Synchronization method and communication device

Abstract

The present application relates to a synchronization method and a communication device. The method comprises: on the basis of a frame structure, a first communication device receives or detects one or more of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), and a narrowband physical broadcast channel (NPBCH). By means of the embodiments of the present application, the synchronization performance of a communication system can be improved.

Description

Synchronization method and communication device TECHNICAL FIELD

[0001] The present application relates to the field of communication, and more particularly, to a synchronization method and a communication device. BACKGROUND

[0002] In a communication system, downlink synchronization of a terminal device can be completed based on multiple types of synchronization signals or channels. In scenarios such as Non-Terrestrial Networks (NTN), a satellite operator can have some restrictions on the use of spectrum, which can affect synchronization performance.

[0003] SUMMARY

[0004] Embodiments of the present application provide a synchronization method and a communication device, which can improve the synchronization performance of a communication system.

[0005] Embodiments of the present application provide a synchronization method, comprising:

[0006] The first communication device receives or detects one or more of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), and a narrowband physical broadcast channel (NPBCH) based on a frame structure.

[0007] Embodiments of the present application provide a first communication device, comprising:

[0008] The transceiver receives or detects one or more of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), and a narrowband physical broadcast channel (NPBCH) based on a frame structure.

[0009] Embodiments of the present application provide a communication device, comprising a transceiver, a processor, and a memory. The memory is configured to store a computer program, the transceiver is configured to communicate with other devices, and the processor is configured to invoke and run the computer program stored in the memory, so that the communication device executes the above-mentioned synchronization method.

[0010] Embodiments of the present application provide a chip for implementing the above-mentioned synchronization method.

[0011] Specifically, the chip comprises a processor configured to invoke and run a computer program from a memory, so that a device installed with the chip executes the above-mentioned synchronization method.

[0012] Embodiments of the present application provide a computer-readable storage medium for storing a computer program, which causes a device to execute the above-mentioned synchronization method when the computer program is run by the device.

[0013] The embodiment of the present application provides a computer program product, comprising computer program instructions, which cause a computer to execute the synchronization method.

[0014] The embodiment of the present application provides a computer program, which, when running on a computer, causes the computer to execute the synchronization method. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 is a schematic diagram of an application scenario according to an embodiment of the present application.

[0016] Fig. 2 is a schematic flowchart of a synchronization method according to an embodiment of the present application.

[0017] Fig. 3a is an example diagram of a special frame structure.

[0018] Fig. 3b is an example diagram of another special frame structure.

[0019] Fig. 4 is a schematic flowchart of a synchronization method according to another embodiment of the present application.

[0020] Fig. 5 is an example diagram of network transmission of NSSS under a special frame structure.

[0021] Fig. 6 is another example diagram of network transmission of NSSS under a special frame structure.

[0022] Fig. 7 is an example diagram of non-repeated transmission of NSSS within 160 ms.

[0023] Fig. 8 is an example diagram of repeated transmission of NSSS within 160 ms through a sub-window.

[0024] Fig. 9 is an example diagram of repeated transmission of NSSS within 320 ms through a sub-window.

[0025] Fig. 10 is an example diagram of determination of a 320 ms boundary through two scrambling codes.

[0026] Fig. 11 is a schematic block diagram of a first communication device according to an embodiment of the present application.

[0027] Fig. 12 is a schematic block diagram of a communication device according to an embodiment of the present application.

[0028] Fig. 13 is a schematic block diagram of a chip according to an embodiment of the present application.

[0029] Fig. 14 is a schematic block diagram of a communication system according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0031] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example, a Long Term Evolution (LTE) system, an Advanced long term evolution (LTE-A) system, a New Radio (NR) system, an evolved system of the NR system, an LTE-based access to unlicensed spectrum (LTE-U) system, an NR-based access to unlicensed spectrum (NR-U) system, a Non-Terrestrial Network (NTN) system, a Universal Mobile Telecommunication System (UMTS), a Wireless Local Area Networks (WLAN), a Wireless Fidelity (WiFi), a 5th-Generation (5G) system, or other communication systems.

[0032] Generally, a conventional communication system supports a limited number of connections and is easy to implement. However, with the development of communication technology, a mobile communication system will not only support conventional communication, but also support, for example, Device to Device (D2D) communication, Machine to Machine (M2M) communication, Machine Type Communication (MTC), Vehicle to Vehicle (V2V) communication, or Vehicle to everything (V2X) communication. The embodiments of the present application can also be applied to these communication systems.

[0033] In an embodiment, the communication system in the embodiments of the present application can be applied to a Carrier Aggregation (CA) scenario, can also be applied to a Dual Connectivity (DC) scenario, and can also be applied to a Standalone (SA) network deployment scenario.

[0034] In an embodiment, the communication system in the embodiments of the present application can be applied to unlicensed spectrum, where the unlicensed spectrum can also be considered as shared spectrum; or the communication system in the embodiments of the present application can also be applied to licensed spectrum, where the licensed spectrum can also be considered as non-shared spectrum.

[0035] The embodiments of the present application describe various embodiments in combination with network devices and terminal devices, wherein the terminal device can also be referred to as a user equipment (UE), an access terminal, a user unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent or a user device, etc.

[0036] The terminal device can be a station (STA) in a WLAN, and can be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA) device, a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a next-generation communication system such as an NR network, or a terminal device in a future evolved Public Land Mobile Network (PLMN) network, etc.

[0037] In the embodiments of the present application, the terminal device can be deployed on land, including indoor or outdoor, handheld, wearable or vehicle-mounted; can also be deployed on the water surface (such as ships, etc.); and can also be deployed in the air (such as airplanes, balloons and satellites, etc.).

[0038] In the embodiments of the present application, the terminal device can be a mobile phone, a tablet computer (Pad), a computer with wireless transceiver function, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical, a wireless terminal device in smart grid, a wireless terminal device in transportation safety, a wireless terminal device in smart city or a wireless terminal device in smart home, etc.

[0039] As an example but not limitation, in embodiments of the present application, the terminal device can also be a wearable device. The wearable device can also be referred to as a wearable smart device, which is a general term for devices that are designed and developed by applying wearable technology to daily wear, such as glasses, gloves, watches, clothing, and shoes. The wearable device is a portable device that can be directly worn on the body or integrated into the user's clothes or accessories. The wearable device is not only a hardware device, but also a powerful function achieved through software support and data interaction, cloud interaction. The broad sense of wearable smart devices includes devices with full functions, large sizes, and the ability to realize complete or partial functions without relying on smart phones, such as smart watches or smart glasses, and devices that focus on a certain application function and need to be used with other devices such as smart phones, such as various smart wristbands, smart jewelry, and other devices for monitoring vital signs.

[0040] In embodiments of the present application, the network device can be a device for communicating with the mobile device, and the network device can be an access point (Access Point, AP) in a WLAN, an evolved node B (Evolutional Node B, eNB or eNodeB) in LTE, or a relay station or an access point, or a vehicle-mounted device, a wearable device, and a network device in an NR network (gNB) or a future evolved PLMN network or a network device in an NTN network, etc.

