Timing synchronization method and device and storage medium

Abstract

The invention provides a timing synchronization method and device and a storage medium. The method comprises the steps that a synchronization sequence is acquired, the synchronization sequence comprises data of M sampling points, and the data of the M sampling points comprises signal values of a plurality of synchronization signal blocks SSB; and determining a target sampling point in the M sampling points according to the signal-to-noise ratio of the ith sampling point in the synchronization sequence and the signal-to-noise ratio of the sampling point corresponding to the SSB after the ith sampling point. And the target sampling point is determined as the positioning position, so that timing synchronization is realized, the false alarm rate and the omission ratio are reduced, and the accuracy of timing synchronization is improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a timing synchronization method, device and storage medium. Background Art

[0002] Orthogonal frequency division multiplexing (OFDM) technology has the characteristics of high spectrum utilization, anti-interference and anti-fading, and has become one of the candidate technologies for future mobile communications.

[0003] Compared with the single-carrier system, the OFDM system has higher synchronization accuracy requirements. At present, the terminal device can perform sliding window sampling on the received signal sequence to obtain the sequence corresponding to the current sampling point, and perform correlation operation on the sequence with the local sequence to obtain a set of correlation values, and then perform peak search on this set of correlation values ​​to find the maximum value of this set of correlation values. If the signal-to-noise ratio corresponding to the maximum value is greater than the preset threshold, the current sampling point can be determined as the synchronization position, thereby achieving timing synchronization.

[0004] However, the missed detection rate and false alarm rate in the above method are high, resulting in low accuracy of timing synchronization. Summary of the invention

[0005] The present application provides a timing synchronization method, device and storage medium to solve the problem of low accuracy of timing synchronization.

[0006] In a first aspect, the present application provides a timing synchronization method, comprising:

[0007] Acquire a synchronization sequence, where the synchronization sequence includes data of M sampling points, where the data of the M sampling points includes signal values ​​of multiple synchronization signal blocks SSB, and M is a positive integer;

[0008] Determine a target sampling point among the M sampling points according to a signal-to-noise ratio of a sampling point among the M sampling points and a signal-to-noise ratio of a corresponding sampling point in an SSB whose time domain position is after the sampling point;

[0009] The target sampling point is determined as a synchronization position.

[0010] In a possible implementation manner, determining a target sampling point among the M sampling points according to a signal-to-noise ratio of a sampling point among the M sampling points and a signal-to-noise ratio of a corresponding sampling point in an SSB whose time domain position is after the sampling point includes:

[0011] If the signal-to-noise ratio of the i-th sampling point among the M sampling points is greater than or equal to a first threshold, determining the i-th sampling point as the target sampling point;

[0012] If the signal-to-noise ratio of the i-th sampling point is less than the first threshold and greater than or equal to the second threshold, then when the first signal-to-noise ratio of the sampling point in the SSB located after the i-th sampling point in the time domain is greater than or equal to the second threshold, the i-th sampling point is determined as the target sampling point;

[0013] Here, i takes values ​​of 1, 2, 3, ... in sequence until the target sampling point is determined.

[0014] In a possible implementation manner, when a first signal-to-noise ratio of a sampling point in the SSB after the i-th sampling point is greater than or equal to the second threshold, determining the i-th sampling point as the target sampling point includes:

[0015] Determine a k-th sampling point corresponding to the SSB whose time domain position is after the i-th sampling point;

[0016] Determining a first noise power of the k-th sampling point;

[0017] determining a first signal power according to the first noise power;

[0018] determining the first signal-to-noise ratio according to the first noise power and the first signal power;

[0019] When the first signal-to-noise ratio is greater than or equal to the second threshold, the i-th sampling point is determined as the target sampling point.

[0020] In a possible implementation manner, determining the kth sampling point corresponding to the SSB whose time domain position is located after the i-th sampling point includes:

[0021] Acquire indication information, where the indication information includes a preset interval;

[0022] According to the preset interval and the i-th sampling point, the k-th sampling point is determined among the M sampling points.

[0023] In one possible implementation, the preset interval is greater than or equal to jW and less than or equal to jW+D, where D is the number of orthogonal frequency division multiplexing technology OFDM symbols occupied by SSB, W is the interval between the starting positions of any two SSBs among the multiple SSBs, and j is a positive integer less than the number of the multiple SSBs.

[0024] In a possible implementation manner, determining the first noise power of the k-th sampling point includes:

[0025] Determine, according to the synchronization sequence and the local sequence, a plurality of first correlation values ​​corresponding to a plurality of sampling points between the k+θ1th sampling point and the k+θ2th sampling point, and a plurality of second correlation values ​​corresponding to the sampling points between the k-θ1th sampling point and the k-θ2th sampling point;

[0026] determining an average of a plurality of the first correlation values ​​and a plurality of the second correlation values ​​as the first noise power;

[0027] Among them, θ1 is not equal to θ2, and θ1 and θ2 are positive integers.

[0028] In a possible implementation manner, determining the first signal power according to the first noise power includes:

[0029] Obtaining the correlation value of the k-th sampling point;

[0030] The first signal power is determined according to a difference between the correlation value of the kth sampling point and the first noise power.

