Method performed by first node in communication system, and first node

Abstract

The present disclosure relates to a 5G communication system or a 6G communication system for supporting higher data rates beyond a 4G communication system such as long term evolution (LTE). Provided are a method performed by a first node in a communication system and a first node, which belong to the technical field of wireless communication. The method comprises steps of: receiving a first signal; determining whether the first signal is a signal that was subjected to power normalization; and, performing channel estimation in a first approach or a second approach based on the determination result on the first signal. Based on the solution provided in the embodiments of the present disclosure, the channel estimation effect can be improved, and the channel estimation requirements can be better satisfied.

Description

METHOD PERFORMED BY FIRST NODE IN COMMUNICATION SYSTEM, AND FIRST NODE

[0001] The present disclosure relates to the technical field of wireless communication, and in particular to a method performed by a first node in a communication system, and a first node.

[0002] Considering the development of wireless communication from generation to generation, the technologies have been developed mainly for services targeting humans, such as voice calls, multimedia services, and data services. With the commercialization of 5th-generation (5G) communication systems, it is expected that the number of connected devices will exponentially grow. Increasingly, these will be connected to communication networks. Examples of internet-of-things may include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructures, construction machines, and factory equipment. Mobile devices are expected to evolve in various form-factors, such as augmented reality glasses, virtual reality headsets, and hologram devices. In order to provide various services by connecting hundreds of billions of devices and things in the 6th-generation (6G) era, there have been ongoing efforts to develop improved 6G communication systems. For these reasons, 6G communication systems are referred to as beyond-5G systems.

[0003] 6G communication systems, which are expected to be commercialized around 2030, will have a peak data rate of tera (1,000 giga)-level bps and a radio latency less than 100μsec, and thus will be 50 times as fast as 5G communication systems and have the 1 / 10 radio latency thereof.

[0004] In order to accomplish such a high data rate and an ultra-low latency, it has been considered to implement 6G communication systems in a terahertz band (for example, 95GHz to 3THz bands). It is expected that, due to severer path loss and atmospheric absorption in the terahertz bands than those in millimeter wave (mmWave) bands introduced in 5G, technologies capable of securing the signal transmission distance (that is, coverage) will become more crucial. It is necessary to develop, as major technologies for securing the coverage, radio frequency (RF) elements, antennas, novel waveforms having a better coverage than orthogonal frequency division multiplexing (OFDM), beamforming and massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, and multiantenna transmission technologies such as large-scale antennas. In addition, there has been ongoing discussion on new technologies for improving the coverage of terahertz-band signals, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable intelligence surface (RIS).

[0005] Moreover, in order to improve the spectral efficiency and the overall network performances, the following technologies have been developed for 6G communication systems: a full-duplex technology for enabling an uplink transmission and a downlink transmission to use the same frequency resource simultaneously; a network technology for utilizing satellites, high-altitude platform stations (HAPS), and the like in an integrated manner; an improved network structure for supporting mobile base stations and the like and making network operation optimization and automation and the like possible; a dynamic spectrum sharing technology via collision avoidance based on a prediction of spectrum usage; an use of artificial intelligence (AI) in wireless communication for improvement of overall network operation by utilizing AI from a designing phase for developing 6G and internalizing end-to-end AI support functions; and a next-generation distributed computing technology for overcoming the limit of user equipment (UE) computing ability through reachable super-high-performance communication and computing resources (such as mobile edge computing (MEC), clouds, and the like) over the network. In addition, by designing new protocols to be used in 6G communication systems, developing mechanisms for implementing a hardware-based security environment and safe use of data, and developing technologies for maintaining privacy, attempts to strengthen the connectivity between devices, optimize the network, promote softwarization of network entities, and increase the openness of wireless communications are continuing.

[0006] It is expected that research and development of 6G communication systems in hyper-connectivity, including person to machine (P2M) as well as machine to machine (M2M), will bring the next hyper-connected experience. Particularly, it is expected that services such as truly immersive extended reality (XR), high-fidelity mobile hologram, and digital replica could be provided through 6G communication systems. In addition, services such as remote surgery for security and reliability enhancement, industrial automation, and emergency response will be provided through the 6G communication system such that the technologies could be applied in various fields such as industry, medical care, automobiles, and home appliances.

[0007] An objective of the embodiments of the present disclosure is to provide a method performed by a first node in a communication system, a first node and a storage medium, which can better satisfy the wireless communication requirements. To achieve this objective, the embodiments of the present disclosure provide the following technical solutions.

[0008] In one aspect, an embodiment of the present disclosure provides a method performed by a first node in a communication system, including steps of:

[0009] receiving a first signal;

[0010] determining whether the first signal is a signal that was subjected to power normalization; and

[0011] performing channel estimation based on the first signal by a first method when the first signal is a signal that was subjected to power normalization, or performing channel estimation based on the first signal by a second method when the first signal is a signal that was not subjected to power normalization.

[0012] According to an embodiment of the present invention, a method performed by a first node in a communication system, a first node and a storage medium, which can better satisfy the wireless communication requirements is provided.

[0013] FIG. 1 shows a schematic structure diagram of a wireless network system to which an embodiment of the present disclosure is applied;

[0014] FIG. 2 shows a schematic structure diagram of an exemplary base station according to the present disclosure;

[0015] FIG. 3 shows a schematic structure diagram of an exemplary user equipment according to the present disclosure;

[0016] FIG. 4 shows a schematic flowchart of a method performed by a first node according to an embodiment of the present disclosure;

[0017] FIG. 5 shows a schematic flowchart of a communication method according to an embodiment of the present disclosure;

[0018] FIG. 6 shows a schematic diagram of a physical signal before and after normalization according to an embodiment of the present disclosure;

[0019] FIG. 7 shows a schematic diagram of the peak to average power ratio of a physical signal before and after normalization according to an embodiment of the present disclosure; and

[0020] FIG. 8 is a schematic structure diagram of an electronic device according to an embodiment of the present disclosure.

[0021] In one aspect, an embodiment of the present disclosure provides a method performed by a first node in a communication system, including steps of:

[0022] receiving a first signal;

[0023] determining whether the first signal is a signal that was subjected to power normalization; and

[0024] performing channel estimation based on the first signal by a first method when the first signal is a signal that was subjected to power normalization, or performing channel estimation based on the first signal by a second method when the first signal is a signal that was not subjected to power normalization.

[0025] In another aspect, an embodiment of the present disclosure provides a method performed by a second node in a communication system, including steps of:

[0026] transmitting a first signal, the first signal being a signal that was subjected to power normalization or a signal that was not subjected to power normalization;

[0027] wherein if the first signal is a signal that was subjected to power normalization, the first signal is used to perform channel estimation by a first method, or if the first signal is a signal that was not subjected to power normalization, the first signal is used to perform channel estimation by a second method.

[0028] In still another aspect, an embodiment of the present disclosure provides a node in a wireless communication system, wherein the node includes a transceiver and at least one processor coupled to the transceiver, and the at least one processor is configured to perform the method provided in any one embodiment of the present disclosure.

[0029] Optionally, the node is a first node, and the at least one processor is configured to perform the method performed by the first node provided in any one embodiment of the present disclosure.

[0030] Optionally, the node is a second node, and the at least one processor is configured to perform the method performed by the second node provided in any one embodiment of the present disclosure.

[0031] In yet another aspect, an embodiment of the present application further provides a computer-readable storage medium having computer programs stored thereon that, when executed by a processor, perform the method provided in any one embodiment of the present disclosure.

[0032] In yet another aspect, a computer program product is provided, including computer programs that, when executed by a processor, perform the method provided in any one optional embodiment of the present disclosure.

[0033] The beneficial effects achieved by the technical solutions in the embodiments of the present disclosure will be described below by specific embodiments.

[0034] Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether those elements are in physical contact with one another. The terms "transmit," "receive," and "communicate," as well as derivatives thereof, encompass both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation. The term "or" is inclusive, meaning and / or. The phrase "associated with," as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term "controller" means any device, system or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase "at least one of," when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, "at least one of: A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. Likewise, the term "set" means one or more. Accordingly, a set of items can be a single item or a collection of two or more items.

[0035] Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer readable medium" includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A "non-transitory" computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

[0036] Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

[0037] The figures included herein, and the various embodiments used to describe the principles of the present disclosure are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Further, those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged wireless communication system.

[0038] FIGS. 1-3 below describe various embodiments of the present disclosure implemented in wireless communication systems. The descriptions of FIGS. 1-3 are not meant to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the present disclosure may be implemented in any suitably-arranged communications system.

[0039] FIG. 1 illustrates an example wireless network according to embodiments of the present disclosure. The embodiment of the wireless network shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 could be used without departing from the scope of the present disclosure.

