Reference signals for MIMO

Abstract

Provided are a wireless communication method and related products. The method includes: transmitting a first sequence over at least one first antenna port; and transmitting a second sequence over at least one second antenna port; where the first sequence and the second sequence are used for measuring a channel with a first bandwidth, a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence. A length of a sequence transmitted on a symbol is thus not limited by a fixed length of the symbol any more, in other words, a sequence length is decoupled from a symbol length. Since the introduction of the second sequence with a length smaller than that of the first sequence, a total number of resource elements occupied by the first sequence and the second sequence is decreased.

Description

REFERENCE SIGNALS FOR MIMOTECHNICAL FIELD

[0001] The present application relates to the field of communication technologies, and in particular, to a wireless communication method and related products.BACKGROUND

[0002] In multiple-input multiple-output (MIMO) systems, a receiving device, for example, a network device or a terminal, can perform channel estimation based on reference signals, and then restore data signals transmitted through data channels based on the channel estimation. Therefore, reference signal allocation is essential for MIMO systems.

[0003] The amount of resources in time and frequency required for the channel estimation is called channel estimation overhead (or simply overhead). The overhead is measured in Resource Elements (REs). There is a tradeoff between accuracy and overhead of the channel estimation. Too high overhead will yield good channel estimation, but few REs will be left for data transmission, thus the capacity will be low. Too small overhead will leave a lot of REs for data transmission, but the channel estimation will be poor, thus again leading to low capacity.

[0004] This background information is provided to reveal information believed by the applicant to be of possible relevance to the present application. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present application.SUMMARY

[0005] In a first aspect, a wireless communication method is provided by the present disclosure, and the method includes: transmitting a first sequence over at least one first antenna port; and transmitting a second sequence over at least one second antenna port; where the first sequence and the second sequence are used for measuring a channel with a first bandwidth, a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence.

[0006] A length of a sequence refers to a total number of resource elements occupied by the sequence on a certain symbol, since the length of the second sequence is smaller than the length of the first sequence, a total number of resource elements occupied by the second sequence is less than a total number of resource elements occupied by the first sequence. Therefore, when a channel with a first bandwidth is measured based on the first sequence and the second sequence, since the introduction of the second sequence with a length smaller than that of the first sequence, a total number of resource elements occupied by the first sequence and the second sequence is decreased. The first sequence and the second sequence correspond to reference signals of the same type, and the reference signals are used for channel estimation, hence, channel estimation overhead is reduced, and more resources can be used for data transmission.

[0007] In a possible implementation of the first aspect, the first sequence is transmitted over a first frequencydomain resource, and the first frequency domain resource includes at least two first frequency domain units; the second sequence is transmitted over a second frequency domain resource, and the second frequency domain resource includes at least two second frequency domain units.

[0008] In a possible implementation of the first aspect, the at least two first frequency domain units of the first frequency domain resource are spaced apart by a first frequency domain interval.

[0009] In a possible implementation of the first aspect, each of the at least two first frequency domain units includes one resource element.

[0010] In frequency domain, reference signals corresponding to the first sequence can be allocated in a comblike structure, and the first frequency domain interval may be the parameter comb of the comb-like structure.

[0011] In a possible implementation of the first aspect, the at least two second frequency domain units of the second frequency domain resource are spaced apart by a second frequency domain interval.

[0012] In a possible implementation of the first aspect, each of the at least two second frequency domain units includes one resource element, and the second frequency domain interval is greater than the first frequency domain interval.

[0013] Reference signals corresponding to the second sequence can be allocated in the same way as reference signals corresponding to the first sequence, for example, reference signals corresponding to the first sequence and the second sequence may both be allocated in a comb-like structure, but the second frequency domain interval corresponding to the second sequence is greater than the first frequency domain interval corresponding to the first sequence, hence, when a channel with a first bandwidth is measured, a total number of resource elements occupied by the first sequence and the second sequence is decreased, i.e., channel estimation overhead is reduced with a simple but effective approach.

[0014] In a possible implementation of the first aspect, at least one of the at least two second frequency domain units includes multiple resource elements, and the multiple resource elements in the at least one of the at least two second frequency domain units are spaced apart by a third frequency domain interval.

[0015] Reference signals corresponding to the second sequence can be allocated with multiple resource elements as a whole in one second frequency domain unit, and the multiple resource elements are spaced apart by a third frequency domain interval, since the second frequency domain units of the second frequency domain resource are spaced apart by the second frequency domain interval, that is, there is already a distance between the second frequency domain units, the foregoing mentioned advantages of introduction of a sequence with a smaller length also apply here, the channel estimation overhead is thus reduced.

[0016] In a possible implementation of the first aspect, the third frequency domain interval is equal to the first frequency domain interval.

[0017] In a second frequency domain unit including multiple resource elements, reference signals corresponding to the second sequence can be configured in the same way as reference signals corresponding to the first sequence with the same parameter.

[0018] In a possible implementation of the first aspect, at least one of the at least two second frequency domain units includes multiple resource elements, and the multiple resource elements in the at least one of the at least two second frequency domain units are continuous.

[0019] There can even be no frequency domain interval in some or all of the second frequency domain units including multiple resource elements, since there is already a second frequency domain interval between the second frequency domain units.

[0020] In a possible implementation of the first aspect, at least one of the at least two second frequency domain units includes multiple resource elements, a location of the first frequency domain resource is determined based a first frequency domain interval and a first offset, a location of the second frequency domain resource is determinedbased on the second frequency domain interval and a second offset, where the second offset is associated with an identification of the at least one second antenna port.

[0021] The second offset is associated with an identification of the at least one second antenna port, antennas / ports of different UEs can be multiplexed in such way, this makes the indication of the frequency hopping for the RSs much easier.

[0022] In a possible implementation of the first aspect, the transmitting the first sequence over the at least one first antenna port includes: transmitting the first sequence over the at least one first antenna port on a first time domain unit; the transmitting the second sequence over the at least one second antenna port includes: transmitting the second sequence over the at least one second antenna port on a second time domain unit.

[0023] Reference signals corresponding to the first sequence and the second sequence are transmitted on different symbols in a slot.

[0024] In a possible implementation of the first aspect, the method further includes: transmitting a third sequence over the at least one second antenna port on a third time domain unit, where a length of the third sequence is equal to a length of the second sequence.

[0025] Reference signals corresponding to the third sequence are transmitted on a symbol different from the aforementioned symbols carrying RSs corresponding to the first and second sequences, and the reference signals corresponding to the third sequence and the second sequence may be reference signals transmitted in the same structure.

[0026] In a possible implementation of the first aspect, the third sequence is transmitted over a third frequency domain resource, and the third frequency domain resource includes at least two third frequency domain units, where the second frequency domain resource and the third frequency domain resource are non-continuous.

[0027] For the reference signals corresponding to the third sequence and the second sequence, it is not necessary to hop over the entire bandwidth, less channel measurements are performed, and channel estimation overhead is thus reduced.

[0028] In a possible implementation of the first aspect, the method further includes: obtaining a first correspondence between the first sequence and the at least one first antenna port, and a second correspondence between the second sequence and the at least one second antenna port.

[0029] In a possible implementation of the first aspect, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are sounding reference signals (SRSs); or, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are demodulation reference signals (DMRS).

[0030] In a possible implementation of the first aspect, the method further includes: obtaining indication information, where the indication information is indicative of a resource available for the second sequence in a first resource, and the first resource is a resource allocated to a terminal device and used for transmitting data of the terminal device.

[0031] Reference signals and data share the first resource, where a second resource can be obtained through excluding a resource available for the reference signals from the first resource, and the second resource can be used for data transmission. This can increase the capacity of the MIMO systems.

[0032] In a possible implementation of the first aspect, the indication information is carried in at least one of MAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC).

[0033] In a possible implementation of the first aspect, both of the first sequence and the second sequence are transmitted over a downlink channel or an uplink channel.

[0034] In a possible implementation of the first aspect, a bandwidth corresponding to the first frequency domain resource is not greater than the first bandwidth, and a bandwidth corresponding to the second frequency domainresource is not greater than the first bandwidth.

[0035] In a second aspect, a wireless communication method is provided by the present disclosure, and the method includes: receiving a first sequence and a second sequence, where a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence; and obtaining a measuring result of a channel with a first bandwidth based on the first sequence and the second sequence.

[0036] During channel estimation, since the introduction of the second sequence with a length smaller than that of the first sequence, a total number of resource elements occupied by the first sequence and the second sequence is decreased, hence, channel estimation overhead is reduced, and more resources can be used for data transmission.

[0037] In a possible implementation of the second aspect, the first sequence is received over a first frequency domain resource, and the first frequency domain resource includes at least two first frequency domain units; the second sequence is received over a second frequency domain resource, and the second frequency domain resource includes at least two second frequency domain units.

[0038] In a possible implementation of the second aspect, the receiving the first sequence first sequence and the second sequence includes: receiving the first sequence on a first time domain unit; and receiving the second sequence on a second time domain unit.

[0039] In a possible implementation ofthe second aspect, the method further includes: receiving a third sequence over the at least one second antenna port on a third time domain unit, where a length of the third sequence is equal to a length of the second sequence.

[0040] In a possible implementation of the second aspect, the third sequence is received over a third frequency domain resource, and the third frequency domain resource includes at least two third frequency domain units; where the second frequency domain resource and the third frequency domain resource are non-continuous.

[0041] In a possible implementation of the second aspect, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are sounding reference signals (SRSs); or, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are demodulation reference signals (DMRS).

[0042] In a possible implementation of the second aspect, the method further includes: transmitting indication information, where the indication information is indicative of a resource available for the second sequence in a first resource, and the first resource is a resource allocated to a terminal device and used for transmitting data of the terminal device.

[0043] Reference signals and data share the first resource, where a second resource can be obtained through excluding a resource available for the reference signals from the first resource, and the second resource can be used for data transmission. This can increase the capacity of the MIMO systems.