[0041] As an example but not limitation, in embodiments of the present application, the network device can have mobile characteristics, for example, the network device can be a mobile device. Alternatively, the network device can be a satellite, a balloon station. For example, the satellite can be a low earth orbit (low earth orbit, LEO) satellite, a medium earth orbit (medium earth orbit, MEO) satellite, a geostationary earth orbit (geostationary earth orbit, GEO) satellite, a high elliptical orbit (High Elliptical Orbit, HEO) satellite, etc. Alternatively, the network device can also be a base station arranged at a position on land, water, etc.

[0042] In the embodiments of the present application, the network device can serve a cell, and a terminal device communicates with the network device through a transmission resource (for example, a frequency domain resource, or a spectrum resource) used by the cell. The cell can be a cell corresponding to the network device (for example, a base station), and the cell can belong to a macro base station or a base station corresponding to a small cell (Small cell). The small cell can include a metro cell, a micro cell, a pico cell, a femto cell, and the like. The small cell has the characteristics of small coverage and low transmit power, and is suitable for providing high-speed data transmission services.

[0043] FIG. 1 illustrates a communication system 100. The communication system includes one network device 110 and two terminal devices 120. In an embodiment, the communication system 100 can include multiple network devices 110, and each network device 110 can include other numbers of terminal devices 120 within its coverage, which is not limited in the embodiments of the present application.

[0044] In an embodiment, the communication system 100 can further include a mobility management entity (MME), an access and mobility management function (AMF), and other network entities, which are not limited in the embodiments of the present application.

[0045] The network device can include an access network device and a core network device. That is, the wireless communication system further includes multiple core networks for communicating with the access network device. The access network device can be an evolved node B (eNB or e-NodeB) macro base station, a micro base station (also referred to as a “small base station”), a pico base station, an access point (AP), a transmission point (TP), or a new generation Node B (gNodeB) in a long-term evolution (LTE) system, a next radio (NR) system, or an authorized auxiliary access long-term evolution (LAA-LTE) system.

[0046] It should be understood that the devices with communication function in the network / system in the embodiments of the present application can be referred to as communication devices. For example, the communication system shown in FIG. 1, the communication devices can include network devices and terminal devices with communication function, which can be specific devices in the embodiments of the present application, and will not be described here. The communication devices can also include other devices in the communication system, such as network controllers, mobile management entities and other network entities, which are not limited in the embodiments of the present application.

[0047] It should be understood that the terms "system" and "network" are often used interchangeably in this paper. The term "and / or" in this paper is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " generally represents an "or" relationship between the associated objects before and after it.

[0048] It should be understood that the "indication" mentioned in the embodiments of the present application can be direct indication, indirect indication, or can represent an associated relationship. For example, A indicates B, which can mean that B can be obtained by A directly, or A indirectly indicates B, for example, A indicates C, and B can be obtained by C, or A and B have an associated relationship.

[0049] In the description of the embodiments of the present application, the term "corresponding" can represent a direct or indirect corresponding relationship between the two, or an associated relationship between the two, or an indication and being indicated, configuration and being configured, etc.

[0050] In order to facilitate the understanding of the technical solutions of the embodiments of the present application, the related technologies of the embodiments of the present application are described as follows, which can be combined with the technical solutions of the embodiments of the present application in any way, and all belong to the protection scope of the embodiments of the present application.

[0051] FIG. 2 is a schematic flowchart of a synchronization method 200 according to an embodiment of the present application. The method can be optionally applied to the system shown in FIG. 1, but is not limited to this. The method includes at least part of the following contents.

[0052] S210, the first communication device receives or detects one or more of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS) and a narrowband physical broadcast channel (NPBCH) based on the frame structure.

[0053] In the embodiments of the present application, in a communication system, the downlink synchronization of a first communication device, for example, a UE, can be completed based on a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS) and a narrowband physical broadcast channel (NPBCH). In a communication scenario such as NTN, the spectrum of NTN can only be used for narrowband internet of things (NB-IOT) service in part of time, and cannot be used continuously and uninterruptedly. In the frame structure of the embodiments of the present application, part of the radio frames in time are available, and the remaining radio frames are unavailable. The first communication device can receive or detect the NPSS and / or NSSS based on the frame structure. The first communication device can receive the NPBCH based on the frame structure. In this way, timing synchronization of NB-IOT under a special frame structure in which available radio frames are discontinuous can be implemented.

[0054] In the embodiments of the present application, a special frame structure, for example, an NTN frame structure, can be adopted for a system such as an NTN. The frame structure can include valid radio frames and invalid radio frames. In the special frame structure mode, the system such as the NTN cannot continuously occupy the bandwidth, so that the NTN frame structure is valid in part of the time. A system frame or a radio frame (SFN) in the special frame structure can include valid radio frames (valid SFN) and invalid radio frames (invalid SFN). The valid radio frames and the invalid radio frames can have a certain ratio. For example, the ratio of the valid radio frames to the invalid radio frames is 1:N. When N=3, it means that there is one valid radio frame every 3*n invalid radio frames, when n=1, as shown in FIG. 3a, when n=2, as shown in FIG. 3b, and n is a positive integer. The value of N can be determined by a second communication device, for example, a network device, and N is a positive integer. The UE first searches for the NPSS according to the value of N to determine the 10 ms radio frame boundary. Then, the UE can search for the NSSS to determine the 10*X ms boundary, where X is a positive integer value. Then, the UE can search for the NPBCH to determine the 10*Y ms boundary, where Y is also a positive integer value, and Y can be equal to or not equal to X. Finally, the UE completes the entire synchronization process according to the content of the MIB-NB in the NPBCH, that is, determines the index of each radio frame.

[0055] That is, 1:N is the ratio of the number of valid radio frames to invalid radio frames in a special frame structure period. In FIG. 3a, the special frame structure period includes 4 radio frames, for example, 40 ms. Each frame structure period includes 1 valid radio frame and 3 invalid radio frames. In FIG. 3b, the special frame structure period is 8 radio frames, for example, 80 ms. Each frame structure period includes 2 valid radio frames and 6 invalid radio frames. In the content of the embodiments of the present application, it can be assumed that the special frame structure includes only one valid radio frame in a special frame structure period for example, but the scheme of the embodiments of the present application can be extended to other cases, for example, the case of multiple valid radio frames in a special frame structure period.

[0056] FIG. 4 is a schematic flowchart of a synchronization method 400 according to another embodiment of the present application. The method can include one or more features of the above synchronization method. In one implementation, in step S210, the first communication device receives or detects the NPSS based on the frame structure, including:

[0057] S410, the first communication device receives or detects the NPSS in the first time window based on the frame structure.

[0058] In the embodiments of the present application, the first time window can include a time window occupied by the valid radio frame in the frame structure period. For example, referring to FIG. 3a, the first time window can include 10 ms. Referring to FIG. 3b, the first time window can include 20 ms. The first communication device can receive or detect the NPSS in the first time window. In the radio frame other than the first time window in the frame structure period, the first communication device does not receive or detect the NPSS.

[0059] In an implementation, the repetition period of the NPSS is a multiple of the period of the frame structure, and the first time window is within the repetition period of the NPSS.

[0060] For example, the repetition period of the NPSS can be equal to the frame structure period in the NTN system, which can also be referred to as the period of the valid radio frame. For another example, the repetition period of the NPSS is equal to 2 or more multiples of the frame structure period in the NTN system. In the embodiments of the present application, the frame structure period can also be referred to as the period of the valid radio frame.

