Method, apparatus, and system for transmitting a reference signal
Patent Information
- Application Number
- PCT/CN2025/096476
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-21
- Filing Date
- 2025-05-22
- Publication Date
- 2026-08-27
Smart Images

Figure CN2025096476_27082026_PF_FP_ABST
Abstract
Description
METHOD, APPARATUS, AND SYSTEM FOR TRANSMITTING A REFERENCE SIGNALCROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to, and claims priority to, United States provisional patent application Serial No. 63 / 761,507, entitled "Decoupled Frequency-Domain Spectral Shaping for Demodulation Reference Signal" , filed on February 21, 2025.
[0002] The disclosure of the aforementioned application is hereby incorporated by reference in its entirety.TECHNICAL FIELD
[0003] Embodiments of the present application relate to the field of communications, and more specifically, to a communication method and a communication apparatus.BACKGROUND
[0004] In wireless systems, in some implementations, frequency-domain spectral shaping (FDSS) with roll-off factor equals to 1 can be used to process a data signal, so that peak to average power ratio (PAPR) of the data signal can be reduced for coverage enhancement. For example, FDSS with a root-raised-cosine (RRC) window can be used to process a π / 2-binary phase shift keying (BPSK) sequence to obtain a data signal with low PAPR. However, if a reference signal with PAPR that does not match the PAPR of the data signal is used to provide channel estimation for the data signal, due to different distortion characteristics of the reference signal and the data signal, channel estimation performance will be reduced.
[0005] Therefore, how to reduce PAPR of a reference signal in FDSS scenarios is a desirable problem to be solved.SUMMARY
[0006] Embodiments of the present application provide a communication method and a communication apparatus. The technical solutions may allow a data signal and a reference signal providing channel estimation for the data signal to have different repetition factor. Thereby, the reference signal may have an appropriate repetition factor to obtain a low PAPR.
[0007] According to a first aspect, a communication method is described. The method may be applied at a terminal side, for example, a terminal (e.g. a user equipment (UE) ) , a module in a terminal, or a circuit or a chip (for example, a modem chip, also referred to as a baseband chip, or a system on chip (SoC) chip or a system in package (SIP) chip that includes a modem core) that is responsible for a communication function in a terminal. For example, the method is applied to a terminal. In this method, the terminal obtains a data signal and a reference signal, where the data signal is obtained by cyclically repeating a first sequence based on a first factor, the fist factor indicates a ratio of a length of the data signal to a length of the first sequence, the reference signal is obtained by cyclically repeating a second sequence based on a second factor, the second factor indicates a ratio of a length of the reference signal to a length of the second sequence, the first factor is different from the second factor, the data signal and the reference signal are processed by frequency-domain spectral shaping (FDSS) using an FDSS window, and a roll-off factor of the FDSS window applied to the data signal is same as the roll-off factor of the FDSS window applied to the reference signal; and transmits the data signal and the reference signal. The reference signal may provide channel estimation for the data signal.
[0008] According to a second aspect, a communication method is described. The method may be applied at a network side, for example, a base station or a component (for example, a circuit, a chip, or a chip system) in a base station on a network side. For example, the method is applied to a base station. In this method, the base station receives a data signal and a reference signal. The reference signal may provide channel estimation for the data signal. The data signal is obtained by cyclically repeating a first sequence based on a first factor, the fist factor indicates a ratio of a length of the data signal to a length of the first sequence, the reference signal is obtained by cyclically repeating a second sequence based on a second factor, the second factor indicates a ratio of a length of the reference signal to a length of the second sequence, the first factor is different from the second factor, the data signal and the reference signal are processed by frequency-domain spectral shaping (FDSS) using an FDSS window, and a roll-off factor of the FDSS window applied to the data signal is same as the roll-off factor of the FDSS window applied to the reference signal.
[0009] In some embodiments, the reference signal may be a demodulation reference signal (DM-RS) .
[0010] According to the above technical solution, a data signal and a reference signal providing channel estimation for the data signal may have different repetition factor (i.e. the first factor and the second factor) in FDSS scenarios. That is, in the case of the data signal being generated based on the first factor to obtain a low PAPR, the reference signal may be generated based on the second factor which is not necessary to be same as the first factor. Therefore, the reference signal may be generated based on an appropriate repetition factor to obtain a low PAPR. Thus, PAPR of a reference signal in FDSS scenarios can be reduced.
[0011] With reference to the first aspect or the second aspect, in a possible design, the second sequence is a Zadoff-Chu (ZC) sequence.
[0012] According to the above technical solution, a ZC sequence can be used to generate the reference signal. Due to the constant modulus feature of the ZC sequence, the frequency domain flatness of the reference signal can be improved. Thus, channel estimation performance can be improved.
[0013] With reference to the first aspect or the second aspect, in a possible design, the first sequence is a π / 2-binary phase shift keying (BPSK) sequence or a single carrier offset quadrature amplitude modulation (SC-OQAM) sequence.
[0014] According to the above technical solution, the data signal can be modulated by using a π / 2-BPSK or a SC-OQAM sequence, which have low PAPR. Thus, the PAPR of the data signal can be further reduced.
[0015] With reference to the first aspect or the second aspect, in a possible design, the first factor is determined based on the roll-off factor of FDSS window.
[0016] In other words, the second factor is not necessary to be determined based on the roll-off factor of FDSS window. That is, the second factor can be decoupled from the roll-off factor.
[0017] According to the above technical solution, the first factor can be determined based on the roll-off factor, which is beneficial for reducing the PAPR of the data signal. Furthermore, the second factor can be decoupled from the roll-off factor, which is beneficial for reducing the PAPR of the reference signal.
[0018] With reference to the first aspect or the second aspect, in a possible design, the length of the second sequence is the maximum prime number less than W2 / (1+β) , W2 is the length of the reference signal, and the length of the data signal complying with W1= (1+α) N, W1 is the length of the data signal, N is the length of the first sequence, α and β are real numbers greater than or equal to 0 and less than or equal to 1, and in the case of α being equal to 1, β is greater than or equal to 0.45 and less than or equal to 0.55.
[0019] According to the above technical solution, a data signal with low PAPR can be obtained, while a reference with low PAPR can be obtained.
[0020] With reference to the first aspect, in a possible design, the transmitting the data signal and the reference signal includes: transmitting a first symbol, where the data signal and the reference signal are frequency division multiplexed in the first symbol.
[0021] With reference to the second aspect, in a possible design, the receiving the data signal and the reference signal includes: receiving a first symbol, where the data signal and the reference signal are frequency division multiplexed in the first symbol.
[0022] According to the above technical solution, the method may be used in scenarios where the reference signal and the data signal are frequency division multiplexed (FDMed) , so that PAPR of the FDMed signal can be reduced.
[0023] With reference to the first aspect, in a possible design, the transmitting the data signal and the reference signal includes: transmitting a second symbol, where the reference signal is carried in the second symbol; and transmitting a third symbol, where the data signal is carried in the third symbol.
[0024] With reference to the second aspect, in a possible design, the receiving the data signal and the reference signal includes: receiving a second symbol, where the reference signal is carried in the second symbol; and receiving a third symbol, where the data signal is carried in the third symbol.
[0025] According to the above technical solution, the method may be used in scenarios where the reference signal is a stand-alone reference signal, so that PAPR of the stand-alone reference signal can be reduced.
[0026] With reference to the first aspect or the second aspect, in a possible design, the reference signal is used for communication and / or sensing.
[0027] According to the above technical solution, the reference signal obtained according to the method can be used for various purposes.
[0028] According to a third aspect, a communication apparatus is described. The communication apparatus has a function of implementing the first aspect. For example, the communication apparatus includes a corresponding module, unit, or means for performing operations in the first aspect. The module, unit, or means may be specifically implemented by using software, may be implemented by using hardware, or may be implemented by using software in combination with hardware.
[0029] According to a fourth aspect, a communication apparatus is described. The communication apparatus has a function of implementing the second aspect. For example, the communication apparatus includes a corresponding module, unit, or means for performing operations in the second aspect. The module, unit, or means may be specifically implemented by using software, may be implemented by using hardware, or may be implemented by using software in combination with hardware.
[0030] According to a fifth aspect, another communication apparatus is described. The communication apparatus includes a memory and one or more processors. The memory is configured to store a part or all of a necessary computer program or instructions for implementing a function in the first aspect. The one or more processors may execute the computer program or the instructions, and when the computer program or the instructions is / are executed, the communication apparatus is enabled to implement the method in any possible design or implementation of the first aspect.
[0031] In some embodiments, the communication apparatus may further include an interface circuit, and the processor is configured to communicate with another apparatus or component through the interface circuit.
[0032] In some embodiments, the communication apparatus may further include the memory.
[0033] The communication apparatus may be a terminal, a module in a terminal, or a chip responsible for a communication function in a terminal, for example, a modem chip (also referred to as a baseband chip) or an SoC chip or a SIP chip that includes a modem module.
[0034] According to a sixth aspect, another communication apparatus is described. The communication apparatus includes a memory and one or more processors. The memory is configured to store a part or all of a necessary computer program or instructions for implementing a function in the second aspect. The one or more processors may execute the computer program or the instructions, and when the computer program or the instructions is / are executed, the communication apparatus is enabled to implement the method in any possible design or implementation of the second aspect.
[0035] In some embodiments, the communication apparatus may further include an interface circuit, and the processor is configured to communicate with another apparatus or component through the interface circuit.
[0036] In some embodiments, the communication apparatus may further include the memory.
[0037] The communication apparatus may be a base station, a module in a base station, or a chip responsible for a communication function in a base station, for example, a modem chip (also referred to as a baseband chip) or an SoC chip or a SIP chip that includes a modem module.
[0038] According to a seventh aspect, a communication system is described. The communication system includes a first communication apparatus and / or a second communication apparatus, the first communication apparatus is configured to perform the method in any possible design or implementation of the first aspect, and the second communication apparatus is configured to perform the method in any possible design or implementation of the second aspect.
[0039] According to an eighth aspect, a computer-readable storage medium is described. The computer-readable storage medium stores computer-readable instructions, and when a computer reads and executes the computer-readable instructions, the computer is enabled to perform the method in any one of the possible designs of the first or the second aspect.
[0040] According to a ninth aspect, this application provides a computer program product. When a computer reads and executes the computer program product, the computer is enabled to perform the method in any one of the possible designs of the first or the second aspect.
[0041] According to a tenth aspect, this application provides a system comprising at least one of an apparatus in (or at) a UE of the present application, or an apparatus in (or at) a network device of the present application.
[0042] According to an eleventh aspect, this application provides a method performed by a system comprising at least one of an apparatus in (or at) a UE of the present application, and an apparatus in (or at) a network device of the present application.
[0043] This application encompasses various embodiments, including not only method embodiments, but also other embodiments such as apparatus embodiments and embodiments related to non-transitory computer readable storage media. Embodiments may incorporate, individually or in combinations, the features disclosed herein.DESCRIPTION OF DRAWINGS
[0044] FIG. 1 is a schematic diagram of an application scenario according to this application;
[0045] FIG. 2 illustrates an example communication system 100;
[0046] FIG. 3 illustrates an example of an electronic device (ED) and a base station;
[0047] FIGS. 4-5 are schematic block diagrams of possible devices according to embodiments of this application;
[0048] FIG. 6 illustrates a block diagram of a NR OFDM system;
[0049] FIG. 7 illustrates a trajectory of a π / 2-BPSK symbol sequence;
[0050] FIG. 8 illustrates a schematic diagram of FDSS applied to a data signal;
[0051] FIG. 9 illustrates a schematic diagram of DM-RS and data signal are FDMed;
[0052] FIG. 10 illustrates another schematic diagram of DM-RS and data signal are FDMed;
[0053] FIG. 11 illustrates a schematic diagram of PAPRs of multiple signals;
[0054] FIG. 12 illustrates another schematic diagram of PAPRs of multiple signals;
[0055] FIG. 13 illustrates a schematic flowchart of a communication method 1300 according to an embodiment of this application;
[0056] FIG. 14 illustrates a schematic diagram of FDSS applied to a reference signal;
[0057] FIG. 15 illustrates another schematic diagram of PAPRs of multiple signals;
[0058] FIG. 16 is schematic block diagrams of a system according to embodiments of this application.DESCRIPTION OF EMBODIMENTS
[0059] The following describes technical solutions of the present application with reference to the accompanying drawings.