[0044] In a possible implementation of the second aspect, the indication information is carried in at least one ofMAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC).

[0045] In a third aspect, a wireless communication apparatus is provided by the present disclosure, and the apparatus includes various modules configured to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect.

[0046] In a fourth aspect, a wireless communication apparatus is provided by the present disclosure, and the apparatus includes various modules configured to execute the wireless communication method according to the second aspect or any possible implementation of the second aspect.

[0047] In a fifth aspect, a wireless communication apparatus is provided by the present disclosure, and theapparatus includes at least one processor, where the at least one processor is configured to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0048] In a possible implementation of the fifth aspect, the above apparatus may further include a memory, and the memory stores instructions that cause the at least one processor to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0049] In a sixth aspect, a wireless communication apparatus is provided by the present disclosure, and the apparatus is configured to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0050] In a seventh aspect, a transmitting end is provided by the present disclosure, and the transmitting end includes processing circuitry for executing the wireless communication method according to the first aspect or any possible implementation of the first aspect.

[0051] In an eighth aspect, a receiving end is provided by the present disclosure, and the receiving end includes processing circuitry for executing the wireless communication method according to the second aspect or any possible implementation of the second aspect.

[0052] In a ninth aspect, a wireless communication system is provided by the present disclosure, and the wireless communication system includes the transmitting end according to the fifth aspect and the receiving end according to the sixth aspect.

[0053] In a tenth aspect, a chip is provided by the present disclosure, and the chip includes an input / output (I / O) interface and a processor, where the processor is configured to call and run computer execution instructions stored in a memory, to enable a device installing with the chip to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0054] In an eleventh aspect, a computer-readable medium is provided by the present disclosure, and the computer-readable medium includes storing computer execution instructions which, when executed by a processor, causes the processor to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0055] In a twelfth aspect, a computer program product is provided by the present disclosure, and the computer program product includes computer execution instructions which, when executed by a processor, causes the processor to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0056] A wireless communication method and related products are provided by the present disclosure. A transmitting end transmits a first sequence over at least one first antenna port, and transmits a second sequence over at least one second antenna port, a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence. A receiving end receives the first sequence and the second sequence, and obtains a measuring result of a channel with a first bandwidth based on the first sequence and the second sequence. Since the introduction of the second sequence with a length smaller than that of the first sequence, a total number of resource elements occupied by the first sequence and the second sequence is decreased, hence, channel estimation overhead is reduced, and more resources can be used for data transmission.BRIEF DESCRIPTION OF DRAWINGS

[0057] The accompanying drawings are used to provide a further understanding of the present disclosure, constitute a part of the specification, and are used to explain the present disclosure together with the following specific embodiments, but should not be construed as limiting the present disclosure.

[0058] FIG. 1 is a schematic illustration of a communication system according to one or more embodiments of the present disclosure.

[0059] FIG. 2 is another schematic illustration of a communication system according to one or more embodiments of the present disclosure.

[0060] FIG. 3 is a schematic illustration of basic component structure of a communication system according to one or more embodiments of the present disclosure.

[0061] FIG. 4 illustrates a block diagram of a device in a communication system according to one or more embodiments of the present disclosure.

[0062] FIG. 5 is a schematic illustration of parameters for wideband reference signals according to one or more embodiments of the present disclosure.

[0063] FIG. 6 is a schematic illustration of channel estimation according to one or more embodiments of the present disclosure.

[0064] FIG. 7 is a schematic illustration of the scenario of channel estimation according to one or more embodiments of the present disclosure.

[0065] FIG. 8 is a flowchart of a wireless communication method according to an embodiment of the present disclosure.

[0066] FIG. 9 is a flowchart of another wireless communication method according to an embodiment of the present disclosure.

[0067] FIG. 10 is a schematic illustration of slab sampled and fiber sampled tensor completion according to one or more embodiments of the present disclosure.

[0068] FIG. 11 is a schematic illustration of splitting channel measurements into two subtensors according to one or more embodiments of the present disclosure.

[0069] FIG. 12 is a schematic illustration of reshaping subtensor-2 into a matrix according to one or more embodiments of the present disclosure.

[0070] FIG. 13 is a schematic illustration of performing tensor train decomposition of subtensor- 1 according to one or more embodiments of the present disclosure.

[0071] FIG. 14 is a schematic illustration of reshaping half of tensor train decomposition into a matrix according to one or more embodiments of the present disclosure.

[0072] FIG. 15 is a schematic illustration of extracting a submatrix from a matrix of tensor train decompositon according to one or more embodiments of the present disclosure.

[0073] FIG. 16 is a schematic illustration of forming and solving a linear system according to one or more embodiments of the present disclosure.

[0074] FIG. 17 is a schematic illustration of recovering full channel tensor according to one or more embodiments of the present disclosure.

[0075] FIG. 18 is a schematic illustration of reference signal allocation according to one or more embodiments of the present disclosure.

[0076] FIG. 19 is another schematic illustration of reference signal allocation according to one or more embodiments of the present disclosure.

[0077] FIG. 20 is a schematic illustration of frequency hopping for reference signals according to one or moreembodiments of the present disclosure.

[0078] FIG. 21A is another schematic illustration of channel estimation according to one or more embodiments of the present disclosure.

[0079] FIG. 21B is a schematic illustration of hopping parameters according to one or more embodiments of the present disclosure.

[0080] FIG. 22 is still another schematic illustration of channel estimation according to one or more embodiments of the present disclosure.

[0081] FIG. 23 is still a schematic illustration of resource allocation according to one or more embodiments of the present disclosure.

[0082] FIG. 24 is a block diagram of a wireless communication apparatus according to one or more embodiments of the present disclosure.

[0083] FIG. 25 is a block diagram of another wireless communication apparatus according to one or more embodiments of the present disclosure.

[0084] FIG. 26 is a schematic structural diagram of a wireless communication apparatus according to one or more embodiments of the present disclosure.DESCRIPTION OF EMBODIMENTS

[0085] In the following description, reference is made to the accompanying figures, which form part of the present disclosure, and which show, by way of illustration, specific aspects of embodiments of the present disclosure or specific aspects in which embodiments of the present disclosure may be used. It is understood that embodiments of the present disclosure may be used in other aspects and include structural or logical changes not depicted in the figures. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.

[0086] To assist in understanding the present disclosure, examples of wireless communication systems and devices are described below.

[0087] Example communication systems and devices

[0088] Referring to FIG. 1, as an illustrative example without limitation, a simplified schematic illustration of a communication system is provided. The communication system 100 includes a radio access network 120. The radio access network 120 may be a next generation (e.g., sixth generation (6G) or later) radio access network, or a legacy (e.g., 5G, 4G, 3G or 2G) radio access network. One or more communication electric device (ED) HOa-llOj (generically referred to as 110) may be interconnected to one another or connected to one or more network nodes (170a, 170b, generically referred to as 170) in the radio access network 120. A core network 130 may be a part of the communication system and may be dependent or independent of the radio access technology used in the communication system 100. Also, the communication system 100 includes a public switched telephone network (PSTN) 140, the internet 150, and other networks 160.

[0089] FIG. 2 illustrates an example communication system 100. In general, the communication system 100 enables multiple wireless or wired elements to communicate data and other content. The purpose of the communication system 100 may be to provide content, such as voice, data, video, and / or text, via broadcast, multicast and unicast, etc. The communication system 100 may operate by sharing resources, such as carrier spectrum bandwidth, between its constituent elements. The communication system 100 may include a terrestrial communication system and / or a non-terrestrial communication system. The communication system 100 may provide a wide range of communication services and applications (such as earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous delivery and mobility, etc.). The communication system 100may provide a high degree of availability and robustness through a joint operation of the terrestrial communication system and the non-terrestrial communication system. For example, integrating a non-terrestrial communication system (or components thereof) into a terrestrial communication system can result in what may be considered a heterogeneous network including multiple layers. Compared to conventional communication networks, the heterogeneous network may achieve better overall performance through efficient multi-link joint operation, more flexible functionality sharing, and faster physical layer link switching between terrestrial networks and non-terrestrial networks.

[0090] The terrestrial communication system and the non-terrestrial communication system could be considered sub-systems of the communication system. In the example shown, the communication system 100 includes electronic devices (ED) llOa-HOd (generically referred to as ED 110), radio access networks (RANs) 120a-120b, nonterrestrial communication network 120c, a core network 130, a public switched telephone network (PSTN) 140, the internet 150, and other networks 160. The RANs 120a-120b include respective base stations (BSs) 170a- 170b, which may be generically referred to as terrestrial transmit and receive points (T-TRPs) 170a-170b. The non-terrestrial communication network 120c includes an access node 120c, which may be generically referred to as a non-terrestrial transmit and receive point (NT-TRP) 172.

[0091] Any ED 110 may be alternatively or additionally configured to interface, access, or communicate with any other T-TRP 170a-170b and NT-TRP 172, the internet 150, the core network 130, the PSTN 140, the other networks 160, or any combination of the preceding. In some examples, ED 110a may communicate an uplink and / or downlink transmission over an interface 190a with T-TRP 170a. In some examples, the EDs 110a, 110b, 110c and 1 lOd may also communicate directly with one another via one or more sidelink air interfaces 190b. In some examples, ED HOd may communicate an uplink and / or downlink transmission over an interface 190c with NT-TRP 172.

[0092] The air interfaces 190a and 190b may use similar communication technology, such as any suitable radio access technology. For example, the communication system 100 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single-carrier FDMA (SC-FDMA) in the air interfaces 190a and 190b. The air interfaces 190a and 190b may utilize other higher dimension signal spaces, which may involve a combination of orthogonal and / or non-orthogonal dimensions.

