1,-1].

[0060] In some exemplary embodiments, one or more OCC sequences of length 3 can be derived from the above six OCC sequences of length 6, e.g., the first three elements from three of the six OCC sequences.

[0061] In some embodiments, the one or more OCC sequences of length 3 are: The first sequence is [1,1,1], a second sequence obtained by multiplying [x1, x2, x3], where x1, x2, x3 each represent three complex numbers corresponding to three of the six points equally dividing the circumference of the unit circle; The third sequence of [x3,x2,x1], may include one or more of:

[0062] Here, the second sequence of length 3 can be, for example, Exp(j*(2 / 6)*pi*i), i=1,3,5.

[0063] As mentioned above, the proposed FD OCC allows for a significant expansion of the number of antenna ports. For example, with an SRS comb size of 2, there are two resource sets per PRB. Any set of resource elements (REs) of length 6 can be used with an OCC sequence of length 6, thereby increasing the number of antenna ports by a factor of six. This results in 2*4*6=48 antenna ports per PRB and base sequence. A preferred way to map, say, eight antenna ports to these resources is to assign four antenna ports to one comb set as follows: The comb set for RE offset 0 includes antenna ports 1000 to 1003, and the comb set for RE offset 1 includes antenna ports 1004 to 1007. The comb set for RE offset 0 includes antenna ports 1000, 1002, 1004, and 1006, and the comb set for RE offset 1 includes antenna ports 1001, 1003, 1005, and 1007.

[0064] Therefore, with the solution proposed here, the number of antenna ports can be increased by a factor of up to six. Also, as already mentioned, the detection time of the OCC sequence does not increase (the interference increases as expected at the SRS reception / detection time, similar to multi-sequence transmission towards non-orthogonal sequences). Similar advantages are obtained when the OCC code length is three.

[0065] Furthermore, it should be noted that adding SRS antenna ports may increase SRS interference in SRS detection. As an example, for comb 2, the conventional method requires a 30*8*2 sequence, but the proposed solution allows for a 30*8*2*6 sequence. Additional transmission reports can be allocated using channel information for a given environment, increasing cell capacity. Therefore, despite the increased SRS interference, the overall throughput increases due to the increased measurement capacity of the SRS antenna ports.

[0066] The same sequence definitions with OCC lengths 6 and / or 3 can be used for DL ​​or UL DMRS purposes. In a UL receiver implementation, if the same time and frequency resources are allocated, the same knowledge of the allocated new SRS sequence can be used to detect previous versions of the SRS sequence (see OCC Removal and Previous Version SRS Sequence Detection above).

[0067] In some embodiments, the OCC sequence length or OCC sequence offset may be dynamically indicated to the UE in a DCI (format 1_0, format 1_1, etc.) configuration along with the DMRS configuration.

[0068] 3 shows an example flowchart of a method 300 implemented in a network device in an exemplary embodiment of the present disclosure. For purposes of explanation, the method 200 will be described from the perspective of the network device 120 with reference to FIGS.

[0069] 3, in block 310, network device 120 may transmit sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain to terminal device 110. The one or more OCC sequences may have one or more lengths of length 3 or length 6.

[0070] At block 320, network device 120 may receive, from terminal device 110, an SRS signal that uses an OCC sequence from one or more OCC sequences.

[0071] In some exemplary embodiments, the SRS configuration information may include length information of one or more OCC sequences and OCC sequence start information of one or more OCC sequences. In some exemplary embodiments, the SRS configuration information is configured in a field of an SRS resource list.

[0072] In some exemplary embodiments, the SRS configuration information may include offset information of one or more OCC sequences for a group of antenna ports, and an OCC sequence from the one or more OCC sequences is determined based on the offset information for the group of antenna ports.

[0073] In some exemplary embodiments, the one or more OCC sequences having a length of 6 are The first sequence is [1,1,1,1,1,1], a second sequence of [x1, x2, x3, x4, x5, x6], where x1, x2, x3, x4, x5, x6 represent six complex numbers corresponding to six equal points on the circumference of the unit circle; The third sequence is [x6,x5,x4,x3,x2,x1], The fourth sequence obtained by multiplying [x2,x3,x4,x5,x6,x1] by [1,-1,1,-1,1,-1], The fifth sequence is an inverted version of the fourth sequence, a sixth sequence of [x,-x,x,-x,x,-x], where x represents a complex number in the unit circle; may include one or more of:

[0074] With respect to the length-6 sequence, the first sequence can be considered a baseline sequence used to detect and / or enable multiplexing of legacy UL SRS with Rel-18 UL SRS.