[0040] As shown in FIG. 1, the wireless network includes a base station (gNB or gNodeB) 101, a gNB 102, and a gNB 103. The gNB 101 communicates with the gNB 102 and the gNB 103. The gNB 101 also communicates with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

[0041] The gNB 102 provides wireless broadband access to the network 130 for a first plurality of user equipments (UEs) within a coverage area 120 of the gNB 102. The first plurality of UEs includes a UE 111, which may be located in a small business; a UE 112, which may be located in an enterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); a UE 114, which may be located in a first residence (R1); a UE 115, which may be located in a second residence (R2); and a UE 116, which may be a mobile device (M), such as a cell phone, a wireless laptop, a wireless personal digital assistant (PDA), or the like. The gNB 103 provides wireless broadband access to the network 130 for a second plurality of UEs within a coverage area 125 of the gNB 103. The second plurality of UEs includes the UE 115 and the UE 116, as well as subscriber stations (SS, for example, UEs) 117, 118 and 119. In some embodiments, one or more of the gNBs 101-103 may communicate with each other and with the UEs 111-116 using existing wireless communication techniques, and one or more of the UE 111-119 may communicate directly with each other (e.g., UEs 117-119) using other existing or proposed wireless communication techniques.

[0042] Depending on the network type, the term "base station" or "BS" can refer to any component (or collection of components) configured to provide wireless access to a network, such as transmit point (TP), transmit-receive point (TRP), an enhanced (or "evolved") base station (eNodeB or eNB), a 5G base station (gNB), a macrocell, a femtocell, a wireless fidelity (WiFi) access point (AP), or other wirelessly enabled devices. Base stations may provide wireless access in accordance with one or more wireless communication protocols, e.g., 3GPP 5G New Radio (NR), Long Term Evolution (LTE), LTE Advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For the sake of convenience, the various names for a base station-type apparatus and functionality are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, the term "user equipment" (UE) can refer to any component such as a mobile station (MS), subscriber station (SS), remote terminal, wireless terminal, receive point, or user device. For the sake of convenience, the various names for a user equipment-type device and functionality are used interchangeably in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer or vending machine).

[0043] Dotted lines show the approximate extents of the coverage areas 120 and 125, which are shown as approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with gNBs, such as the coverage areas 120 and 125, may have other shapes, including irregular shapes, depending upon the configuration of the gNBs and variations in the radio environment associated with natural and man-made obstructions.

[0044] As described in more detail below, one or more of the UEs 111-119 include circuitry, programing, or a combination thereof. In certain embodiments, and one or more of the gNBs 101-103 includes circuitry, programing, or a combination thereof.

[0045] Although FIG. 1 illustrates one example of a wireless network, various changes may be made to FIG. 1. For example, the wireless network 100 could include any number of gNBs and any number of UEs in any suitable arrangement. Also, the gNB 101 could communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each gNB 102-103 could communicate directly with the network 130 and provide UEs with direct wireless broadband access to the network 130. Further, the gNBs 101, 102, and / or 103 could provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0046] FIG. 2 illustrates an example base station according to embodiments of the present disclosure. The embodiment of the gNB 102 illustrated in FIG. 2 is for illustration only, and the gNBs 101 and 103 of FIG. 1 could have the same or similar configuration. However, gNBs come in a wide variety of configurations, and FIG. 2 does not limit the scope of the present disclosure to any particular implementation of a gNB.

[0047] As shown in FIG 2, the gNB 102 includes multiple antennas 200a-200n, multiple radio frequency (RF) transceivers 201a-201n, transmit (TX) processing circuitry 203, and receive (RX) processing circuitry 204. The gNB 102 also includes a controller / processor 205, a memory 206, and a backhaul or network interface 207.

[0048] The RF transceivers 201a-201n receive, from the antennas 200a-200n, incoming RF signals, such as signals transmitted by UEs in the network 100. The RF transceivers 201a-201n down-convert the incoming RF signals to generate intermediate frequency (IF) or baseband signals. The IF or baseband signals are sent to the RX processing circuitry 204, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The RX processing circuitry 204 transmits the processed baseband signals to the controller / processor 205 for further processing.

[0049] The TX processing circuitry 203 receives analog or digital data (such as voice data, web data, electronic mail, or interactive video game data) from the controller / processor 205. The TX processing circuitry 203 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate processed baseband or IF signals. The RF transceivers 201a-201n receive the outgoing processed baseband or IF signals from the TX processing circuitry 203 and up-converts the baseband or IF signals to RF signals that are transmitted via the antennas 201a-201n.

[0050] The controller / processor 205 can include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 205 could control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers 201a-201n, the RX processing circuitry 204, and the TX processing circuitry 203 in accordance with well-known principles. The controller / processor 205 could support additional functions as well, such as more advanced wireless communication functions.

[0051] For instance, the controller / processor 205 could support beam forming or directional routing operations in which outgoing signals from multiple antennas 200a-200n are weighted differently to effectively steer the outgoing signals in a desired direction. Any of a wide variety of other functions could be supported in the gNB 102 by the controller / processor 205.

[0052] The controller / processor 205 is also capable of executing programs and other processes resident in the memory 206, such as an operating system (OS). The controller / processor 205 can move data into or out of the memory 206 as required by an executing process.

[0053] The controller / processor 205 is also coupled to the backhaul or network interface 207. The backhaul or network interface 207 allows the gNB 102 to communicate with other devices or systems over a backhaul connection or over a network. The interface 207 could support communications over any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (such as one supporting 5G, LTE, or LTE-A), the interface 207 could allow the gNB 102 to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 207 could allow the gNB 102 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface 207 includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or RF transceiver.

[0054] The memory 206 is coupled to the controller / processor 205. Part of the memory 206 could include a random access memory (RAM), and another part of the memory 206 could include a Flash memory or other read only memory (ROM).

[0055] Although FIG. 2 illustrates one example of gNB 102, various changes may be made to FIG. 2. For example, the gNB 102 could include any number of each component shown in FIG. 2. As a particular example, an access point could include a number of interfaces 207, and the controller / processor 205 could support routing functions to route data between different network addresses. As another particular example, while shown as including a single instance of TX processing circuitry 203 and a single instance of RX processing circuitry 204, the gNB 102 could include multiple instances of each (such as one per RF transceiver). Also, various components in FIG. 2 could be combined, further subdivided, or omitted and additional components could be added according to particular needs.

[0056] FIG. 3 illustrates an example user equipment according to embodiments of the present disclosure. The embodiment of the UE 116 illustrated in FIG. 3 is for illustration only, and the UEs 111-115 and 117-119 of FIG. 1 could have the same or similar configuration. However, UEs come in a wide variety of configurations, and FIG. 3 does not limit the scope of the present disclosure to any particular implementation of a UE.

[0057] As shown in FIG. 3, the UE 116 includes an antenna 301, a radio frequency (RF) transceiver 302, TX processing circuitry 303, a microphone 304, and receive (RX) processing circuitry 305. The UE 116 also includes a speaker 306, a controller or processor 307, an input / output (I / O) interface (IF) 308, an input device 309, a touchscreen display 310, and a memory 311. The memory 311 includes an OS 312 and one or more applications 313.

[0058] The RF transceiver 302 receives, from the antenna 301, an incoming RF signal transmitted by an gNB of the network 100. The RF transceiver 302 down-converts the incoming RF signal to generate an IF or baseband signal. The IF or baseband signal is sent to the RX processing circuitry 305, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry 305 transmits the processed baseband signal to the speaker 306 (such as for voice data) or to the processor 307 for further processing (such as for web browsing data).

[0059] The TX processing circuitry 303 receives analog or digital voice data from the microphone 304 or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the processor 307. The TX processing circuitry 303 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 302 receives the outgoing processed baseband or IF signal from the TX processing circuitry 303 and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna 301.

[0060] The processor 307 can include one or more processors or other processing devices and execute the OS 312 stored in the memory 311 in order to control the overall operation of the UE 116. For example, the processor 307 could control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceiver 302, the RX processing circuitry 305, and the TX processing circuitry 303 in accordance with well-known principles. In some embodiments, the processor 307 includes at least one microprocessor or microcontroller.

[0061] The processor 307 is also capable of executing other processes and programs resident in the memory 311, such as processes for CSI reporting on uplink channel. The processor 307 can move data into or out of the memory 311 as required by an executing process. In some embodiments, the processor 307 is configured to execute the applications 313 based on the OS 312 or in response to signals received from gNBs or an operator. The processor 307 is also coupled to the I / O interface 308, which provides the UE 116 with the ability to connect to other devices, such as laptop computers and handheld computers. The I / O interface 308 is the communication path between these accessories and the processor 307.

[0062] The processor 307 is also coupled to the touchscreen display 310. The user of the UE 116 can use the touchscreen display 310 to enter data into the UE 116. The touchscreen display 310 may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and / or at least limited graphics, such as from web sites.

[0063] The memory 311 is coupled to the processor 307. Part of the memory 311 could include RAM, and another part of the memory 311 could include a Flash memory or other ROM.

[0064] Although FIG. 3 illustrates one example of UE 116, various changes may be made to FIG. 3. For example, various components in FIG. 3 could be combined, further subdivided, or omitted and additional components could be added according to particular needs. As a particular example, the processor 307 could be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Also, while FIG. 3 illustrates the UE 116 configured as a mobile telephone or smartphone, UEs could be configured to operate as other types of mobile or stationary devices.