[0093] The air interface 190c can enable communication between the ED HOd and one or multiple NT-TRPs 172 via a wireless link or simply a link. In some examples, the link is a dedicated connection for unicast transmission, a connection for broadcast transmission, or a connection between a group of EDs and one or multiple NT-TRPs for multicast transmission.

[0094] The RANs 120a and 120b are in communication with the core network 130 to provide the EDs 110a 110b, and 110c with various services such as voice, data, and other services. The RANs 120a and 120b and / or the core network 130 may be in direct or indirect communication with one or more other RANs (not shown), which may or may not be directly served by core network 130, and may or may not employ the same radio access technology as RAN 120a, RAN 120b or both. The core network 130 may also serve as a gateway access between (i) the RANs 120a and 120b or EDs 110a 110b, and 110c or both, and (ii) other networks (such as the PSTN 140, the internet 150, and the other networks 160). In addition, some or all of the EDs 110a 110b, and 110c may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies and / or protocols. Instead of wireless communication (or in addition thereto), the EDs 110a 110b, and 110c may communicate via wired communication channels to a service provider or switch (not shown), and to the internet 150. PSTN 140 may include circuit switched telephone networks for providing plain old telephone service (POTS). Internet 150 may include a network of computers and subnets (intranets) or both, and incorporate protocols, such as Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP). EDs 110a 110b, and110c may be multimode devices capable of operation according to multiple radio access technologies, and incorporate multiple transceivers necessary to support such.

[0095] Basic component structure

[0096] FIG. 3 illustrates another example of an ED 110 and a base station 170a, 170b and / or 170c. The ED 110 is used to connect persons, objects, machines, etc. The ED 110 may be widely used in various scenarios, for example, cellular communications, device-to-device (D2D), vehicle to everything (V2X), peer-to-peer (P2P), machine-to- machine (M2M), machine-type communications (MTC), internet of things (IOT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility, etc.

[0097] Each ED 110 represents any suitable end user device for wireless operation and may include such devices (or may be referred to) as a user equipment / device (UE), a wireless transmit / receive unit (WTRU), a mobile station, a fixed or mobile subscriber unit, a cellular telephone, a station (STA), a machine type communication (MTC) device, a personal digital assistant (PDA), a smartphone, a laptop, a computer, a tablet, a wireless sensor, a consumer electronics device, a smart book, a vehicle, a car, a truck, a bus, a train, or an loT device, an industrial device, or apparatus (e.g. communication module, modem, or chip) in the forgoing devices, among other possibilities. Future generation EDs 110 may be referred to using other terms. The base station 170a and 170b is a T-TRP and will hereafter be referred to as T-TRP 170. Also shown in FIG. 3, a NT-TRP will hereafter be referred to as NT-TRP 172. Each ED 110 connected to T-TRP 170 and / or NT-TRP 172 can be dynamically or semi-statically tumed-on (i.e., established, activated, or enabled), turned-off (i.e., released, deactivated, or disabled) and / or configured in response to one of more of: connection availability and connection necessity.

[0098] The ED 110 includes a transmitter 201 and a receiver 203 coupled to one or more antennas 204. Only one antenna 204 is illustrated. One, some, or all of the antennas may alternatively be panels. The transmitter 201 and the receiver 203 may be integrated, e.g. as a transceiver. The transceiver is configured to modulate data or other content for transmission by at least one antenna 204 or network interface controller (NIC). The transceiver is also configured to demodulate data or other content received by the at least one antenna 204. Each transceiver includes any suitable structure for generating signals for wireless or wired transmission and / or processing signals received wirelessly or by wire. Each antenna 204 includes any suitable structure for transmitting and / or receiving wireless or wired signals.

[0099] The ED 110 includes at least one memory 208. The memory 208 stores instructions and data used, generated, or collected by the ED 110. For example, the memory 208 could store software instructions or modules configured to implement some or all of the functionality and / or embodiments described herein and that are executed by the processing unit(s) 210. Each memory 208 includes any suitable volatile and / or non-volatile storage and retrieval device(s). Any suitable type of memory may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disc, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, on-processor cache, and the like.

[0100] The ED 110 may further include one or more input / output devices (not shown) or interfaces (such as a wired interface to the internet 150 in FIG. 1). The input / output devices permit interaction with a user or other devices in the network. Each input / output device includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communications.

[0101] The ED 110 further includes a processor 210 for performing operations including those related to preparing a transmission for uplink transmission to the NT-TRP 172 and / or T-TRP 170, those related to processing downlink transmissions received from the NT-TRP 172 and / or T-TRP 170, and those related to processing sidelinktransmission to and from another ED 110. Processing operations related to preparing a transmission for uplink transmission may include operations such as encoding, modulating, transmit beamforming, and generating symbols for transmission. Processing operations related to processing downlink transmissions may include operations such as receive beamforming, demodulating and decoding received symbols. Depending upon the embodiment, a downlink transmission may be received by the receiver 203, possibly using receive beamforming, and the processor 210 may extract signaling from the downlink transmission (e.g. by detecting and / or decoding the signaling). An example of signaling may be a reference signal transmitted by NT-TRP 172 and / or T-TRP 170. In some embodiments, the processor 276 implements the transmit beamforming and / or receive beamforming based on the indication of beam direction, e.g. beam angle information (BAI), received from T-TRP 170. In some embodiments, the processor 210 may perform operations relating to network access (e.g. initial access) and / or downlink synchronization, such as operations relating to detecting a synchronization sequence, decoding and obtaining the system information, etc. In some embodiments, the processor 210 may perform channel estimation, e.g. using a reference signal received from the NT-TRP 172 and / or T-TRP 170.

[0102] Although not illustrated, the processor 210 may form part of the transmitter 201 and / or receiver 203. Although not illustrated, the memory 208 may form part of the processor 210.

[0103] The processor 210, and the processing components of the transmitter 201 and receiver 203 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory (e.g. in memory 208). Alternatively, some or all of the processor 210, and the processing components of the transmitter 201 and receiver 203 may be implemented using dedicated circuitry, such as a programmed field- programmable gate array (FPGA), a graphical processing unit (GPU), or an application-specific integrated circuit (ASIC).

[0104] The T-TRP 170 may be known by other names in some implementations, such as a base station, a base transceiver station (BTS), a radio base station, a network node, a network device, a device on the network side, a transmit / receive node, a Node B, an evolved NodeB (eNodeB or eNB), a Home eNodeB, a next Generation NodeB (gNB), a transmission point (TP) ), a site controller, an access point (AP), or a wireless router, a relay station, a remote radio head, a terrestrial node, a terrestrial network device, or a terrestrial base station, base band unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distribute unit (DU), positioning node, among other possibilities. The T-TRP 170 may be macro BSs, pico BSs, relay node, donor node, or the like, or combinations thereof. The T-TRP 170 may refer to the forging devices or apparatus (e.g. communication module, modem, or chip) in the forgoing devices.

[0105] In some embodiments, the parts of the T-TRP 170 may be distributed. For example, some of the modules of the T-TRP 170 may be located remote from the equipment housing the antennas of the T-TRP 170, and may be coupled to the equipment housing the antennas over a communication link (not shown) sometimes known as front haul, such as common public radio interface (CPRI). Therefore, in some embodiments, the term T-TRP 170 may also refer to modules on the network side that perform processing operations, such as determining the location of the ED 110, resource allocation (scheduling), message generation, and encoding / decoding, and that are not necessarily part of the equipment housing the antennas of the T-TRP 170. The modules may also be coupled to other T-TRPs. In some embodiments, the T-TRP 170 may actually be a plurality of T-TRPs that are operating together to serve the ED 110, e.g. through coordinated multipoint transmissions.

[0106] The T-TRP 170 includes at least one transmitter 252 and at least one receiver 254 coupled to one or more antennas 256. Only one antenna 256 is illustrated. One, some, or all of the antennas may alternatively be panels. The transmitter 252 and the receiver 254 may be integrated as a transceiver. The T-TRP 170 further includes a processor 260 for performing operations including those related to: preparing a transmission for downlink transmission to the ED 110, processing an uplink transmission received from the ED 110, preparing a transmission for backhaultransmission to NT-TRP 172, and processing a transmission received over backhaul from the NT-TRP 172. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as encoding, modulating, precoding (e.g. MIMO precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to processing received transmissions in the uplink or over backhaul may include operations such as receive beamforming, and demodulating and decoding received symbols. The processor 260 may also perform operations relating to network access (e.g. initial access) and / or downlink synchronization, such as generating the content of synchronization signal blocks (SSBs), generating the system information, etc. In some embodiments, the processor 260 also generates the indication of beam direction, e.g. BAI, which may be scheduled for transmission by scheduler 253. The processor 260 performs other network-side processing operations described herein, such as determining the location ofthe ED UO, determining where to deploy NT-TRP 172, etc. In some embodiments, the processor 260 may generate signaling, e.g. to configure one or more parameters of the ED 110 and / or one or more parameters of the NT-TRP 172. Any signaling generated by the processor 260 is sent by the transmitter 252. Note that “signaling”, as used herein, may alternatively be called control signaling. Dynamic signaling may be transmitted in a control channel, e.g. a physical downlink control channel (PDCCH), and static or semi-static higher layer signaling may be included in a packet transmitted in a data channel, e.g. in a physical downlink shared channel (PDSCH).

[0107] A scheduler 253 may be coupled to the processor 260. The scheduler 253 may be included within or operated separately from the T-TRP 170, which may schedule uplink, downlink, and / or backhaul transmissions, including issuing scheduling grants and / or configuring scheduling-free (“configured grant”) resources. The T-TRP 170 further includes a memory 258 for storing information and data. The memory 258 stores instructions and data used, generated, or collected by the T-TRP 170. For example, the memory 258 could store software instructions or modules configured to implement some or all of the functionality and / or embodiments described herein and that are executed by the processor 260.