[0075] The network equipment 120 can use this baseline OCC sequence together with the SRS sequence of the previous release, and then treat all signal sequences with OCC detection, where the resource elements covered by the OCC are averaged (or summed) to form a single sample across the OCC resource. The resulting sample can be used for SRS measurements and can be upsampled (e.g., by a repeater, filter, or finite impulse response filter) according to the intended sampling rate.

[0076] The second sequence is, for example, Exp(j*(2 / 6)*pi*i), i=0,1,...5, where j represents the imaginary unit. Note that the third, fourth, and fifth sequences can be derived from the second sequence.

[0077] In some exemplary embodiments, the one or more OCC sequences of length 3 are: The first sequence is [1,1,1], a second sequence obtained by multiplying [x1, x2, x3], where x1, x2, x3 each represent three complex numbers corresponding to three of the six points equally dividing the circumference of the unit circle; The third sequence of [x3,x2,x1], may include one or more of: The second sequence of length 3 can be, for example, Exp(j*(2 / 6)*pi*i), i=1,3,5.

[0078] In some exemplary embodiments, the index of the OCC sequence from the one or more OCC sequences is rotated based on one or more of the time slot or cell identity for transmission of the SRS signal.

[0079] In example embodiments, the length of the OCC sequence may be determined based on the size of the terminal device's SRS transmit comb, which in some example embodiments may indicate the density of subcarriers occupied by resource elements of the SRS sequence.

[0080] In some exemplary embodiments, when the SRS transmit comb size is 2, the length of the OCC sequence may be determined to be 6. In some exemplary embodiments, when the SRS transmit comb size is 4, the length of the OCC sequence may be determined to be 3. In some exemplary embodiments, when the SRS transmit comb size is 8, the length of the OCC sequence may be determined to be 3.

[0081] 4 shows an example signaling process for SRS enhancement in some embodiments of the present disclosure. For purposes of illustration, process 400 will be described with reference to FIGS. 1 through 3. Process 400 may include terminal equipment 110 and network equipment 120, as shown in FIG. 1. Although process 400 has been described in communication environment 100 of FIG. 1, it will be understood that this process may be equally applicable to other communication scenarios having similar problems.

[0082] In process 400, at 401, terminal device 110 receives sounding reference signal (SRS) configuration information from a network device indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, where the one or more OCC sequences have one or more lengths of length 3 or 6. In some embodiments, the SRS configuration information is included in a field of an SRS resource list.

[0083] The SRS configuration information may include one or more of length information of one or more OCC sequences and OCC sequence start information of one or more OCC sequences. The SRS configuration information may further include offset information of the one or more OCC sequences for a group of antenna ports. The terminal device 110 may use the offset information for a group of antenna ports to determine a sequence from the one or more OCC sequences.

[0084] In some embodiments, the one or more OCC sequences of length 6 are: a first sequence of [1,1,1,1,1,1]; a second sequence of [x1,x2,x3,x4,x5,x6], where x1, x2, x3, x4, x5, and x6 represent six complex numbers corresponding to six equal points on the circumference of a unit circle; The third sequence is [x6,x5,x4,x3,x2,x1], The fourth sequence obtained by multiplying [x2,x3,x4,x5,x6,x1] by [1,-1,1,-1,1,-1], The fifth sequence is an inverted version of the fourth sequence, a sixth sequence of [x,-x,x,-x,x,-x], where x represents a complex number in the unit circle; may include:

[0085] In some embodiments, the one or more OCC sequences of length 3 are: The first sequence is [1,1,1], a second sequence obtained by multiplying [x1, x2, x3], where x1, x2, x3 each represent three complex numbers corresponding to three of the six points equally dividing the circumference of the unit circle; The third sequence of [x3,x2,x1], may include:

[0086] In some embodiments, the length of the OCC sequence may be determined based on the size of the SRS transmit comb of the terminal device. For example, when the SRS transmit comb size is 2, the length of the OCC sequence is determined to be 6, and / or when the SRS transmit comb size is 4, the length of the OCC sequence is determined to be 3, and / or when the SRS transmit comb size is 8, the length of the OCC sequence is determined to be 3. The size of the SRS transmit comb may indicate the density of subcarriers occupied by resource elements of the SRS sequence.