[0065] How to improve the spectrum utilization of the communication system has always been a hot issue concerned by practitioners. In recent years, with the development of the operating frequency band of the communication system towards high frequency, the communication system will inevitably have resource conflicts with the radar system in the high frequency band. However, the communication system and the radar system are highly similar in terms of background theoretical knowledge and hardware structure, so the two seemingly independent systems can be converged theoretically to realize the function enhancement of the communication system and the improvement of the spectrum efficiency, thereby achieving the mutually beneficial effect. Therefore, the integrated sensing and communications (ISAC) is a hot research direction in the communication field and also one of the candidate technologies of 6G. The core purpose of the ISAC system is to use the same set of hardware devices to realize the function of sensing the surrounding environment at the expense of as few resources as possible on the basis of ensuring the basic communication function. The sensing contents include the distance, orientation, speed and even type of the object in the surrounding environment. Unlike the technology of locating the access terminal in the conventional communication system, the ISAC technology can also realize the sensing of various information of non-access objects, so that the capability of the communication system to dynamically adjust the operating state (scheduling, beam management, early warning of access terminals, etc.) according to the surrounding environment is greatly improved.

[0066] To realize the sensing function on the basis of ensuring the communication performance, the signal used by the ISAC technology should have both communication and sensing functions. Here, the communication function means that this signal can be used for frequency domain channel estimation and thus can assist in data demodulation. However, in a communication system, in order to reduce the probability of deep fading of each sub-carrier, the reference signal will be designed as a signal having constant amplitude in the frequency domain. However, for the sake of improving the sensing range and reducing the signal distortion, the reference signal with the sensing function is preferably a signal having constant amplitude in the time domain, that is, the peak to average power ratio (PAPR) is 0 dB. As a result, no matter whether linear frequency-modulated signals commonly used in radar or other constant amplitude signals, the spectrum amplitude will not be strictly constant, and the difference between the highest power and the lowest power can reach above 4 dB. Accordingly, lthough the reference signal with the sensing function can also be used for channel estimation, the reliability of channel estimation will be reduced. Therefore, how to further improve the channel estimation capability of the signal to better satisfy the requirements of ISAC when the reference signal in the ISAC technology can have both the channel estimation capability and the sensing capability is one of the technical problems to be solved.

[0067] In order to solve or improve one or more of the existing problems, the embodiments of the present disclosure provide a communication method (a method performed by a first node / second node in a wireless communication system) and a corresponding node. In this method, additional processing can be performed on a signal, so that the processed signal is constant in spectrum and also has a low enough PAPR. Moreover, by performing channel estimation based on the processed signal, the channel estimation result can be effectively improved.

[0068] The method provided in the embodiments of the present disclosure can be performed by any electronic device / node. For example, this node may be a user equipment in a wireless communication system or may be a network node, where the network node may be a base station or other network nodes (e.g., transmission / reception points (TRPs)).

[0069] It is to be noted that, some term names involved in the embodiments of the present disclosure may adopt the term names that already exist in the communication standards, while some term names may be newly added or defined term names. These newly added or defined term names may also adopt other names in future communication standards, or may be described in other ways (e.g., a paragraph of text description). The names or appellations of various information / messages / parameters / configurations involved in the embodiments of the present disclosure are not unique, and the names or appellations of these information / messages / parameters / configurations can be altered as long as the functions or contents of these information / messages / parameters / configurations or the explanations or descriptions of these information / messages / parameters / configurations can be corresponding or associated. For example, in the embodiments of the present disclosure, the configuration information may also be called a first message or other messages or signal configuration information; the first information may also be called indication information; the information related to sequence generation may also be called sequence information; the second information may also be called resource information; the resource information may be frequency domain resource information and / or time domain resource information; and, the first signal may also called a sensing signal, a channel estimation signal, a physical signal or other names.

[0070] The technical solutions provided by the present disclosure and the technical effects produced by the technical solutions will be described below by referring to some optional implementations. The following implementations can be referred to, learned from or combined with each other if not conflicted or contradicted, and the same terms, similar characteristics and similar implementation steps in different implementations will not be repeated. For the interaction steps between different nodes, the corresponding scheme of a network node at the other side can be obtained based on the description of the scheme of a network node at one side. For example, one network node receives configuration information from other network node. Correspondingly, it can be deduced that the other network node transmits the configuration information to the one network node. In an embodiment including multiple steps, if the multiple steps have no clear precedence order, the implementation order of the multiple steps is not uniquely defined in embodiments of the present disclosure.

[0071] The optional implementations of the method provided by the present disclosure will be further described below by referring to the principle of the solutions provided by the present disclosure and some optional embodiments, and the steps in different embodiments can be combined or replaced with each other if not conflicted.

[0072] FIG. 4 shows a method performed by a first node in a wireless communication system according to an embodiment of the present disclosure. The first node is a receiving node / receiver. Optionally, the first node may be a user equipment, or the first node may be an intermediate node in the communication system, for example, a relay node in a relay network. As shown in FIG. 4, the method may include the following steps.

[0073] In step S410, a first signal is received.

[0074] In step S420, it is determined whether the first signal is a signal that was subjected to power normalization.

[0075] In step S430, channel estimation is performed based on the first signal by a first method when the first signal is a signal that was subjected to power normalization, or channel estimation is performed based on the first signal by a second method when the first signal is a signal that was not subjected to power normalization.

[0076] In the embodiment of the present disclosure, the first signal is transmitted to the first node by a second node (which may be called a transmitter), wherein the first signal may be a physical signal generated by the second node in a time domain resource mapping manner. Optionally, the second node may generate a first sequence and maps the first sequence to a time domain resource to obtain a second signal. The second signal may be used as the first signal, or the second signal is subjected to power normalization to obtain the first signal.

[0077] In the embodiment of the present disclosure, environment sensing (the sensing content may include, but not limited to, the physical distance, orientation, speed, type or the like in the environment) and / or channel estimation may be performed based on the first signal. That is, the first signal may be used as a sensing signal or a reference signal.

[0078] For the convenience of description, in the embodiment of the present disclosure, the first signal may also be called the received physical signal, and the third signal generated by the first node hereinafter may also be called a local physical signal.

[0079] Optionally, the first signal may be used for channel estimation, and the first node may generate a local physical signal according to the configuration of the second node (e.g., base station) and perform channel estimation based on the local physical signal and the received physical signal. The local physical signal and the received physical signal are generated by time domain resource mapping.

[0080] In the embodiment of the present disclosure, the signal power normalization may also be called signal power standardization or signal scaling, and means normalization on the power of the signal, i.e., scaling of the signal, which may be scaling of the signal amplitude (amplitude of the signal frequency domain). The signal power normalization can achieve the same average power in different modulation modes.

[0081] Optionally, the power normalization is power normalization at a sub-carrier level, that is, power normalization is performed on signals on resource units.

[0082] By using this solution, the signal amplitude of the received physical signal (i.e., the power-normalized signal generated by the second node) on all sub-carriers can be the same (that is, the normalized signal has the same signal amplitude on each sub-carrier within the signal bandwidth), and there is no situation where the signal amplitude on individual sub-carriers is too low. Accordingly, the probability of deep fading of the signal on individual sub-carriers is effectively reduced, and it is beneficial to the accuracy of channel estimation.

[0083] In the embodiment of the present disclosure, when the first node needs to perform channel estimation, by learning whether the received physical signal is a signal that was subjected to power normalization, it can be determined whether the local physical signal also needs to be subjected to power normalization during channel estimation. Thus, channel estimation may be performed by using the received physical signal that was not subjected to power normalization and the local physical signal that was not subjected to power normalization, or channel estimation may be performed by using the received physical signal that was subjected to power normalization and the local physical signal that was subjected to power normalization, thereby ensuring the accuracy of the channel estimation result. That is, whether the received physical signal was subjected to power normalization will affect the subsequent operation of the first node.

[0084] The specific way of learning by the first node whether the received signal has been subjected to power normalization will not be uniquely defined in the embodiment of the present disclosure. As an optional solution, the first node may explicitly learn whether the received signal was subjected to power normalization. This solution may include:

[0085] receiving first information for indicating whether the received signal is a signal that was subjected to power normalization; and, determining, based on the first information, whether the first signal is a signal that was subjected to power normalization.

[0086] In this solution, the first information may be explicit indication information, and the first information may be called power normalization indication information. The indication information indicates that the received signal is a signal that was subjected to power normalization, or indicates that the received signal is a signal that was not subjected to power normalization. The form of the power normalization indication information will not be limited in the embodiment of the present application. For example, the signal transmitting terminal / transmitter may transmit configuration information to the first node before or when transmitting the first signal. The configuration information may include power normalization indication information. For example, the power normalization indication information may occupy 1 bit in the configuration information. If the value of this bit is 1, it indicates that power normalization has been performed; and, if the value of this bit is 0, it indicates that power normalization has not been performed. Or, the configuration information may be resource configuration information, for example, resource configuration information related to the generation of the local physical signal. The power normalization indication information may be a newly added field in the configuration information, or may be an existing field in the resource configuration information. This field may be redefined or reused as the power normalization indication information. As an optional solution, the first information may be cyclic prefix indication information. If the indication information indicates to the first node that received physical signal is a signal with a cyclic prefix, it indicates that the signal is a signal that was subjected to power normalization; otherwise, the signal is not a signal that was subjected to power normalization.