[0108] Although not illustrated, the processor 260 may form part of the transmitter 252 and / or receiver 254. Also, although not illustrated, the processor 260 may implement the scheduler 253. Although not illustrated, the memory 258 may form part of the processor 260.

[0109] The processor 260, the scheduler 253, and the processing components of the transmitter 252 and receiver 254 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory, e.g. in memory 258. Alternatively, some or all of the processor 260, the scheduler 253, and the processing components of the transmitter 252 and receiver 254 may be implemented using dedicated circuitry, such as a FPGA, a GPU, or an ASIC.

[0110] Although the NT-TRP 172 is illustrated as a drone only as an example, the NT-TRP 172 may be implemented in any suitable non-terrestrial form. Also, the NT-TRP 172 may be known by other names in some implementations, such as a non-terrestrial node, a non-terrestrial network device, or a non-terrestrial base station. The NT-TRP 172 includes a transmitter 272 and a receiver 274 coupled to one or more antennas 280. Only one antenna 280 is illustrated. One, some, or all of the antennas may alternatively be panels. The transmitter 272 and the receiver 274 may be integrated as a transceiver. The NT-TRP 172 further includes a processor 276 for performing operations including those related to: preparing a transmission for downlink transmission to the ED 110, processing an uplink transmission received from the ED 110, preparing a transmission for backhaul transmission to T-TRP 170, and processing a transmission received over backhaul from the T-TRP 170. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as encoding, modulating, precoding (e.g. MIMO precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to processing received transmissions in the uplink or over backhaul may include operations such as receive beamforming, and demodulating and decoding received symbols. In some embodiments,the processor 276 implements the transmit beamforming and / or receive beamforming based on beam direction information (e.g. BAI) received from T-TRP 170. In some embodiments, the processor 276 may generate signaling, e.g. to configure one or more parameters of the ED 110. In some embodiments, the NT-TRP 172 implements physical layer processing, but does not implement higher layer functions such as functions at the medium access control (MAC) or radio link control (RLC) layer. As this is only an example, more generally, the NT-TRP 172 may implement higher layer functions in addition to physical layer processing.

[0111] The NT-TRP 172 further includes a memory 278 for storing information and data. Although not illustrated, the processor 276 may form part of the transmitter 272 and / or receiver 274. Although not illustrated, the memory 278 may form part of the processor 276.

[0112] The processor 276 and the processing components of the transmitter 272 and receiver 274 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory, e.g. in memory 278. Alternatively, some or all of the processor 276 and the processing components of the transmitter 272 and receiver 274 may be implemented using dedicated circuitry, such as a programmed FPGA, a GPU, or an ASIC. In some embodiments, the NT-TRP 172 may actually be a plurality of NT-TRPs that are operating together to serve the ED 110, e.g. through coordinated multipoint transmissions.

[0113] The T-TRP 170, the NT-TRP 172, and / or the ED 110 may include other components, but these have been omitted for the sake of clarity.

[0114] Basic module structure

[0115] One or more steps of the embodiment methods provided herein may be performed by corresponding units or modules, according to FIG. 4. FIG. 4 illustrates units or modules in a device, such as in ED 110, in T-TRP 170, or in NT-TRP 172. For example, a signal may be transmitted by a transmitting unit or a transmitting module. For example, a signal may be transmitted by a transmitting unit or a transmitting module. A signal may be received by a receiving unit or a receiving module. A signal may be processed by a processing unit or a processing module. Other steps may be performed by an artificial intelligence (Al) or machine learning (ML) module. The respective units or modules may be implemented using hardware, one or more components or devices that execute software, or a combination thereof. For instance, one or more of the units or modules may be an integrated circuit, such as a programmed FPGA, a GPU, or an ASIC. It will be appreciated that where the modules are implemented using software for execution by a processor for example, they may be retrieved by a processor, in whole or part as needed, individually or together for processing, in single or multiple instances, and that the modules themselves may include instructions for further deployment and instantiation. It should be noted that, the modules shown in FIG. 4 are only illustrative and should not be construed as limitations to the embodiments of the present disclosure, more or less modules may be included in the device, which is not limited here. For example, the transmitting module and the receiving module may be replaced with one transceiving module. For another example, the ML module can be included or excluded from the device, depending on actual needs.

[0116] Additional details regarding the EDs 110, T-TRP 170, and NT-TRP 172 are known to those of skill in the art. As such, these details are omitted here.

[0117] Example concepts of some terms

[0118] Slab: a sub-matrix of a three-dimensional tensor.Fiber: one-dimensional array, formed as continuous parts of a three-dimensional tensor along one dimension.Tensor Fusion: the process of combining two partially observed tensors into one full tensor.Hopping, jumping hopping: the process of shifting frequency resource allocation inside several adjacent time-domain intervals (e.g. symbols).Antenna port: generalization of antenna, may include a group of antennas.Resource Block (RB): a group of 12 continuous Resource Elements along subcarrier (frequency) domain. Resource Element (RE): one subcarrier-one symbol resource atom, in terms of resource allocation, the smallest possible piece of resource.Capacity: the maximum amount of data system is able to transmit.Ultra Massive MIMO (UM-MIMO): multi-antenna multi-frequency wireless communication systems with extremely large number of antennas and frequency channels (subcarriers).Tensor Completion: the process of recovering the entire tensor (multi-dimensional cube) of data based on partially measured samples thereof.Pilot: a reference signal in frequency domain.Wideband: spanning over all or almost all available subcarriers.Narrowband: spanning over a few subcarriers of all available ones.Symbol: the smallest resource in time domain.

[0119] The above describes possible scenarios or generalized description of the examples of the present disclosure, the motivation and technical concepts of the present disclosure are illustrated in the following.

[0120] In modem mobile wireless communications, multi-antenna systems (multiple-input multiple-output systems, MIMO systems) are highly popular. MIMO systems are usually used in combination with multi-frequency scheme (Orthogonal Frequency Division Multiplexing, OFDM). The coefficients between each pair of TX (transmitter) and RX (receiver) antennas at each frequency together form a three-dimensional data-cube, called channel tensor. Base Station (BS) needs to estimate this tensor or its approximation to be able to send data to User Equipment (UE) efficiently.

[0121] In Time Division Duplex (TDD) MIMO OFDM systems, UE sends reference signals (RSs) to BS, BS estimates the channel based on these RSs. The amount of resources in time and frequency required for channel estimation is called channel estimation overhead (or simply overhead). The overhead is measured in resource elements (REs). There is a tradeoff between accuracy and overhead of channel estimation. Too high overhead will yield good estimation, but few REs will be left for data transmission, thus the capacity will be low. Too small overhead will leave a lot of REs for data transmission, but the channel estimation will be poor, thus again leading to low capacity.

[0122] In existing MIMO OFDM systems, for a given number of BS and UE antennas and for a given bandwidth (BW) and a given number of subcarriers, there is a solution with acceptable tradeoff overhead, yielding acceptable accuracy and occupying acceptable amount of REs. At the same time, MIMO OFDM systems are evolving into Massive MIMO (M-MIMO) OFDM systems or Ultra Massive MIMO (UM-MIMO) OFDM systems, with significantly higher number of antennas at both BS and UE and significantly larger BW and subcarrier number.

[0123] M-MIMO and UM-MIMO systems promise large capacity increase, but the problem is that the channel estimation overhead increases dramatically as the number of antennas and subcarriers grow. If existing solutions are used for channel estimation in M-MIMO or UM-MIMO systems, the channel overhead becomes impractically large, few REs are left for data transmission and the system capacity drops.

[0124] An existing solution that can be used for channel estimation in UM-MIMO systems is based on wideband Sounding Reference Signals (SRSs) sent from UE to BS. In frequency domain, SRSs are allocated in a regular comblike structure with parameter comb, specifying a distance between any two subcarriers carrying SRSs, as shown in FIG. 5. For a given comb value, several antennas / ports can be measured on the same subcarriers using Zadoff-Chu sequence and cyclic shift. The number of antennas multiplexed on the same subcarriers in that way equals the cyclic shift parameter csh.

[0125] The comb-like structure of wideband SRS can be shifted in frequency domain by values from 0 to comb- 1, as it is shown in FIG. 5. Thus, for given comb and csh values, the maximum number of antennas / ports that can beestimated in one time instance (one symbol) is the product of comb and csh values. After each antenna / port was estimated at comb locations, interpolation is further applied in subcarrier domain.

[0126] FIG. 6 illustrates channel estimation of the above existing solution. For example, TX (UE) has 16 antennas, the whole BW is 16 RBs. In the existing solution, as shown in FIG. 6, there are two options for channel estimation, and the two options cannot be combined. Option 1: use wideband channel estimation for all antennas. Option 2: use frequency hopping for all antennas. It should be noted that, for option 2, the entire BW of 16 RBs are hopped over all blocks of 4 RBs, otherwise the channel estimation cannot be performed in the entire BW for the given antennas. This is caused by one-dimensional (only frequency domain) processing in the existing solution.

[0127] The main disadvantage of the existing channel estimation is the large overhead required for UEs with large antenna array in UM-MIMO systems. But if the overhead is reduced in the existing channel estimation, the accuracy of the channel estimation drops significantly and the capacity of the system is largely decreased.

[0128] In view of the above, the present disclosure provides a reference signal allocation scheme to reduce overhead with little or no loss in accuracy. The reference signal allocation scheme is applicable to uplink channel estimation in TDD MIMO OFDM systems, it should be noted that, it is only an illustrative scenario, and the scheme can also be applicable to downlink channel estimation, or in other MIMO systems, which is not limited here.