[0031] In a second aspect, the present application provides a timing synchronization device, comprising:

[0032] An acquisition module, configured to acquire a synchronization sequence, wherein the synchronization sequence includes data of M sampling points, wherein the data of the M sampling points includes signal values ​​of multiple synchronization signal blocks SSB, and M is a positive integer;

[0033] A first determination module is used to determine a target sampling point among the M sampling points according to a signal-to-noise ratio of a sampling point among the M sampling points and a signal-to-noise ratio of a corresponding sampling point in an SSB whose time domain position is after the sampling point;

[0034] The second determining module is used to determine the target sampling point as a synchronization position.

[0035] In a third aspect, the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0036] The memory stores computer-executable instructions;

[0037] The processor executes the computer-executable instructions stored in the memory to implement the method according to the first aspect.

[0038] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a computer, they are used to implement the method described in the first aspect.

[0039] In a fifth aspect, the present application provides a computer program product, including a computer program, which is used to implement the method described in the first aspect when executed by a computer.

[0040] The timing synchronization method, device and storage medium provided by the present application obtain a synchronization sequence, which includes data of M sampling points, and the data of the M sampling points includes signal values ​​of multiple synchronization signal blocks SSB. According to the signal-to-noise ratio of the i-th sampling point in the synchronization sequence and the signal-to-noise ratio of the sampling point corresponding to the SSB after the i-th sampling point, the target sampling point is determined among the M sampling points. The target sampling point is determined as the positioning position, thereby achieving timing synchronization, reducing the false alarm rate and missed detection rate, and improving the accuracy of timing synchronization. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0042] Figure 1 It is a schematic diagram of the structure of SSB;

[0043] Figure 2 A schematic diagram of an application scenario applicable to the present application;

[0044] Figure 3 A flowchart of a timing synchronization method provided by this application;

[0045] Figure 4 A schematic diagram of a synchronization sequence exemplified in this application;

[0046] Figure 5 A flowchart of another timing synchronization method provided by the present application;

[0047] Figure 6 A flowchart of another timing synchronization method provided by the present application;

[0048] Figure 7 A flowchart of another timing synchronization method provided by the present application;

[0049] Figure 8 This is a schematic diagram of the i-th sampling point and the k-th sampling point of the example of this application;

[0050] Fig. 9 A schematic diagram of a preset sliding window slidingly taking values ​​in a synchronization sequence according to an example of the present application;

[0051] Fig.10 A schematic diagram of the structure of a timing synchronization device provided by the present application;

[0052] Fig.11A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0053] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0054] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0055] The technical solution of the embodiment of the present application can be applied to various communication systems, such as: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, 5G mobile communication system or new radio access technology (NR). Among them, the 5G mobile communication system may include a non-standalone (NSA) 5G mobile communication system and / or a standalone (SA) 5G mobile communication system.

[0056] The technical solution provided in the embodiment of the present application may also be applied to future communication systems, such as the sixth generation (6G) mobile communication system, etc. The present application does not limit this.

[0057] The technical solution provided in this application can also be applied to satellite communication systems, such as low earthorbit (LEO) satellite systems, non-terrestrial network (NTN) communication systems. As an example, the NTN system may include a 4G-based NTN system, an NR-based NTN system, an Internet of Things (IoT)-based NTN system, and a narrowband Internet of Things (NB-IoT)-based NTN system.

[0058] In order to explain the present application more clearly, the following first introduces the terms involved in the embodiments of the present application:

[0059] (1)OFDM

[0060] OFDM is a multi-carrier transmission technology that divides a data stream into multiple low-speed data streams, each of which is transmitted through a different orthogonal subcarrier. In other words, in an OFDM system, a broadband signal is divided into multiple independent subchannels, each of which can be regarded as an independent signal carrier, called a subcarrier. The frequency range is divided into multiple subcarriers, each of which has a fixed frequency and phase and can transmit data independently.

[0061] (2) Synchronization signal / physical broadcast channel block (SSB)

[0062] The synchronization signal / physical broadcast channel block SSB may be referred to as the synchronization signal block SSB for short. SSB includes primary synchronization signals (PSS), secondary synchronization signals (SSS) and physical broadcast channel (PBCH).

[0063] Figure 1 Figure 1 is a schematic diagram of the structure of SSB. PSS, SSS and PBCH can be sent as a whole SSB on 4 consecutive OFDM symbols. PSS and SSS each occupy one OFDM symbol, and two PBCHs each occupy one OFDM symbol. That is to say, one SSB occupies four OFDM symbols in the time domain. Among them, the time domain position of OFDM symbol 0 is before the time domain position of OFDM symbol 2, and the others are similar.

[0064] The terminal device searches for cells and synchronizes by detecting SSB. For example, in 5G networks, SSB can be used to synchronize the frequency and time of the terminal device with the network device. Specifically, the receiver RF is first tuned to the specified frequency point, and then the PSS is detected in the time domain to obtain the cell ID (Identities). The SSS is detected in the frequency domain to obtain frequency domain synchronization and obtain the cell group ID. Then the PBCH is demodulated to obtain the master information block (MIB) information to achieve cell access.

[0065] Among them, the PSS is detected in the time domain to obtain the cell ID, which specifically includes that the terminal device needs to determine the starting position of the PSS, and use the starting position to calculate the position of the SSS, so as to obtain the cell ID.

[0066] The determination of the starting position of the PSS may be referred to as symbol timing synchronization or coarse timing synchronization, and in this application, is referred to as timing synchronization for short.