[0061] In an implementation, the period of the frame structure is determined based on a ratio of valid radio frames to invalid radio frames in the frame structure, a number of valid radio frames in one period of the frame structure, and a time window occupied by one valid radio frame.

[0062] For example, the period of the frame structure can be represented by the following formula:

[0063] (N+1)*n*10 ms;

[0064] wherein the ratio of valid radio frames to invalid radio frames in the frame structure can be 1:N. That is, N can be understood as the ratio of the number of invalid radio frames to the number of valid radio frames in the frame structure. n is the number of valid radio frames in one period of the frame structure, for example, one or two. 10 ms is the time window occupied by one valid radio frame.

[0065] For example, if n is 1 and N is 3, the repetition period of the NPSS = the frame structure period = 40 ms. If n is 2 and N is 3, the repetition period of the NPSS = the frame structure period = 80 ms. If n is 1 and N is 7, the repetition period of the NPSS = the frame structure period = 80 ms.

[0066] In addition, the repetition period of the NPSS can be different from the period of the NPSS. The period of the NPSS can be equal to the time length of one radio frame. The repetition period of the NPSS can be understood as the period of repeatedly sending the NPSS multiple times. For example, if the period of the NPSS is 10 ms and the repetition period of the NPSS is 40 ms, the period of the repetition period of the NPSS is four times the period of the NPSS.

[0067] In an embodiment, the first time window is less than or equal to a time window occupied by all valid radio frames in a period of the frame structure, and greater than or equal to a time window occupied by one valid radio frame.

[0068] In an embodiment, if one period of the frame structure includes one valid radio frame, the first time window can be equal to a time window occupied by the one valid radio frame, for example, 10 ms. If the number of valid radio frames included in one period of the frame structure is greater than one, the first time window can be less than or equal to a time window occupied by all valid radio frames in the period. For example, if one period of the frame structure includes two valid radio frames, the first time window can be 10 ms or 20 ms. If one period of the frame structure includes three valid radio frames, the first time window can be 10 ms, 20 ms, or 30 ms.

[0069] In an embodiment, a boundary of one valid radio frame is determined based on a subframe index position of the NPSS in the valid radio frame.

[0070] In an embodiment, the boundary of one valid radio frame can be understood as a 10 ms boundary of the valid radio frame, or as a start and end time position of the 10 ms duration of the valid radio frame. For example, when determining the 10 ms boundary of the radio frame, the UE can determine the boundary position of the current radio frame, for example, the valid radio frame. The UE can perform single NPSS detection in each valid radio frame, or joint detection according to the NPSS repetition period. The NPSS can be at the subframe index 5 position in the valid radio frame. Each radio frame can include 10 subframes, and the index can be from 0 to 9. After the UE determines the subframe index position of the NPSS in the valid radio frame, the UE can determine the 10 ms boundary of the valid radio frame.

[0071] In an embodiment, the first communication device can determine the M ms boundary of the radio frame, and M can be a multiple of the duration of one radio frame, for example, 10 ms. If M is greater than 10, the UE determining the M ms boundary of the radio frame can be understood as the UE determining the current radio frame in the M ms. For example, when determining the 80 ms boundary of the radio frame, the UE can determine the current radio frame, for example, the valid radio frame, in the 80 ms. The 80 ms includes 8 consecutive 10 ms.

[0072] In an embodiment, in step S210, the first communication device receives or detects the NSSS based on the frame structure, including:

[0073] S420, the first communication device receives or detects the NSSS in a second time window based on the cyclic shift factor of the NSSS, the boundary of the active radio frame, and the proportion of active radio frames to inactive radio frames in the frame structure.

[0074] In the embodiments of the present application, the cyclic shift factor (CS) can also be referred to as a rotation shift factor, or simply a shift factor. For example, if the second communication device transmits multiple NSSS in the second time window, the sequences of different NSSS can be represented by the cyclic shift factor. If the first communication device, for example, the UE, searches for the NSSS in the second time window, the boundary timing of the second time window can be determined according to the sequence of the NSSS corresponding to the cyclic shift factor, the proportion of active radio frames to inactive radio frames, and the 10ms boundary of the active radio frame. For example, to determine which radio frame (10ms) of the NSSS in the second time window, and / or to determine the start and end time position of the second time window.

[0075] In an implementation, the proportion of active radio frames to inactive radio frames in the frame structure is 1:N, where N is a positive integer. For example, under the special frame structure, the second communication device, for example, the network, cannot transmit all NSSS, and the number of transmittable NSSS in a certain time window, for example, 80ms, of the frame structure is related to the value of N of the proportion of active radio frames to inactive radio frames. As the value of N increases, the number of transmittable NSSS of the frame structure decreases. For example, if the period of the NSSS is 20ms, N is 3, then the frame structure can transmit NSSS twice in 80ms; N is 7, then the frame structure can transmit NSSS once in 80ms. In addition, the number of transmittable NSSS of the frame structure is related to the number n of active radio frames in a frame structure period. For example, if the period of the NSSS is 20ms, N is 3, and n is 1, then the frame structure can transmit NSSS twice in 80ms; N is 3 and n is 1, then the frame structure can transmit NSSS once in 80ms.

[0076] Since the reduction of the active radio frames in the frame structure can result in insufficient repetition of the NSSS in a certain time window, for example, 80ms, which can affect the reception performance of the NPBCH of the first communication device. Therefore, in the embodiments of the present application, the synchronization determination boundary range of the NSSS can be expanded to determine a larger second time window boundary. For example, 160ms or 320ms boundary.

[0077] In an implementation, the second time window is a multiple of the period of the NSSS.

[0078] For example, the period of the NSSS is 20 ms, if the second time window is 160 ms, which is 8 times of the period of the NSSS. If the second time window is 320 ms, which is 16 times of the period of the NSSS.

[0079] In an embodiment, the different transmission positions of the NSSS in the second time window correspond to different cyclic shift factors.

[0080] In the embodiments of the present application, one NSSS can be transmitted in each of the transmission positions in the second time window. The cyclic shift factor of the NSSS transmitted in each transmission position can be different. In this way, according to the cyclic shift factor corresponding to each transmission position, it can be determined in which radio frame of the second time window each NSSS is located. The radio frame of the second time window in which the NSSS is located is the valid radio frame.

[0081] In an embodiment, the second time window is 160 ms, and the 8 transmission positions of the NSSS in the second time window correspond to 8 cyclic shift factors. For example, if the second time window is 160 ms, the UE finds the NSSS in the frame structure, and the NSSS corresponds to the 1st cyclic shift factor, it can be determined that the valid radio frame in which the NSSS is transmitted is located in the 2nd 10 ms (i.e., the 2nd radio frame) of the 160 ms. For another example, if the second time window is 160 ms, the UE finds the NSSS in the frame structure, and the NSSS corresponds to the 7th cyclic shift factor, it can be determined that the valid radio frame in which the NSSS is transmitted is located in the 14th 10 ms (i.e., the 14th radio frame) of the 160 ms.