[0087] In process 400, at 402, terminal device 110 may send an acknowledgement message to network device 120. In this way, network device 120 recognizes at 401 that terminal device 110 has been successfully configured with SRS setting information.

[0088] In process 400, at 403, terminal device 110 transmits an SRS signal using an OCC sequence from one or more OCC sequences to network device 120. Terminal device 110 may determine an index of the OCC sequence to use with the SRS signal. In some embodiments, the index of the OCC sequence from the one or more OCC sequences is rotated based on one or more of a time slot index or a cell identity for transmission of the SRS signal. For example, if occIndex indicates an index, it may be determined based on an equation such as: occIndex=mod(occOffset-n6-r18+slotIndex,OCC sequence length) Here, the parameter "occOffset-n6-r18" indicates the above offset information, the parameter "slotIndex" indicates the index of the time slot, and the parameter "OCC sequence length" indicates the length of the OCC sequence, which may be 3 or 6.

[0089] For illustrative purposes, Figures 5A to 6 show some simulation results for the solution proposed here.

[0090] FIG. 5A illustrates the correlation of a baseline SRS sequence without the proposed OCC sequence for a resource length of 306, and FIG. 5B illustrates the correlation of a baseline SRS sequence with the proposed OCC sequence for a resource length of 306. In the simulation, there are 30 base sequences with an 8-cycle shift of the baseline configuration. In particular, in each of FIGS. 5A and 5B, the left graph shows the correlation of the correct code, and the right graph shows the correlation of the incorrect sequence. Simulation results show that when using the proposed OCC sequence of length 6, the sequence space can be significantly increased, for example, by nearly six times, as indicated by the dark areas in the center of the two right graphs in FIGS. 5A and 5B. Meanwhile, the proposed OCC sequence can still maintain good correlation.

[0091] Figures 6A and 6B show the cubic metric (CM) and peak-to-average power ratio (PAPR) of SRS symbols comparing the conventional configuration and the proposed OCC sequence, respectively. In Figures 6A and 6B, the dashed lines represent the conventional configuration, and the solid lines represent the proposed OCC sequence. From Figures 6A and 6B, it can be seen that the proposed solution can achieve comparable CM performance and PAPR while supporting a large number of SRS antenna ports.

[0092] 7 is a simplified block diagram of a device 700 suitable for implementing embodiments of the present disclosure. The device 700 may be provided to implement a communication device such as, for example, the terminal equipment 110 or the network equipment 120 shown in FIG. 1. As shown, the device 700 includes one or more processors 710, one or more memories 740 coupled to the processors 710, and one or more transmitters and / or receivers (TX / RX) 740 coupled to the processors 710.

[0093] The TX / RX 740 is for bidirectional communication. The TX / RX 740 has at least one antenna to facilitate communication. The communication interface can represent any interface required for communication with other network elements.

[0094] The processor 710 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 700 may have multiple processors, such as application-specific integrated circuit chips that are time-slaved to a clock that synchronizes a main processor.

[0095] The memory 720 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) 724, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic and / or optical storage. Examples of volatile memory include, but are not limited to, random access memory (RAM) 722 and other volatile memory that does not persist through power-down periods.

[0096] The computer program 730 includes computer-executable instructions that are executed by the associated processor 710. The program 730 may be stored in ROM 724. The processor 710 may load the program 730 into RAM 722 to perform any suitable operations and processes.

[0097] The embodiments of the present disclosure may be implemented by a program such that device 700 can execute any process of the present disclosure, as described with reference to Figures 2 to 4. The embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0098] 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 memory 720) or other storage device accessible by the device 700. The device 700 may load the program 730 from the computer-readable medium into RAM 722 for execution. The computer-readable medium may include any type of tangible non-volatile storage device, such as ROM, EPROM, Flash memory, hard disk, CD, DVD, etc. Figure 8 shows an example of a computer-readable medium 800 in the form of a CD or DVD. The computer-readable medium stores the program 730.