[0067] In related technologies, terminal devices can achieve timing synchronization in the following ways:

[0068] Step 1: filter the synchronization sequence and then downsample it to obtain a downsampled receiving sequence.

[0069] Step 2: Perform sliding window sampling on the downsampled synchronization sequence to obtain data corresponding to the current sampling point.

[0070] Step 3: perform correlation operation on the data corresponding to the current sampling point and the local sequence to obtain a set of correlation values.

[0071] Step 4: Perform a peak search on this set of correlation values ​​to find the maximum value, and calculate the signal-to-noise ratio of the position corresponding to the maximum value.

[0072] Step 5: compare the signal-to-noise ratio with a preset threshold. If the signal-to-noise ratio is greater than the preset threshold, the position corresponding to the maximum value can be determined as the synchronization position. Otherwise, move the sliding window according to the preset step size and repeat steps 2 to 5 until the synchronization position is determined.

[0073] In the above method, there are the following disadvantages:

[0074] (1) High false alarm rate: If there is no signal value of the SSB signal in the sliding window, but the signal-to-noise ratio is greater than the preset threshold, false synchronization will occur, resulting in a false alarm.

[0075] (2) High missed detection rate: In a scenario where there is only one SSB in the synchronization sequence, if the current sampling point is the synchronization position but the signal-to-noise ratio is less than the preset threshold, synchronization failure will occur, resulting in missed detection.

[0076] (3) It is necessary to perform a peak search before making a synchronization judgment. If the synchronization position is located at a relatively front position in the sliding window, then the calculation of the correlation value of the sampling point after the synchronization position will cause a waste of computing time and storage resources.

[0077] Therefore, the present application provides a timing synchronization method, which determines the target sampling point according to the signal-to-noise ratio of the current sampling point and the sampling point of the SSB after the current sampling point, implements multiple judgments, and can improve the accuracy of synchronization. Exemplarily, the current sampling point is, for example, a sampling point whose signal-to-noise ratio is less than the first threshold and greater than or equal to the second threshold. For example, if the signal-to-noise ratio of the sampling point of the SSB is also greater than or equal to the second threshold, it means that the signal-to-noise ratio of the current sampling point is credible, and the current sampling point can be determined to be the target position. In other words, if the current sampling point is a synchronization position, but the signal-to-noise ratio is lower than the first threshold due to large noise, but the signal-to-noise ratio is greater than or equal to the second threshold, it means that the current sampling point is likely to be a synchronization position. Since the noise of each SSB is different, the signal-to-noise ratio of the sampling point of the SSB after the current sampling point is combined for judgment. For example, when the signal-to-noise ratio of the sampling point of the SSB is greater than the second threshold, the current sampling point can be determined to be a synchronization position, which reduces the false alarm rate and missed detection rate, and improves the accuracy of timing synchronization.

[0078] For ease of understanding, the following Figure 1 The examples are used to illustrate the application scenarios to which the embodiments of the present application are applicable.

[0079] Figure 2 For a schematic diagram of an application scenario applicable to this application, please see Figure 2 , including: a terminal device 101 and a network device 102. The terminal device 101 can receive a signal sequence sent by the network device 102, wherein the signal sequence includes signal values ​​of multiple SSBs distributed in multiple sampling points in the signal sequence, that is, the values ​​of these sampling points are signal values ​​of multiple SSBs. The terminal device 101 can achieve timing synchronization based on the signal series.

[0080] It can be understood that the number of terminal devices 101 and network devices 102 can be multiple, which is not shown in the figure.

[0081] In the embodiment of the present application, the network device may be any device with wireless transceiver function. The device includes but is not limited to: evolved node B (eNB), radio network controller (RNC), node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (for example, home evolved nodeB, or homenode B, HNB), baseband unit (BBU), access point (AP) in wireless fidelity (WiFi) system, wireless relay node, wireless backhaul node, transmission point (TP) or transmission and reception point (TRP), etc., and can also be the next generation base station (gNB) or transmission point (TRP or TP) in 5G, such as NR, system, one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, or can also be a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DU), etc.

[0082] In some deployments, the gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some functions of the gNB, and the DU implements some functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, and implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, and implementing the functions of the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer. The AAU implements some physical layer processing functions, radio frequency processing, and related functions of active antennas. Since the information of the RRC layer will eventually become the information of the PHY layer, or be converted from the information of the PHY layer, under this architecture, high-level signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by the DU+AAU. It can be understood that the network device can be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU can be considered as a network device in the access network (radio access network, RAN), and can also be considered as a network device in the core network (core network, CN), and this application does not limit this.

[0083] The network equipment provides services for the cell, and the terminal equipment communicates with the cell through the transmission resources (for example, frequency domain resources, or spectrum resources) allocated by the network equipment. The cell can belong to a macro base station (for example, macro eNB or macro gNB, etc.), or it can belong to a base station corresponding to a small cell. The small cells here may include: metroCell, microcell, picocell, femtocell, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0084] In an embodiment of the present application, the terminal device may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device.

[0085] The terminal device may be a device that provides voice / data connectivity to the user, for example, a handheld device with wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals may be: mobile phones, tablet computers (pad), computers with wireless transceiver functions (such as laptops, PDAs, etc.), mobile Internet devices (mobile internet devices, MIDs), virtual reality (virtual reality, VR) devices, augmented reality (augmented Reality, AR) devices, extended reality (extended Reality, XR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (session initiation protocol, SIP) phones, wireless local loop (wireless local loop, WLL) stations, personal digital assistants (personal The invention relates to a mobile phone or a digital assistant (PDA), 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 5G network, or a terminal device in a public land mobile communication network (PLMN) to be evolved in the future, etc.