[0082] In an embodiment, the second time window includes a plurality of sub-windows, and the size of the sub-window is related to the frame structure. In the embodiments of the present application, the second time window is divided into a plurality of sub-windows, and the size of each sub-window can be related to the frame structure. For example, in the frame structure, the ratio of the valid radio frame to the invalid radio frame is 1:3, and each frame structure period has 1 valid radio frame. In this case, the size of the sub-window of the second time window can include 4 radio frames. For another example, in the frame structure, the ratio of the valid radio frame to the invalid radio frame is 1:7, and each frame structure period has 1 valid radio frame. In this case, the size of the sub-window of the second time window can include 8 radio frames. For another example, in the frame structure, the ratio of the valid radio frame to the invalid radio frame is 1:3, and each frame structure period has 2 valid radio frames. In this case, the size of the sub-window of the second time window can include 8 radio frames.

[0083] In an embodiment, the NSSS is repeatedly transmitted within a sub-window of the second time window, and the same sub-window corresponds to the same cyclic shift factor, and different sub-windows correspond to different cyclic shift factors. In the embodiments of the present application, the NSSS can also be repeatedly transmitted within the second time window. For example, the NSSS is repeatedly transmitted within a sub-window of the second time window. For example, if one sub-window includes 4 radio frames, the NSSS can be repeatedly transmitted 2 times. If one sub-window includes 8 radio frames, the NSSS can be repeatedly transmitted 4 times.

[0084] According to the cyclic shift factor corresponding to each sub-window, it can be determined on which effective radio frame of the second time window each NSSS is transmitted. For example, the second time window includes 4 sub-windows, and the first communication device detects the NSSS within the frame structure. If the NSSS corresponds to the cyclic shift factor of the first sub-window, it can be determined that the effective radio frame on which the NSSS is transmitted is located on the effective radio frame of the first sub-window (if the effective radio frame of the first sub-window is the second radio frame in the second time window, the effective radio frame is located on the 10th of the second time window). If the NSSS corresponds to the cyclic shift factor of the third sub-window, it can be determined that the effective radio frame on which the NSSS is transmitted is located on the effective radio frame of the third sub-window (if the effective radio frame of the third sub-window is the tenth radio frame in the second time window, the effective radio frame is located on the 10th of the second time window).

[0085] In an embodiment, the second time window is 160 ms, the sub-window is 40 ms, the NSSS is repeatedly transmitted 2 times within the sub-window, and the 4 transmission positions of the second time window correspond to 4 cyclic shift factors. For example, if the second time window is 160 ms, the sub-window is 40 ms, and the frame structure is that the second radio frame of each period is an effective radio frame. The UE detects the NSSS within the frame structure. If the NSSS corresponds to the cyclic shift factor of the first sub-window, it can be determined that the effective radio frame on which the NSSS is transmitted is located on the second 10 ms (i.e., the second radio frame) within 160 ms. If the NSSS corresponds to the cyclic shift factor of the fourth sub-window, it can be determined that the effective radio frame on which the NSSS is transmitted is located on the 14th 10 ms (i.e., the 14th radio frame) within 160 ms.

[0086] In an embodiment, the second time window is 320 ms, the sub-window is 80 ms, the NSSS is repeatedly transmitted 4 times within the sub-window, and the 4 transmission positions of the second time window correspond to 4 cyclic shift factors.

[0087] For example, if the second time window is 320 ms, the sub-window is 80 ms, and the frame structure is that the 2nd radio frame in each cycle is a valid radio frame. The UE searches for the NSSS in the frame structure. If the NSSS corresponds to the cyclic shift factor of the 1st sub-window, it can be determined that the valid radio frame transmitting the NSSS is located on the 2nd 10 ms (i.e., the 2nd radio frame) in the 320 ms. If the NSSS corresponds to the cyclic shift factor of the 4th sub-window, it can be determined that the valid radio frame transmitting the NSSS is located on the 26th 10 ms (i.e., the 26th radio frame) in the 320 ms.

[0088] The durations of the second time window and the sub-window, and the position of the valid radio frame in the frame structure, are examples and are not limited. In actual applications, they can be flexibly adjusted according to specific requirements. For example, the second time window is 320 ms, the sub-window is 40 ms, and the 8 transmission positions of the NSSS in the second time window correspond to 8 cyclic shift factors. For another example, the second time window is 160 ms, the sub-window is 80 ms, and the 2 transmission positions of the NSSS in the second time window correspond to 2 cyclic shift factors.

[0089] In an embodiment, the step S210 includes that the first communication device receives the NPBCH based on the frame structure, including:

[0090] S430, the first communication device receives the NPBCH in a third time window based on the scrambling code of the NPBCH, the second time window of the valid radio frame, and the proportion of the valid radio frame and the invalid radio frame in the frame structure.

[0091] In the embodiments of the present application, the NPBCH can be repeatedly transmitted in a larger time range, for example, the second time window. Moreover, different NPBCH scrambling codes can be used to determine the boundary of a larger time range, for example, the third time window. The first communication device can determine the boundary of the third time window, for example, which radio frame (10 ms) of the valid radio frame in the third time window, based on the scrambling code of the NPBCH, the second time window of the valid radio frame, and the proportion of the valid radio frame and the invalid radio frame in the frame structure, for example, the N value in the proportion.

[0092] In an embodiment, the third time window includes a plurality of the second time windows.

[0093] In an embodiment, the NPBCH is repeatedly transmitted in each of the second time windows, the scrambling codes corresponding to the same second time window are the same, and the scrambling codes corresponding to different second time windows are different.

[0094] For example, the third time window is composed of multiple second time windows, and the NPBCH is repeatedly transmitted in each second time window. And the second communication device repeatedly transmits the NPBCH using the same scrambling code in each second time window. The second communication device repeatedly transmits the NPBCH using different scrambling codes in different second time windows. The first communication device can receive the NPBCH in the valid radio frame of each second time window.

[0095] In an embodiment, when the second time window is 160 ms and the third time window is 640 ms, the scrambling code corresponding to the third time window is 4.

[0096] For example, the third time window 640 ms is composed of 4 second time windows 160 ms. In each 160 ms, the NPBCH is repeatedly transmitted twice, and the repeatedly transmitted NPBCHs use the same scrambling code. But the NPBCHs in different 160 ms use different scrambling codes. So 4 different scrambling codes are needed in 640 ms. The UE can determine the second time window 160 ms boundary of the frame structure through the NSSS (which 10 ms of the second time window is the valid radio frame), and then determine the 640 ms boundary of the frame structure (which radio frame (10 ms) in 640 ms is the valid radio frame) through the NPBCH scrambling code (which 160 ms in 640 ms is the valid radio frame).

[0097] In an embodiment, when the second time window is 320 ms and the third time window is 640 ms, the scrambling code corresponding to the third time window is 2.

[0098] For example, the third time window 640 ms is composed of 2 second time windows 320 ms. In each 320 ms, the NPBCH is repeatedly transmitted four times, and the repeatedly transmitted NPBCHs use the same scrambling code. But the NPBCHs in different 320 ms use different scrambling codes. So 2 different scrambling codes are needed in 640 ms. The UE can determine the second time window 320 ms boundary of the frame structure through the NSSS, and then determine the 640 ms boundary of the frame structure (which radio frame (10 ms) in 640 ms is the valid radio frame) through the NPBCH scrambling code (which 320 ms in 640 ms is the valid radio frame).

[0099] In an embodiment, the second time window includes multiple first time windows, and the NPBCH is transmitted in each first time window in the second time window. The scrambling codes corresponding to different first time windows in the same second time window are the same.