[0060] The technical solutions in embodiments of this application may be applied to various communication systems, such as a fifth generation (5G) wireless communications system, a new radio (NR) wireless communications system, a future communication system, integrated access and backhaul (IAB) system, a mesh network, a side link system, or other evolving communication systems. The technical solutions in embodiments of this application may be applied to the communication system that integrates the above two or more systems.
[0061] For ease of understanding the embodiments of this application, a communications system shown in FIGS. 1-3 is first used as an example to describe in detail a communications system to which the embodiments of this application are applicable.
[0062] FIG. 1 is a schematic diagram of an application scenario according to this application. Referring to FIG. 1, as an illustrative example, a simplified schematic illustration of a communication system is provided. The communication system 100 may include a radio access network 120. The radio access network (RAN) 120 may be an advanced radio access network, or a legacy (e.g. 5th generation (5G) , 4th generation (4G) , 3th generation (3G) or 2nd generation (2G) ) radio access network. In some implementations, advanced radio access refers to a next generation air interface of standards which may include both terrestrial networks (TNs) and non-terrestrial networks (NTNs) , and more details will be described below. One or more communication electronic devices (ED) 110a, 110b, 110c, 110d, 110e, 110f, 110g, 110h, 110i, 110j (generically referred to as 110) may be interconnected to one another or connected to one or more network nodes 170a, 170b (generically referred to as 170) in the RAN 120. A core network (CN) 130 may be a part of the communication system and may be dependent or independent of the radio access technology used in the communication system 100. The communication system 100 may also include a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160.
[0063] In general, the communication system 100 enables communication of multiple wireless or wired elements. The communication system 100 may provide content, such as voice, data, video, and / or text, via broadcast, multicast, groupcast, unicast, etc. The communication system 100 may operate by sharing resources, such as carrier spectrum bandwidth, among its constituent elements.
[0064] The communication system 100 may provide a wide range of communication services and applications including enhanced Mobile Broadband (eMBB) services, ultra-reliable low-latency communication (URLLC) services, massive machine type communication (mMTC) services, integrated sensing and communication (ISAC) , immersive communication, massive communication, Hyper reliable and low-latency communication, ubiquitous connectivity, integrated AI and communication, and other services that can be provided by a future generation communication system. The communication system 100 may provide other services and applications such as earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous delivery and mobility, etc.
[0065] The communication system 100 may include a terrestrial communication system (or network) and / or a non-terrestrial communication system (or network) . The communication system 100 may provide a high degree of availability and robustness through a joint operation of a terrestrial communication system and a non-terrestrial communication system. For example, integrating a non-terrestrial communication system (or components thereof) into a terrestrial communication system can result in a heterogeneous network comprising multiple layers. The heterogeneous network may achieve better overall performance through efficient multi-link joint operation, more flexible functionality sharing, and faster physical layer link switching between terrestrial networks and non-terrestrial networks. The terrestrial communication system and the non-terrestrial communication system could be considered sub-systems of the communication system 100.
[0066] FIG. 2 illustrates another example for communication system 100. As described earlier, the communication system 100 may include ED 110a, 110b, 110c, 110d (generically referred to as ED 110) , RAN 120a, 120b, and one or more of a CN 130, a PSTN 140, the Internet 150, and other networks 160. In addition, the communication system 100 may also include a non-terrestrial network (NTN) 120c. The RANs 120a, 120b may include respective network nodes 170a, 170b such as base stations 170a, 170b, which may be generically referred to as terrestrial network (TN) devices or terrestrial transmit and receive points (T-TRPs) 170a, 170b (generically referred to as 170) . As referred to herein, the terms “TRP” and “base station” may be used interchangeably unless explicitly noted otherwise in a given example or section. For brevity, this disclosure may primarily refer to base station; however, absent an explicit limitation, references to TRP are merely non-limiting instances of interchangeable use. The T-TRPs 170a, 170b may be base stations mounted on a building or tower. In one implementation, the NTN 120c includes a RAN node such as base station 172, which may be generically referred to as an NTN device, a non-terrestrial node, a non-terrestrial network device, a non-terrestrial base station, or a non-terrestrial transmit and receive point (NT-TRP) 172.
[0067] In some implementations, the NT-TRP 172 is not attached to the ground, for example, in the case of an airborne base station. An airborne base station may be implemented using communication equipment supported or carried by a flying device. For example, a flying device may include an airborne platform (e.g. a blimp or an airship) , balloon, drone (e.g. quadcopter) , and other types aerial vehicles. In some implementations, an airborne base station may be supported or carried by an unmanned aerial system (UAS) or an unmanned aerial vehicle (UAV) , such as a drone. An airborne base station may be a moveable or mobile base station that can be flexibly deployed in different locations to meet network demand. A satellite base station is another example of a non-terrestrial base station. A satellite base station may be implemented using communication equipment supported or carried by a satellite. A satellite base station may also be referred to as an orbiting base station. High altitude platform is yet another example of a non-terrestrial base station, including international mobile telecommunication base stations.
[0068] As referred to herein, and unless specified otherwise, a “TRP” may also refer to a T-TRP or a NT-TRP, a “T-TRP” may also refer to a “TN TRP” , and a “NT-TRP” may also refer to a “NTN TRP” . The NTN 120c may be considered to be a radio access network (RAN) , with operational aspects in common with the RANs 120a, 120b. The NTN 120c may include at least one NTN device and at least one corresponding terrestrial network device, the at least one NTN device may function as a transport layer device and the at least one corresponding terrestrial network device may function as a RAN node, which communicates with the ED 110 via the non-terrestrial network device. In addition, there may be an NTN gateway in the ground (i.e., referred as a terrestrial network device) that also functions as a transport layer device to communicate with both the NTN device and the RAN node. The RAN node may communicate with the ED 110 via the NTN device and the NTN gateway. In some implementations, the NTN gateway and the RAN node may be located in the same device.
[0069] A base station (also referred to as TRP as stated above) 170 may be a network element in radio access network responsible for radio transmission and reception in one or more cells to or from the user equipment. Base station 170 may be known by other names in some implementations, such as a base transceiver station (BTS) , a radio base station, a network node, a network device, a device on the network side, a transmit / receive node, a Node B, an evolved NodeB (eNodeB or eNB) , a Home eNodeB, a next Generation NodeB (gNB) , a transmission point (TP) , a site controller, an access point (AP) , a wireless router, a relay station, a terrestrial node, a terrestrial network device, a terrestrial base station, a positioning node, among other possibilities. The base station 170 may be a macro base station (BS) , a pico BS, a relay node, a donor node, or the like, or combinations thereof. When a base station 170 performs (or is configured to perform) a method described herein, it may be interpreted as the base station, one or more modules (or units) in the base station, a circuit or chip, or a combination thereof, may perform the method. For example, the circuit or chip may include a modem chip, also referred to as a baseband chip, a system on chip (SoC) including a modem core, system in package (SIP) ) , and the like, and may be responsible for one or more communication functions in the base station.
[0070] The EDs 110a-110d and TRPs 170a-170b, 172 are examples of communication equipment that can be configured to implement some or all of the operations and / or embodiments described herein. The T-TRP 170a forms part of the RAN 120a, which may include other TRPs, and / or other devices. Also, the TRP 170b forms part of the RAN 120b, which may include other TRPs, and / or devices. Each TRP 170a, 170b may transmit and / or receive wireless signals within a particular geographic region or area, sometimes referred to as a “cell” or “coverage area” . The TRPs 170a-170b may be responsible for allocating and / or configuring resources and transmission and / or reception in a set of cells. A cell may be a radio network object that can be uniquely identified from an identification (or a cell identification) that is broadcasted over a geographical region or area from base stations associated with the cell. A cell can be either FDD or TDD mode. A cell may also refer to the carrier frequencies within the DL / UL carrier bandwidth resources of a single standalone carrier or a component carrier in a carrier aggregation mode. A cell may be further divided into cell sectors, and a base station 170a-170b may, for example, employ multiple transceivers to provide service to multiple sectors. In some implementations, there may be established pico or femto cells where the radio access technology supports such. In some implementations, multiple transceivers could be used for each cell, for example using multiple-input multiple-output (MIMO) technology. The number of RAN 120a-120b shown is exemplary only. Any number of RAN may be contemplated when devising the communication system 100.
[0071] Any base station may be a single element, as shown, or multiple elements, distributed in the corresponding RAN, or otherwise. In some implementations, a plurality of RAN nodes coordinate to assist the ED 110 in implementing radio access, and different RAN nodes separately implement different functions of the base station. For example, the RAN node may be a central unit (CU) , a distributed unit (DU) , a CU-control plane (CP) , a CU-user plane (UP) , or a radio unit (RU) etc. The CU and the DU may be separately deployed, or may be included in a same element (i.e., a baseband unit (BBU)) . The RU may be included in a radio frequency device or a radio frequency unit (i.e., a remote radio unit (RRU) , an active antenna unit (AAU) , or a remote radio head (RRH) ) . In different systems, the CU (or the CU-CP and the CU-UP) , the DU, or the RU may also have different names, but a person skilled in the art may understand meanings thereof. For example, in an open radio access network (ORAN) system, a CU may also be referred to as an open CU (O-CU) , a DU may also be referred to as an open DU (O-DU) , and a CU-CP may also be referred to as an open CU-CP (O-CU-CP) . The CU-UP may also be referred to as an open CU-UP (O-CU-UP) , and the RU may also be referred to as an open RU (O-RU) . Any one of the CU (or the CU-CP, the CU-UP) , the DU, and the RU may be implemented by using a software module, a hardware module, or a combination of a software module and a hardware module.
[0072] Further, communication between different devices / apparatuses in various embodiments of this application may refer to direct communication between different devices / apparatuses (that is, no forwarding is required by another device / apparatuses) , or may refer to communication between different devices / apparatuses via another device / apparatus (that is, forwarding is required by another device / apparatus) . Alternatively, it may refer to that a functional unit inside the device / apparatus uses another functional unit in the device / apparatus to communicate with another device / apparatus. In other words, "sending (or transmitting) information to. . . (an ED or a base station) " in this application may be understood as that a destination endpoint of the information is an ED or a base station. It may include sending / transmitting information directly or indirectly to an ED or a base station. Similarly, "receiving information from. . . (an ED or a base station) " may be understood as that a source endpoint of the information is an ED or a base station, and may include directly or indirectly receiving information from an ED or a base station. Necessary processing such as format conversion, digital-to-analog conversion, amplification, and filtering may be performed on the information between the source endpoint that sends the information and the destination endpoint. However, the destination endpoint may understand valid information from the source endpoint. Similar descriptions in this application may be understood similarly. Details are not described herein again. In the present disclosure, the terms "send" and "transmit" may be used interchangeably in embodiments of this application.