[0086] Among them, wearable devices can also be called wearable smart devices, which are a general term for the intelligent design and development of wearable devices for daily wear using wearable technology, such as glasses, gloves, watches, clothing and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also realize powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include full-featured, large-sized, and independent of smartphones to achieve complete or partial functions, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0087] In addition, the terminal device can also be a terminal device in the IoT system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection. IoT technology can achieve massive connections, deep coverage, and power saving through narrow band (NB) technology, for example.

[0088] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments may exist independently or in combination with each other, and the same or similar concepts or processes may not be described in detail in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0089] Figure 3 A schematic diagram of a timing synchronization method provided by the present application, which can be executed by a terminal device, refer to Figure 3 , the method comprises the following steps:

[0090] S301. Acquire a synchronization sequence, where the synchronization sequence includes data of M sampling points, where the data of the M sampling points include signal values ​​of multiple synchronization signal blocks SSB, and M is a positive integer.

[0091] In a possible implementation, the terminal device may receive a signal sequence sent by the network device, and the signal sequence may include multiple SSBs. The terminal device may filter the signal sequence to obtain a filtered signal sequence, and downsample the filtered signal sequence to obtain the synchronization sequence.

[0092] Exemplarily, the terminal device may filter the signal sequence through an anti-aliasing filter, thereby reducing the bandwidth of the signal, thereby saving transmission bandwidth and improving spectrum utilization.

[0093] In a possible implementation, the downsampling multiple can be determined according to the window length of the preset sliding window and the length of the local sequence. By downsampling the filtered signal sequence, the demand for computing resources can be reduced and the processing efficiency of the terminal device can be improved.

[0094] For example, Figure 4 This is a schematic diagram of a synchronization sequence of the present application example. The synchronization sequence includes data of M sampling points, and the data of the M sampling points includes signal values ​​of multiple SSBs. There is a preset interval between each SSB, and the preset interval can be determined by the network device when sending, that is, the network device sends multiple SSBs at the preset interval. It can be understood that in the sampling points where there is no SSB, the data of these sampling points are all noise values. Since M is large, for example, M is a value greater than 10000, Figure 4 The sampling points are not shown.

[0095] The terminal device can be based on e.g. Figure 4 The synchronization sequence shown, starting from the first sampling point among the M sampling points and proceeding backward in sequence, determines the starting position of the SSB (ie, the target sampling point). Exemplarily, the SSB may be SSB1.

[0096] S302: Determine a target sampling point from among the M sampling points according to the signal-to-noise ratio of the sampling point from among the M sampling points and the signal-to-noise ratio of the corresponding sampling point in the SSB whose time domain position is after the sampling point.

[0097] The terminal device may determine a target sampling point among the M sampling points according to the signal-to-noise ratio of the sampling point among the M sampling points and the signal-to-noise ratio of the corresponding sampling point in the SSB whose time domain position is after the sampling point.

[0098] In a possible implementation, the signal-to-noise ratio of the sampling point is less than the first threshold and greater than or equal to the second threshold. The first threshold may be a threshold for directly determining whether the sampling point is a synchronization position. The second threshold may be slightly less than the first threshold. Exemplarily, the ratio of the second threshold to the first threshold may be 90%. When the signal-to-noise ratio is greater than the second threshold and less than the first threshold, it indicates that the probability that the sampling point corresponding to the signal-to-noise ratio is a synchronization position is high. For such a sampling point, the signal-to-noise ratio of the corresponding sampling point in the SSB located after the sampling point in the time domain may be combined to further determine whether such a sampling point is a target sampling point.

[0099] It is understandable that for a sampling point without SSB, its signal-to-noise ratio is generally less than the second threshold. For a sampling point with SSB, its signal-to-noise ratio is generally greater than or equal to the second threshold, but due to the influence of noise, the signal-to-noise ratio of the sampling point may be less than the first threshold. If only the signal-to-noise ratio is compared with the first threshold, it is easy to misjudge the sampling point as an asynchronous position, which makes the accuracy of timing synchronization low. Of course, if the signal-to-noise ratio of the sampling point is greater than or equal to the first threshold, it can be determined that the sampling point is a synchronous position.

[0100] The arrangement information of multiple SSBs in the synchronization sequence (i.e., the number of SSBs and the interval between each SSB, etc.) is known, and the noise of multiple SSBs is different. Figure 4Taking SSB1 and SSB2 as an example, SSB2 exists at a preset interval after the end position of SSB1, and SSB1 exists at a preset interval before the start position of SSB2. Then, if the signal-to-noise ratio of a certain sampling point a is greater than or equal to the second threshold, but less than the first threshold, it means that there may be an SSB at the sampling point a, for example, the SSB is SSB1. At this time, based on the known arrangement information of the SSB, combined with the signal-to-noise ratio of the sampling point corresponding to SSB2, further auxiliary judgment can be made on whether the sampling point a is a synchronization position, thereby improving reliability.

[0101] S303: Determine the target sampling point as the synchronization position.