[0100] In the embodiments of the present application, the second time window comprises a plurality of first time windows. The NPBCH is repeatedly transmitted in each first time window. And the second communication device repeatedly transmits the NPBCH in the first time window within each second time window using the same scrambling code. The second communication device repeatedly transmits the NPBCH in the first time window within different second time windows using different scrambling codes. The first communication device can receive the NPBCH in the first time window included in each second time window. For example, the second time window is 160 ms, the second time window comprises 2 first time windows, and the NPBCH is repeatedly transmitted in each first time window, so the NPBCH is repeatedly transmitted twice in the second time window. And the scrambling codes of the NPBCH corresponding to the two first time windows are the same. The first communication device can receive the NPBCH in the two first time windows within the second time window. And the first communication device can determine the first time window according to the NPSS, and then determine the boundary of the second time window (for example, which 10 ms of the second time window is the valid radio frame) according to the corresponding cyclic shift factor of the NSSS, and then determine the boundary of the third time window (for example, which 10 ms of the third time window is the valid radio frame) according to the scrambling code corresponding to the second time window, etc.

[0101] In the NB-IOT system, the period of the NPSS is 10 ms, and the UE can determine the boundary timing of 10 ms after detecting the NPSS. The period of the NSSS is 20 ms, which is transmitted four times in a 80 ms window, and the sequences of the four transmissions are different. In this way, when the UE searches for the NSSS in the window, the boundary timing of 80 ms can be obtained according to the sequence of the NSSS. Then the UE continues to detect the NPBCH, which is transmitted in the first subframe of each radio frame, and the NPBCH is repeatedly transmitted by 8 radio frames in the 80 ms window, so as to improve the system coverage. And the NPBCH transmitted in different 80 ms windows within 640 ms uses 8 different scrambling codes, so that the UE finally obtains the boundary timing of 640 ms.

[0102] However, when NB-IOT is applied to NTN scenarios, the satellite operator can have some restrictions on the use of spectrum. For example, in some cases, the spectrum of NTN can only be used for NB-IOT service part of the time, and cannot be used continuously and uninterruptedly. Under such conditions, a special frame structure can be used, that is, only part of the radio frames are available in time, and the remaining radio frames are unavailable. For example, the radio frames available for NB-IOT can be referred to as valid radio frames, and the radio frames unavailable for NB-IOT can be referred to as invalid radio frames. Under such a special frame structure, not only the downlink synchronization performance of NB-IOT will be affected, but also the coverage of NB-IOT will be affected. The embodiments of the present application can use a new synchronization design to solve the synchronization problem of NB-IOT under the special frame structure.

[0103] Under the special frame structure mode, the NTN system cannot continuously occupy the bandwidth, so that the NTN frame structure is valid for part of the time. Taking the ratio of valid radio frames (SFN) and invalid radio frames as 1:N for example. When N=3, it means that there is a valid radio frame every three invalid radio frames, as shown in FIG. 3a. The value of N can be determined by the network and N is a positive integer. When the UE initially synchronizes the frame, the UE needs to have a default value of N. In some deployment scenarios, the value of N can be associated with the operating frequency band, for example, when searching for NPSS in the first frequency band, the UE will assume the first value as the N value; and when searching for NPSS in the second frequency band, the UE will assume the second value as the N value. The operating frequency point here can include the synchronization raster (sync raster) for searching for NPSS. Then search for NPSS according to the value of N to determine the 10 ms radio frame boundary. Then search for NSSS to determine the 10*X ms boundary (where X is a positive integer value). Then search for NPBCH to determine the 10*Y ms boundary (where Y is also a positive integer value, and Y can be equal to X or not equal to X). Finally, complete the entire synchronization process according to the content of MIB-NB in NPBCH, that is, determine the index of each radio frame.

[0104] The special frame structure can also be adjusted according to the ratio, for example, also 1:N, N=3, the special frame structure can also be represented as in FIG. 3b.

[0105] That is, 1:N is the ratio of the number of valid radio frames and the number of invalid radio frames in a special frame structure period. In FIG. 3a, the special frame structure period is 4 radio frames, that is, 40 ms. In FIG. 3b, the special frame structure period is 8 radio frames, that is, 80 ms. In the content of the embodiments of the present application, it is assumed that the special frame structure has only one valid radio frame in a special frame structure period to illustrate, and the scheme illustrated can be extended to other cases, for example, there are multiple valid radio frames in a special frame structure period.

[0106] In the embodiment of the present application, determining the 10 ms boundary can be understood as: the UE can determine the position of the current radio frame in the 10 ms. For example, when determining the 10 ms boundary, the UE can only determine the boundary position of the current radio frame. When determining the 80 ms boundary, the UE can determine the position of the current radio frame in the 80 ms (Note: 80 ms is composed of 8 consecutive 10 ms).

[0107] Embodiment 1: Searching for NPSS method, determining 10 ms boundary method

[0108] The UE determines the NPSS repetition period according to the N value, that is, the period of the effective radio frame in the NTN system, that is, (N+1)*10 ms. For example, when N=3, the UE assumes that the period of NPSS is 40 ms. The UE can perform single NPSS detection in each effective radio frame, or perform joint detection according to the NPSS repetition period. NPSS is located at the subframe index 5 in the effective radio frame. Each radio frame is composed of 10 subframes, and the index is from 0 to 9. After the UE determines the position of NPSS, the UE can determine the 10 ms boundary of the radio frame.

[0109] Embodiment 2: Searching for NSSS method, determining a boundary greater than 80 ms method

[0110] After determining the 10 ms boundary, the UE can determine a larger boundary. First, in the NB-IOT system, the period of NSSS is 20 ms, and there are four NSSS in 80 ms, and the cyclic shift (abbreviated as CS) of the four NSSS is different, and the NSSS is repeatedly transmitted in each 80 ms. In this way, the UE can determine the 80 ms boundary by searching for NSSS. However, in the special frame structure, the network cannot transmit all NSSS, and the number of transmittable NSSS in 80 ms is related to the N value. For example, as shown in FIG. 5, when N=3, the network can transmit NSSS twice in 80 ms, but when the N value increases, the number of transmittable NSSS decreases.

[0111] For example, as shown in FIG. 6, when N=7, the network can transmit NSSS at most once in 80 ms. Since the reduction of the effective radio frame will result in insufficient repetition times in 80 ms, the search for NSSS is not very large, but it may affect the reception performance of the subsequent NPBCH. Because in the NB-IOT system, the NPBCH is repeatedly transmitted 8 times in the consecutive radio frames in 80 ms. In order to solve this problem, the synchronization determination boundary range of NSSS can be expanded. For example, the 80 ms boundary needs to be determined, and the larger boundary such as 160 ms or 320 ms boundary is expanded.

[0112] As shown in FIG. 7, the first way is to increase the cyclic shift factor of the NSSS, so that the NSSS corresponds to different cyclic shift factors in the 8 transmission positions of 160 ms (for example, n / 132, where n=0 / 16 / 33 / 49 / 66 / 82 / 99 / 115), and then repeats the period every 160 ms, so that the UE can determine the boundary of 160 ms. Specifically, taking FIG. 7 as an example, when the UE searches for the NSSS in the first valid radio frame in the first 80 ms, the UE can determine, according to the CS index of the NSSS, that this radio frame is located in the second 10 ms of 160 ms. Similarly, when the UE searches for the NSSS in the first valid radio frame in the second 80 ms, the UE can determine, according to the CS index of the NSSS, that this radio frame is located in the tenth 10 ms of 160 ms.