[0099] In general, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. While some aspects may be implemented in hardware, other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of embodiments of the present disclosure have been illustrated and described using block diagrams, flowcharts, or some other graphical representations, it should be understood that the blocks, 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 device, or some combination thereof, in non-limiting examples.

[0100] 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 on a target real or virtual processor device to perform the method 200, 300, or process 400 described above with reference to FIGS. 2, 3, and 4. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split among program modules as desired in various embodiments. The machine-executable instructions of the program modules may be executed in local or distributed devices. In distributed devices, the program modules may be located in both local and remote storage media.

[0101] Program code for implementing the methods of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a general-purpose computer, a special-purpose computer, or other programmable data processing processor or controller, and when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The program code can run entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0102] In the context of the present disclosure, computer program code or associated data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform various processes and operations, such as, for example, a computer-readable signal.

[0103] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. Computer-readable media include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of computer-readable storage media 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. The term "non-transitory" as used herein refers to the medium itself (i.e., tangible, not a signal), and is distinct from the permanence of data storage (e.g., RAM versus ROM).

[0104] Furthermore, although operations are depicted in a particular order, this should not be understood as requiring such operations to be performed in the particular order depicted, or sequentially, or that all of the depicted operations be performed, to achieve desirable results. Certain multitasking and parallel processing may be preferred. Similarly, while several specific implementation details are included in the above description, these should not be construed as limiting 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.

[0105] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the present disclosure, as 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. A terminal device, at least one processor; at least one memory containing computer program code, said at least one memory and said computer program code being transmitted by said at least one processor to said terminal device; receiving, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; transmitting an SRS signal to the network device using an OCC sequence from the one or more OCC sequences; at least one memory configured to execute A terminal device comprising:

2. The terminal device of claim 1 , wherein the SRS configuration information includes one or more of length information of the one or more OCC sequences and OCC sequence start information of the one or more OCC sequences.

3. The terminal device according to claim 1 or 2, wherein the SRS configuration information is included in a field of an SRS resource list.

4. 4. The terminal device according to claim 1, wherein the SRS configuration information includes offset information for the one or more OCC sequences of an antenna port group, and the OCC sequence from the one or more OCC sequences is determined based on the offset information for the antenna port group.

5. The one or more OCC sequences of length 6 are A first sequence of [1,1,1,1,1,1,1], a second sequence of [x1, x2, x3, x4, x5, x6], where x1, x2, x3, x4, x5, x6 represent six complex numbers corresponding to six equal points on the circumference of the unit circle; a third sequence of [x6, x5, x4, x3, x2, x1], a fourth sequence obtained by multiplying [x2, x3, x4, x5, x6, x1] by [1, −1, 1, −1, 1, −1]; a fifth sequence, an inverted version of the fourth sequence; a sixth sequence of [x, -x, x, -x, x, -x], where x represents a complex number in the unit circle; 5. A terminal device according to claim 1, comprising one or more of:

6. The one or more OCC sequences of length 3 are The first sequence of [1,1,1], a second sequence obtained by multiplying [x1, x2, x3], where x1, x2, x3 each represent three complex numbers corresponding to three of the six points equally dividing the circumference of the unit circle; a third sequence of [x3, x2, x1], 6. A terminal device according to claim 1, comprising one or more of:

7. 7. The terminal device according to claim 1, wherein an index of the OCC sequence from the one or more OCC sequences is rotated based on one or more of an index of a time slot for transmission of the SRS signal or a cell identity.

8. The terminal device according to claim 1 , wherein the length of the OCC sequence is determined based on a size of an SRS transmission comb of the terminal device.

9. When the size of the SRS transmission comb is 2, the length of the OCC sequence is determined to be 6; and / or When the size of the SRS transmission comb is 4, the length of the OCC sequence is determined to be 3; and / or When the size of the SRS transmit comb is 8, the length of the OCC sequence is determined to be 3. The terminal device according to claim 8.