[0073] The ED 110 is used to connect persons, objects, machines, etc. The ED 110 may be widely used in various scenarios including, for example, cellular communications, device-to-device (D2D) , vehicle to everything (V2X) , peer-to-peer (P2P) , machine-to-machine (M2M) , MTC, internet of things (IoT) , virtual reality (VR) , augmented reality (AR) , mixed reality (MR) , metaverse, digital twin, industrial control, self-driving, remote medical, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility, etc.
[0074] Each ED 110 represents any suitable end user device for wireless operation and may include such devices (or may be referred to but not limited to) as a user equipment (UE) or a user device or a terminal device, a wireless transmit / receive unit (WTRU) , a mobile station, a fixed or mobile subscriber unit, a cellular telephone, a station (STA) , a MTC device, a personal digital assistant (PDA) , a smartphone, a laptop, a computer, a tablet, a wireless sensor, a consumer electronics device, a smart book, a vehicle, a car, a truck, a bus, a train, or an IoT device, wearable devices (such as a watch, a pair of glasses, head mounted equipment, etc. ) , an industrial device, or an apparatus in (e.g. module, modem, or chip) or including the forgoing devices, among other possibilities. Future generation EDs 110 may be referred to using other terms. When an ED 110 performs (or is configured to perform) a method described herein, it may be interpreted as the ED, one or more modules (or units) in the ED, a circuit or chip, or a combination thereof, may perform the method. For example, the circuit or chip may include a modem chip, also referred to as a baseband chip, a system on chip (SoC) including a modem core, or system in package (SIP) ) , and the like, and may be responsible for one or more communication functions in the ED.
[0075] Alternatively, ED 110 may be a device that provides voice / data connectivity for a user, for example, a handheld device with a wireless connection function or a vehicle-mounted device.
[0076] Alternatively, ED 110 may be a wearable device. The wearable device may also be referred to as a wearable smart device, and is a general term for performing intelligent design on daily wear by using a wearable technology, and developing wearable devices, such as glasses, gloves, watches, clothing, and shoes. The wearable device is a portable device that is directly worn on the body or integrated into the clothes or accessories of the user. Wearable devices are not only hardware devices, but also powerful functions through software support, data interaction, and cloud interaction. In a broad sense, the wearable smart device includes full-function, large-size, and complete or partial functions implemented without relying on a smartphone, for example, a smart watch or smart glasses, and only focuses on a specific type of application function, and needs to be used with another device, such as a smartphone. For example, smart bracelets and smart jewelry are used for physical sign monitoring.
[0077] Alternatively, ED 110 may be a terminal device in an Internet of things (IoT) system. The IoT is an important part of future information technology development, and a main technical feature of the IoT is that articles are connected to a network by using a communications technology, so as to implement an intelligent network of man-machine interconnection and object interconnection.
[0078] Each ED 110 connected to TRPs 170a-170b, and / or TRPs 172 can be dynamically or semi-statically turned-on (i.e., established, activated, or enabled) , turned-off (i.e., released, deactivated, or disabled) and / or configured in response to one of more of: connection availability and connection necessity.
[0079] Any ED 110 may be alternatively or additionally configured to interface, access, or communicate with any TRPs 170a, 170b and 172, the Internet 150, the CN 130, the PSTN 140, the other networks 160, or any combination of the preceding. In some examples, the ED 110a may communicate an uplink (UL) and / or downlink (DL) transmission over a terrestrial air interface 190a with the station-TRP 170a. In some examples, the EDs 110a, 110b, 110c, and 110d may also communicate directly with one another via one or more sidelink (SL) air interfaces 190b. In some examples, the ED 110d may communicate an UL and / or DL transmission over a non-terrestrial air interface 190c with the NT-TRP 172.
[0080] An air interface (e.g., 190a, 190b, 190c) generally includes a number of components and associated parameters that collectively specify how a transmission is to be sent and / or received over a wireless communications link between two or more communicating devices such as ED and base station. For example, an air interface may include one or more components defining the waveform (s) , frame structure (s) , multiple access scheme (s) , protocol (s) , coding scheme (s) and / or modulation scheme (s) for conveying information (e.g., data) over a wireless communications link. The air interfaces 190a and 190b may use similar communication technology, such as any suitable radio access technology.
[0081] The non-terrestrial air interface 190c can enable communication between the ED 110d and one or more NT-TRPs 172 via a wireless link or simply a link. For some examples, the link is a dedicated connection for unicast transmission, a connection for broadcast transmission, or a connection between a group of EDs 110 and one or more NT-TRPs 172 for multicast transmission.
[0082] The TRPs 170a-170b, 172 may communicate with one another over one or more air interfaces 190e, 190f using wireless communication links (e.g., radio frequency (RF) , microwave, infrared (IR) , etc. ) or wired communication links. The air interfaces 190e, 190f may utilize any suitable radio access technology, and may be substantially similar to the air interfaces 190a, 190c over which the EDs 110a-110d communicate with one or more of the TRP 170a-170b, 172 or they may be substantially different. For example, the communication system 100 may implement one or more channel access methods, such as code division multiple access (CDMA) , space division multiple access (SDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal FDMA (OFDMA) , or single-carrier FDMA (SC-FDMA) (also known as discrete Fourier transform spread OFDMA (DFT-s-OFDMA) ) in the air interfaces 190a and 190b. The air interfaces 190a and 190b may utilize other higher dimension signal spaces, which may involve a combination of orthogonal and / or non-orthogonal dimensions.
[0083] The RANs 120a and 120b are in communication with the CN 130 to provide the EDs 110a 110b, and 110c with various services such as voice, data, and other services. The RANs 120a and 120b and / or the CN 130 may be in direct or indirect communication with one or more other RANs (not shown) , which may or may not be directly served by the CN 130, and may or may not employ the same radio access technology as the RAN 120a, the RAN 120b or both. The CN 130 may also serve as a gateway access between (i) the RANs 120a and 120b or the EDs 110a 110b, and 110c or both, and (ii) other networks (such as the PSTN 140, the Internet 150, and the other networks 160) . In addition, some or all of the EDs 110a 110b, and 110c may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies and / or protocols. Instead of wireless communication (or in addition thereto) , the EDs 110a 110b, and 110c may communicate via wired communication channels to a service provider or switch (not shown) , and to the Internet 150. The PSTN 140 may include circuit switched telephone networks for providing plain old telephone service (POTS) . The Internet 150 may include a network of computers and subnets (intranets) or both, and incorporate protocols, such as internet protocol (IP) , transmission control protocol (TCP) , user datagram protocol (UDP) . The EDs 110a 110b, and 110c may be multimode devices capable of operation according to multiple radio access technologies, and incorporate multiple transceivers necessary to support such.
[0084] In addition, the communication system 100 may include a sensing agent (not shown) to manage the sensed data from the ED 110 and / or any one of the TRPs 170 a-170b, 172. In one implementation, the sensing agent may be part of any one of the TRPs 170 a-b, 172. In another implementation, the sensing agent is a separate node that can communicate with the CN 130 and / or the RAN 120 (e.g., any one of the TRPs 170 a-b, 172) .
[0085] FIG. 3 illustrates an example of an apparatus 310 wirelessly communicating with an apparatus 320 in a communication system (e.g., the communication system 100) . The apparatus 310 may be an electronic device (e.g. ED 110) . The apparatus 320 may be a network node (e.g. network node 170) such as T-TRP 170 or a NT-TRP 172. Although there is only one apparatus 310, and one apparatus 320 shown in the figure, the number of apparatus 310 and / or apparatus 320 could be one or more. For example, one ED 110 may be served by only one T-TRP 170 (or one NT-TRP 172) , by more than one T-TRP 170 (or more than one NT-TRP 172) . One ED 110 may be served by one or more T-TRPs 170 and one or more NT-TRPs 172. Similarly, one T-TRP 170 (or one NT-TRP 172) may serve one or more EDs 110.
[0086] The apparatus 310 includes at least one processor 210. Only one processor 210 is illustrated to avoid congestion in the drawing. The apparatus 310 may further include a transmitter 201 and a receiver 203 coupled to one or more antennas 204. Only one antenna 204 is illustrated to avoid congestion in the drawing. One, some, or all of the antennas 204 may alternatively be panels. The transmitter 201 and the receiver 203 may be integrated, e.g. as a transceiver. The transceiver is configured to modulate data or other content for transmission by at least one antenna 204 or network interface controller (NIC) . The transceiver is further configured to demodulate data or other content received by the at least one antenna 204. Each transceiver includes any suitable structure for generating signals for wireless or wired transmission and / or processing signals received wirelessly or by wire. Each antenna 204 includes any suitable structure for transmitting and / or receiving wireless or wired signals. The apparatus 310 may include at least one memory 208. Only the transmitter 201, the receiver 203, the processor 210, the memory 208, and the antenna 204 are illustrated for simplicity, but the apparatus 310 may include one or more other components. In the present disclosure, the transceiver (or the transmitter 201 and / or the receiver203) may be viewed as an interface circuit.
[0087] The memory 208 stores instructions used to perform operations described herein. The memory 208 may further store data used, generated, or collected by the apparatus 310. For example, the memory 208 could store software instructions or modules configured to implement some or all of the functionality and / or embodiments described herein and that are executed by one or more processor 210.
[0088] The apparatus 310 may further include one or more input / output devices (not shown) or interfaces. The input / output devices or interfaces permit interaction with a user or other devices in the network. Each input / output device or interface includes any suitable structure for providing information to or receiving information from a user, and / or for network interface communications. Suitable structures include, for example, a speaker, microphone, keypad, keyboard, display, touch screen, etc.
[0089] The processor 210 may perform (or control the apparatus 310 to perform) operations (or methods) described herein as being performed by the apparatus 310. For example, the processor 210 performs or controls the apparatus 310 to perform receiving transport blocks (TBs) , using a resource for decoding of one of the received TBs, releasing the resource for decoding of another of the received TBs, and / or receiving configuration information configuring a resource. In detail, the operation may include those operations related to preparing a transmission for UL transmission to the apparatus 320; those operations related to processing DL transmissions received from the apparatus 320; and those operations related to processing SL transmission to and from another apparatus 310. Processing operations related to preparing a transmission for UL transmission may include operations such as encoding, modulating, transmit beamforming, and generating symbols for transmission. Processing operations related to processing DL transmissions may include operations such as receive beamforming, demodulating and decoding received symbols. Processing operations related to processing SL transmissions may include operations such as transmit / receive beamforming, modulating / demodulating and encoding / decoding symbols. Depending upon the embodiment, a DL transmission may be received by the receiver 203, possibly using receive beamforming, and the processor 210 may extract signaling from the DL transmission (e.g. by detecting and / or decoding the signaling) . An example of signaling may be a reference signal transmitted by the apparatus 320. In some implementations, the processor 210 implements the transmit beamforming and / or the receive beamforming based on the indication of beam direction, e.g. beam angle information (BAI) , received from the apparatus 320. In some implementations, the processor 210 may perform operations relating to network access (e.g. initial access) and / or downlink synchronization, such as operations relating to detecting a synchronization sequence, decoding and obtaining the system information, etc. In some implementations, the processor 210 may perform channel estimation, e.g. using a reference signal received from the apparatus 320.
[0090] Although not illustrated, the processor 210 may form part of the transmitter 201 and / or part of the receiver 203. Although not illustrated, the memory 208 may form part of the processor 210.
[0091] The processor 210, the processing components of the transmitter 201, and the processing components of the receiver 203 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory (e.g. in the memory 208) .
[0092] Alternatively, some or all of the processor 210, the processing components of the transmitter 201, and the processing components of the receiver 203 may each be implemented using dedicated circuitry, such as a programmed field-programmable gate array (FPGA) , an application-specific integrated circuit (ASIC) , or a hardware accelerator such as a graphics processing unit (GPU) or an artificial intelligence (AI) accelerator.