[0129] As shown in FIG. 7, to perform channel estimation, BS determines RS allocation for UE: which UE antennas / ports will use type-1 pilots (reference signals corresponding to a first sequence hereinafter, or referred to as type-1 RS, where type-1 RS represents a type of RS allocation) and which antennas / ports will use type-2 pilots (reference signals corresponding to a second sequence hereinafter, or referred to as type-2 RS, where type-2 RS represents another type of RS allocation). BS also chooses parameters of type-1 pilots and parameters of type-2 pilots, as well as allocations of type-1 and type-2 pilots in time domain. BS also determines allocation of data in the available resources. BS then sends information about the above configuration to UE through control channel. It should be noted that here different numbers in type-1 and type-2 are used for distinguishing different RS allocations rather than the types of reference signals corresponding to the sequences.

[0130] UE receives said information, and sends the configured reference signals to BS, as shown in FIG. 7. Based on the reference signals, BS performs slab sampled tensor completion based on tensor train model, and the procedure will be described later.

[0131] The above describes technical concepts of the present disclosure, and then specific embodiments of the present disclosure will be elaborated in the following description.

[0132] An embodiment of the present disclosure provides a wireless communication method, as shown in FIG.8, the method includes: step 802, transmitting a first sequence over at least one first antenna port; and step 804, transmitting a second sequence over at least one second antenna port; where the first sequence and the second sequence are used for measuring a channel with a first bandwidth, a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the sajie as a type of a reference signal corresponding to the second sequence.

[0133] The method can be implemented by a transmitting end, and the transmitting end may be a terminal device, or may be a part of the terminal device (e.g., implemented as a module which can be integrated into a device), which is not limited here. It should be noted that in a case where the transmitting end is implemented as a module, the transmitting operation may also be an outputting operation, it is not necessary to transmit but just to output the first sequence, the second sequence and a correspondence between a sequence and an antenna port to a certain device with a transmission function, the specific details with regard to the transmitting operation performed by the transmitting end throughout the document also apply for the outputting operation.

[0134] Here, a sequence corresponds to a reference signal of a certain type, and transmitting the sequence meanstransmiting the reference signal, and the reference signal is used for measuring a channel with a given bandwidth, for example, obtaining channel state information of the channel. A length of a sequence refers to a total number of resource elements occupied by the sequence on a certain symbol, and sequences with different lengths are supported. Since the length of the second sequence is smaller than the length of the first sequence, a total number of resource elements occupied by the second sequence is less than a total number of resource elements occupied by the first sequence. For example, if the sequence is transmited in a comb-like structure, the sequence occupies multiple REs on a symbol, and adjacent REs are spaced apart by a comb value, then the length of the sequence may be the number of REs on the symbol.

[0135] A type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence, e.g., both the first sequence and the second sequences may be generated using Zadoff-Chu sequence. The first sequence and the second sequence correspond to reference signals of the same type, and the reference signals are used for channel estimation, hence, channel estimation overhead is reduced, and more resources can be used for data transmission. A transmitting end (e.g., UE) can transmit reference signals corresponding to the first sequence and the second sequence over different antenna ports to perform channel estimation. An accurate channel estimation can be performed in this case due to the tensor completion, which will be described later.

[0136] The type of the reference signal is not limited in the present disclosure, in a possible implementation, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are sounding reference signals (SRSs); or, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are demodulation reference signals (DMRS).

[0137] Regarding specific antenna port allocation, in a possible implementation, UE may obtain a first correspondence between the first sequence and the at least one first antenna port, and a second correspondence between the second sequence and the at least one second antenna port. It should be noted that, the first correspondence and the second correspondence may be predefined for UE or indicated by BS via indication information, and indication information may be carried in at least one of MAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC).

[0138] In a possible implementation, the first sequence is transmited over a first frequency domain resource, and the first frequency domain resource includes at least two first frequency domain units; the second sequence is transmited over a second frequency domain resource, and the second frequency domain resource includes at least two second frequency domain units. A frequency domain resource may also be referred to as a frequency resource. It should be noted that, a bandwidth corresponding to the first frequency domain resource is not greater than the first bandwidth, and a bandwidth corresponding to the second frequency domain resource is not greater than the first bandwidth. This means a resource occupied by the first frequency domain resource is not greater than a resource corresponding to the first bandwidth, and a resource occupied by the second frequency domain resource is also not greater than a resource corresponding to the first bandwidth.

[0139] In a possible implementation, the at least two first frequency domain units of the first frequency domain resource are spaced apart by a first frequency domain interval. A frequency domain interval may also be referred to as a frequency interval. When there are two first frequency domain units, they are spaced apart by a first frequency domain interval, the sum of a resource occupied by the first frequency domain resource and a resource occupied by the first frequency domain interval is a resource corresponding to the first bandwidth. When there are more than two first frequency domain units, each pair of adjacent first frequency domain units are spaced apart by a first frequency domain interval, so there may be multiple first frequency domain intervals, in this case, the sum of a resource occupied by the first frequency domain resource and a resource occupied by the multiple first frequency domain intervals is a resource corresponding to the first bandwidth.

[0140] In a possible implementation, each of the at least two first frequency domain units includes one resource element (RE). In this case, reference signals corresponding to the first sequence (type-1 RSs) may be allocated in a comb-like structure with parameter comb, comb here specifies the distance between any two subcarriers carrying the reference signals. The first frequency domain interval may indicate parameter comb, and a value ofthe first frequency domain interval may be equal to the (value of parameter comb -1), where the cardinal may be one RE. For example, the first frequency domain interval is set to be 4, so in this case, there are 4 REs between two adjacent REs (two adjacent first frequency domain units), but in practical application, the comb value can be set as 5, so as to describe that there are 5-1=4 REs between two adjacent REs (two adjacent first frequency domain units). Generally, the value of parameter comb depends on the coherence bandwidth of the channel over which the first sequence is transmitted, the larger the coherence bandwidth, the larger the value of parameter comb.

[0141] In a possible implementation, the at least two second frequency domain units of the second frequency domain resource are spaced apart by a second frequency domain interval. When there are two second frequency domain units, they are spaced apart by a second frequency domain interval, the sum of a resource occupied by the second frequency domain resource and a resource occupied by the second frequency domain interval is a resource corresponding to the first bandwidth. When there are more than two second frequency domain units, each pair of adjacent second frequency domain units are spaced apart by a second frequency domain interval, or some pairs of adjacent second frequency domain units are spaced apart by a second frequency domain interval, some pairs of adjacent second frequency domain units are continuous, so there may be multiple second frequency domain intervals, in this case, the sum of a resource occupied by the second frequency domain resource and a resource occupied by the multiple second frequency domain intervals is a resource corresponding to the first bandwidth.

[0142] It should be noted that, the second frequency domain interval can be larger than the value of parameter comb determined for a normal comb-like structure based on the coherence bandwidth. That is, the distance between two adjacent second frequency domain units (which equals to the second frequency domain interval) is decoupled from the coherence bandwidth for type-2 RSs. This may be advantageous especially in the case where the comb value determined based on the coherence bandwidth is relatively small. A single second frequency domain unit can include one or more resource elements since said distance is decoupled from the coherence bandwidth, while a single first frequency domain unit can only include one resource element due to the fact that the first frequency domain interval (e.g., a value of parameter comb) is relatively small.

[0143] In a possible implementation, each of the at least two second frequency domain units includes one resource element, and the second frequency domain interval is greater than the first frequency domain interval. Reference signals corresponding to the second sequence (type-2 RSs) can be configured in the same way as reference signals corresponding to the first sequence (type-1 RSs). For example, type-2 RS may also be allocated in a comblike structure with parameter comb, which specifies the distance between any two subcarriers carrying type-2 RSs. The second frequency domain interval may indicate parameter comb, and a value of the second frequency domain interval may be (value of parameter comb -1), where the cardinal may be one RE. For example, the second frequency domain interval is set to be 24, so in this case, there are 24 REs between two adjacent REs (two adjacent second frequency domain units), but in practical application, the comb value can be set as 25, so as to describe that there are 25-1=24 REs between two adjacent REs (two adjacent second frequency domain units). In this case, a value of parameter comb for type-2 RSs is larger than that for type-1 RSs. Comparing with the existing solution where each symbol carrying RSs with relatively small parameter comb, when a channel with a first bandwidth is measured by using the solution proposed by the present disclosure, a total number of resource elements occupied by the first sequence and the second sequence is decreased, i.e., channel estimation overhead is reduced with a simple but effective approach.

[0144] In a possible implementation, at least one of the at least two second frequency domain units includesmultiple resource elements, and the multiple resource elements in the at least one of the at least two second frequency domain units are spaced apart by a third frequency domain interval. In a case that one second frequency domain unit includes multiple resource elements, the second frequency domain unit may also be referred to as a narrow band. Type-2 RSs can be configured in a form of narrow bands, there may be one or more narrow bands in the second frequency domain resource, which is not limited here. The multiple resource elements included in a single narrow band can be spaced apart by a third frequency domain interval. It should be noted that, when there are multiple narrow bands in the second frequency domain resource, third frequency domain intervals may be respectively set for each of the multiple narrow bands according to actual requirements, for example, third frequency domain intervals of all the multiple narrow bands are the same, or third frequency domain intervals of some of the multiple narrow bands are different, which is not limited here. Similarly, for example, the third frequency domain interval is set to be 4, so in this case, there are 4 REs between two adjacent REs in one second frequency domain unit, but in practical application, the comb value for this second frequency domain unit can be set as 5, so as to describe that there are 5-1=4 REs between two adjacent REs in this second frequency domain unit.

[0145] Since the second frequency domain units of the second frequency domain resource are spaced apart by the second frequency domain interval, that is, there is already a distance between adjacent second frequency domain units, in a possible implementation, the third frequency domain interval may be equal to the first frequency domain interval. It means that in a narrow band, type-2 RSs can be configured in the same way as type-1 RSs with the same parameter, for example, with the same comb value.

[0146] In a possible implementation, at least one of the at least two second frequency domain units includes multiple resource elements, and the multiple resource elements in the at least one of the at least two second frequency domain units are continuous. Reference may be made to the foregoing description, there can even be no third frequency domain interval in some or all of the second frequency domain units, since there is already a second frequency domain interval between adjacent second frequency domain units.