[0102] After determining the target sampling point among the M sampling points, the target sampling point can be determined as the synchronization position. The terminal device can perform subsequent signal demodulation based on the synchronization position, for example, demodulate the SSS in the SSB, so as to obtain the cell ID.

[0103] In this embodiment, the terminal device can determine the target sampling point among M sampling points based on the signal-to-noise ratio of the i-th sampling point in the synchronization sequence and the signal-to-noise ratio of the sampling point corresponding to the SSB after the i-th sampling point, thereby reducing the false alarm rate and the missed detection rate and improving the accuracy of timing synchronization.

[0104] Next, how the terminal device determines the target sampling point is described.

[0105] Figure 5 A flowchart of another timing synchronization method provided by the present application, which can be executed by a terminal device, is shown in FIG. Figure 5 , the method comprises the following steps:

[0106] S501: Determine the signal-to-noise ratio of the i-th sampling point among M sampling points.

[0107] In a possible implementation, the terminal device may determine the noise power of the i-th sampling point, and then determine the signal power according to the noise power, and determine the signal-to-noise ratio of the i-th sampling point according to the signal power and the noise power.

[0108] The specific implementation method may refer to the first signal-to-noise ratio of the kth sampling point in the following embodiment. k may be replaced by i for understanding.

[0109] S502: Determine whether the signal-to-noise ratio of the i-th sampling point is less than a first threshold.

[0110] If the signal-to-noise ratio of the i-th sampling point is greater than or equal to the first threshold, S506 is executed; if the signal-to-noise ratio of the i-th sampling point is less than the first threshold, S503 is executed.

[0111] S503: Determine whether the signal-to-noise ratio of the i-th sampling point is greater than or equal to a second threshold.

[0112] If yes, execute S504.

[0113] If not, it means that there is no SSB at the i-th sampling point, that is, it is not a synchronization position, and the above steps S501 to S503 can be repeated for the next sampling point of the i-th sampling point. For example, if i is 3, then the above steps are repeated for the fourth sampling point.

[0114] S504: Determine a first signal-to-noise ratio of a sampling point corresponding to an SSB after the i-th sampling point.

[0115] S505: Determine whether the first signal-to-noise ratio is greater than or equal to a second threshold.

[0116] If yes, execute S506 , if no, repeat the above steps for the next sampling point of the i th sampling point.

[0117] That is to say, if the signal-to-noise ratio of the i-th sampling point is less than the first threshold value and greater than or equal to the second threshold value, it means that the i-th sampling point is more likely to be the synchronization position, but due to the influence of noise, signal strength, or errors in the transmission process of the signal processing process and other factors, the signal-to-noise ratio is less than the first threshold value. At this time, if the first signal-to-noise ratio of the sampling point corresponding to the SSB after the i-th sampling point is greater than the second threshold value, it means that the signal-to-noise ratio of the i-th sampling point is greater than or equal to the second threshold value not due to large noise, but due to the existence of SSB at the i-th sampling point, which means that the i-th sampling point has a high degree of credibility as the synchronization position, and the i-th sampling point can be determined to be the target sampling point.

[0118] S506: Determine the i-th sampling point as the target sampling point.

[0119] Among them, i takes the value of 1, 2, 3, ... in sequence until the target sampling point is determined.

[0120] S507: Determine the target sampling point as the synchronization position.

[0121] In this embodiment, for a sampling point whose signal-to-noise ratio is less than the first threshold and greater than or equal to the second threshold, the signal-to-noise ratio of the sampling point corresponding to the SSB after the sampling point can be combined to determine whether the sampling point is the target sampling point, thereby reducing the false alarm rate and missed detection rate and improving the accuracy of timing synchronization.

[0122] Figure 6 A flowchart of another timing synchronization method provided by the present application, which can be executed by a terminal device, is shown in FIG. Figure 6 , the method comprises the following steps:

[0123] S601: Determine the signal-to-noise ratio of the i-th sampling point among M sampling points.

[0124] S602: Determine whether the signal-to-noise ratio of the i-th sampling point is greater than or equal to a first threshold.

[0125] If yes, execute S603.

[0126] S603: Determine a first signal-to-noise ratio of a sampling point corresponding to an SSB after the i-th sampling point.

[0127] S604: Determine whether the first signal-to-noise ratio is greater than or equal to a first threshold.

[0128] If so, it means that the signal-to-noise ratio of the sampling point corresponding to the SSB after the i-th sampling point is also greater than the first threshold, and the i-th sampling point can be determined as the target sampling point, and S605 is executed.

[0129] S605: Determine the i-th sampling point as the target sampling point.

[0130] Among them, i takes the value of 1, 2, 3, ... in sequence until the target sampling point is determined.

[0131] S606: Determine the target sampling point as the target sampling point.

[0132] In this embodiment, when the signal-to-noise ratio of the i-th sampling point and the k-th sampling point corresponding to the SSB whose time domain position is after the i-th sampling point is greater than or equal to the first threshold, the i-th sampling point can be determined as the target sampling point, thereby improving the accuracy of timing synchronization.

[0133] Below, before explaining how the terminal device determines the signal-to-noise ratio of the sampling point in the SSB after the i-th sampling point, the sampling point in the SSB after the i-th sampling point is explained as follows:

[0134] In a possible implementation, the number of sampling points corresponding to the SSB after the i-th sampling point may be one or more. That is, if the signal-to-noise ratio of the i-th sampling point is greater than or equal to the second threshold and less than the first threshold, the terminal device may perform auxiliary judgment on whether the i-th sampling point is the target sampling point by using the signal-to-noise ratio of one or more sampling points corresponding to the SSB after the i-th sampling point.