[0093] The apparatus 320 includes one or more processors 260 (only one processor 260 is illustrated in the figure) . The apparatus 320 may further include at least one transmitter 252 and at least one receiver 254 coupled to one or more antennas 256. Only one antenna 256 is illustrated to avoid congestion in the drawing. One, some, or all of the antennas 256 may alternatively be panels. The transmitter 252 and the receiver 254 may be integrated as a transceiver. The apparatus 320 may further include at least one memory 258. The apparatus 320 may further include scheduler 253. Only the transmitter 252, receiver 254, processor 260, memory 258, antenna 256 and scheduler 253 are illustrated for simplicity, but the apparatus 320 may include one or more other components. In the present disclosure, the transceiver (or transmitter 252 and / or receiver254) may be viewed as an interface circuit.
[0094] In some implementations, the parts of the apparatus 320 may be distributed. For example, some of the modules of the apparatus 320 may be located remote from the equipment that houses the antennas 256 for the apparatus 320 (thereby also can be viewed as one of more nodes) , and may be coupled to the equipment that houses the antennas 256 over a communication link (not shown) sometimes known as front haul, such as common public radio interface (CPRI) . Therefore, in some implementations, the term apparatus 320 may also refer to nodes on the network side that perform processing operations, such as determining the location of the apparatus 310, resource allocation (scheduling) , message generation, and encoding / decoding, and that are not necessarily part of the equipment that houses the antennas 256 of the apparatus 320. The nodes may also be coupled to other apparatus 320s. In some implementations, the apparatus 320 may actually be a plurality of nodes that are operating together to serve the apparatus 310, e.g. through the use of coordinated multipoint transmissions, or the use of ORAN system as described above in the application.
[0095] The processor 260 performs operations including those related to: preparing a transmission for DL transmission to the apparatus 310, processing an UL transmission received from the apparatus 310, preparing a transmission for backhaul transmission to another apparatus 320, and processing a transmission received over backhaul from another apparatus 320. Processing operations related to preparing a transmission for DL or backhaul transmission may include operations such as encoding, modulating, precoding (e.g. multiple input multiple output (MIMO) precoding) , transmit beamforming, and generating symbols for transmission. Processing operations related to processing received transmissions in the UL or over backhaul may include operations such as receive beamforming, demodulating received symbols, and decoding received symbols. The processor 260 may also perform operations relating to network access (e.g. initial access) and / or DL synchronization, such as generating the content of synchronization signal blocks (SSBs) , generating the system information, etc. In some implementations, the processor 260 also generates an indication of beam direction, e.g. BAI, which may be scheduled for transmission by a scheduler 253 which will be described below. In some implementations, the processor 276 implements the transmit beamforming and / or receive beamforming based on beam direction information (e.g. BAI) received from another apparatus 320. The processor 260 performs other network side processing operations described herein, such as determining the location of the apparatus 310, determining where to deploy another apparatus 320, etc. In some implementations, the processor 260 may generate signaling, e.g. to configure one or more parameters of the apparatus 310 and / or one or more parameters of another apparatus 320. Any signaling generated by the processor 260 is sent by the transmitter 252. In some implementations, the apparatus 320 implements physical layer processing. In some implementations, the apparatus 320 may implement higher layer functions such as functions at the medium access control (MAC) or radio link control (RLC) layer in addition to physical layer processing. The apparatus 320 may further include the scheduler 253 coupled to the processor 260 or integrated in the processor 260. The scheduler 253 may be included within or operated separately from the apparatus 320. The scheduler 253 may schedule UL, DL, SL, and / or backhaul transmissions, including issuing scheduling grants and / or configuring scheduling-free (e.g., “configured grant” ) resources.
[0096] The apparatus 320 may further include a memory 258 storing instructions used to perform operations described herein. The memory 258 may also store data used, generated, or collected by the apparatus 320. For example, the memory 258 could store software instructions or modules configured to implement some or all of the functionality and / or embodiments described herein and that are executed by the processor 260.
[0097] Although not illustrated, the processor 260 may form part of the transmitter 252 and / or part of the receiver 254. Also, although not illustrated, the processor 260 may implement the scheduler 253. Although not illustrated, the memory 258 may form part of the processor 260.
[0098] The processor 260, the scheduler 253, the processing components of the transmitter 252, and the processing components of the receiver 254 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory, e.g. in the memory 258.
[0099] Alternatively, some or all of the processor 260, the scheduler 253, the processing components of the transmitter 252, and the processing components of the receiver 254 may be implemented using dedicated circuitry, such as a programmed FPGA, a hardware accelerator (e.g., a GPU or AI accelerator) , or an ASIC.
[0100] When the apparatus 320 is an apparatus (also called as a component) , for example, a communication module, modem, chip, or chipset in a device, it includes at least one processor, and an interface or at least one pin. In this scenario, the transmitter 252 and receiver 254 may be replaced by the interface or at least one pin, where the interface or at least one pin is to connect the apparatus (e.g., chip) and other apparatus (e.g., chip, memory, or bus) . Accordingly, the transmitting information to the apparatus 320 and / or apparatus 310 may be referred to as transmitting information to the interface or at least one pin, and receiving information from the apparatus 320 and / or apparatus 310 may be referred to as receiving information from the interface or at least one pin. The information may include control signaling and / or data.
[0101] The apparatus 320 and / or the apparatus 310 may include other components, but these have been omitted for the sake of clarity.
[0102] It should be noted that “signaling” , as used herein, may alternatively be called control signaling, control message, control information, or message for simplicity. Signaling between a base station (e.g., the TRP 170a-b, 172) and a UE or sensing device (e.g., ED 110) , or signaling between a different UE or sensing device (e.g., between ED 110a and ED 110b) may be carried in physical layer signaling (also called as dynamic signaling) , which is transmitted in a physical layer control channel. For DL, the physical layer signaling may be known as downlink control information (DCI) which is transmitted in a physical downlink control channel (PDCCH) . For UL, the physical layer signaling may be known as uplink control information (UCI) which is transmitted in a physical uplink control channel (PUCCH) . For SL, signaling between different UEs or sensing devices (e.g., between ED 110a and ED 110b) may be known as SL control information (SCI) which is transmitted in a physical sidelink control channel (PSCCH) . Signaling may be carried in a higher layer (e.g., higher than physical layer) signaling, which is transmitted in a physical layer data channel, e.g. in a physical downlink shared channel (PDSCH) for downlink signaling, in a physical uplink shared channel (PUSCH) for uplink signaling, and in a physical sidelink shared channel (PSSCH) for SL signaling. Higher layer signaling may also be called static signaling, or semi-static signaling. Higher layer signaling may be radio resource control (RRC) protocol signaling or media access control -control element (MAC-CE) signaling. Signaling may be included in a combination of physical layer signaling and higher layer signaling.
[0103] It should be noted that in the present disclosure, “information” , when different from “message” , may be carried in one single message, or be carried in more than one separate message.
[0104] Additional details regarding the EDs 110, the T-TRP 170, and the NT-TRP 172 are known to those of skill in the art. As such, these details are omitted here.
[0105] FIG. 4 illustrates an example of an apparatus 410. The apparatus 410 may be a communication device or an apparatus implemented in a communication device such as ED 110 or TRPs 170a-170b, 172. For example, the apparatus implemented in a communication device may be an integrated circuit, which in some contexts may be known by other colloquial names, such as chip, modem, modem chip, baseband chip, or baseband processor. In some implementations, one or more integrated circuits can be packaged into a system-on-chip, a system-in-package, or a multi-chip module. The apparatus may comprise one or more integrated circuits or comprise one or more integrated circuits and other discrete components. In some implementations, the apparatus 410 may be a module in ED 110, or apparatus 310. In some implementations, the apparatus 410 may be a module in one of TRPs 170a-170b, 172, or apparatus 320.
[0106] In an example, the apparatus 410 may include one or more processors / processor cores 411, and an interface circuit 412. The apparatus 410 may further include a memory 413. The one or more processors / processor cores 411 are configured to process signals and execute one or more communication protocols. The memory 413 is configured to store at least a part of corresponding computer program instructions and / or data. In an example, the one or more processors (or processor cores) 411 execute the computer program instructions stored in the memory 413 to implement related operations (for example, inputting, outputting, receiving, and transmitting) in the method embodiments disclosed herein. In some implementations, the memory 413 being configured to store the corresponding computer program instructions and / or data may mean that the memory 413 is configured to store all of the corresponding computer program instructions and / or data for execution by the one or more processors / processor cores 411. In some implementations, the memory 413 being configured to store the corresponding computer program instructions and / or data may mean that the memory 413 is configured to store a part of the corresponding computer program instructions and / or data. For example, the part of the corresponding computer program instructions and / or data include computer program instructions and / or data that need to be currently executed by the one or more processors / processor cores 411. Thus, the memory 413 may store different parts of computer program instructions and / or data for a plurality times for the one or more processors (or processor cores) 411 to perform related operations in the method embodiments disclosed herein. As a communication interface, the interface circuit 412 is configured to implement communication with another component. For example, the interface circuit 412 may communicate a signal with other apparatus / system such as a radio frequency processing apparatus, or processor system. Optionally, to reduce a load of the processor core, a baseband signal processing circuit 414 may be also disposed to implement processing of at least a part of baseband signals, including signal demodulation, modulation, encoding, decoding, or the like.
[0107] Apparatus 410 may be processor 210 (or 260) in apparatus 310 (or 320) , in some scenario, or included in processor 210 (or 260) in apparatus 310 (or 320) in some scenario. Apparatus 410 may be or include a baseband chip. In some implementations, the apparatus 410 may be independently packaged into a chip. In some implementations, the apparatus 310 (or 320) includes different types of chips. The apparatus 410 may be packaged into a processor chip (for example, a SoC chip or a SIP chip) with the different types of chips. In some implementations, the apparatus 410 may be packaged into a chip with some or all of circuits of a radio frequency processing system that may be further included in the apparatus 310 (or 320) .
[0108] FIG. 5 illustrates example of apparatus 510. Apparatus 510 may include corresponding modules or units configured to implement methods and / or embodiments described herein. In some implementations, the apparatus 510 includes a processing unit 512 and a communication unit 513. Optionally, the apparatus 510 may further include a storage unit 511 configured to store apparatus program code (or instructions) and / or data.
[0109] The apparatus 510 may be an ED side apparatus, for example, an ED or a module in an ED, or a circuit or a chip responsible for a communication function in an ED. In some implementations, apparatus 510 may be implemented as apparatus 310, accordingly, the processing unit 512 is implemented as processor 210, the communication unit 513 is implemented as transmitter 201 and / or receiver 203, and the storage unit 511 is implemented as memory 208.
[0110] The apparatus 510 may be a base station side apparatus, for example, a base station or a module in a base station, or a circuit or a chip responsible for a communication function in a base station. In some implementations, apparatus 510 may be implemented as apparatus 320, accordingly, the processing unit 512 is implemented as processor 260 (the scheduler 253 may also be included) , the communication unit 513 is implemented as transmitter 252 and / or receiver 254, and the storage unit 511 is implemented as memory 258.
[0111] In some implementations, when the apparatus 510 is an ED 110 or a module in an ED 110, a function of the apparatus 510 may be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system on chip SoC chip or a SIP chip that includes a modem core. A function of the communication unit 513 may be implemented by a transceiver circuit.
[0112] In some implementations, when the apparatus 510 is a circuit or a chip that is responsible for a communication function in an ED 110, for example, a modem chip, a system on chip SoC chip or a SIP chip that includes a modem core, a function of the processing unit 512 may be implemented by a circuit system that is in the chip and that includes one or more processors or processor cores. A function of the communication unit 513 may be implemented by an interface circuit or a data transceiver circuit on the foregoing chip.