[0087] Optionally, the power normalization indication information may be aperiodic, semi-persistent, or periodic. That is, the timeliness of the power normalization indication information may be configured to as required. For example, the power normalization indication information may be only applied to the currently received physical signal, i.e., the first signal as described above, or the first information may be applied to signals (including the first signal) received in a long period of time (e.g., several time slots). The power normalization indication information may be used for determining whether the signals for channel estimation received in this long period of time (e.g., in several time slots after receiving the power normalization indication information) are normalized signals. Or, the first information is periodically valid.

[0088] The specific configuration mode of the first information will not be limited in the embodiment of the present disclosure. Optionally, the first information may be acquired from a physical layer signaling, or may be acquired from a media access control (MAC) layer signaling, or may be acquired from a high-layer signaling.

[0089] Optionally, the first node may also implicitly determine whether the received physical signal is a signal that was subjected to power normalization. For example, the first node may perform determination based on the information about determining whether the signal is subjected to power normalization appointed in the protocol. As an optional solution, the determining whether the first signal is a signal that was subjected to power normalization as described above may include:

[0090] determining, based on at least one of the following, whether the received signal is a signal that was subjected to power normalization:

[0091] whether there is data to be received in the time unit (time slot) where the first signal is located;

[0092] whether a demodulation reference signal is configured in the time unit where the first signal is located;

[0093] the comparison result of the bandwidth of the demodulation reference signal configured in the time slot where the first signal is located with the bandwidth of the first signal; and

[0094] whether the data received in the time slot where the first signal is located is data transmitted by multiple ports.

[0095] In this optional solution, the first node may determine, according to whether there is data or signal to be received in the time unit where the first signal is located, whether the first signal is a signal that has subjected to power normalization. In this way, the first node may implicitly determine whether the first signal was subjected to power normalization by executing the above determination operation.

[0096] In the embodiment of the present disclosure, optionally, if there is data or signal to be demodulated in the time unit where the first signal is located, the first node requires a more accurate channel estimation result. Therefore, to improve the accuracy of channel estimation, the signal used for channel estimation should have a constant amplitude in the frequency domain, so that the signal can better satisfy the communication requirements; and, the first signal should be a signal that was subjected to power normalization in the frequency domain. Based on this, the first node may assume, according to whether there is data and / or signal to be received in the time unit where the received signal is located, whether the received first signal was subjected to power normalization. For example, if there is data to be received in this time unit and a demodulation reference signal is configured, the first node should assume that the channel estimation result will be used for subsequent signal demodulation, and the quality of channel estimation my affect signal demodulation and thus affect the quality of the communication system. At this time, the first node should assume that the received signal (including the first signal) is a signal that was subjected to power normalization.

[0097] Optionally, the first node determines that the received signal is a signal that was subjected to power normalization when at least one of the following is satisfied:

[0098] there is data to be received in the time unit where the first signal is located;

[0099] a demodulation reference signal is configured in the time unit where the first signal is located;

[0100] the bandwidth of the demodulation reference signal configured in the time unit where the first signal is located is not greater than the bandwidth of the first signal; and

[0101] the data received in the time unit where the first signal is located is not data transmitted by multiple ports.

[0102] In the embodiment of the present disclosure, the granularity / unit of the time unit will not be limited in the embodiment of the present disclosure. The time domain resource occupied by the first signal is the sub-unit in the time unit where the first signal is located. For example, one time unit may be one time slot or a time unit with other granularities, and the sub-unit may be a OFDM symbol. For example, the first signal is transmitted by the second node on one or some symbols in the time slot 1, and the time unit there the first signal received by the first node is located is the time slot 1. If the first node determines that at least one of the following is satisfied: there is data to be received on other symbols in the time slot 1, a demodulation reference signal being configured in the time slot 1 and the bandwidth of the demodulation reference signal is less than or equal to the bandwidth of the first signal, or the data received in the time slot 1 is not data transmitted by multiple ports, the first node should assume that the first signal transmitted by the second node is a signal that was subjected to power normalization. For example, when all of the four conditions are satisfied, the first node considers that the received first signal is a signal that was subjected to power normalization. Optionally, the first node may receive downlink control information (DCI) and then determines according to the DCI whether at least one of the four conditions is satisfied.

[0103] In an optional embodiment of the present disclosure, the first node should assume that the first signal is obtained based on a second signal, wherein the second signal is generated by mapping a second sequence to a time domain resource; the first signal is the second signal when the first signal is a signal that was not subjected to power normalization; and, the first signal is obtained by performing power normalization on the second signal when the first signal is a signal that was subjected to power normalization.

[0104] That is, the first node should assume that the second node generates the first signal in the following ways:

[0105] mapping a first sequence to the time domain resource to obtain a second signal; and

[0106] using the second signal as the first signal when the first signal is not a signal that was subjected to power normalization, or performing power normalization on the second signal to obtain the first signal when the first signal is a signal that was subjected to power normalization.

[0107] In the embodiment of the present disclosure, the form of the sequence used for generating the second signal will not be limited. The sequence may include, but not limited to, a Chirp sequence or a chaotic frequency modulated sequence. It should be understood that the second signal and the local physical signal should be generated in the same signal generation mode. If the first signal is a signal that was subjected to power normalization, after the first sequence is mapped to the time domain resource to generate the second signal, the second signal needs to be subjected to power normalization; and, if the first signal is a signal that was not subjected to power normalization, the second signal is directly used as the first signal. By performing time domain mapping on the first sequence to generate the physical signal, instead of performing resource mapping in the frequency domain and then performing inverse Fourier transform, the generated time domain signal can have a lower PAPR and be not easily affected by nonlinear factors, and can better satisfy the communication requirements.

[0108] The first sequence may be generated by the second node in advance or may be generated in real time, and the second signal may be a physical signal generated in advance or in real time. For example, the second node (e.g., the base station, or the relay node according to the configuration of the base station) may determine the resource actually occupied by the first signal to be generated, and the resource may include a time domain resource and / or a frequency domain resource. The second node maps the first sequence onto the resource actually occupied by the first signal to be generated, to obtain the second signal. If it is determined that signal power normalization is to be performed, the second signal is scaled to obtain the first signal that was subjected to power normalization; and, if power normalization is not performed, the second signal is used as the first signal that was not subjected to power normalization.

[0109] To perform channel estimation, the second node may transmit to the first node the resource configuration information related to the resource actually occupied by the first signal, and the first node may receive, based on the resource configuration information, the first signal transmitted by the second node on the resource actually occupied by the first signal. Correspondingly, the first node may generate a local sequence (second sequence) and then map the local sequence to the time domain resource actually occupied by the first signal to obtain a local physical signal, so that channel estimation is performed based on the local physical signal and the received physical signal.

[0110] In the embodiment of the present disclosure, the resources configured for the first node may include time domain resources and frequency domain resources, and the time domain resources and the frequency domain resources may be configured for the user equipment jointly or separately. The information related to the generation of the local physical signal may include at least one of the information related to the generation of the local sequence and the information related to the time domain resource actually occupied by the first signal. The two pieces of information may be configured simultaneously or separately. For example, the base station may first configure the information related to the generation of the local sequence for the user equipment, and then configure the information related to the time domain resource actually occupied by the first signal for the user equipment when it is required to transmit the first signal to the user equipment.

[0111] Optionally, the resource configured in the resource configuration information as described above may be the resource actually occupied by the first signal, or the resource configuration information includes the related information of resources (total resources) configured for the first node and the related information for determining the resource actually occupied by the first signal from the resources configured for the first node (e.g., the information related to resources that cannot be occupied by the first signal, or the information related to the resource actually occupied by the first signal). At this time, the resource actually occupied by the first signal is a subset of the total resources.

[0112] In the embodiment of the present disclosure, when first node determines that the received signal is a signal that was subjected to power normalization, the first node should assume that the first signal is obtained by performing inverse Fourier transform on a second frequency domain signal, the second frequency domain signal is obtained by performing power normalization on a first frequency domain signal, and the first frequency domain signal is obtained by performing Fourier transform on the second signal.

[0113] Since the second signal is a time domain signal and the signal power normalization operation is performed in the frequency domain, when the second node generates the first signal that was subjected to power normalization, it is necessary to first perform time frequency transform (i.e., Fourier transform) on the second signal to obtain the first frequency domain signal, then perform power normalization on the first frequency domain signal and perform inverse Fourier transform on the normalized second frequency domain signal to obtain the first signal that was subjected to signal power normalization.