[0147] In a possible implementation, at least one of the at least two second frequency domain units includes multiple resource elements, a location of the first frequency domain resource is determined based a first frequency domain interval and a first offset, a location of the second frequency domain resource is determined based on the second frequency domain interval and a second offset, where the second offset is associated with an identification of the at least one second antenna port. When type-1 RSs are allocated in a comb-like structure, the first frequency domain interval refers to (comb value-1), where the cardinal may be one RE, and the first offset refers to a comb offset.

[0148] In a possible implementation, the transmitting end transmits the first sequence over the at least one first antenna port on a first time domain unit; and transmits the second sequence over the at least one second antenna port on a second time domain unit. A time domain unit may be a symbol in a slot, reference signals corresponding to the first sequence and the second sequence are transmitted on different symbols in a slot.

[0149] In a possible implementation, the transmitting end transmits a third sequence over the at least one second antenna port on a third time domain unit, where a length of the third sequence is equal to a length of the second sequence. The third sequence can be the same as the second sequence, and can also be different from the second sequence, which is not limited here. Taking Zadoff-Chu sequence as an example, the third sequence and the second sequence can be the same Zadoff-Chu sequence, and can also be different Zadoff-Chu sequences, as long as they are used for measuring the channel with the first bandwidth. Reference signals corresponding to the third sequence are transmitted on a symbol different from the aforementioned symbols carrying RSs corresponding to the first and second sequences. Reference signals corresponding to the third sequence and reference signals corresponding to the second sequence are RSs with the same structure, e.g., type-2 RSs. Regarding a resource allocation for the third sequence, it is similar to the second sequence.

[0150] In a possible implementation, the third sequence is transmitted over a third frequency domain resource, and the third frequency domain resource includes at least two third frequency domain units, where the second frequency domain resource and the third frequency domain resource are non-continuous. There may be a fourth frequency domain interval between the second frequency domain resource and the third frequency domain resource. When the fourth frequency domain interval is one frequency domain unit, it indicates that the second frequency domain resource and the third frequency domain resource are continuous. When the fourth frequency domain interval is larger than one frequency domain unit, it indicates that the second frequency domain resource and the third frequency domain resource are non-continuous. It means that for type-2 RSs, it is not necessary to hop over the entire bandwidth, less channel measurements are performed, and channel estimation overhead is thus reduced. In a possible implementation, the fourth frequency domain interval may be associated with an identification of the at least one second antenna port, that is, the hopping position can be determined based on the identification of the antenna port. This would be advantageous for overhead reduction. For the channel estimation using type-1 RSs, it can be performed using wideband or frequency hopping for all antennas, and the entire bandwidth needs to be hopped, once a beginning position (location) and the abovementioned first offset is determined, positions of other antenna ports can be determined successively. It can be seen that there is no association between the comb offset and an identification of the antenna ports. However, in the embodiments of the present disclosure, for type-2 RSs with frequency hopping, since the channel estimation is performed based on the combination of type-1 RSs and type-2 RSs, it is not necessary to hop over the entire bandwidth, and a hopping position depends on an identification of an antenna port. Antennas / ports of different UEs can be multiplexed in such way, this makes the indication of the frequency hopping for the RSs much easier.

[0151] In a possible implementation, the transmitting end obtains indication information, where the indication information is indicative of a resource available for the second sequence in a first resource, and the first resource is a resource allocated to a terminal device and used for transmitting data of the terminal device. The indication information may be from BS. In a possible implementation, the indication information is carried in at least one of MAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC). In a case that type-2 RSs do not occupy all the subcarriers, the remaining subcarriers can be used for data transmission. In other words, type-2 RSs and data share the first resource. A second resource can be obtained through excluding a resource available for type-2 RSs from the first resource, and the second resource can be used for data transmission. This can increase the capacity of the MIMO systems. In another possible implementation, the indication information is indicative of a resource not available for the second sequence in the first resource, so the transmitting end can then determine the resource available for the second sequence in the first resource based on the resource not available for the second sequence in the first resource and the total resource.

[0152] With the wireless communication method provided by the present disclosure, a length of a sequence refers to a total number of resource elements occupied by the sequence on a certain symbol, since the length of the second sequence is smaller than the length of the first sequence, a total number of resource elements occupied by the second sequence is less than a total number of resource elements occupied by the first sequence. Therefore, when a channel with a first bandwidth is measured based on the first sequence and the second sequence, since the introduction of the second sequence with a length smaller than that of the first sequence, a total number of resource elements occupied by the first sequence and the second sequence is decreased. The first sequence and the second sequence correspond to reference signals of the same type, and the reference signals are used for channel estimation, hence, channel estimation overhead is reduced, and more resources can be used for data transmission.

[0153] In the above, the wireless communication method of the present disclosure is described from the perspective of a transmitting end. In the following, a wireless communication method of the present disclosure will be described from the perspective of a receiving end in combination with FIG. 9. FIG. 9 shows a schematic flowchartReference signals and data share the first resource, where a second resource can be obtained through excluding a resource available for the reference signals from the first resource, and the second resource can be used for data transmission. This can increase the capacity of the MIMO systems.

[0184] In a possible implementation, the indication information is carried in at least one of MAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC).

[0185] During channel estimation, since the introduction of the second sequence with a length smaller than that of the first sequence, a total number of resource elements occupied by the first sequence and the second sequence is decreased, hence, channel estimation overhead is reduced, and more resources can be used for data transmission.

[0186] It should be understood by a person skilled in the art that, the relevant description of the wireless communication method from the perspective of the receiving end in the embodiments of the present disclosure may be understood with reference to the relevant description of the wireless communication method from the perspective of the transmitting end in the embodiments of the present disclosure.

[0187] In order to elaborate the wireless communication methods of the present disclosure more clearly, in the following, taking sounding reference signals being allocated in a comb-like structure as an example, the method will be described in more details.

[0188] In the present disclosure, each UE can use type-1 and type-2 reference sequences. BS chooses which UE antennas / antenna ports will use Type-1 reference signals and which UE antennas / antenna ports will use Type-2 reference signals. BS also determines the parameters of these references signals, as well as the resource allocation for them in frequency, antenna and time domain. Both Type-1 and Type-2 reference signals can be used by the same UE at the same time.

[0189] Type-1 reference signals are wideband pilots with Zadoff-Chu sequence mapped on the subcarriers with comb 2, 4, 8 or 16. Within one symbol, UE can map antennas / ports to Type-1 reference signal on the same subcarriers, but the Zadoff-Chu sequence in such case contains different cyclic shifts for different antenna ports.

[0190] Type-2 reference signals can be implemented in the following ways. Option 1 : Type-2 reference signals can be configured in the same way as Type-1 reference signals, but with much higher comb value more than 16 and less than 96 (e.g. 24, 28, 32, 36), larger than the coherence bandwidth of the channel (see FIG. 18). Option 2: Type- 2 reference signals can be configured as several narrow bands, each narrow band containing a comb-like structure. The distance between the narrow bands in such case is larger than the coherence bandwidth of the channel (see FIG. 19). Narrow bands implementing type-2 reference signals can be mapped to different frequency positions on different symbols, performing frequency hopping, as shown in FIG. 20. For type-2 reference signals with frequency hopping, the hop position depends on the port. Antennas / ports of different UEs can be multiplexed in such way.

[0191] In this example, in FIG. 18, there are multiple columns, each column contains multiple black blocks and white intervals, black blocks on two adjacent columns are separated by an offset with respect to the subcarrier, the second frequency domain resource refers to the black blocks on a column (one antenna port or multiple antenna ports multiplexed with csh value), and the number of second frequency domain units is the number of the black blocks on a column with the same offset. The second frequency domain interval refers to the white interval between two adjacent black blocks on a column, and the first bandwidth is the combination of all the black blocks and all white intervals on the column. The large comb shown in FIG. 18 equals to the second frequency domain interval plus a size of one RE.

[0192] In FIG. 19, there are multiple grey blocks which represent multiple narrow bands, the second frequency domain resource refers to the grey blocks, and the number of second frequency domain units is the number of the grey blocks. The second frequency domain interval refers to the white interval between two adjacent grey blocks, and the first bandwidth is the combination of all the grey blocks and all white intervals. On the upper right comer of FIG. 19, a narrow band (a grey block) may include multiple small grey blocks. The third frequency domain intervalrefers to the white interval between two adjacent small grey blocks. For example, each narrow band is with 4 RBs, when the first bandwidth equals to 28 RBs, that means there could be 7 narrow bands, assume that a first narrow band and a third narrow band are used for transmitting type-2 RSs. For the first narrow band, it corresponds to the first RB to the fourth RB, and for the third narrow band, it corresponds to the 9-th RB to the 12-th RB, in this case, the second frequency domain interval equals to one which means that there is one narrow band between the first narrow band and the third narrow band, that is, the narrow band corresponds to the 5-th RB to the 8-th RB. In practical setting, the above first narrow band may be with index 1, and the above third narrow band may be with index 3, so we can directly set the second frequency domain interval to be one (one narrow band between the two adjacent narrow bands), or we can also set a parameter two for describing the distance of two adjacent narrow bands which carry type2-RSs, this distance actually equals to the second frequency domain interval plus a size of one narrow band. For other cases when the narrow bands are of different sizes, similar setting manner would be applied, as long as the position of the narrow band is well described.