[0135] In a possible implementation, the number of sampling points corresponding to the SSB after the i-th sampling point may be one, for example, the sampling point is the k-th sampling point. Exemplarily, the terminal device may determine the k-th sampling point according to the indication information of the network device.

[0136] In a possible implementation, if the number of sampling points corresponding to the SSB after the i-th sampling point is multiple, the terminal device can determine that the i-th sampling point is the target sampling point when the signal-to-noise ratios of the multiple sampling points corresponding to the SSB after the i-th sampling point are greater than or equal to the second threshold, thereby improving the accuracy of the judgment.

[0137] In a possible implementation, if the number of sampling points corresponding to the SSB after the i-th sampling point is multiple, the terminal device can determine that the i-th sampling point is the target sampling point when any signal-to-noise ratio among the multiple sampling points corresponding to the SSB after the i-th sampling point is greater than or equal to the second threshold, thereby reducing the missed detection rate.

[0138] In this way, if the number of sampling points corresponding to the SSB after the i-th sampling point is multiple, then among the multiple sampling points corresponding to the SSB after the i-th sampling point, when the terminal device determines the signal-to-noise ratio of any one of the multiple sampling points, it determines whether the signal-to-noise ratio is greater than or equal to the second threshold. If so, the i-th sampling point can be determined as the target sampling point, without calculating and judging the signal-to-noise ratio of the sampling points after the sampling point among the multiple sampling points, thereby saving computing resources of the terminal device.

[0139] The following takes the example that the number of sampling points corresponding to the SSB after the i-th sampling point is one to illustrate how the terminal device determines the first signal-to-noise ratio of the k-th sampling point.

[0140] Figure 7 A flowchart of another timing synchronization method provided by the present application, which can be executed by a terminal device, is shown in FIG. Figure 7 , the method comprises the following steps:

[0141] S701. Determine a kth sampling point corresponding to an SSB whose time domain position is after the ith sampling point.

[0142] In a possible implementation, the terminal device may obtain indication information, which includes a preset interval. Then, according to the preset interval and the i-th sampling point, the k-th sampling point is determined among the M sampling points. That is, the time distance between the k-th sampling point and the i-th sampling point is the preset interval. By determining the k-th sampling point by the preset interval, it can be ensured that the k-th sampling point has an SSB, so that the synchronization judgment can be performed in combination with the signal-to-noise ratio of the sampling point of the SSB, thereby improving the accuracy of synchronization.

[0143] In a possible implementation, the preset interval may be greater than or equal to jW, and less than or equal to jW+D, where D is the number of OFDM symbols occupied by the SSB, W is the interval between the starting positions of any two SSBs in the multiple SSBs in the synchronization sequence, and j is a positive integer less than the number of SSBs. According to the preset interval, the kth sampling point where the SSB exists can be determined.

[0144] For example, if each SSB occupies 4 OFDM symbols, then W=4+n, where n is the interval between any two SSBs in the multiple SSBs in the synchronization sequence, such as Figure 7 As shown, the unit of n can be OFDM symbol, and n is a positive integer.

[0145] Figure 8 This is a schematic diagram of the i-th sampling point and the k-th sampling point of the example of this application. Taking the number of multiple SSBs in the synchronization sequence as 3 as an example, j can be 1 or 2. When j=1, the k-th sampling point can be any sampling point among the sampling points corresponding to SSB2. Figure 7 The kth sampling point in the example is the first sampling point among the sampling points corresponding to SSB2. When j=2, the kth sampling point can be any sampling point among the sampling points corresponding to SSB3. Figure 8 The kth sampling point in the example is the first sampling point among the sampling points corresponding to SSB3.

[0146] In a possible implementation, the terminal device may slide in the synchronization sequence through a preset sliding window to obtain the signal-to-noise ratio of each sampling point. Exemplarily, the step size of the preset sliding window may be 1 sampling point. Exemplarily, Fig. 9 This is a schematic diagram of the preset sliding window sliding value in the synchronization sequence of the present application example. The terminal device can obtain the signal-to-noise ratio of the kth sampling point when the signal-to-noise ratio of the i-th sampling point is less than the first threshold and greater than or equal to the second threshold. Fig. 9 As shown, the first sampling point of the preset sliding window is the i-th sampling point currently judged.

[0147] In a possible implementation, the window length of the preset sliding window may be 1 OFDM symbol. Exemplarily, the length of one OFDM symbol may be 256 sampling points.

[0148] S702: Determine a first noise power of the kth sampling point.

[0149] In one possible implementation, the terminal device can determine, based on the synchronization sequence and the local sequence, multiple first correlation values ​​corresponding to multiple sampling points between the k+θ1th sampling point and the k+θ2th sampling point, and multiple second correlation values ​​corresponding to the sampling points between the k-θ1th sampling point and the k-θ2th sampling point.

[0150] Then, an average value of the plurality of first correlation values ​​and the plurality of second correlation values ​​is determined as the first noise power.

[0151] Among them, θ1 is not equal to θ2, and θ1 and θ2 are positive integers.