[0114] The specific way of performing power normalization on the first frequency domain signal is not uniquely limited in the embodiment of the present disclosure. Optionally, the signal amplitude of the first frequency domain signal may be scaled according to the signal scaling coefficient to achieve normalization process. The signal scaling coefficient may be a coefficient related to the second signal. For example, the signal scaling coefficient may be determined according to the information of the second signal itself, or the signal scaling coefficient may also be determined in other ways. For example, power normalization may be performed on the first frequency domain signal based on at least one of the following:

[0115] a first coefficient β; the length N of the sequent for generating the second signal, i.e., the number of elements in the first sequence; and, a parameter related to windowing.

[0116] The β is associated with the transmit power of the first signal. When the second node generates the second signal, after the first sequence is mapped to the time domain resource to generate a time domain signal, the signal may be scaled by using a scaling factor β to satisfy the transmit power requirement of the signal. Based on this, when the first signal is obtained based on the second signal, since the average power of the signal remains unchanged, the normalization of the signal may be related to the power scaling factor β.

[0117] Since the second signal is generated by mapping the first sequence to the time domain resource, the length of the sequence for generating the second sequence (i.e., the number of elements in the sequence) determines the number of sample points in the signal actually to be transmitted. Therefore, the power normalization of the signal may also be related to the length of the sequence. In addition, if the signal is windowed during the generation of the first signal, the way of power normalization may also be related to the parameter related to windowing, for example, the size of the window or other parameters.

[0118] Optionally, the first frequency domain signal and / or the second frequency domain signal satisfies at least one of the following:

[0119] the first frequency domain signal has the same bandwidth as the second frequency domain signal;

[0120] the first frequency domain signal occupies the same sub-carriers as the second frequency domain signal;

[0121] the second frequency domain signal has the same signal amplitude on each sub-carrier within its bandwidth;

[0122] the signal amplitude of the second frequency domain signal is of a first value, the first value being determined based on the signal amplitudes on all sub-carriers of the first frequency domain signal within its bandwidth;

[0123] the second frequency domain signal and the first frequency domain signal have the same signal phase on the same sub-carrier;

[0124] the signal amplitude of a sub-carrier of the second frequency domain signal outside its bandwidth is a second value;

[0125] the signal phase of a sub-carrier of the second frequency domain signal outside its bandwidth is a third value; and

[0126] the signal amplitude and signal behavior of a sub-carrier of the second frequency domain signal outside its bandwidth are 0.

[0127] The first value may be directly calculated according to the signal amplitudes of the first frequency domain signal on all sub-carriers, or may be obtained in other ways. Optionally, the first value may be equal to the arithmetic mean value of the signal amplitudes of the first frequency domain signal on all sub-carriers within its bandwidth.

[0128] In the embodiment of the present disclosure, the signal amplitude and signal phase of the normalized second frequency domain signal on a sub-carrier outside its bandwidth may be arbitrary values, that is, the second value and the third value may be arbitrary values, because the sub-carriers outside the bandwidth will not affect the finally resultant first signal. Optionally, the second value and the third value may be 0. The signal amplitudes of the second frequency domain signal on all sub-carriers within its bandwidth are kept equal, so that the first signal has a constant amplitude in the frequency domain, which can be beneficial for channel estimation. By using the solution of maintaining the original phase before normalization, although the PAPR of the first signal in the time domain may be deteriorated, the degree of deterioration is relatively low, and the nonlinear interference in the first signal will not be increased obviously.

[0129] Optionally, if it is determined that the first signal is a signal that was subjected to power normalization, when the first node performs channel estimation, it is also necessary to perform power normalization on the generated local physical signal. Fourier transform is first performed on the local physical signal, power normalization is then performed on the frequency domain signal after transform, and the channel estimation result is calculated based on the time frequency transform result of the normalized frequency domain signal and the received physical signal. When the first node performs power normalization on the frequency domain signal corresponding to the local physical signal, optionally, the amplitude of the frequency domain signal after power normalization may be obtained by calculating the signal amplitudes of the frequency domain signal on all sub-carriers. Optionally, it is also possible that the second node informs the first node of the corresponding power normalization coefficient and the first node scales the amplitude of the frequency domain signal before normalization based on this coefficient to obtain the normalized amplitude.

[0130] As an optional solution, the second frequency domain signal is obtained by remapping the signal, which is obtained after performing power normalization on the signal on each sub-carrier in the first frequency domain signal within a signal bandwidth, to the corresponding sub-carrier.

[0131] Optionally, the signals (amplitudes of signals) of the sub-carriers within the bandwidth of the physical signal may be extracted from the first frequency domain signal to form a sequence a, and a sequence b is obtained according to the sequence a, wherein the amplitude of each element in the sequence b is equal to the square root of the arithmetic mean value of the squares of the amplitudes of all elements in the sequence a, and the phase of any element in the sequence b is the same as the phase sequence of the corresponding element in the second sequence. After the sequence b is obtained, the sequence b may be remapped to each sub-carrier within the bandwidth of the physical signal sequentially (to obtain the second frequency domain signal) and then subjected to inverse Fourier transform to obtain the first signal.

[0132] Based on the above solutions provided in the embodiment of the present disclosure, the power-normalized signal at a sub-carrier level can be obtained. If the first signal is used for channel estimation and if the first signal is a signal that has been subjected to power normalization, the second node must notify the first node that whether power normalization has been performed on the transmitted first signal during its generation, or the first node must determine, based on the related information, whether the received first signal is a signal that was subjected to power normalization. This is because whether the normalization was performed or not will affect the subsequent operation of the first node.

[0133] In the embodiment of the present disclosure, in a channel estimation scenario, the performing channel estimation includes:

[0134] generating a third signal; and

[0135] performing channel estimation based on the first signal and the third signal.

[0136] The performing channel estimation based on the first signal and the third signal includes:

[0137] performing Fourier transform on the first signal to obtain a third frequency domain signal;

[0138] performing Fourier transform on the third signal to obtain a fourth frequency domain signal;

[0139] when it is determined that the first signal is a signal that was not subjected to power normalization, performing channel estimation based on the third frequency domain signal and the fourth frequency domain signal; and

[0140] when it is determined that the first signal is a signal that was subjected to power normalization, performing power normalization on the fourth frequency domain signal to obtain a fifth frequency domain signal, and performing channel estimation based on the fifth frequency domain signal and the third frequency domain signal.

[0141] The third signal may be called a local physical signal which is generated by the first node by mapping the second sequence to the time domain resource. If the first node learns that the received signal was not subjected to power normalization, the first node may directly perform channel estimation based on the local physical signal and the first signal. For example, the channel estimation result may be obtained by calculating of the ratio of the signal amplitude of the local physical signal to the signal amplitude of the first signal in the frequency domain. If the first node learns that the received signal was subjected to power normalization, the first node needs to perform power normalization on the local physical signal, and then performs channel estimation based on the signal that was subjected to power normalization and the first signal.

[0142] It should be understood that the first node should generate the local physical signal in the same way as generating the second signal by the second node.

[0143] Optionally, the first node may acquire second information related to the generation of the third signal and then generate the third signal based on the second information. The second information related to signal generation may include third information related to the generation of the second sequence and fourth information related to the resource actually occupied by the signal. The first node may generate the second sequence based on the third information and map the second sequence to the time domain resource based on the fourth information to obtain the third signal.

[0144] In the embodiment of the present disclosure, the fourth information may include the information related to the time domain resource actually occupied by the signal, and may also include a frequency domain resource. The first node may map, based on the time domain resource actually occupied by the third signal, the second sequence to the time domain resource to obtain the third signal. It should be understood that the resource actually occupied by the third signal is the same as the resource actually occupied by the first signal.

[0145] The third information and the fourth information may be configured simultaneously or separately. If the first node determines, based on the power normalization indication information, that whether the received physical signal was a normalized signal, the power normalization indication information and the fourth information may be configured simultaneously or separately. Optionally, the method may further include:

[0146] receiving configuration information, the configuration information including resource configuration information and power normalization indication information.

[0147] Optionally, in the embodiment of the present disclosure, in a channel estimation scenario, the first signal may be a signal with a cyclic prefix as default. Of course, it is also possible that the second node transmits the corresponding indication information to the first node and informs the first node whether the received first signal has a cyclic prefix by using the indication information.

[0148] Upon acquiring the third information and the fourth information, the first node may generate, based on the third information, a second sequence for generating the local physical signal, and the first node may determine at least the time domain resource actually occupied by the first signal according to the fourth information and map the second sequence to the time domain resource to generate the local physical signal (i.e., the third signal).During channel estimation, if the first node determines that the received physical signal is a signal that was subjected to power normalization, the first node will perform power normalization on the third signal.