[0193] FIG. 21A is a schematic illustration of channel estimation with the hopping solution provided by the present disclosure for the same scenario as in FIG. 6. As shown in FIG. 21 A, the proposed solution allows combining wideband RS and narrowband RS. That is why narrowband RSs do not need to hop over all the bandwidth, some hops are enough. Using joint antenna-frequency tensor processing, the entire channel tensor can be recovered even though some antennas / ports were not measured in the full band. In FIG. 21 A, for symbol 9 to symbol 12, the second frequency domain resource may refer to the first black block (close to the horizontal axis) occupied by type-2 RS, and the third frequency domain resource may refer to the second black block (away from the horizontal axis) occupied by type-2 RS; or, the second frequency domain resource may refer to the first grey block (close to the horizontal axis) occupied by type-2 RS, and the third frequency domain resource may refer to the second grey block (away from the horizontal axis) occupied by type-2 RS. The location of the second frequency domain resource may be determined based on the second frequency domain interval and a second offset, and this second offset can be associated with an identification of a port (the second antenna port). In this example as shown in FIG. 21 A, the offset of the first black block is 0, and the offset of the first grey block is also 0. The offset of the black block is associated with an identification of port 2 or port 4, and the offset of the grey block is associated with an identification of port 6 or port 8. In fact, as shown in FIG. 2 IB, for describing a hopping configuration, a hopping offset, a hopping block width and a hopping interval are sufficient. The hopping offset is the distance relative to the horizontal axis, the hopping block width is the width of continuous RBs occupied on one symbol by the type2-RSs, and the hopping interval is the distance between a resource on one symbol for carrying the type2-RS(s) of antenna port(s) and a resource on a next symbol for carrying the type2-RS(s) of the same antenna port(s).

[0194] A practical example for 32-antenna UE is demonstrated in FIG. 22. In symbol #7, antennas are measured using Type-1 reference signal. The comb parameter is set to 4, so there are 4 different positions of the comb in frequency domain. For a given comb offset, 2 antennas are multiplexed on the same subcarrier using cyclic shift. Thus, 8 antennas are measured using Type-1 Reference Signals. Note that there is also a comb-like structure in antenna domain: the antenna numbers chosen for Type-1 RS may be 1, 5, 9, 13, 17, 21, 25 and 29.

[0195] The remaining 24 antennas are measured using type-2 RS. The comb value here is 24, which is much higher than in Type-1 RS. Cyclic shift is not used here, for every comb-like subcarrier configuration only one antenna is measured. Different antennas are measured on different subcarriers: the comb-like structure is shifted by some offset values. In the example in FIG. 22, the maximum offset value is 4, so 4 antennas are estimated in one symbol. Note that the remaining 20 values of the offset are left unused, which means that in frequency domain 5 / 6 of resources are unused by the Type-2 RS. This pattern is repeated for symbols 8 to 13, on each symbol different 4 antennas are estimated.

[0196] Thus, 24 antennas are estimated with Type-2 RS. These measurements are combined with 8 antennasmeasurements from Type-1 RS and are further used for Tensor Train completion algorithm, which yields the channel estimation.

[0197] Based on the above channel estimation of combining wideband RS and narrowband RS, in an example, data and Type-2 RS can be carried in the same symbol. For each symbol, type-2 pilots do not occupy all the subcarriers. The remaining subcarriers can be used for data transmission, as shown FIG. 23. Inside every slot, some symbols can be used for Downlink (DL) data / reference signal transmission, some symbols can be used as a Gap to switch between DL and Uplink (UL) transmission. For UL transmission, some symbols can be occupied entirely by SRS, some symbols can have both UL Data and UL SRS symbols. There also can be some symbols used only for UL Data.

[0198] In summary, in order to increase the accuracy of channel estimation for low-overhead solutions (especially in UM-MIMO systems), the present disclosure introduces two types of reference signal allocation: type- 1 : wideband pilots as in the existing solution, type-2: wideband reference signals with comb value larger than in the existing solution or a group of narrowband blocks with large spacing between them in frequency domain. Type-2 RSs use less resources, channel estimation overhead is thus reduced. The two types of reference signals can be used by the same UE, type-1 RS can be used at some antennas / ports, while type-2 RS at the others. In addition, a flexible configuration of reference signals and data can be transmitted on one symbol, for example, type-2 reference signals and data can be transmitted at the same time but on different subcarriers. Further, flexible configuration of Type- 1 and Type-2 RSs for UE antennas can be implemented. The capacity of the system may be increased while reducing channel estimation overhead. The comb value in type-2 reference signals may be several times larger than used in the existing solution, larger than 16 and lower than 128 (e.g. 16, 24, 36 and more).

[0199] It should be noted that, the foregoing mentioned scheme can also be applied to Wi-Fi channel estimation. For type-2 RSs, some non-regular blocks allocation can be used. The distance between wide blocks can be large, but varying from block to block.

[0200] Next, embodiments of products related to the wireless communication methods will be described.

[0201] FIG. 24 shows a schematic structural diagram of a wireless communication apparatus according to one or more embodiments of the present disclosure. As shown in FIG. 24, the wireless communication apparatus 2400 may include: a first transmitting module 2402, configured to transmit a first sequence over at least one first antenna port; a second transmitting module 2404, configured to transmit a second sequence over at least one second antenna port; where the first sequence and the second sequence are used for measuring a channel with a first bandwidth, a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence.

[0202] It should be noted that, the first transmitting module and the second transmitting module are only illustrative for their functions, in practice, the functions of the first transmitting module and the second transmitting module may be implemented by one transmitting module, which is not limited here.

[0203] In a possible implementation, the first sequence is transmitted over a first frequency domain resource, and the first frequency domain resource includes at least two first frequency domain units; the second sequence is transmitted over a second frequency domain resource, and the second frequency domain resource includes at least two second frequency domain units.

[0204] In a possible implementation, the at least two first frequency domain units of the first frequency domain resource are spaced apart by a first frequency domain interval.

[0205] In a possible implementation, each of the at least two first frequency domain units includes one resourceelement.

[0206] In a possible implementation, the at least two second frequency domain units of the second frequency domain resource are spaced apart by a second frequency domain interval.

[0207] In a possible implementation, each of the at least two second frequency domain units includes one resource element, and the second frequency domain interval is greater than the first frequency domain interval.

[0208] In a possible implementation, at least one of the at least two second frequency domain units includes multiple resource elements, and the multiple resource elements in the at least one of the at least two second frequency domain units are spaced apart by a third frequency domain interval.

[0209] In a possible implementation, the third frequency domain interval is equal to the first frequency domain interval.

[0210] In a possible implementation, at least one of the at least two second frequency domain units includes multiple resource elements, and the multiple resource elements in the at least one of the at least two second frequency domain units are continuous.

[0211] In a possible implementation, at least one of the at least two second frequency domain units includes multiple resource elements, a location of the first frequency domain resource is determined based a first frequency domain interval and a first offset, a location of the second frequency domain resource is determined based on the second frequency domain interval and a second offset, where the second offset is associated with an identification of the at least one second antenna port.

[0212] In a possible implementation, the first transmitting module is specifically configured to transmit the first sequence over the at least one first antenna port on a first time domain unit; the second transmitting module is specifically configured to transmit the second sequence over the at least one second antenna port on a second time domain unit.

[0213] In a possible implementation, the apparatus further includes a third transmitting module, configured to transmit a third sequence over the at least one second antenna port on a third time domain unit, where a length of the third sequence is equal to a length of the second sequence.

[0214] In a possible implementation, the third sequence is transmitted over a third frequency domain resource, and the third frequency domain resource includes at least two third frequency domain units, where the second frequency domain resource and the third frequency domain resource are non-continuous.

[0215] In a possible implementation, the apparatus further includes a first obtaining module, configured to obtain a first correspondence between the first sequence and the at least one first antenna port, and a second correspondence between the second sequence and the at least one second antenna port.

[0216] In a possible implementation, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are sounding reference signals (SRSs); or, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are demodulation reference signals (DMRS).

[0217] In a possible implementation, the apparatus further includes a second obtaining module, configured to obtain indication information, where the indication information is indicative of a resource available for the second sequence in a first resource, and the first resource is a resource allocated to a terminal device and used for transmitting data of the terminal device.

[0218] In a possible implementation, the indication information is carried in at least one of MAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC).

[0219] The wireless communication apparatus may be applied to the transmitting end as described in the above method embodiments or may be the transmitting end as described in the above method embodiments. It should be understood by a person skilled in the art that, the relevant description of the above modules in the embodiments ofthe present disclosure may be understood with reference to the relevant description of the wireless communication method in the embodiments of the present disclosure.

[0220] FIG. 25 shows a schematic structural diagram of another wireless communication apparatus according to one or more embodiments of the present disclosure. As shown in FIG. 25, the wireless communication apparatus 2500 may include: a first receiving module 2502, configured to receive a first sequence and a second sequence, where a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence; and an obtaining module 2504, configured to obtain a measuring result of a channel with a first bandwidth based on the first sequence and the second sequence.

[0221] In a possible implementation, the first sequence is received over a first frequency domain resource, and the first frequency domain resource includes at least two first frequency domain units; the second sequence is received over a second frequency domain resource, and the second frequency domain resource includes at least two second frequency domain units.

[0222] In a possible implementation, the first receiving module is specifically configured to receive the first sequence on a first time domain unit; and receive the second sequence on a second time domain unit.

[0223] In a possible implementation, the apparatus further includes a second receiving module, configured to receive a third sequence over the at least one second antenna port on a third time domain unit, where a length of the third sequence is equal to a length of the second sequence.

[0224] In a possible implementation, the third sequence is received over a third frequency domain resource, and the third frequency domain resource includes at least two third frequency domain units; where the second frequency domain resource and the third frequency domain resource are non-continuous.

[0225] In a possible implementation, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are sounding reference signals (SRSs); or, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are demodulation reference signals (DMRS).

[0226] In a possible implementation, the apparatus further includes a transmitting module, configured to transmit indication information, where the indication information is indicative of a resource available for the second sequence in a first resource, and the first resource is a resource allocated to a terminal device and used for transmitting data of the terminal device.

[0227] In a possible implementation, the indication information is carried in at least one of MAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC).