[0113] This way is relatively simple, but increasing the cyclic shift factor reduces the orthogonality between different cyclic shift factors. This way is suitable for a special frame structure with a small N value and more than one transmission opportunity of NSSS in 80 ms, for example, N=3. When the number of cyclic shift factors is further increased, the UE can determine a larger boundary, and more embodiments will not be described.

[0114] Alternatively, another way is to make the NSSS repeat in 40 ms, and use different CSs in 40 ms, as shown in FIG. 8. Since the position of the valid radio frame is unique in 40 ms, different CSs are not needed to distinguish the position in 40 ms. The advantage of this is that the total number of CSs can be reduced, and the orthogonality between different CSs is stronger.

[0115] Another way is to repeat the NSSS in 320ms period, i.e. 320ms is composed of 4 80ms, and the NSSS in each 80ms is with the same cyclic shift factor, and different 80ms corresponds to different selection factor. So the number of different cyclic shift factor in 320ms is still 4 times (e.g. n / 132, where n=0 / 33 / 66 / 99). This way is more suitable for the case that N is large, since in some N value case, the NSSS is sent at most once in 80ms. So the position of the sending is determined in 80ms, UE does not need to determine the 80ms boundary through different cyclic shift factor, so the dimension of cyclic shift factor can be used to determine larger boundary, e.g. 320ms. Space is left for the later repetition of NPBCH reception. Specifically, take Figure 9 as an example, in the case of special frame structure with N=7, when UE finds the NSSS in the first 80ms of the valid radio frame, UE can determine that it is CS#0 according to the CS index of the NSSS, so UE can determine that the current radio frame is the first 80ms radio frame in 320ms. And since the position of the first valid radio frame is unique in 80ms, UE can determine that the current radio frame is the second 10ms in 80ms.

[0116] When the number of cyclic shift factors is further increased, UE can determine larger range of boundaries, and more embodiments are not described.

[0117] Embodiment 3: Method for determining 640ms boundary according to NPBCH

[0118] Based on the above, under the special frame structure condition, the NTN network cannot transmit continuous radio frames within 80 ms. Especially when the value of N is large, the NTN network can have at most one valid radio frame, which results in that the NTN network cannot repeatedly transmit the NPBCH within 80 ms, thereby causing the NTN network to be severely limited in coverage under the special frame structure. In order to solve this problem, in the above embodiments, it has been introduced that the UE obtains a larger range of boundary information by using the NSSS, such as determining a 160 ms or 320 ms boundary. In this way, the NPBCH can be repeated within a time range greater than 80 ms, for example, repeated transmission within 160 ms or within 320 ms. And two or four different scrambling codes can be used to determine a 640 ms boundary. For example, 640 ms has 4 groups of 160 ms, and the NPBCH is repeatedly transmitted in each 160 ms, and the repeatedly transmitted NPBCH uses the same scrambling code. But the NPBCH in different 160 ms uses different scrambling codes, so a total of 4 different scrambling codes are needed within 640 ms. In this way, the UE determines the 160 ms boundary through the NSSS, and then determines the 640 ms boundary by judging the scrambling code of the NPBCH to determine which 160 ms it is in within 640 ms.

[0119] Optionally, as shown in FIG. 10, when the UE determines a 320 ms boundary through the NSSS, the system only needs to use two different scrambling codes. That is, the NPBCH is repeatedly transmitted within the first 320 ms and uses the same scrambling code, and the NPBCH is repeatedly transmitted within the last 320 ms and uses another scrambling code. In this way, the UE can also determine a 640 ms boundary. The advantage of this method is that even in the special mode and in the case of a large value of N, the network has multiple valid radio frames within 160 ms or 320 ms. In this way, multiple repeated NPBCHs can be successfully transmitted, thereby enabling the UE to obtain coverage gain. For example, when the NPBCH is repeatedly transmitted within 320 ms, when N = 7, the UE can obtain the gain brought by a maximum of 4 times of repeated transmission (i.e., a coverage gain of 6 dB).

[0120] When the UE determines the 640 ms boundary, the UE has the 6-bit LSB of the SFN index. Note that the SFN index ranges from 0 to 1023, and a total of 10 bits are needed, and when the UE determines the lowest 6 bits.

[0121] Optionally, there is also a way to make the NPBCH repeatedly transmit through different subframes within a 10 ms radio frame. This method can be applied to any special frame structure under any value of N, but occupies multiple subframe resources within a radio frame.

[0122] FIG. 11 is a schematic block diagram of a first communication device 1100 according to an embodiment of the present application. The terminal device 1100 can include:

[0123] The transceiver 1110 is configured to receive or detect one or more of the NPSS, the NSSS, and the NPBCH based on the frame structure.

[0124] In an embodiment, the transceiver 1110 is configured to receive or detect the NPSS within a first time window based on the frame structure.

[0125] In an embodiment, a repetition period of the NPSS is a multiple of a period of the frame structure, and the first time window is within the repetition period of the NPSS.

[0126] In an embodiment, the period of the frame structure is determined based on a proportion of valid wireless frames and invalid wireless frames in the frame structure, a number of valid wireless frames within a period of the frame structure, and a time window occupied by one valid wireless frame.

[0127] In an embodiment, the first time window is less than or equal to a time window occupied by all valid wireless frames within a period of the frame structure, and greater than or equal to a time window occupied by one valid wireless frame.

[0128] In an embodiment, a boundary of one valid wireless frame is determined based on a subframe index position of the NPSS within the valid wireless frame.

[0129] In an embodiment, the transceiver 1110 is configured to receive or detect the NSSS within a second time window based on a cyclic shift factor of the NSSS, the boundary of the valid wireless frame, and the proportion of valid wireless frames and invalid wireless frames in the frame structure.

[0130] In an embodiment, the second time window is a multiple of a period of the NSSS.

[0131] In an embodiment, different transmission positions of the NSSS within the second time window correspond to different cyclic shift factors.

[0132] In an embodiment, the second time window is 160 ms, and eight transmission positions of the NSSS within the second time window correspond to eight cyclic shift factors.

[0133] In an embodiment, the second time window includes a plurality of sub-windows, and a size of the sub-window is related to the frame structure.

[0134] In an embodiment, the NSSS is repeatedly transmitted within a sub-window of the second time window, a same sub-window corresponds to a same cyclic shift factor, and different sub-windows correspond to different cyclic shift factors.

[0135] In an embodiment, the second time window is 160 ms, the sub-window is 40 ms, the NSSS is repeatedly transmitted 2 times within the sub-window, and the 4 transmission positions within the second time window correspond to 4 cyclic shift factors.

[0136] In an embodiment, the second time window is 320 ms, the sub-window is 80 ms, the NSSS is repeatedly transmitted 4 times within the sub-window, and the 4 transmission positions within the second time window correspond to 4 cyclic shift factors.

[0137] In an embodiment, the transceiver 1110 is configured to receive the NPBCH within a third time window based on a scrambling code of the NPBCH, a second time window of the valid radio frame, and a proportion of valid radio frames to invalid radio frames in the frame structure.