[0149] As an implementation of the embodiment of the present disclosure, the method may include:

[0150] receiving information related to the generation of the third signal and power normalization indication information;

[0151] receiving the first signal;

[0152] generating the third signal based on the information related to the generation of the third signal;

[0153] performing time frequency transform on the first signal to obtain a third frequency domain signal;

[0154] performing time frequency transform on the third signal to obtain a fourth frequency domain signal;

[0155] if it is determined based on the power normalization indication information that the first signal is not a signal that was subjected to power normalization, performing channel estimation based on the third frequency domain signal and the fourth frequency domain signal; and

[0156] if it is determined based on the power normalization indication information that the first signal is a signal that was subjected to power normalization, performing power normalization on the fourth frequency domain signal to obtain a fifth frequency domain signal, and performing channel estimation based on the fifth frequency domain signal and the third frequency domain signal, for example, performing division on the signal on each sub-carrier of the fifth frequency domain signal within the signal bandwidth and the signal on the corresponding sub-carrier of the third frequency domain signal to obtain a frequency domain channel value on each sub-carrier.

[0157] The way of performing, by the first node, power normalization on the fourth frequency domain signal to obtain the fifth frequency domain signal may refer to the above way of performing signal power normalization on the first frequency domain signal to obtain the second frequency domain signal and will not be repeated here.

[0158] The present disclosure further provides an optional communication method. The method may be a method performed by a second node in a communication system. The method includes the following steps of:

[0159] transmitting a first signal, the first signal being a signal that was subjected to power normalization or a signal that was not subjected to power normalization;

[0160] wherein if the first signal is a signal that was subjected to power normalization, the first signal is used to perform channel estimation by a first method, or if the first signal is a signal that was not subjected to power normalization, the first signal is used to perform channel estimation by a second method.

[0161] The second node may be a transmitting node / transmitter, e.g., a base station. The transmitter transmits a first signal for channel estimation to a receiver, and the receiver may generate a local physical signal based on the received second information and perform channel estimation based on the received first signal and the local physical signal. The receiver may perform channel estimation by different methods according to whether the first signal is a signal that was subjected to power normalization.

[0162] Optionally, the method further includes:

[0163] transmitting first information for indicating whether the transmitted signal is a signal that was subjected to power normalization.

[0164] The method performed by a second node corresponds to the essential content of the method performed by a first node described above, except that one method is described from the perspective of the transmitter while the other method is described from the perspective of the receiver. Other optional implementations of the method performed by a second node may refer to the corresponding description in the above embodiments and will not be repeated here.

[0165] To better explain the solutions provided by the present disclosure, the solutions will be described in more detail below by various specific embodiments. Some embodiments of the present disclosure will be described below by taking the first node as an executive body. It should be understood that the steps involved in these embodiments may also be described by taking the second node as an executive body. For example, the first node receiving information may be described as the second node transmitting information. For another example, the first node should assume that the first signal is generated in the following way. Since the first signal is transmitted by the second node, it can be correspondingly described as: the second node generates the first signal in the following way.

[0166] In the solutions provided in the embodiments of the present disclosure, the signal can be allowed to have the advantages of very low PAPR and the smallest probability of deep fading, and thus can better satisfy the signal requirement in the ISAC system.

[0167] It is to be noted that, during practical implementations, some steps in the following embodiments may be omitted or replaced in other ways that can achieve the same purpose. For example, the way of generating the sequence for generating the physical signal will not be limited in the present disclosure, and the acquisition or configuration of information such as the information for generating the local sequence and the resource actually occupied by the signal will also not be limited in the present disclosure. It is possible to adopt the ways given in the embodiments of the present disclosure, but it is not limited thereto.

[0168] As an optional embodiment, FIG. 5 shows a schematic flowchart of a method performed by a first node according to the present application. As shown in FIG. 5, the method may include the following steps.

[0169] In S510, configuration information of a physical signal is acquired.

[0170] In S520, a physical signal (first signal) is received according to the configuration information.

[0171] In S530, a local physical signal is generated in time domain according to the configuration information.

[0172] In S540, channel estimation is performed according to the received physical signal and the local physical signal.

[0173] The configuration information may include at least one of the following:

[0174] sequence information related to the sequence for generating the physical signal (it should be understood that the sequence information can be construed as information related to the generation of the first sequence or can also be construed as information related to the generation of the second sequence); resource information related to the time-frequency domain resource allocated for the physical signal (similarly, the resource information here can be construed as the resource information corresponding to the local physical signal or can also be construed as the resource information corresponding to the received physical signal); and, first information.

[0175] Optionally, the configuration information includes the first information. The information is power normalization indication information, and the power normalization indication information is used to indicate whether the received signal was subjected signal power normalization on the signal on each resource unit within the signal bandwidth during its generation process.

[0176] Optionally, the configuration information may also not include the first information. Optionally, when the following conditions are all satisfied, the first node assume that the received physical signal was subjected to signal power normalization on each resource unit during its generation process by default; otherwise, the first node should assume that the received physical signal was not subjected to signal power normalization on each resource unit during its generation process:

[0177] ① the first node needs to receive data in the time slot where the physical signal is located;

[0178] ② the first node configures a demodulation reference signal in the time slot where the physical signal is located;

[0179] ③ the bandwidth of the configured demodulation reference signal is not greater than the bandwidth of the physical signal; and

[0180] ④ the data received by the first node in the time slot where the physical signal is located is not transmitted by multiple ports, or the physical signal is not transmitted by multiple ports.

[0181] Based on the configuration of the second node, the first node may receive a physical signal transmitted by the base station on a transmission resource corresponding to the physical signal, as shown in step S520. The configuration information may include resource information related to the time domain resource and / or frequency domain resource allocated for the physical signal. The first node may receive the physical signal on the corresponding resource based on this information in the configuration information. Correspondingly, the first node may generate a local physical signal based on the configuration information. For example, the first node generates a local sequence (second sequence) for generating the local physical signal according to the configuration information, and performs resource mapping on the local sequence in the time domain according to the resource information to obtain the local physical signal (third signal). The sequence type / form of the local sequence will not be limited in the embodiment of the present disclosure.

[0182] After generating the local physical signal, the first node may perform channel estimation based on the local physical signal and the received physical signal. Optionally, the performing channel estimation may include:

[0183] performing Fourier transform on the local physical signal to obtain a fourth frequency domain signal; obtaining a fifth frequency domain signal from the fourth frequency domain signal according to the first information (power normalization indication information); and, performing channel estimation according to the received physical signal and the fifth frequency domain signal.

[0184] If the power normalization indication information indicates that the received physical signal was not subjected to power normalization on each resource unit during its generation process, the fifth frequency domain signal is the fourth frequency domain signal; and, if the first information indicates that the received physical signal was subjected to power normalization, the fifth frequency domain signal that has the same bandwidth and occupies the same sub-carrier as the fourth frequency domain signal may be generated from the fourth frequency domain signal. Optionally, the fourth frequency domain signal has the same signal amplitude on each sub-carrier within its bandwidth, and the amplitude is the square root of the arithmetic mean value of the squares of the signal amplitudes of the third frequency domain signal on all sub-carriers within its bandwidth; and, the signal phase of the fourth frequency domain signal on each sub-carrier within its bandwidth is the same as the signal phase of the third frequency domain signal on the same sub-carrier. That is, the frequency domain resources occupied by the third frequency domain signal and the fourth frequency domain signal before and after normalization and the signal phases on the same sub-carrier remain unchanged. In addition, the signal amplitude and signal phase of the fourth frequency domain signal on each sub-carrier outside its bandwidth will not be limited and may all be zero.

[0185] The performing channel estimation according to the received physical signal and the fifth frequency domain signal may include: performing Fourier transform on the received physical signal to obtain a third frequency domain signal; and, performing division on the third frequency domain signal on each sub-carrier within the signal bandwidth and the fifth frequency domain signal on the corresponding sub-carrier to obtain a frequency domain channel value on each sub-carrier. That is, division is performed on the local physical signal and the received physical signal in the frequency domain to obtain the signal estimation result.

[0186] Although the sequence (the first sequence or the second sequence) for generating the physical signal is not limited in the embodiment of the present application, in order to explain the specific steps in the solutions provided in the embodiment of the present disclosure more clearly, the sequence for generating the physical signal will be explained by taking a Chirp sequence as an example in some of the following embodiments.

[0187] Optionally, the solution provided in the embodiment of the present disclosure may include at least some of the following steps 1 to 4.

[0188] In step 1, the first node acquires configuration information.

[0189] Optionally, the configuration information may include resource information, and the first node may directly or indirectly acquire, from the resource information in the configuration information, a parameter related to the generation of a physical signal and / or a parameter related to the resource actually occupied by the physical signal. Optionally, the configuration information may include, but not limited to, the following parameters:

[0190] ① the serial number kstartof the sub-carrier with the lowest frequency within the bandwidth allocated for the physical signal;

[0191] ② the serial number kendof the sub-carrier with the highest frequency within the bandwidth allocated for the physical signal;

[0192] ③ the serial number l0of the OFDM symbol allocated for the physical signal in the time slot;

[0193] ④ the number N of time domain sample points allocated for the physical signal; and

[0194] ⑤ the serial number Dstart(which may also be considered as offset) of the sample point where the first element of the physical signal is located in the OFDM symbol. The sample point of Dstart=0 is the first sample point in one OFDM symbol except for the cyclic prefix.