[0113] It may be understood that division into the units in the foregoing apparatus is merely logical function division. Each function may correspond to one functional unit, or two or more functions may be integrated into one functional unit. In actual implementation, all or some of the units may be integrated into one physical entity, or may be distributed in different physical entities. In addition, the foregoing functional units may be implemented in a form of hardware, may be implemented in a form of software, or may be implemented in a form of a combination of hardware and software. Whether a function is performed in a form of hardware or software depends on particular applications and design constraint conditions of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this application.
[0114] In an example, a functional unit in any one of the foregoing apparatuses may be configured as one or more integrated circuits for implementing the method embodiments disclosed herein, for example, one or more application-specific integrated circuits (application-specific integrated circuits, ASICs) , one or more central processing units (central processing units, CPUs) , one or more microprocessors (microcontroller units, MCUs) , one or more digital signal processors (digital signal processors, DSP) , one or more field programmable gate arrays (field programmable gate arrays, FPGAs) , or a combination of at least two of these integrated circuit forms.
[0115] In an example, the storage unit 511 may include a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, and / or a register.
[0116] A processor, a processor system, an application processor, a baseband processor, a processor circuit, or a processor core may be collectively referred to as a processor. The processor may include one or a combination of a central processing unit (central processing unit, CPU) , a digital signal processor (digital signal processor, DSP) , a microprocessor (microprocessor unit, MPU) , a microcontroller (microcontroller unit, MCU) , a graphics processing unit (graphics processing unit, GPU) , a field programmable gate array (field programmable gate array, FPGA) , an artificial intelligence processor (artificial intelligence processor, AI processor) , or a neural network processing unit (neural network processing unit, NPU) .
[0117] The memory may include one or more of the following storage media: a random access memory (random access memory, RAM) , a static random access memory (static RAM, SRAM) , a dynamic random access memory (dynamic RAM, DRAM) , a phase-change memory (phase-change memory, PCM) , a resistive random access memory (resistive RAM, ReRAM) , a magnetoresistive random access memory (magnetoresistive RAM, MRAM) , a ferroelectric random access memory (ferroelectric RAM, FRAM) , a cache (cache) , a register (register) , a read-only memory (read-only memory, ROM) , a flash memory (flash memory) , an erasable programmable read-only memory (erasable programmable ROM, EPROM) , a hard disk (hard disk) , and the like. In an example, the computer program instructions used to execute the foregoing embodiments may be stored in a non-volatile memory, for example, at least a part of the memory (for example, one or more of a ROM, a flash memory, an EPROM, or a hard disk) . When the terminal runs, a part or all of corresponding computer program instructions may be loaded to a memory that has a higher transmission speed with the processor, for example, at least a part of the memory (for example, one or more of a RAM, an SRAM, a DRAM, a PCM, a RERAM, an MRAM, a FRAM, a cache (cache) , or a register) , so that the processor executes the computer program instructions to perform the steps in the method embodiments disclosed herein.
[0118] For ease of understanding the embodiments of this application, the terms involved in this application are briefly explained below.
[0119] 1. Orthogonal frequency division multiplexing (OFDM)
[0120] FIG. 6 illustrates a typical block diagram of an NR OFDM system. A signal {S (p) } is a frequency domain signal. A serial-to-parallel (S / P, also denoted as S-to-P in FIG. 6) conversion module is used to convert consecutive data sequence into parallel data blocks. Through a subcarrier mapping module, subcarriers which carry the data sequence Sk= [S (kM) , S (kM+1) , …, S (kM+M-1) ] Tare modulated, while other remaining subcarriers may be understood as being modulated by data 0. Then, a group of complex-value time-domain sampling points xk= [xk (0) , xk (1) , …, xk (N-1) ] T can be obtained by using the point IDFT for the data vector xk= [xk (0) , xk (1) , …, xk (N-1) ] T.
[0121] xk (n) , n=0, 1, …, N-1 can be written as:
[0122]
[0123] where Xk (n′) , n′=0, 1, …, N-1 denotes an output of the subcarrier mapping module, e denotes the Euler constant, and j denotes the imaginary unit (i.e. j2=-1) .
[0124] The subcarrier mapping rules are as follows:
[0125]
[0126] where n0 is an integer, Sk (l) denotes l-th element of Sk, and l=0, 1, …, Nsc-1. Nsc may be understood as a quantity of subcarriers in the transmission bandwidth. In the above, Nsc=M. It should be understood that Nsc may also be greater than M. For example, in some embodiments, the data sequence Sk extension may be performed on the length of M, and it is assumed that a length of the extended sequence is equal to Nsc. Therefore, Nsc≥M.
[0127] Next operation for generating OFDM signals is to insert a protection field at the beginning of each OFDM symbol, which can eliminate multipath propagation. This is because propagation of a radio signal through two or more channels to a receiver may cause inter-symbol interference (ISI) . The protection field is obtained by adding a cyclic prefix (CP) to a start position of a symbol. For example, the last G sample points of xk can be copied and appended to the start position of the symbol to obtain a time domain OFDM signal Thus, an OFDM symbol may contain valid data and cyclic prefixes (redundant data) .
[0128] At the receiving end, the OFDM signal is demodulated by inverse processing. Assuming that time and frequency synchronization can be obtained and CP length is sufficient, a data block that has no ISI and includes sampling values is obtained after a CP de-operation (that is, a previous G sampling value in a received signal is removed) , and the data block that has no ISI is further equal to a time domain cyclic convolution of the OFDM symbol and a channel impulse response. The time domain cyclic convolution can be converted into frequency domain point multiplication by using DFT, and channel equalization can be completed with low complexity by using frequency domain single tap equalization.
[0129] Sk may include modulated symbols and / or redundant signal sampling points. The modulation symbol may be a modulation symbol obtained by modulating the (coded) bit stream. The modulation scheme may include but is not limited to pulse amplitude modulation (pulse amplitude modulation, PAM) , phase shift keying (phase shift keying, PSK) , quadrature amplitude modulation (quadrature amplitude modulation, QAM) , amplitude phase shift keying (APSK) , and so on.
[0130] The redundant signal sampling points may include but are not limited to a phase tracking reference signal (phase tracking reference signal, PTRS) sampling point, a demodulation reference signal, a tone reservation signal, and the like.
[0131] It should be understood that, when the quantity of transform points meets a specific constraint, for example, N is a power of 2, 3, or 5, the IDFT may also be implemented by using an efficient inverse fast Fourier transform (IFFT) . Accordingly, the DFT may also be implemented with efficient fast Fourier transform (FFT) . In the following description, IDFT and IFFT are interchangeable, and DFT and FFT are interchangeable.
[0132] 2. Discrete Fourier transform spreading OFDM (DFT-s-OFDM)
[0133] As shown in FIG. 6, the DFT-s-OFDM defines a data block sk transmitted in the time domain, and an additional DFT processing is performed before the OFDM processing. That is, a point DFT operation is performed on each data block sk including data, to obtain Sk. By this operation, the DFT-s-OFDM signal has a single carrier characteristic, and has a peak to average power ratio (PAPR) much lower than a multicarrier signal such as OFDM. Therefore, the DFT-s-OFDM can provide higher output power and higher power amplifier (PA) efficiency at the same power drop, thereby improving coverage and reducing energy consumption. Advantages of DFT-s-OFDM in coverage and power consumption are particularly obvious on a terminal device side. Therefore, in both LTE and NR versions, DFT-s-OFDM is applied to uplink transmission.
[0134] sk may include modulated symbols and / or redundant signal sampling points. The modulation symbol may be a modulation symbol obtained by modulating a (coded) bit stream. The modulation scheme may include but is not limited to PAM, PSK, QAM, offset quadrature amplitude modulation (offset quadrature amplitude modulation, OQAM) , APSK, and so on.
[0135] The redundant signal sampling points may include but are not limited to a PTRS sampling point, a unique word (unique word) , zero, or the like.
[0136] 3. QPSK, QAM and π / 2-BPSK
[0137] Quadrature phase shift keying (QPSK) , quadrature amplitude modulation (QAM) , and π / 2-binary phase shift keying (BPSK) are bit mapping schemes defined in NR protocol. QPSK may also be referred to as 4QAM. A BPSK modulation mapper is used as an example, and the BPSK modulation mapper maps the i-th bit b (i) to the i-th BPSK symbol d (i) according to the following formula:
[0138]
[0139] A π / 2-BPSK modulation mapper is used as an example, and the modulation mapper maps the i-th bit b(i) to the i-th π / 2-BPSK symbol d (i) according to the following formula:
[0140]
[0141] Two adjacent symbols in a π / 2-BPSK symbol sequence have a 90-degree phase jump.
[0142] FIG. 7 plots a trajectory of a π / 2-BPSK symbol sequence, with the horizontal axis being the real part of the symbol and the vertical axis being the imaginary part of the symbol. In other words, a phase difference between two adjacent symbols in the sequence may be π / 2.
[0143] A QPSK modulation mapper is used as an example. The QPSK modulation mapper maps two consecutive bits into one QPSK symbol. The specific mapping is as follows:
[0144]
[0145] where b (2i) and b (2i+1) denote the 2i-th bit and the (2i+1) -th bit, respectively, and d (i) denotes the i-th QPSK symbol.
[0146] 16QAM is another bit mapping scheme. A 16QAM modulation mapper is used as an example. The 16QAM modulation mapper maps four consecutive bits into one 16QAM symbol, and specific mapping is as follows:
[0147]
[0148] where b (4i) , b (4i+1) , b (4i+2) and b (4i+3) respectively denote the 4i-th, the (4i+1) -th, the (4i+2) -th, and the (4i+3) -th bit, and d (i) denotes the i-th 16QAM symbol.
[0149] 4. Power amplifier output power backoff
[0150] Before a signal is transmitted by an antenna, the signal power may be increased by a power amplifier (PA) . One of the most basic ways to describe PA behavior is the amplitude modulation-amplitude modulation (AM-AM) and amplitude modulation-phase modulation (AM-PM) characteristics of the PA. In an AM-AM curve for a typical solid-state PA, which depicts the output power as a function of the input power, the amplifier has a linear region. In this region, the output power of the amplifier increases linearly with the input power. It can also be understood as the PA gain (that is, the ratio of the PA output power to the input power) remains unchanged or the slope of the AM-AM curve remains unchanged. As the input power continues to increase, the amplifier enters the non-linear region, and the output power does not increase linearly with the input power. As a result, the gain is compressed, and the slope of the AM-AM curve decreases. When the output power is saturated, that is, the output power does not increase with the input power, and the slope is 0.
[0151] Impact of the non-linear feature of the PA on the transmitted signal is reflected in in-band distortion and out-of-band distortion. The in-band distortion is mainly the amplitude and phase distortion of signals, which deteriorates signal demodulation / detection performance. The out-of-band distortion is mainly manifested by signal spectrum expansion / regeneration, which increases interference to adjacent channel users. To reduce the non-linear impact of the PA, power of the input signal may be appropriately reduced, that is, input power backoff (IBO) or output power backoff (OBO) is performed, so that the PA works in a linear region as much as possible. But this is an approach that comes at the expense of reducing PA efficiency.