[0152] Similarly, for the ith sampling point, the noise power of the ith sampling point can also be determined by the correlation values ​​of some sampling points before and after the ith sampling point, without the need to calculate the correlation values ​​of multiple sampling points in the preset sliding window, thereby reducing the waste of computing time and storage resources.

[0153] Exemplarily, the terminal device may determine the first noise power of the kth sampling point according to the following formula.

[0154] The terminal device can determine the first noise power according to formula (1):

[0155] P noise =E{Λ(x)},x∈(k-θ1,k-θ2)∪(k+θ1,k+θ2) (1)

[0156] Wherein, E{·} represents the average value of the data, Λ(k-θ1), ..., Λ(k-θ2) are multiple second correlation values, Λ(k+θ1), ..., Λ(k+θ2) are multiple first correlation values. θ1 and θ2 are the sizes of the window used for noise estimation, θ1 is not equal to θ2, and θ1 and θ2 are positive integers. Λ(x) is the correlation value of the x-th sampling point, which can be determined according to the following formula (2):

[0157]

[0158] Where r(x) = [r(x), r(x+1), ..., r(x+N-1)] T , where N is the window length of the preset sliding window, r(x), r(x+1), ..., r(x+N-1) represents the data of N consecutive sampling points starting from the xth sampling point, that is, the data of the sampling points corresponding to the window length of a preset sliding window in the synchronization sequence. (·) H Indicates the conjugate transpose operation on the data. (·) T Indicates the transpose operation on a vector. jIt is a local sequence multiplied by a corresponding weight coefficient. It can be understood that the local sequence refers to a partial sequence of the total local sequence involved in the calculation whose length is the window length of the preset sliding window.

[0159] X j =V j ⊙s (3)

[0160] V j ∈C N×1 , s∈C N×1 , that is, V j and s are both N-dimensional complex column vectors, and the ⊙ operation represents the dot product of the vectors. j is the jth weight coefficient vector in the weight coefficient set, which is based on the parameter is the modulation downlink primary synchronization signal (DPSS) basis vector generated by the parameters, λ j is the eigenvalue corresponding to the DPSS basis vector, and s is a local sequence of length N.

[0161] in, K=2Nω. max is the maximum value of the normalized frequency offset search range in the current communication scenario, ε min is the minimum value of the normalized frequency offset search range in the current communication scenario.

[0162] By determining the first power noise through the correlation values ​​of several sampling points around the kth sampling point, the uncertainty caused by the instantaneous noise fluctuation of a single sampling point can be effectively reduced, thereby improving the accuracy of power noise estimation.

[0163] S703: Determine a first signal power according to the first noise power.

[0164] In a possible implementation, after determining the first noise power, the terminal device may obtain a correlation value of the kth sampling point. It is understandable that the correlation value of the kth sampling point may be obtained by the terminal device performing a correlation operation on the first sequence and the local sequence. The first signal power is determined according to the difference between the correlation value of the kth sampling point and the first noise power.

[0165] The first signal power may be determined according to the first noise power. Exemplarily, the terminal device may determine the first noise power according to the following formula (4):

[0166] P sig =Λ(k)-P noise (4)

[0167] Wherein, Λ(k) is the correlation value of the kth sampling point.

[0168] S704: Determine a first signal-to-noise ratio according to the first noise power and the first signal power.

[0169] The terminal device may determine the first signal-to-noise ratio according to the following formula (5):

[0170]

[0171] In this embodiment, the first signal-to-noise ratio can be determined based on the noise power and signal power of the kth sampling point corresponding to the SSB after the ith sampling point, so that it can be determined whether the ith sampling point is the target sampling point based on the first signal-to-noise ratio, thereby reducing the false alarm rate and missed detection rate and improving the accuracy of timing synchronization.

[0172] Fig.10 The schematic diagram of the structure of a timing synchronization device provided by the present application is as follows: The device 100 comprises: an acquisition module 1001 , a first determination module 1002 and a second determination module 1003 .

[0173] The acquisition module 1001 is used to acquire a synchronization sequence, where the synchronization sequence includes data of M sampling points, where the data of the M sampling points includes signal values ​​of multiple synchronization signal blocks SSB, and M is a positive integer.

[0174] The first determination module 1002 is used to determine a target sampling point among the M sampling points according to the signal-to-noise ratio of the sampling point among the M sampling points and the signal-to-noise ratio of the corresponding sampling point in the SSB whose time domain position is after the sampling point.

[0175] The second determining module 1003 is configured to determine the target sampling point as the synchronization position.

[0176] In a possible implementation, the first determining module 1002 is specifically configured to:

[0177] Determine the kth sampling point corresponding to the SSB whose time domain position is after the ith sampling point.

[0178] Determine the first noise power at the kth sampling point.

[0179] A first signal power is determined based on the first noise power.

[0180] A first signal-to-noise ratio is determined according to the first noise power and the first signal power.

[0181] When the first signal-to-noise ratio is greater than or equal to the second threshold, the i-th sampling point is determined as the target sampling point.

[0182] In a possible implementation, the first determining module 1002 is specifically configured to:

[0183] Obtaining indication information, the indication information including a preset interval;

[0184] According to the preset interval and the i-th sampling point, a k-th sampling point is determined among the M sampling points.