[0195] The kstartand kendrepresent the index of the lowest sub-carrier (minimum index number) and the index of the highest sub-carrier (maximum index number) actually occupied by the physical signal, respectively, i.e., the minimum index number and the maximum index number of the actually occupied sub-carriers. The number of sub-carriers actually occupied by the physical signal may be determined according to kstartand kend.

[0196] The l0represents the index of the OFDM symbol actually occupied by the physical signal in the time slot, i.e., an OFDM symbol index. It may be determined according to this index that the physical signal is transmitted on the OFDM symbol.

[0197] The number N of time domain sample points is the length of the sequence for generating the physical signal, i.e., the number of elements in the sequence.

[0198] The Dstartis the index of the sample point that actually transmits the first element of the physical signal in the first OFDM symbol actually occupied by the physical signal, and the physical signal starts to be transmitted at the moment corresponding to this sample point.

[0199] The specific ways of learning various parameters listed above will not be limited in the embodiment of the present disclosure, and the parameters may be directly indicated in the resource information or indirectly inferred from other parameters. For example, if the serial number pstartof the resource block with the lowest frequency within the bandwidth allocated for the physical signal may be obtained from the resource information, kstartmay be calculated according to kstart=12pstart; if the number M of resource blocks within the bandwidth allocated for the physical signal may be obtained from the resource information, kendmay be calculated according to kend=kstart+12M-1; if the time domain length (i.e., the number N of time domain sample points) of the physical signal is given as the proportion α of this length in the length of one OFDM symbol, N may be calculated according to N=[αㆍNFFT], where NFFTis the number of Fourier transform points, and [ㆍ] is the rounding operation; if the serial number Dstart(i.e., offset) of the sample point where the first element of the physical signal is located in the OFDM symbol is given as the proportion β in the length of one OFDM symbol, N may be calculated according to Dstart=[βㆍNFFT]; and, the l0may be configured for the first node through the configuration information, or may be a value known by the first node by default.

[0200] In step S2, a physical signal is received.

[0201] The first node receives a physical signal on the resource corresponding to the physical signal. The first node may learn the resource actually occupied by the physical signal according to the resource information configured for the physical signal and receive the physical signal on this resource. Optionally, the resource information may be configured to the first node by the second node through the configuration information in the step 1, or may be configured to the first node by the second node through other configurations independent of the configuration information.

[0202] Optionally, by taking a Chirp sequence, the first node should assume that the received physical signal is generated in the following way.

[0203] The first node should assume that the sequence s[n] (i.e., the first sequence) is defined as:

[0204]

[0205] or

[0206]

[0207] where N represents the length of the sequence, the value of n is the index of an element in the sequence, and n=0 represents the first element. The NFFTis the number of inverse Fourier transform points and the number of Fourier transform points, and is the parameter that must to be acquired by the first node when accessing to the network.

[0208] Any one of the above two implementations may be adopted, and there is no essential difference between the two.

[0209] The first node should assume that the sequence s[n] is mapped to a time domain resource to obtain the received physical signal. Optionally, to satisfy the requirements of the transmit power, the first node should assume that the sequence s[n] is scaled by using the factor β to satisfy the requirements of the transmit power and mapped to the (Dstart+n)thsample point on the (l0)thOFDM symbol according to the following formula:

[0210]

[0211] If the power normalization indication information indicates that the received physical signal was not subjected to signal power normalization on each resource unit during its generation process, the first node should assume the physical signal as x[n]=xnoCP[(n-NCP) mod NFFT], where mod represents the operation of taking the remainder, and NCPis the number of points of the cyclic prefix.

[0212] If the power normalization indication information indicates that the received physical signal was subjected to signal power normalization on each resource unit during its generation process, the first node should assume that the physical signal is generated in the following ways:

[0213] ① NFFT-point Fourier transform is performed on xnoCP[n] to obtain a first frequency domain signal X1[k], where k=0,1,…,NFFT-1.

[0214] ② Power normalization is performed on X1[k] to obtain a second frequency domain signal X2[k].

[0215] Optionally,

[0216]

[0217] where

[0218] where M=kend-kstart+1 represents the number of sub-carriers within the signal bandwidth, i.e., the number of sub-carriers actually occupied by the physical signal.

[0219] ③ NFFT-point inverse Fourier transform is performed on X2[k] to obtain [n], where n=0,1,…,NFFT-1.

[0220] ④ The physical signal x[n]= [(n-NCP) mod NFFT] is obtained based on [n], where mod represents the operation of taking the remainder.

[0221] The first node receives, on the (l0)thOFDM symbol, the signals on all NCP+NFFTsample points, discards first NCPpieces of data, and merely reserves last NFFTpieces of data to obtain the received physical signal, which is denoted by y[n], where n=0,1,…,NFFT-1.

[0222] The signal processing method provided in the embodiment of the present disclosure has the following beneficial effects.

[0223] If power normalization was not performed, the physical signal transmitted by the second node can completely maintain the original characteristics of the sequence, and the PAPR of the physical signal is relatively low, so that the physical signal can be transmitted at higher power, and the signal to noise ratio can be improved. On the other hand, a very low PAPR can make the physical signal not be affected by the nonlinear characteristics of the power amplifier when passing through the power amplifier.

[0224] If power normalization was performed, the physical signal transmitted by the second node can have the same signal amplitude on all sub-carriers, and there is no situation where the signal amplitude on individual sub-carriers is relatively low. Accordingly, the probability of deep fading on this sub-carrier is reduced, which is beneficial to the accuracy of channel estimation. On the other hand, since the original phase is maintained, although the PAPR of the physical signal in the time domain is deteriorated, the degree of deterioration is relatively low, and the nonlinear interference in the received physical signal will not be increased obviously.

[0225] As an example, FIGS. 6 and 7 show schematic diagrams in which change of the physical signal in the frequency domain before and after power normalization is shown. In this example, the normalized spectral amplitude is adjusted as 1. It can be seen from FIG. 6 that the physical signal has a constant amplitude in the frequency domain. It can be seen from FIG. 7 that the PAPR (shown by the vertical axis) of the normalized signal will be increased. It can also be seen from FIG. 7 that the PAPR will be very low and the signal can have better sensing capability if the physical signal was not subjected to power normalization. Thus, based on the solutions provided in the embodiment of the present disclosure, it can be determined, according to the practical application scenario, whether to perform power normalization on the physical signal or not, and the physical signal can satisfy both the sensing requirements and the communication requirements.

[0226] In step 3, a local physical signal is generated in time domain according to the configuration information.

[0227] The order in which the first node receives the physical signal and the first node generates the physical signal will not be limited in the embodiment of the present disclosure. The step 3 may include the following steps.

[0228] In step 3.1, a local sequence for generating the local physical signal is generated according to the configuration information.

[0229] Since a Chirp sequence is taken as an example in this embodiment, the first node may generate the local sequence in the following way:

[0230]

[0231] or

[0232]

[0233] Any one of the above two sequences can be sampled, and there is no difference between the two as long as the used sequence generation method is the same as that in the transmitting end.

[0234] In step 3.2, resource mapping is performed on the local sequence in the time domain according to the resource information to obtain the local physical signal.

[0235] Optionally, the local physical signal xlocal[n] may be obtained in the following way:

[0236]

[0237] In step 4, channel estimation is performed according to the received physical signal and the local physical signal.

[0238] The step 4 may include the following steps.

[0239] In step 4.1, Fourier transform is performed on the local physical signal to obtain a frequency domain signal.

[0240] NFFT-point Fourier transform is performed on the local physical signal xlocal[n] to obtain a local frequency domain signal (i.e., fourth frequency domain signal), which is denoted by Xlocal,1[k], where k=0,1,…,NFFT-1.

[0241] In step 4.2, a fifth frequency domain signal is generated from the fourth frequency domain signal according to the power normalization indication information.

[0242] The specific method is described below.

[0243] (1) If the power normalization indication information indicates that the received physical signal was not subjected to power normalization on each resource unit during its generation process, the fifth frequency domain signal is Xlocal,2[k]=Xlocal,1[k], where k=0,1,…,NFFT-1.

[0244] (2) If the power normalization indication information indicates that the received physical signal was subjected to power normalization on each resource unit during its generation process, the fifth frequency domain signal is generated by the following method:

[0245]

[0246] where,

[0247] In step 4.3, channel estimation is performed according to the received physical signal and the fifth frequency domain signal. This step may include the following steps.

[0248] In step 4.3.1, Fourier transform is performed on the received physical signal y[n] to obtain a third frequency domain signal, which is denoted by Y[k], where k=0,1,…,NFFT-1.

[0249] In step 4.3.2, signal processing is performed on the third frequency domain signal on each sub-carrier within the bandwidth of the physical signal and the fifth frequency domain signal on the corresponding sub-carrier to obtain a frequency domain channel value on each sub-carrier. The signal processing method includes, but not limited to:

[0250]

[0251] or

[0252]

[0253] where is the conjugate of Xlocal,2[k].