[0152] 5. Peak to average power ratio (PAPR)
[0153] PAPR is a ratio of peak power to average power of a signal. For a signal x (t) , the peak power of the signal within a certain time interval (for example, from t0 to t1) is and the average power is Then, the PAPR can be written as:
[0154]
[0155] A communication signal (including an OFDM signal and a DFT-s-OFDM signal) is a random signal. An average power of the communication signal may be regarded as a fixed value, and a peak power of the communication signal is indeed a random variable. Therefore, PAPR is also a random variable. In statistics, the probability density function may be used to describe a value of a random signal at a certain time. In the communications field, a complementary cumulative distribution function (CCDF) curve may be used to describe the PAPR. The CCDF is a probability that the instantaneous power exceeds the average power xx dB is yy, or a ratio of the time when the instantaneous power exceeds the average power xx dB to the total time is yy. The formula can be written as:
[0156]
[0157] where P (·) denotes the probability. In the PAPR diagram shown in this application, the horizontal axis corresponds to xx and the vertical axis corresponds to yy.
[0158] A higher PAPR of the input signal x (t) of the PA indicates a larger floating range of the input power. Therefore, to ensure that all signals are within the linear range, more power value backoff is needed. Therefore, designing a signal with a low PAPR can reduce the PA OBO, increase the transmit power, and improve the coverage.
[0159] 6. Demodulation reference signal (DM-RS)
[0160] Information is sent from a transmitter and received by a receiver after passing through a transmission channel. The information may change (because of such as noise, fading, etc. ) in the transmission channel. As a result, the received information may be different from the transmitted information. To accurately restore correct information, it is necessary to understand what changes the information undergoes in a transmission process. Therefore, a reference signal (RS) is introduced.
[0161] The transmitter and the receiver agree on a known signal (i.e. RS) in advance, and the RS and the information to be sent are transmitted on the transmission channel together. After receiving a reference signal (denoted by RS') , the receiver can learn about the change of the information on the transmission channel by comparing the difference between the RS and the RS'. Then, channel characteristic estimation can be performed to obtain a channel characteristic H. According to the channel characteristic H, the received information may be restored to the correct sending information. It should be noted that, in some embodiments, the RS may be named as pilot. Thus, the terms "pilot" and "reference signal" may be used interchangeably in embodiments of this application.
[0162] DM-RS is a reference signal used for channel estimation during demodulation.
[0163] In the cellular communication system known as 5G NR, a low PAPR π / 2-BPSK waveform (with roll-off factor equal to 1) can be adopted for coverage enhancement. Specifically, the π / 2-BPSK waveform is used for the DM-RS so that the PAPR of the DM-RS can match that of the data signal. However, a disadvantage of a π / 2-BPSK based DM-RS is that its frequency-domain spectrum is not flat, which can affect channel estimation performance.
[0164] Frequency-domain spectral shaping (FDSS) is a signal processing technique that is applied to data and other signals for reducing PAPR. FIG. 8 is a schematic diagram illustrating FDSS with roll-off factor α, which involves copying the whole original data sequence 811 once, and then applying an root-raised cosine (RRC) window 820 on the combined signal (including the original data sequence 811 and the cyclic copy of the original data sequence 812 illustrated in FIG. 8) , where the window length W is defined by W= (1+α) N, and N is the length of the original data sequence 811. The resulting signal part which is not covered by the window is discarded. This maintains the property that the resulting pulse is a Nyquist pulse. A Nyquist pulse is a pulse that satisfies the Nyquist criterion.
[0165] In the above example shown in FIG. 8, the resulting signal obtained after FDSS may be referred to as a data signal. The RRC window 820 applied to the combined signal may be referred to as a data window. The length of the data signal is equal to the length of the data window.
[0166] For the FDSS, a repetition factor can be introduced to indicate a ratio of a length of the signal after FDSS processed and a length of the original sequence. In the example illustrated in FIG. 8, the repetition factor of the data signal (denoted by α′) equals to the roll-off factor α. That is, the repetition factor of the data signal α′complies with W1=(1+α′) N, where W1 is the length of the data signal which is equal to the length of the data window W= (1+α) N, and N is the length of the original data sequence 811.
[0167] The FDSS can also be applied to a ZC sequence-based DM-RS. While the ZC sequence is typically defined by the maximum prime number that is less than the length of the DM-RS, a ZC sequence length other than the maximum prime number may be used to reduce PAPR. The result of applying the FDSS to DM-RS creates a close-to-Nyquist pulse; therefore, the repetition factor of the DM-RS is similar to that of the data. However, the resulting DM-RS may not have an optimal PAPR, especially when the roll-off factor approaches 1.
[0168] As explained above, the repetition factor of the data signal (denoted by β′) indicate a ratio of a length of the DM-RS and a length of the original ZC sequence. That is, the repetition factor of the data signal β′complies with W2=(1+β′) M, where W2 is the length of DM-RS which is equal to the length of the reference window, and M is the length of the original ZC sequence. The reference window is an RRC window applied to the combined signal (including the original ZC sequence and the cyclic copy of the ZC sequence) . When the length of the original ZC sequence M is the maximum prime number that is less than the length of the DM-RS W2, which means M approaches W2, the repetition factor of the data signal β′is close to 0.
[0169] The DM-RS may also be frequency-division multiplexed (FDMed) with DFT-spread data, and still result in a signal with a relatively low PAPR. Multiplexing data and DM-RS in one OFDM symbol, as shown in FIG. 9 and FIG. 10, is an example implementation of such a scheme. The RRC window 1010 shown in FIG. 10 can be referred to as FDSS window.
[0170] While the multiplexed signal has a relatively low PAPR, there is some potential to further improve PAPR performance. Specifically, if a typical maximum prime number length ZC sequence DM-RS is multiplexed with an SC-OQAM waveform data, and the roll-off factor approaches 1, the PAPR of the multiplexed signal does not further decrease, as shown in FIG. 11.
[0171] As shown in FIG. 11, the PAPR of the multiplexed signal in the case of roll-off factor α being equal 1 is close to the PAPR of the multiplexed signal in the case of roll-off factor α being equal 0.5. Thus, there is some potential to further improve PAPR performance (i.e. reducing PAPR) when the roll-off factor approaches 1.
[0172] To further reduce PAPR when the roll-off factor approaches 1, an SC-OQAM waveform may be used for the DM-RS. This implementation of DM-RS generation aligns the real pulse in the DM-RS with the imaginary pulse in the data, and vice versa. FIG. 12 shows an example reduction in PAPR according to this multiplexing implementation. However, since the power spectrum of an SC-OQAM-based DM-RS is not flat in the frequency domain, its channel estimation performance is inferior to a ZC-sequence-based DM-RS. Thus, this example multiplexing implementation may be generally unsuitable for sensing operations.
[0173] Therefore, how to reduce PAPR of a reference signal in FDSS scenarios is a desirable problem to be solved.
[0174] Therefore, this application provides a communication method. The technical solutions may allow a data signal and a reference signal providing channel estimation for the data signal to have different repetition factor. Thereby, the reference signal may have an appropriate repetition factor to obtain a low PAPR. For example, in the case of the repetition factor of the data signal being determined based on the roll-off factor to reduce PAPR of the data signal, the repetition factor of the reference signal may be decoupled from the roll-off factor to reduce PAPR of the reference signal.
[0175] Some aspects of the present disclosure relate to configuration or generation of a reference signal, such as DM-RS, with improved channel estimation performance. In some aspects, the DM-RS may also be used for a sensing operation. Some implementations embodying these aspects of the present disclosure include a constant modulus sequence such as a ZC sequence. These embodiments may achieve sufficient PAPR performance (low PAPR performance similar to the the π / 2-BPSK waveform) , as roll-off factor approaches to 1.
[0176] In the following, the communication method provided in this application will be described in combination with FIG. 13.
[0177] FIG. 13 is a schematic flowchart of a communication method 1300 according to an embodiment of this application. The communication method 1300 may be applied to the communications system described above.
[0178] At S1310, a transmitting apparatus obtains a data signal and a reference signal.
[0179] The transmitting apparatus could be a terminal device or a chip in the terminal device. Alternatively, the transmitting apparatus could be a network device or a chip in the network device.
[0180] In some implementations, the reference signal may be a DM-RS. The following will use DMRS as an example to explain, but it should be noted that the method provided in this application can also be applied to other reference signals, such as a phase track reference signal (PT-RS) , a channel status indication reference signal (CSI-RS) , a sounding reference signal (SRS) and a cell reference signal (CRS) , which is not limited in this application.
[0181] The data signal may be obtained by cyclically repeating a first sequence based on a first factor, where the first factor indicates a ratio of a length of the data signal to a length of the first sequence. For example, the data signal may include the original first sequence and a cyclic copy of the first sequence. The cyclic copy of the first sequence may be all or part of the original first sequence. The first factor may be the proportion of cyclic copy to the original first sequence, which complies with the following formula:
[0182] W1= (1+α′) N
[0183] where W1 is the length of the data signal, N is the length of the first sequence, and α′is the first factor. The first factor α′may be a real number greater than or equal to 0 and less than or equal to 1. When the first factor α′approaches to 0, the data signal is close to the original first sequence. When the first factor α′approaches to 1, the cyclic copy of the first sequence is close to all of the original first sequence. When the first factor α′is greater than 0 and less than 1, the cyclic copy of the first sequence is a part of the original first sequence. In some implementations, for example in FDSS scenarios, the first factor α′may also be referred to as the repetition factor of the data signal.
[0184] In some implementations, the first sequence may be a π / 2-BPSK sequence or a SC-OQAM sequence. That is, the data signal may be generated from a π / 2-BPSK sequence or a SC-OQAM sequence. Such sequences have low PAPR. Thus, the PAPR of the data signal can be reduced.
[0185] The reference signal may be obtained by cyclically repeating a second sequence based on a second factor, where the second factor indicates a ratio of a length of the reference signal to a length of the second sequence. For example, the reference signal may include the original second sequence and a cyclic copy of the second sequence. The cyclic copy of the second sequence may be all or part of the original second sequence. The second factor may be the proportion of cyclic copy to the original second sequence, which complies with the following formula:
[0186] W2= (1+β′) M
[0187] where W2 is the length of the reference signal, M is the length of the second sequence, and β′is the second factor. The second factor β′may be a real number greater than or equal to 0 and less than or equal to 1. When the second factor β′approaches to 0, the reference signal is close to the original second sequence. When the second factor β′approaches to 1, the cyclic copy of the second sequence is close to all of the original second sequence. When the second factor β′is greater than 0 and less than 1, the cyclic copy of the second sequence is a part of the original second sequence. In some implementations, for example in FDSS scenarios, the second factor β′may also be referred to as the repetition factor of the reference signal.
[0188] In some implementations, the second sequence may be a ZC sequence. Due to the constant modulus feature of the ZC sequence, the frequency domain flatness of the reference signal can be improved. Thus, channel estimation performance can be improved.
[0189] It should be noted that the second sequence may be other constant modulus sequence which can be used to generate DMRS, such as a Frank sequence, a Chu sequence, a Golay complementary sequence (GCS) , and other constant amplitude zero auto-correlation (CAZAC) sequences, which is not limited in this application.
[0190] The data signal and the reference signal are processed by FDSS with the same roll-off factor. That is, a roll-off factor of FDSS window applied to the data signal is same as a roll-off factor of FDSS window applied to the reference signal.
[0191] It should be noted that the FDSS window is different from the data window and / or the reference window mentioned above. The same FDSS window is applied to the data sequence and the reference signal, while the data window applied to the data signal and the reference window applied to the reference signal may be different.
[0192] In other word, in some implementations, the length of the data signal and the length of the reference signal may be different. In some other implementations, the length of the data signal may equal to the length of the reference signal. For example, the length of the data signal and the length of the reference signal are both equal to the length of the FDSS window. That is, W1=W2=W, where W1 is the length of the data signal, W2 is the length of the reference signal, and W is the length of the FDSS window.
[0193] The first factor is different from the second factor, which means the first factor and the second factor may be determined based on different parameters. For example, in FDSS scenarios, when the first factor is determined based on the roll-off factor of the FDSS, the second factor may be decoupled from the roll-off factor of the FDSS.