[0228] The wireless communication apparatus may be applied to the receiving end as described in the above method embodiments or may be the receiving end as described in the above method embodiments. It should be understood by a person skilled in the art that, the relevant description of the above modules in the embodiments of the present disclosure may be understood with reference to the relevant description of the wireless communication method in the embodiments of the present disclosure.

[0229] FIG. 26 is a schematic structural diagram of a wireless communication apparatus according to one or more embodiments of the present disclosure, the apparatus may be a transmitting end or a receiving end. As shown in FIG. 26, the wireless communication apparatus 2600 includes a processor 2602, an interface 2604 for communicating with other devices, and a memory 2606. The memory 2606 may be stored with computer execution instructions, and the processor 2602 executes computer execution instructions stored in the memory 2606 to enable the apparatus to execute any of the above wireless communication methods.

[0230] In some aspects of the present disclosure, there is provided a transmitting end including processing circuitry for executing any of the above wireless communication methods. It should be understood that the transmitting end can execute the steps performed by the transmitting end in the above method embodiments, which will not be repeated here.

[0231] In some aspects of the present disclosure, there is provided a receiving end including processing circuitry for executing any of the above wireless communication methods. It should be understood that the receiving end can execute the steps performed by the receiving end in the above method embodiments, which will not be repeated here.

[0232] In some aspects of the present disclosure, there is provided a wireless communication apparatus which includes a processor and a memory. The memory is storing instructions that cause the processor to perform any of the above wireless communication methods.

[0233] In some aspects of the present disclosure, there is provided a wireless communication system, including a transmitting end and a receiving end. The transmitting end is configured to execute the steps executed by the transmitting end in any of the above wireless communication methods, and the receiving end is configured to execute the steps executed by the receiving end in any of the above wireless communication methods.

[0234] In some aspects of the present disclosure, there is provided a chip, including an input / output (I / O) interface and a processor, where the processor is configured to call and run computer execution instructions stored in a memory, to enable a device installing with the chip to execute any of the above wireless communication methods.

[0235] In some aspects of the present disclosure, there is provided a computer-readable medium storing computer execution instructions which, when executed by a processor, causes the processor to execute any of the above wireless communication methods.

[0236] In some aspects of the present disclosure, there is provided a computer program product including computer execution instructions which, when executed by a processor, causes the processor to execute any of the above wireless communication methods.

[0237] Although the present disclosure describes methods and processes with steps in a certain order, one or more steps of the methods and processes may be omitted or altered as appropriate. One or more steps may take place in an order other than that in which they are described, as appropriate.

[0238] Note that the expression “at least one of A or B”, as used herein, is interchangeable with the expression “A and / or B”. It refers to a list in which you may select A or B or both A and B. Similarly, “at least one of A, B, or C”, as used herein, is interchangeable with “A and / or B and / or C” or “A, B, and / or C”. It refers to a list in which you may select: A or B or C, or both A and B, or both A and C, or both B and C, or all of A, B and C. The same principle applies for longer lists having a same format.

[0239] Although the present disclosure is described, at least in part, in terms of methods, a person of ordinary skill in the art will understand that the present disclosure is also directed to the various components for performing at least some of the aspects and features of the described methods, be it by way of hardware components, software or any combination of the two. Accordingly, the technical solution of the present disclosure may be embodied in the form of a software product. A suitable software product may be stored in a pre-recorded storage device or other similar non-volatile or non-transitory computer readable medium, including DVDs, CD-ROMs, USB flash disk, a removable hard disk, or other storage media, for example. The software product includes instructions tangibly stored thereon that enable a processing device (e.g., a personal computer, a server, or a network device) to execute examples of the methods disclosed herein. The machine-executable instructions may be in the form of code sequences, configuration information, or other data, which, when executed, cause a machine (e.g., a processor or other processing device) to perform steps in a method according to examples of the present disclosure.

[0240] The present disclosure may be embodied in other specific forms without departing from the subject matter of the claims. The described example embodiments are to be considered in all respects as being onlyillustrative and not restrictive. Selected features from one or more of the above-described embodiments may be combined to create alternative embodiments not explicitly described, features suitable for such combinations being understood within the scope of this disclosure.

[0241] All values and sub-ranges within disclosed ranges are also disclosed. Also, although the systems, devices and processes disclosed and shown herein may include a specific number of elements / components, the systems, devices and assemblies could be modified to include additional or fewer of such elements / components. For example, although any of the elements / components disclosed may be referenced as being singular, the embodiments disclosed herein could be modified to include a plurality of such elements / components. The subject matter described herein intends to cover and embrace all suitable changes in technology.

[0242] Although embodiments have been described above with reference to the accompanying drawings, those of skill in the art will appreciate that variations and modifications may be made without departing from the scope thereof as defined by the appended claims.

Claims

CLAIMS1. A wireless communication method, comprising: transmitting a first sequence over at least one first antenna port; and transmitting a second sequence over at least one second antenna port; wherein the first sequence and the second sequence are used for measuring a channel with a first bandwidth, a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence.

2. The method according to claim 1, wherein the first sequence is transmitted over a first frequency domain resource, and the first frequency domain resource comprises at least two first frequency domain units; the second sequence is transmitted over a second frequency domain resource, and the second frequency domain resource comprises at least two second frequency domain units.

3. The method according to claim 2, wherein the at least two first frequency domain units of the first frequency domain resource are spaced apart by a first frequency domain interval.

4. The method according to claim 3, wherein each of the at least two first frequency domain units comprises one resource element.

5. The method according to any one of claims 2 to 4, wherein the at least two second frequency domain units of the second frequency domain resource are spaced apart by a second frequency domain interval.

6. The method according to claim 5, wherein each of the at least two second frequency domain units comprises one resource element, and the second frequency domain interval is greater than the first frequency domain interval.

7. The method according to claim 5, wherein at least one of the at least two second frequency domain units comprises multiple resource elements, and the multiple resource elements in the at least one of the at least two second frequency domain units are spaced apart by a third frequency domain interval.

8. The method according to claim 7, wherein the third frequency domain interval is equal to the first frequency domain interval.

9. The method according to claim 5, wherein at least one of the at least two second frequency domain units comprises multiple resource elements, and the multiple resource elements in the at least one of the at least two second frequency domain units are continuous.

10. The method according to claim 5, wherein at least one of the at least two second frequency domain units comprises multiple resource elements, a location of the first frequency domain resource is determined based a first frequency domain interval and a first offset, a location of the second frequency domain resource is determined based on the second frequency domain interval and a second offset, wherein the second offset is associated with an identification of the at least one second antenna port.

11. The method according to any one of claims 2 to 10, wherein the transmitting the first sequence over the at least one first antenna port comprises: transmitting the first sequence over the at least one first antenna port on a first time domain unit; wherein the transmitting the second sequence over the at least one second antenna port comprises: transmitting the second sequence over the at least one second antenna port on a second time domain unit.

12. The method according to claim 11, further comprising: transmitting a third sequence over the at least one second antenna port on a third time domain unit, wherein a length of the third sequence is equal to a length of the second sequence.

13. The method according to claim 12, wherein the third sequence is transmitted over a third frequency domainresource, and the third frequency domain resource comprises at least two third frequency domain units; wherein the second frequency domain resource and the third frequency domain resource are non-continuous.

14. The method according to any one of claims 1 to 13, further comprising: obtaining a first correspondence between the first sequence and the at least one first antenna port, and a second correspondence between the second sequence and the at least one second antenna port.

15. The method according to any one of claims 1 to 14, wherein both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are sounding reference signals (SRSs); or, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are demodulation reference signals (DMRS).

16. The method according to any one of claims 1 to 15, further comprising: obtaining indication information, where the indication information is indicative of a resource available for the second sequence in a first resource, and the first resource is a resource allocated to a terminal device and used for transmitting data of the terminal device.

17. The method according to claim 16, wherein the indication information is carried in at least one of MAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC).

18. A wireless communication method, comprising: receiving a first sequence and a second sequence, wherein a length of the first sequence is larger than a length of the second sequence, and a type of a reference signal corresponding to the first sequence is the same as a type of a reference signal corresponding to the second sequence; and obtaining a measuring result of a channel with a first bandwidth based on the first sequence and the second sequence.

19. The method according to claim 18, wherein the first sequence is received over a first frequency domain resource, and the first frequency domain resource comprises at least two first frequency domain units; the second sequence is received over a second frequency domain resource, and the second frequency domain resource comprises at least two second frequency domain units.

20. The method according to claim 18 or 19, wherein the receiving the first sequence first sequence and the second sequence comprises: receiving the first sequence on a first time domain unit; and receiving the second sequence on a second time domain unit.

21. The method according to claim 20, further comprising: receiving a third sequence over the at least one second antenna port on a third time domain unit, wherein a length of the third sequence is equal to a length of the second sequence.

22. The method according to claim 21, wherein the third sequence is received over a third frequency domain resource, and the third frequency domain resource comprises at least two third frequency domain units; wherein the second frequency domain resource and the third frequency domain resource are non-continuous.

23. The method according to any one of claims 18 to 22, wherein both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are sounding reference signals (SRSs); or, both of the reference signal corresponding to the first sequence and the reference signal corresponding to the second sequence are demodulation reference signals (DMRS).

24. The method according to any one of claims 18 to 23, further comprising: transmitting indication information, wherein the indication information is indicative of a resource available forthe second sequence in a first resource, and the first resource is a resource allocated to a terminal device and used for transmitting data of the terminal device.

25. The method according to claim 24, wherein the indication information is carried in at least one of MAC control element (MAC CE), downlink control information (DCI), radio resource control (RRC).

26. A wireless communication apparatus, comprising modules for performing the method according to any one of claims 1 to 17.

27. A wireless communication apparatus, comprising modules for performing the method according to any one of claims 18 to 25.

28. A computer-readable medium storing computer execution instructions which, when executed by a processor, causes the processor to execute the method according to any one of claims 1 to 17 or the method according to any one of claims 18 to 25.

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