10. The terminal device according to claim 8 , wherein the size of the SRS transmission comb indicates a density of subcarriers occupied by resource elements of the SRS sequence.

11. A network device, at least one processor; at least one memory containing computer program code, said at least one memory and said computer program code being transmitted by said at least one processor to said network device; transmitting, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; receiving an SRS signal from the terminal device using an OCC sequence from the one or more OCC sequences; at least one memory configured to execute A network device comprising:

12. The network equipment of claim 11 , wherein the SRS configuration information includes one or more of length information of the one or more OCC sequences and OCC sequence start information of the one or more OCC sequences.

13. The network device according to claim 11 or 12, wherein the SRS configuration information is included in a field of an SRS resource list.

14. 14. The network device according to claim 11, wherein the SRS configuration information includes offset information for the one or more OCC sequences of an antenna port group, and the OCC sequence from the one or more OCC sequences is determined based on the offset information of the antenna port group.

15. The one or more OCC sequences of length 6 are A first sequence of [1,1,1,1,1,1,1], a second sequence of [x1, x2, x3, x4, x5, x6], where x1, x2, x3, x4, x5, x6 respectively represent six complex numbers corresponding to six equal points on the circumference of the unit circle; a third sequence of [x6, x5, x4, x3, x2, x1], a fourth sequence obtained by multiplying [x2, x3, x4, x5, x6, x1] by [1, −1, 1, −1, 1, −1]; a fifth sequence, an inverted version of the fourth sequence; a sixth sequence of [x, -x, x, -x, x, -x], where x represents a complex number in the unit circle; 15. A network device according to claim 11, comprising one or more of:

16. The one or more OCC sequences of length 3 are The first sequence of [1,1,1], a second sequence obtained by multiplying [x1, x2, x3], where x1, x2, x3 each represent three complex numbers corresponding to three of the six points equally dividing the circumference of the unit circle; a third sequence of [x3, x2, x1], 16. A network device according to any one of claims 11 to 15, comprising one or more of:

17. 17. The network equipment of claim 11, wherein an index of the OCC sequence from the one or more OCC sequences is rotated based on one or more of a time slot for transmission of the SRS signal or a cell identity.

18. 18. The network equipment of claim 11, wherein the length of the OCC sequence is determined based on a size of an SRS transmission comb of the terminal equipment.

19. When the size of the SRS transmission comb is 2, the length of the OCC sequence is determined to be 6; and / or When the size of the SRS transmission comb is 4, the length of the OCC sequence is determined to be 3; and / or When the size of the SRS transmit comb is 8, the length of the OCC sequence is determined to be 3.

20. The network device of claim 18.

20. 20. The network equipment of claim 18, wherein the size of the SRS transmission comb indicates a density of subcarriers occupied by resource elements of the SRS sequence.

21. A method in a terminal device, comprising: receiving, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; transmitting an SRS signal to the network device using an OCC sequence from the one or more OCC sequences; A method comprising:

22. 22. The method of claim 21, wherein the SRS configuration information includes one or more of length information of the one or more OCC sequences and OCC sequence start information of the one or more OCC sequences.

23. The method of claim 21 or 22, wherein the SRS configuration information is included in a field of an SRS resource list.

24. 24. The method of claim 21, wherein the SRS configuration information includes offset information for the one or more OCC sequences of an antenna port group, and the OCC sequence from the one or more OCC sequences is determined based on the offset information of the antenna port group.

25. The one or more OCC sequences of length 6 are A first sequence of [1,1,1,1,1,1,1], a second sequence of [x1, x2, x3, x4, x5, x6], where x1, x2, x3, x4, x5, x6 represent six complex numbers corresponding to six equal points on the circumference of the unit circle; a third sequence of [x6, x5, x4, x3, x2, x1], a fourth sequence obtained by multiplying [x2, x3, x4, x5, x6, x1] by [1, −1, 1, −1, 1, −1]; a fifth sequence, which is an inverted version of the fourth sequence; a sixth sequence of [x, -x, x, -x, x, -x], where x represents a complex number in the unit circle; 25. The method of any of claims 21 to 24, comprising one or more of:

26. The one or more OCC sequences of length 3 are The first sequence of [1,1,1], a second sequence obtained by multiplying [x1, x2, x3], where x1, x2, x3 each represent three complex numbers corresponding to three of the six points equally dividing the circumference of the unit circle; a third sequence of [x3, x2, x1], 26. The method of any of claims 21 to 25, comprising one or more of:

27. 27. The method of claim 21, wherein an index of the OCC sequence from the one or more OCC sequences is rotated based on one or more of an index of a time slot for transmission of the SRS signal, or a cell identity.