[0194] In some implementations, the first factor is determined based on the roll-off factor of the FDSS window. For example, the first factor may equal to the roll-off factor of the FDSS window. In some implementations, the roll-off factor of the FDSS window may approach to 1. That is, the first factor may approach to 1. Thus, a low PAPR data signal can be obtained.
[0195] In some implementations, when the first factor is equal to the roll-off factor which approaches to 1, the second factor may be greater than or equal to 0.45 and less than or equal to 0.55. Thus, a low PAPR reference signal can be obtained.
[0196] Furthermore, in the case of the second factor being greater than or equal to 0.45 and less than or equal to 0.55, the length of the second sequence may be selected as the maximum prime number less than W2 / (1+β) , where W2 is the length of the reference window (i.e. the length of the reference signal) , and β is a real number greater than or equal to 0.45 and less than or equal to 0.55. Thus, the second sequence can meet the length requirement of a ZC sequence, while reducing PAPR of the reference signal.
[0197] At S1320, the transmitting apparatus transmits the data signal and the reference signal. Correspondingly, a receiving apparatus receives the data signal and the reference signal.
[0198] The reference signal provides channel estimation for the data signal. For example, the receiving apparatus may estimate the channel based on the reference signal to demodulate the data signal.
[0199] In some implementations, the transmitting apparatus may transmit a first symbol, where the data signal and the reference signal are frequency division multiplexed in the first symbol. That is, the method 1300 may be used in scenarios where the reference signal and the data signal are frequency division multiplexed (FDMed) , so that PAPR of the FDMed signal can be reduced.
[0200] For example, the first symbol may be a time-frequency resource, which includes P first subcarriers and Q second subcarriers in the frequency domain. P and Q are positive integers. The P first subcarriers respectively carry the P first frequency domain signals which are obtained according to the data signal through DFT, and the Q second subcarriers respectively carry the Q second frequency domain signals which are obtained according to the reference signal through DFT.
[0201] Optionally, the data signal and the pilot may be mapped to the frequency domain subcarriers in an interleaving manner. For example, K first subcarriers and K second subcarriers are interleaved, where K is a positive integer, and K=P=Q. In this case, a distance between the i-th first subcarrier and the (i+1) -th first subcarrier may be a second subcarrier, and i is a positive integer less than K.
[0202] It should be noted that, the K first subcarriers and the K second subcarriers may be interleaved in other manner, which is not limited in this application. It is assumed that “a” denotes a first subcarrier and “b” denotes a second subcarrier. For example, the K first subcarriers and the K second subcarriers may be placed as [a, a, b, b, a, a, b, b, …] . For another example, the K first subcarriers and the K second subcarriers may be placed as [a, a, a, b, b, b, a, a, a. b, b, b, …] .
[0203] In some other implementations, the transmitting apparatus may transmit a second symbol, where the reference signal is carried in the second symbol, and transmit a third symbol, where the data signal is carried in the third symbol. That is, the method 1300 may be used in scenarios where the reference signal is a stand-alone reference signal, so that PAPR of the stand-alone reference signal can be reduced.
[0204] For example, the transmitting apparatus may transmit the second symbol carrying the stand-alone reference signal first, and then transmit the third symbol carrying the data signal. The receiving apparatus may obtain the stand-alone reference signal first and estimate the channel based on the stand-alone reference signal. Then, the receiving apparatus may obtain the data signal and demodulate the data signal based on result of channel estimation.
[0205] According to the above technical solution, a data signal and a reference signal providing channel estimation for the data signal may have different repetition factor (i.e. the first factor and the second factor) in FDSS scenarios. That is, in the case of the data signal being generated based on the first factor to obtain a low PAPR, the reference signal may be generated based on the second factor which is not necessary to be same as the first factor. Therefore, the reference signal may be generated based on an appropriate repetition factor to obtain a low PAPR. Thus, PAPR of a reference signal in FDSS scenarios can be reduced.
[0206] In some other implementations, the reference signal generated or obtained according to the above method may be used for communication and / or sensing.
[0207] In the following, some embodiments according to the above method as specific examples will be described in combination with FIG. 14 and FIG. 15.
[0208] As previously explained, the length of a typical ZC sequence used for DM-RS is defined as the maximum prime number that is smaller than the length of DM-RS. With a roll-off factor being 0, the repetition factor of the DM-RS is also close to 0. As explained above in relation to FIG. 8, to ensure that the resulting pulses are Nyquist pulses, the repetition factor of the data may be chosen to be equal to the roll-off factor.
[0209] In order to further improve PAPR performance of some example implementations in the present disclosure, some embodiments include decoupling the repetition factor β from the roll-off factor α, as α→1. A schematic diagram of an example is shown in FIG. 14. In some embodiments, the length M of the original ZC sequence 1411 is selected as the maximum prime number that is less than:
[0210] W / (1+β)
[0211] where β=0.45~0.55. In the above example shown in FIG. 14, the resulting signal obtained after FDSS may be referred to as a DM-RS. The RRC window 1420 applied to the combined signal (including the original ZC sequence 1411 and the cyclic copy of the ZC sequence 1412) may be referred to as a reference window. The window length W shown in FIG. 14 is the length of the reference window. The length of the DM-RS is equal to the length of the reference window.
[0212] The resulting PAPR of the ZC sequence when α→1 is 1.72dB. By comparison, with β≈α→1, the corresponding PAPR is 3.31dB, as shown in Table 1.
[0213] Table 1
[0214] It should be noted that, in the above example, β is an expected repetition factor rather than a real repetition factor. As explained above, the real repetition factor β′may comply with W= (1+β′) M. Because M is selected as the maximum prime number that is less than W / (1+β) , which means M may be close to W / (1+β) , the expected repetition factor β may be close to the real repetition factor β′. Thus, the expected repetition factor β may also be abbreviated as the repetition factor in some implementations.
[0215] FIG. 15 is a graph showing PAPR performance of frequency-division multiplexing of data and DM-RS, in accordance with embodiments of decoupling the repetition factor from the roll-off factor, such as the example shown in FIG. 14. Comparing the graphs in FIG. 15 and FIG. 11 illustrates that the PAPR of the multiplexed signal is further reduced by 1.5dB, with 1: 1 ratio data and DM-RS multiplexing.
[0216] Moreover, comparing the graphs in FIG. 15 and FIG. 12 illustrates that the PAPR of the multiplexed signal is very similar to that of SC-OQAM-based DM-RS, yet does not suffer the disadvantages of the SC-OQAM-based DM-RS that cause that implementation to be unsuitable for sensing operations.
[0217] The DM-RS based on ZC sequences has a flat power spectrum in the frequency domain, which not only improves the performance of channel estimation, but also makes the DM-RS more effective for monostatic sensing. Embodiments include both stand-alone DM-RS applications and multiplexing DM-RS with data applications.
[0218] In some embodiments, FDSS of roll-off factor close to 1 is applied to a signal, to form a Nyquist data pulse in the time domain. A repetition factor β is used for the DM-RS and a roll-off factor α is used to apply the FDSS window to the DM-RS. Values for the repetition factor and the roll-off factor are decoupled.
[0219] Some embodiments involve cyclically repeating data according to the roll-off factor α to fill the FDSS window length. A ZC sequence with length being the maximum prime number that is smaller than W / (1+β) is selected, where W is the FDSS window length and β is the repetition factor. In some embodiments, β=0.45~0.55. The ZC-sequence is cyclically repeated fill the FDSS window length. The data and DM-RS are multiplexed in the frequency domain and the FDSS window is applied to the multiplexed data and DM-RS.
[0220] Some embodiments involve select a ZC-sequence with length being the maximum prime number that is smaller than W / (1+β) , where W is the FDSS window length and β is the repetition factor. In some embodiments, β=0.45~0.55. The ZC-sequence is cyclically repeated to fill the FDSS window length. An FDSS window with roll-off factor α~1 is applied to the resulting DM-RS. This DM-RS may be used as a stand-alone DM-RS in place of conventional π / 2-BPSK based or SC-OQAM based DM-RS.
[0221] The DM-RS generated according to any of the previous embodiments may also be used for both communication and sensing, such as in an ISAC application.
[0222] In summary of the various aspects of the present disclosure, some features may enable certain advantageous effects. Decoupling the repetition factor β of DM-RS from the roll-off factor α, where α~1, helps to lower PAPR of a resulting frequency-domain multiplexed data and DM-RS signal, or lower PAPR of a stand-alone DM-RS signal. Use of ZC-sequences instead of π / 2-BPSK or SC-OQAM as the basis for the DM-RS also helps to lower PAPR, while comparatively achieving better channel estimation, enable effective sensing, or both, due to the constant modulus feature of DM-RS in the frequency domain.
[0223] The communication method according to the embodiments of this application is described in detail above with reference to FIG. 13 to FIG. 15 and the apparatuses provided in embodiments of this application are described below. The description of apparatus embodiments corresponds to the description of the method embodiments. Therefore, for content that is not described in detail, refer to the foregoing method embodiments. For brevity, details are not described herein again.
[0224] As aforementioned in FIG. 4, the apparatus 410 may be configured to perform actions performed by the network side in the foregoing method embodiments. In this case, the apparatus 410 may be the network side or a component that can be configured in the network side.
[0225] The apparatus 410 may implement steps or procedures performed by the network side (or the receiving apparatus) in FIGS. 13-15 according to embodiments of this application. The apparatus 410 may include units configured to perform the method performed by the network side (or the receiving apparatus) in FIGS. 13-15. In addition, the units in the communication apparatus 410 and the foregoing other operations and / or functions are separately used to implement corresponding procedures in FIGS. 13-15.
[0226] Alternatively, the apparatus 410 may be configured to perform actions performed by the terminal side in the foregoing method embodiments. In this case, the apparatus 410 may be the terminal side or a component that can be configured in the terminal side.
[0227] The apparatus 410 may implement steps or procedures performed by the terminal side (or the transmitting apparatus) in FIGS. 13-15 according to embodiments of this application. The apparatus 410 may include units configured to perform the method performed by the terminal side (or the transmitting apparatus) in FIGS. 13-15. In addition, the units in the communication apparatus 410 and the foregoing other operations and / or functions are separately used to implement corresponding procedures in FIGS. 13-15.
[0228] A specific process in which the units perform the foregoing corresponding steps is described in detail in the foregoing method embodiments. For brevity, details are not described herein again.
[0229] As aforementioned in FIG. 5, the methods in the foregoing method embodiments are executed by the apparatus 510.
[0230] In some embodiments, the apparatus 510 may be a network side or a component (e.g., a chip, a circuit, or a processing system) that can be configured in the network side; or the communication apparatus 510 may be a terminal side or a component (e.g., a chip, a circuit, or a processing system) that can be configured in the terminal side.
[0231] In a solution, the apparatus 510 is configured to perform the operations performed by the network side (or the receiving apparatus) in the foregoing method embodiments.
[0232] For example, the processor unit 511 may be configured to perform a processing-related operation performed by the receiving apparatus in the foregoing method embodiments, and the communication unit 513 may be configured to perform a communicating-related (e.g., receiving / transmitting-related) operation performed by the receiving apparatus in the foregoing method embodiments.
[0233] In another solution, the apparatus 510 is configured to perform the operations performed by the terminal side (or the transmitting apparatus) in the foregoing method embodiments.
[0234] For example, the processor unit 511 may be configured to perform a processing-related operation performed by the transmitting apparatus in the foregoing method embodiments, and the communication unit 513 may be configured to perform a communicating-related (e.g., receiving / transmitting-related) operation performed by the transmitting apparatus in the foregoing method embodiments.