[0138] In an embodiment, the third time window comprises a plurality of the second time windows.

[0139] In an embodiment, the NPBCH is repeatedly transmitted within each of the second time windows, and scrambling codes corresponding to the same second time window are the same.

[0140] In an embodiment, when the second time window is 160 ms and the third time window is 640 ms, the scrambling codes corresponding to the third time window are 4.

[0141] In an embodiment, when the second time window is 320 ms and the third time window is 640 ms, the scrambling codes corresponding to the third time window are 2.

[0142] In an embodiment, the second time window comprises a plurality of first time windows, and the NPBCH is transmitted within each of the first time windows within the second time window, and scrambling codes corresponding to different first time windows within the same second time window are the same.

[0143] In an embodiment, the proportion of valid radio frames to invalid radio frames in the frame structure is 1:N, and N is a positive integer.

[0144] The terminal device 1100 of the embodiments of this application can realize the corresponding functions of the terminal device in the method embodiments described above. The processes, functions, implementation manners and advantages of the respective modules (sub-modules, units or components, etc.) in the terminal device 1100 can be referred to the corresponding descriptions in the method embodiments described above, and will not be described herein again. It should be noted that the functions described with respect to the respective modules (sub-modules, units or components, etc.) in the terminal device 1100 of the embodiments of this application can be realized by different modules (sub-modules, units or components, etc.), or can be realized by the same module (sub-module, unit or component, etc.).

[0145] FIG. 12 is a schematic structural diagram of a communication device 1200 according to the embodiments of this application. The communication device 1200 comprises a processor 1210, which can invoke and run a computer program from a memory to enable the communication device 1200 to implement the methods in the embodiments of this application.

[0146] In an implementation manner, the communication device 1200 can further comprise a memory 1220. The processor 1210 can invoke and run a computer program from the memory 1220 to enable the communication device 1200 to implement the methods in the embodiments of this application.

[0147] The memory 1220 can be a separate device independent of the processor 1210, or can be integrated in the processor 1210.

[0148] In an implementation manner, the communication device 1200 can further comprise a transceiver 1230, and the processor 1210 can control the transceiver 1230 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices.

[0149] The transceiver 1230 can comprise a transmitter and a receiver. The transceiver 1230 can further comprise an antenna, and the number of antennas can be one or more.

[0150] In an implementation manner, the communication device 1200 can be a network device of the embodiments of this application, and the communication device 1200 can realize the corresponding processes in the methods of the embodiments of this application realized by the network device. For the sake of brevity, the details will not be described herein again.

[0151] In an implementation manner, the communication device 1200 can be a terminal device of the embodiments of this application, and the communication device 1200 can realize the corresponding processes in the methods of the embodiments of this application realized by the terminal device. For the sake of brevity, the details will not be described herein again.

[0152] FIG. 13 is a schematic structural diagram of a chip 1300 according to an embodiment of the present application. The chip 1300 includes a processor 1310, which can invoke and run a computer program from a memory to implement the method in the embodiments of the present application.

[0153] In an embodiment, the chip 1300 can further include a memory 1320. The processor 1310 can invoke and run a computer program from the memory 1320 to implement the method performed by the terminal device or the network device in the embodiments of the present application.

[0154] The memory 1320 can be a separate device independent of the processor 1310, or can be integrated in the processor 1310.

[0155] In an embodiment, the chip 1300 can further include an input interface 1330. The processor 1310 can control the input interface 1330 to communicate with other devices or chips, and specifically, can acquire information or data sent by other devices or chips.

[0156] In an embodiment, the chip 1300 can further include an output interface 1340. The processor 1310 can control the output interface 1340 to communicate with other devices or chips, and specifically, can output information or data to other devices or chips.

[0157] In an embodiment, the chip can be applied to the network device in the embodiments of the present application, and the chip can implement the corresponding procedures in the methods of the embodiments of the present application performed by the network device. For brevity, details are not described herein.

[0158] In an embodiment, the chip can be applied to the terminal device in the embodiments of the present application, and the chip can implement the corresponding procedures in the methods of the embodiments of the present application performed by the terminal device. For brevity, details are not described herein.

[0159] The chip applied to the network device and the terminal device can be the same chip or different chips.

[0160] It should be understood that the chip mentioned in the embodiments of the present application can also be referred to as a system chip, a system-on-chip, a chip system or a system-on-chip, etc.

[0161] The aforementioned processor can be a general-purpose processor, a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC) or other programmable logic device, a transistor logic device, a discrete hardware component, and the like. Among them, the aforementioned general-purpose processor can be a microprocessor or any conventional processor and the like.

[0162] The aforementioned memory can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM).

[0163] It should be understood that the aforementioned memory is an exemplary but non-limiting description, for example, the memory in the embodiments of the present application can also be a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous DRAM (SDRAM), a double data rate SDRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synch link DRAM (SLDRAM) and a direct memory bus random access memory (Direct Rambus RAM, DR RAM) and the like. That is, the memory in the embodiments of the present application is intended to include but not limited to these and any other suitable type of memory.

[0164] FIG. 14 is a schematic block diagram of a communication system 1400 according to an embodiment of the present application. The communication system 1400 includes a first communication device 1410 and a second communication device 1420.

[0165] The first communication device 1410 is configured to receive or detect one or more of the NPSS, the NSSS and the NPBCH based on the frame structure.

[0166] The second communication device 1420 is configured to transmit one or more of the NPSS, the NSSS and the NPBCH.

[0167] The first communication device 1410 can be configured to implement the corresponding functions of the first communication device in the above-described methods, and the second communication device 1420 can be configured to implement the corresponding functions of the second communication device in the above-described methods. For brevity, details are not repeated here.

[0168] In the above-described embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed by a computer, all or part of the computer program instructions generate the processes or functions in the embodiments of the present application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that includes one or more available media sets. The available medium can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, DVD), or a semiconductor medium (for example, solid state disk (SSD)) and the like.

[0169] It should be understood that in various embodiments of the present application, the size of the sequence number of each process described above does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0170] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0171] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A synchronization method, comprising: receiving or detecting, by a first communication device, one or more of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS) and a narrowband physical broadcast channel (NPBCH) based on a frame structure.

2. The method of claim 1, wherein, receiving or detecting, by the first communication device, the NPSS based on the frame structure, comprising: receiving or detecting, by the first communication device, the NPSS based on the frame structure within a first time window.

3. The method of claim 2, wherein, a repetition period of the NPSS is a multiple of a period of the frame structure, and the first time window is within the repetition period of the NPSS.

4. The method of claim 2 or 3, wherein, the period of the frame structure is determined based on a proportion of valid radio frames and invalid radio frames in the frame structure, a number of valid radio frames within one period of the frame structure, and a time window occupied by one valid radio frame.

5. The method of any one of claims 2 to 4, wherein, the first time window is less than or equal to a time window occupied by all valid radio frames within one period of the frame structure, and greater than or equal to a time window occupied by one valid radio frame.

6. The method of claim 4 or 5, wherein, a boundary of one valid radio frame is determined based on a subframe index position of the NPSS within the valid radio frame.