28. 28. The method of claim 21, wherein the length of the OCC sequence is determined based on a size of an SRS transmit comb of the terminal device.

29. When the size of the SRS transmission comb is 2, the length of the OCC sequence is determined to be 6; and / or When the size of the SRS transmission comb is 4, the length of the OCC sequence is determined to be 3; and / or When the size of the SRS transmit comb is 8, the length of the OCC sequence is determined to be 3.

29. The method of claim 28.

30. 30. The method of claim 28, wherein the size of the SRS transmit comb indicates a density of subcarriers occupied by resource elements of the SRS sequence.

31. 1. A method in a network device, comprising: transmitting, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; receiving an SRS signal from the terminal device using an OCC sequence from the one or more OCC sequences; A method comprising:

32. 32. The method of claim 31 , wherein the SRS configuration information includes one or more of length information of the one or more OCC sequences and OCC sequence start information of the one or more OCC sequences.

33. 33. The method of claim 31 or 32, wherein the SRS configuration information is included in a field of an SRS resource list.

34. 34. The method of claim 31, wherein the SRS configuration information includes offset information for the one or more OCC sequences of a group of antenna ports, and the OCC sequence from the one or more OCC sequences is determined based on the offset information of the group of antenna ports.

35. The one or more OCC sequences of length 6 are A first sequence of [1,1,1,1,1,1,1], a second sequence of [x1, x2, x3, x4, x5, x6], where x1, x2, x3, x4, x5, x6 represent six complex numbers corresponding to six equal points on the circumference of the unit circle; a third sequence of [x6, x5, x4, x3, x2, x1], a fourth sequence obtained by multiplying [x2, x3, x4, x5, x6, x1] by [1, −1, 1, −1, 1, −1]; a fifth sequence, which is an inverted version of the fourth sequence; a sixth sequence of [x, -x, x, -x, x, -x], where x represents a complex number in the unit circle; 35. The method of any of claims 31 to 34, comprising one or more of:

36. The one or more OCC sequences of length 3 are The first sequence of [1,1,1], a second sequence obtained by multiplying [x1, x2, x3], where x1, x2, x3 each represent three complex numbers corresponding to three of the six points equally dividing the circumference of the unit circle; a third sequence of [x3, x2, x1], 36. The method of any of claims 31 to 35, comprising one or more of:

37. 37. The method of claim 31, wherein an index of the OCC sequence from the one or more OCC sequences is rotated based on one or more of a time slot for transmission of the SRS signal or a cell identity.

38. 38. The method of claim 31, wherein the length of the OCC sequence is determined based on a size of an SRS transmit comb of the terminal device.

39. When the size of the SRS transmission comb is 2, the length of the OCC sequence is determined to be 6; and / or When the size of the SRS transmission comb is 4, the length of the OCC sequence is determined to be 3; and / or When the size of the SRS transmit comb is 8, the length of the OCC sequence is determined to be 3.

39. The method of claim 38.

40. 39. The method of claim 38, wherein the size of the SRS transmit comb indicates a density of subcarriers occupied by resource elements of the SRS sequence.

41. A terminal device, comprising: means for receiving, from a network device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; means for transmitting an SRS signal to the network equipment using an OCC sequence from the one or more OCC sequences; An apparatus comprising:

42. A network equipment device, means for transmitting, to a terminal device, sounding reference signal (SRS) configuration information indicating one or more orthogonal cover code (OCC) sequences in the frequency domain, the one or more OCC sequences having one or more lengths of length 3 or length 6; means for receiving an SRS signal from the terminal device using an OCC sequence from the one or more OCC sequences; An apparatus comprising:

43. A non-transitory computer readable medium containing program instructions for causing an apparatus to perform the method of any of claims 21 to 40.

Images