[0254] An embodiment of the present disclosure further provides a node. This node may include a transceiver and at least one processor coupled to the transceiver. The at least one processor may perform the solutions provided in any one of the optional embodiments of the present disclosure. This node may be any electronic device, e.g., an electronic user equipment or network node.

[0255] Optionally, the node may be a first node, and the at least one processor may be configured to perform the method performed by a first node provided in any one of the embodiments of the present disclosure.

[0256] Optionally, the node may be a second node, and the at least one processor may be configured to perform the method performed by a second node provided in any one of the embodiments of the present disclosure.

[0257] An embodiment of the present disclosure further provides an electronic device, including at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor is configured to perform the method provided in any one of the optional embodiments of the present disclosure.

[0258] FIG. 8 shows a schematic structure diagram of an electronic device to which the solution of the embodiment of the present disclosure is applied. As shown in FIG. 8, the electronic device 4000 shown in FIG. 8 may include a processor 4001 and a memory 4003. The processor 4001 is connected to the memory 4003, for example, through a bus 4002. Optionally, the electronic device 4000 may further include a transceiver 4004. The transceiver 4004 may be configured for data interaction between the electronic device and other electronic devices, for example, transmitting data and / or receiving data, etc. It should be noted that, in practical applications, the number of the transceivers 4004 is not limited to one, and the structure of the electronic device 4000 does not constitute any limitations to the embodiments of the present disclosure. Optionally, the electronic device may be a first network node, a second network node or a third network node.

[0259] The processor 4001 may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute various exemplary logical blocks, modules and circuits described in connection with the present disclosure. The processor 4001 may also be a combination for realizing computing functions, for example, a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0260] The bus 4002 may include a path to transfer information between the components described above. The bus 4002 may be a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus, etc. The bus 4002 may be an address bus, a data bus, a control bus, etc. For ease of presentation, the bus is represented by only one thick line in FIG. 8. However, it does not mean that there is only one bus or one type of buses.

[0261] The memory 4003 may be, but not limited to, read only memories (ROMs) or other types of static storage devices that can store static information and instructions, random access memories (RAMs) or other types of dynamic storage devices that can store information and instructions, may be electrically erasable programmable read only memories (EEPROMs), compact disc read only memories (CD-ROMs) or other optical disk storages, optical disc storages (including compact discs, laser discs, discs, digital versatile discs, blue-ray discs, etc.), magnetic storage media or other magnetic storage devices, or any other media that can carry or store desired program codes in the form of instructions or data structures and that can be accessed by computers.

[0262] The memory 4003 is used to store application program codes for executing the solutions of the present disclosure, and is controlled by the processor 4001. The processor 4001 is used to execute the application programs stored in the memory 4003 to implement the solution provided in any method embodiment described above.

[0263] Embodiments of the present disclosure provide a computer-readable storage medium having computer programs stored thereon, the computer programs, when executed by a processor, implement the steps and corresponding contents of the foregoing method embodiments.

[0264] Embodiments of the present disclosure also provide a computer program product including computer programs, the computer programs, when executed by a processor, implement the steps and corresponding contents of the preceding method embodiments.

[0265] The terms "first", "second", "third", "fourth", "1", "2", etc. (if present) in the Description and claims of the present disclosure and the accompanying drawings above are used to distinguish similar objects and need not be used to describe a particular order or sequence. It should be understood that the data so used is interchangeable where appropriate so that embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described in the text.

[0266] It should be understood that while the flow diagrams of embodiments of the present disclosure indicate the individual operational steps by arrows, the order in which these steps are performed is not limited to the order indicated by the arrows. Unless explicitly stated herein, in some implementation scenarios of embodiments of the present disclosure, the implementation steps in the respective flowcharts may be performed in other orders as desired. In addition, some, or all of the steps in each flowchart may include multiple sub-steps or multiple phases based on the actual implementation scenario. Some or all of these sub-steps or stages can be executed at the same moment, and each of these sub-steps or stages can also be executed at different moments separately. The order of execution of these sub-steps or stages can be flexibly configured according to requirements in different scenarios of execution time, and the embodiments of the present disclosure are not limited thereto.

[0267] The above text and drawings are provided as examples only to help readers understand the present disclosure. They are not intended and should not be interpreted as limiting the scope of the present disclosure in any way. While some embodiments and examples have been provided, based on the contents disclosed herein, it is obvious to a person skilled in the art that the embodiments and examples as shown may be altered without departing from the scope of the present disclosure, the use of other similar implementation means based on the technical concept of the present disclosure also falls within the protection scope of the embodiments of the present disclosure.

Claims

1.A method performed by a first node in a communication system, comprising steps of:receiving a first signal;determining whether the first signal is a signal that was subjected to power normalization; andperforming channel estimation based on the first signal by a first method when the first signal is a signal that was subjected to power normalization, or performing channel estimation based on the first signal by a second method when the first signal is a signal that was not subjected to power normalization.2.The method according to claim 1, wherein the determining whether the first signal is a signal that was subjected to power normalization comprises:receiving first information for indicating whether the received signal is a signal that was subjected to power normalization; anddetermining, based on the first information, whether the first signal is a signal that was subjected to power normalization.3.The method according to claim 1, wherein the determining whether the first signal is a signal that was subjected to power normalization comprises:determining, based on at least one of the following, whether the first signal is a signal that was subjected to power normalization:whether there is data to be received in the time slot where the first signal is located;whether a demodulation reference signal is configured in the time slot where the first signal is located;the comparison result of the bandwidth of the demodulation reference signal configured in the time slot where the first signal is located with the bandwidth of the first signal; andwhether the data received in the time slot where the first signal is located is data transmitted by multiple ports.4.The method according to claim 1, wherein the power normalization is power normalization at a sub-carrier level.5.The method according to any one of claims 1, wherein the first signal is obtained based on a second signal; the second signal is generated by mapping a second sequence to a time domain resource; the first signal is the second signal when the first signal is a signal that was not subjected to power normalization; and, the first signal is obtained by performing power normalization on the second signal when the first signal is a signal that was subjected to power normalization.6.The method according to claim 5, wherein, when the first signal is a signal that was subjected to power normalization, the first signal is obtained by performing inverse Fourier transform on a second frequency domain signal, the second frequency domain signal is obtained by performing power normalization on a first frequency domain signal, and the first frequency domain signal is obtained by performing Fourier transform on the second signal.7.The method according to claim 6, wherein the second frequency domain signal is obtained by remapping the signal, that is obtained after performing power normalization on the signal on each sub-carrier in the first frequency domain signal within a signal bandwidth, to the corresponding sub-carrier.8.The method according to claim 6, wherein the first frequency domain signal and / or the second frequency domain signal satisfies at least one of the following:the first frequency domain signal has the same bandwidth as the second frequency domain signal;the first frequency domain signal occupies the same sub-carriers as the second frequency domain signal;the second frequency domain signal has the same signal amplitude on each sub-carrier within its bandwidth;the signal amplitude of the second frequency domain signal is of a first value, the first value being determined based on the signal amplitudes of all sub-carriers of the first frequency domain signal within its bandwidth;the second frequency domain signal and the first frequency domain signal have the same signal phase on the same sub-carrier;the signal amplitude of a sub-carrier of the second frequency domain signal outside its bandwidth is of a second value;the signal phase of a sub-carrier of the second frequency domain signal outside its bandwidth is of a third value; andthe signal amplitude and signal behavior of a sub-carrier of the second frequency domain signal outside its bandwidth are 0.9.The method according to any one of claims 1, wherein the performing channel estimation comprises:generating a third signal;performing Fourier transform on the first signal to obtain a third frequency domain signal;performing Fourier transform on the third signal to obtain a fourth frequency domain signal;when it is determined that the first signal is a signal that was not subjected to power normalization, performing channel estimation based on the third frequency domain signal and the fourth frequency domain signal; andwhen it is determined that the first signal is a signal that was subjected to power normalization, performing power normalization on the fourth frequency domain signal to obtain a fifth frequency domain signal, and performing channel estimation based on the fifth frequency domain signal and the third frequency domain signal.10.A method performed by a second node in a communication system, comprising steps of:transmitting a first signal, the first signal being a signal that was subjected to power normalization or a signal that was not subjected to power normalization;wherein if the first signal is a signal that was subjected to power normalization, the first signal is used to perform channel estimation by a first method, or if the first signal is a signal that was not subjected to power normalization, the first signal is used to perform channel estimation by a second method.11.The method according to claim 10, further comprising:transmitting first information for indicating whether the transmitted signal is a signal that was subjected to power normalization.12.A first node in a wireless communication system, wherein the first node comprises a transceiver and at least one processor coupled to the transceiver, and the at least one processor is configured to perform the method according to claims 1.13.A second node in a wireless communication system, wherein the second node comprises a transceiver and at least one processor coupled to the transceiver, and the at least one processor is configured to perform the method according to claim 10.14.A computer-readable storage medium having computer programs stored thereon that, when executed by a processor, perform the method according to claims 1.

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