7. The method of any one of claims 1 to 6, wherein, receiving or detecting, by the first communication device, the NSSS based on the frame structure, comprising: receiving or detecting, by the first communication device, the NSSS within a second time window based on a cyclic shift factor of the NSSS, a boundary of a valid radio frame, and a proportion of valid radio frames and invalid radio frames in the frame structure.

8. The method of claim 7, wherein, the second time window is a multiple of a period of the NSSS.

9. The method of claim 7 or 8, wherein, different transmission positions of the NSSS within the second time window correspond to different cyclic shift factors.

10. The method of claim 9, wherein, the second time window is 160 ms, and 8 transmission positions of the NSSS within the second time window correspond to 8 cyclic shift factors. 11.The method of claim 7 or 8, wherein the second time window comprises a plurality of sub-windows, and a size of the sub-window is related to the frame structure.

12. The method of claim 7 or 8 or 11, wherein, the NSSS is repeatedly transmitted within a sub-window of the second time window, a same sub-window corresponds to a same cyclic shift factor, and different sub-windows correspond to different cyclic shift factors.

13. The method of claim 12, wherein, the second time window is 160 ms, the sub-window is 40 ms, the NSSS is repeatedly transmitted 2 times within the sub-window, and 4 transmission positions of the NSSS within the second time window correspond to 4 cyclic shift factors.

14. The method of claim 12, wherein, the second time window is 320 ms, the sub-window is 80 ms, the NSSS is repeatedly transmitted 4 times within the sub-window, and 4 transmission positions of the NSSS within the second time window correspond to 4 cyclic shift factors.

15. The method of any one of claims 7 to 14, wherein, receiving, by the first communication device, the NPBCH based on the frame structure, comprising: receiving, by the first communication device, the NPBCH within a third time window based on a scrambling code of the NPBCH, a second time window of a valid radio frame, and a proportion of valid radio frames and invalid radio frames in the frame structure.

16. The method of claim 15, wherein, the third time window comprises a plurality of the second time windows.

17. The method of claim 16, wherein, the NPBCH is repeatedly transmitted within each of the second time windows, a same second time window corresponds to a same scrambling code, and different second time windows correspond to different scrambling codes.

18. The method of claim 17, wherein, In a case that the second time window is 160 ms and the third time window is 640 ms, the third time window corresponds to 4 scrambling codes.

19. The method of claim 17, wherein, In a case that the second time window is 320 ms and the third time window is 640 ms, the third time window corresponds to 2 scrambling codes.

20. The method of any one of claims 15 to 19, wherein, The second time window includes a plurality of first time windows, and the NPBCH is transmitted in each first time window within the second time window, and scrambling codes corresponding to different first time windows within the same second time window are the same.

21. The method of any one of claims 1 to 20, wherein, A ratio of the valid wireless frame and the invalid wireless frame in the frame structure is 1:N, and N is a positive integer. 22.A first communication device, comprising: a transceiver configured to receive or detect one or more of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS) and a narrowband physical broadcast channel (NPBCH) based on a frame structure.

23. The first communication device of claim 22, wherein, The transceiver is configured to receive or detect the NPSS in a first time window based on the frame structure.

24. The first communication device of claim 23, wherein, A repetition period of the NPSS is a multiple of a period of the frame structure, and the first time window is within the repetition period of the NPSS.

25. A first communications device according to claim 23 or 24, wherein, The period of the frame structure is determined based on a ratio of the valid wireless frame and the invalid wireless frame in the frame structure, a number of the valid wireless frames in one period of the frame structure and a time window occupied by one valid wireless frame.

26. The first communication device of any one of claims 23 to 25, wherein, The first time window is less than or equal to a time window occupied by all the valid wireless frames in one period of the frame structure, and greater than or equal to a time window occupied by one valid wireless frame.

27. A first communications device according to claim 25 or 26, wherein, A boundary of one valid wireless frame is determined based on a subframe index position of the NPSS in the valid wireless frame.

28. The first communication device of any one of claims 22 to 27, wherein, The transceiver is configured to receive or detect the NSSS in a second time window based on a cyclic shift factor of the NSSS, the boundary of the valid wireless frame and the ratio of the valid wireless frame and the invalid wireless frame in the frame structure.

29. The first communication device of claim 28, wherein, The second time window is a multiple of a period of the NSSS.

30. A first communications device according to claim 28 or 29, wherein, Different transmission positions of the NSSS in the second time window correspond to different cyclic shift factors.

31. The first communication device of claim 30, wherein, In a case that the second time window is 160 ms, 8 transmission positions of the NSSS in the second time window correspond to 8 cyclic shift factors. 32.The first communication device of claim 8 or 29, wherein the second time window includes a plurality of sub-windows, and a size of the sub-window is related to the frame structure.

33. The first communication device as claimed in claim 28 or 29 or 32, wherein, The NSSS is repeatedly transmitted in the sub-window of the second time window, the same sub-window corresponds to the same cyclic shift factor, and different sub-windows correspond to different cyclic shift factors.

34. The first communication device of claim 33, wherein, In a case that the second time window is 160 ms, the sub-window is 40 ms, the NSSS is repeatedly transmitted 2 times in the sub-window, and 4 transmission positions of the NSSS in the second time window correspond to 4 cyclic shift factors.

35. The first communication device of claim 33, wherein, In a case that the second time window is 320 ms, the sub-window is 80 ms, the NSSS is repeatedly transmitted 4 times in the sub-window, and 4 transmission positions of the NSSS in the second time window correspond to 4 cyclic shift factors.

36. A first communications device according to any one of claims 28 to 35, wherein, The transceiver is configured to receive the NPBCH within a third time window based on a scrambling code of the NPBCH, a second time window of the valid radio frames, and a ratio of valid radio frames to invalid radio frames in the frame structure.

37. The first communication device of claim 36, wherein, The third time window comprises a plurality of the second time windows.

38. The first communication device of claim 37, wherein, The NPBCH is repeatedly transmitted within each of the second time windows, and scrambling codes corresponding to a same second time window are identical.

39. The first communication device of claim 38, wherein, In a case where the second time window is 160 ms and the third time window is 640 ms, the third time window corresponds to four scrambling codes.

40. The first communication device of claim 38, wherein, In a case where the second time window is 320 ms and the third time window is 640 ms, the third time window corresponds to two scrambling codes.

41. A first communications device according to any one of claims 36 to 40, wherein, The second time window comprises a plurality of first time windows, and the NPBCH is transmitted within each of the first time windows of the second time window, and scrambling codes corresponding to different first time windows of a same second time window are identical.

42. A first communications device according to any one of claims 22 to 41, wherein, The ratio of valid radio frames to invalid radio frames in the frame structure is 1:N, where N is a positive integer.

43. A communication device comprising: A transceiver, a processor, and a memory, the memory is configured to store a computer program, the transceiver is configured to communicate with other devices, and the processor is configured to invoke and run the computer program stored in the memory, so that the communication device executes the method of any one of claims 1-21.

44. A chip comprising: A processor is configured to invoke and run a computer program from a memory, so that a device installed with the chip executes the method of any one of claims 1-21. 45.A computer readable storage medium configured to store a computer program, which, when executed by a device, causes the device to perform the method of any one of claims 1-21. 46.A computer program product comprising computer program instructions configured to cause a computer to perform the method of any one of claims 1-21. 47.A computer program configured to cause a computer to perform the method of any one of claims 1-21.

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