[0235] An embodiment of this application further provides a system. As shown in FIG. 16, a system 50 includes the transmitting apparatus 10 according to the embodiments of this application and the receiving apparatus 30 according to the embodiments of this application.
[0236] The transmitting apparatus 10 may be implemented by the apparatus 510 according to the embodiments of this application, and the receiving apparatus 30 may be implemented by the apparatus 510 according to the embodiments of this application.
[0237] For explanations and beneficial effects of related content of any communication apparatus provided above, refer to a corresponding method embodiment provided above. Details are not described herein again.
[0238] An embodiment of this application further provides a computer-readable storage medium, and the computer-readable storage medium may store computer instructions used to implement any of the foregoing methods.
[0239] Optionally, the storage medium may be specifically the memory 413.
[0240] An embodiment of this application further provides a computer program product including instructions. When the instructions are executed by a computer, the computer is enabled to implement any of the foregoing methods.
[0241] A person of ordinary skill in the art will be aware that, in combination with the examples described in the embodiments disclosed in this specification, units and algorithm steps may be implemented by using electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by using hardware or software depends on particular applications and design constraint conditions of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the embodiment goes beyond the scope of this application.
[0242] It would be understood by a person skilled in the art that, for the purpose of convenience and brevity, in a detailed working process of the foregoing system, apparatus, and unit, reference may be made to a corresponding process in the foregoing method embodiments, and details are not described herein again.
[0243] In the several embodiments provided in this application, the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, the unit division is a logical function division and other methods of division may be used in an actual embodiment. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented by using some communication interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms.
[0244] The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, the parts may be located in one unit, or may be distributed among a plurality of network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the embodiments.
[0245] In addition, function units in the embodiments of this application may be integrated into one processing unit, each of the units may exist alone physically, or two or more units may be integrated into one unit.
[0246] When the functions are implemented in the form of a software functional unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. The technical solutions of this application may be implemented in the form of a software product. The software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the steps of the methods described in the embodiments of this application. The foregoing storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (Read-Only Memory, ROM) , a random access memory (Random Access Memory, RAM) , a magnetic disk, an optical disc or the like.
[0247] In the present disclosure, the terms “a” , “an” and “one” are defined to mean “at least one” , that is, these terms do not exclude a plural number of items, unless stated otherwise.
[0248] In the present disclosure, terms such as “substantially” , “generally” and “about” , which modify a value, condition or characteristic of a feature of an exemplary embodiment, should be understood to mean that the value, condition or characteristic is defined within tolerances that are acceptable for the proper operation of this exemplary embodiment for its intended application.
[0249] In the present disclosure, unless stated otherwise, the terms “connected” and “coupled” , and derivatives and variants thereof, refer herein to any structural or functional connection or coupling, either direct or indirect, between two or more elements. For example, the connection or coupling between the elements can be acoustical, mechanical, optical, electrical, thermal, logical, or any combinations thereof.
[0250] In the present disclosure, expressions such as “match” , “matching” and “matched” , including variants and derivatives thereof, are intended to refer herein to a condition in which two or more elements are either the same or within some predetermined tolerance of each other. That is, these terms are meant to encompass not only “exactly” or “identically” matching the two elements but also “substantially” , “approximately” or “subjectively” matching the two or more elements, as well as providing a higher or best match among a plurality of matching possibilities.
[0251] In the present disclosure, the expression “based on” is intended to mean “based at least partly on” , that is, this expression can mean “based solely on” or “based partially on” , and so should not be interpreted in a limited manner. More particularly, the expression “based on” could also be understood as meaning “depending on” , “representative of” , “indicative of”, “associated with” or similar expressions.
[0252] In the present disclosure, the terms “system” and “network” may be used interchangeably in embodiments of this application. “At least one” means one or more, and “aplurality of” means two or more. The term “and / or” describes an association relationship of associated objects, and indicates that three relationships may exist. For example, A and / or B may indicate the following three cases: Only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. The character “ / ” usually indicates an “or” relationship between associated objects. “At least one of the following items (pieces) ” or a similar expression thereof indicates any combination of these items, including a single item (piece) or any combination of a plurality of items (pieces) . For example, “at least one of A, B, or C” includes A, B, C, A and B, A and C, B and C, or A, B, and C, and “at least one of A, B, and C” may also be understood as including A, B, C, A and B, A and C, B and C, or A, B, and C. In addition, unless otherwise specified, ordinal numbers such as "first" and "second" in embodiments of this application are used to distinguish between a plurality of objects, and are not used to limit a sequence, a time sequence, priorities, or importance of the plurality of objects.
[0253] A person skilled in the art should understand that embodiments of this application may be provided as a method, an apparatus (or system) , computer-readable storage medium, or a computer program product. Therefore, this application may use a form of a hardware-only embodiment, a software-only embodiment, or an embodiment with a combination of software and hardware. Moreover, this application may use a form of a computer program product that is implemented on one or more computer-usable storage media (including but not limited to a disk memory, an optical memory, and the like) that include computer-usable program code.
[0254] This application is described with reference to the flowcharts and / or block diagrams of the method, the device (system) , and the computer program product according to this application. It should be understood that computer program instructions may be used to implement each process and / or each block in the flowcharts and / or the block diagrams and a combination of a process and / or a block in the flowcharts and / or the block diagrams. The computer program instructions may be provided for a general-purpose computer, a dedicated computer, an embedded processor, or a processor of another programmable data processing device to generate a machine, so that the instructions executed by the computer or the processor of another programmable data processing device generate an apparatus for implementing a specific function in one or more procedures in the flowcharts and / or in one or more blocks in the block diagrams.
[0255] The computer program instructions may alternatively be stored in a computer-readable memory that can indicate a computer or another programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate an artifact that includes an instruction apparatus. The instruction apparatus implements a specific function in one or more procedures in the flowcharts and / or in one or more blocks in the block diagrams.
[0256] The computer program instructions may alternatively be loaded onto a computer or another programmable data processing device, so that a series of operations and steps are performed on the computer or another programmable device, so that computer-implemented processing is generated. Therefore, the instructions executed on the computer or another programmable device provide steps for implementing a specific function in one or more procedures in the flowcharts and / or in one or more blocks in the block diagrams.
[0257] It is clear that a person skilled in the art can make various modifications and variations to this application without departing from the scope of this application. This application is intended to cover these modifications and variations of this application provided that they fall within the scope of protection defined by the following claims and their equivalent technologies.
Claims
1.A communication method, comprising:obtaining a data signal and a reference signal, wherein the data signal is obtained by cyclically repeating a first sequence based on a first factor, the fist factor indicates a ratio of a length of the data signal to a length of the first sequence, the reference signal is obtained by cyclically repeating a second sequence based on a second factor, the second factor indicates a ratio of a length of the reference signal to a length of the second sequence, the first factor is different from the second factor, the data signal and the reference signal are processed by frequency-domain spectral shaping (FDSS) using an FDSS window, and a roll-off factor of the FDSS window applied to the data signal is same as the roll-off factor of the FDSS window applied to the reference signal; andtransmitting the data signal and the reference signal.2.The method according to claim 1, wherein the second sequence is a Zadoff-Chu (ZC) sequence.3.The method according to claim 1 or 2, wherein the first sequence is a π / 2-binary phase shift keying (BPSK) sequence or a single carrier offset quadrature amplitude modulation (SC-OQAM) sequence.4.The method according to any one of claims 1 to 3, wherein the first factor is determined based on the roll-off factor of FDSS window.5.The method according to any one of claims 1 to 4, wherein the length of the second sequence is the maximum prime number less than W2 / (1+β) , W2 is the length of the reference signal, and the length of the data signal complying with W1= (1+α) N, W1 is the length of the data signal, N is the length of the first sequence, α and β are real numbers greater than or equal to 0 and less than or equal to 1, andin the case of α being equal to 1, β is greater than or equal to 0.45 and less than or equal to 0.55.6.The method according to any one of claims 1 to 5, wherein the transmitting the data signal and the reference signal comprises:transmitting a first symbol, wherein the data signal and the reference signal are frequency division multiplexed in the first symbol.7.The method according to any one of claims 1 to 5, wherein the transmitting the data signal and the reference signal comprises:transmitting a second symbol, wherein the reference signal is carried in the second symbol; andtransmitting a third symbol, wherein the data signal is carried in the third symbol.8.The method according to any one of claims 1 to 7, wherein the reference signal is used for communication and / or sensing.9.The method according to any one of claims 1 to 8, wherein the reference signal provides channel estimation for the data signal.10.A communication method, comprising:receiving a data signal and a reference signal, wherein the data signal is obtained by cyclically repeating a first sequence based on a first factor, the fist factor indicates a ratio of a length of the data signal to a length of the first sequence, the reference signal is obtained by cyclically repeating a second sequence based on a second factor, the second factor indicates a ratio of a length of the reference signal to a length of the second sequence, the first factor is different from the second factor, the data signal and the reference signal are processed by frequency-domain spectral shaping (FDSS) using an FDSS window, and a roll-off factor of the FDSS window applied to the data signal is same as the roll-off factor of the FDSS window applied to the reference signal.11.The method according to claim 10, wherein the second sequence is a Zadoff-Chu (ZC) sequence.12.The method according to claim 10 or 11, wherein the first sequence is a π / 2-binary phase shift keying (BPSK) sequence or a single carrier offset quadrature amplitude modulation (SC-OQAM) sequence.13.The method according to any one of claims 10 to 12, wherein the first factor is determined based on the roll-off factor of FDSS window.14.The method according to any one of claims 10 to 13, wherein the length of the second sequence is the maximum prime number less than W2 / (1+β) , W2 is the length of the reference signal, and the length of the data signal complying with W1= (1+α) N, W1 is the length of the data signal, N is the length of the first sequence, α and β are real numbers greater than or equal to 0 and less than or equal to 1, andin the case of α being equal to 1, β is greater than or equal to 0.45 and less than or equal to 0.55.15.The method according to any one of claims 10 to 14, wherein the receiving the data signal and the reference signal comprises:receiving a first symbol, wherein the data signal and the reference signal are frequency division multiplexed in the first symbol.16.The method according to any one of claims 10 to 14, wherein the transmitting the data signal and the reference signal comprises:receiving a second symbol, wherein the reference signal is carried in the second symbol; andreceiving a third symbol, wherein the data signal is carried in the third symbol.17.The method according to any one of claims 10 to 16, wherein the reference signal is used for communication and / or sensing.18.The method according to any one of claims 10 to 17, wherein the reference signal provides channel estimation for the data signal.19.A communication apparatus, configured to perform the method according to any one of claims 1 to 18.20.The communication apparatus of claim 19, comprising:a processing unit configured to obtain the data signal and the reference signal; anda transmitting unit configured to transmit the data signal and the reference signal.21.The communication apparatus of claim 19, comprising:a receiving unit configured to receive the data signal and the reference signal.22.The communication apparatus of claim 19, comprising one or more processors coupled to an interface circuit, the one or more processors and the interface circuit configured to cause the apparatus to perform the method of any one of claims 1 to 18.23.The communication apparatus of claim 22, wherein the interface circuit comprises one or more transceivers.24.An apparatus comprising:one or more processors; anda memory storing instructions which, when executed by the one or more processors, cause the apparatus to perform the method of any one of claims 1 to 18.25.A communication system, wherein the communication system comprises a first communication apparatus configured to perform the method of any one of claims 1 to 9 and a second communication apparatus configured to perform the method of any one of claims 10 to 18.26.A computer-readable storage medium having instructions stored thereon which, when executed by an apparatus, cause the apparatus to perform the method of any one of 1 to 18.27.A computer program product storing instructions which, when executed, cause an apparatus to perform the method of any one of claims 1 to 18.