[0185] In one possible implementation, the preset interval is greater than or equal to jW and less than or equal to jW+D, where D is the number of orthogonal frequency division multiplexing technology OFDM symbols occupied by SSB, W is the interval between the starting positions of any two SSBs among multiple SSBs, and j is a positive integer less than the number of multiple SSBs.

[0186] In a possible implementation, the first determining module 1002 is specifically configured to:

[0187] Determine, according to the synchronization sequence and the local sequence, a plurality of first correlation values ​​corresponding to a plurality of sampling points between the k+θ1th sampling point and the k+θ2th sampling point, and a plurality of second correlation values ​​corresponding to the sampling points between the k-θ1th sampling point and the k-θ2th sampling point;

[0188] An average of the plurality of first correlation values ​​and the plurality of second correlation values ​​is determined as a first noise power.

[0189] Among them, θ1 is not equal to θ2, and θ1 and θ2 are positive integers.

[0190] In a possible implementation, the first determining module 1002 is specifically configured to:

[0191] Get the correlation value of the kth sampling point;

[0192] The first signal power is determined according to a difference between the correlation value of the kth sampling point and the first noise power.

[0193] The device of this embodiment can be used to execute the steps of the method in the above method embodiment. The specific implementation method and technical effect are similar and will not be repeated here.

[0194] Fig.11 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown in FIG. Fig.11 As shown, the electronic device 110 may include: at least one processor 1101 and a memory 1102 .

[0195] The memory 1102 is used to store programs. Specifically, the programs may include program codes, and the program codes include computer-executable instructions.

[0196] The memory 1102 may include a random access memory (RAM), and may also include a non-volatile memory (Non-volatile Memory), such as at least one disk memory.

[0197] The processor 1101 is used to execute the computer-executable instructions stored in the memory 1102 to implement the method described in the aforementioned method embodiment. The processor 1101 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0198] Optionally, the electronic device 110 may further include: a communication interface 1103. In a specific implementation, if the communication interface 1103, the memory 1102 and the processor 1101 are implemented independently, the communication interface 1103, the memory 1102 and the processor 1101 may be interconnected through a bus and communicate with each other. The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc., but it does not mean that there is only one bus or one type of bus.

[0199] Optionally, in a specific implementation, if the communication interface 1103, the memory 1102 and the processor 1101 are integrated on a chip, the communication interface 1103, the memory 1102 and the processor 1101 can communicate through an internal interface.

[0200] The electronic device 110 may be a terminal device or the like.

[0201] The electronic device of this embodiment can be used to execute the technical solution of the above method embodiment. The specific implementation method and technical effect are similar and will not be repeated here.

[0202] The embodiment of the present application provides a computer-readable storage medium, which may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a RAM, a disk or an optical disk, and other media that can store computer-executable instructions. Specifically, the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a computer, the technical solution shown in the above method embodiment is executed. The specific implementation method and technical effect are similar and will not be repeated here.

[0203] An embodiment of the present application provides a computer program product, including a computer program. When the computer program is executed by a computer, the technical solution shown in the above method embodiment is executed. The specific implementation method and technical effect are similar and will not be repeated here.

[0204] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0205] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

[0206] In this application, "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article indicates that the associated objects before and after are in an "or" relationship.

[0207] In this application, "at least one" means one or more. "Multiple" means two or more. The first, second, etc. descriptions that appear in the embodiments of this application are only used for illustration and distinction of the described objects. There is no order, nor does it represent a special limitation on the number of devices in the embodiments of this application, and cannot constitute any limitation on the embodiments of this application. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and do not represent the difference in size, priority or importance of the two thresholds.

[0208] In this application, "exemplary", "in some embodiments", "in other embodiments", etc. are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present concepts in a concrete way.

[0209] In this application, "of", "corresponding, relevant", "corresponding", and "associated" can sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, the meanings they express are consistent. In the embodiments of this application, communication and transmission can sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, the meanings they express are consistent. For example, transmission can include sending and / or receiving, which can be a noun or a verb.

[0210] In this application, "equal to" can be used in conjunction with "less than" or "greater than", but not with both "less than" and "greater than". When "equal to" is used in conjunction with "less than", it is applicable to the technical solution adopted by "less than". When "equal to" is used in conjunction with "greater than", it is applicable to the technical solution adopted by "greater than".

Claims

1. A timing synchronization method, characterized in that: include: Acquire a synchronization sequence, where the synchronization sequence includes data of M sampling points, where the data of the M sampling points includes signal values ​​of multiple synchronization signal blocks SSB, and M is a positive integer; Determine a target sampling point among the M sampling points according to a signal-to-noise ratio of a sampling point among the M sampling points and a signal-to-noise ratio of a corresponding sampling point in an SSB whose time domain position is after the sampling point; The target sampling point is determined as a synchronization position.

2. The method according to claim 1, characterized in that: Determining a target sampling point from among the M sampling points according to a signal-to-noise ratio of a sampling point from among the M sampling points and a signal-to-noise ratio of a corresponding sampling point in an SSB whose time domain position is after the sampling point includes: If the signal-to-noise ratio of the i-th sampling point among the M sampling points is greater than or equal to a first threshold, determining the i-th sampling point as the target sampling point; If the signal-to-noise ratio of the i-th sampling point is less than the first threshold and greater than or equal to the second threshold, then when the first signal-to-noise ratio of the sampling point in the SSB located after the i-th sampling point in the time domain is greater than or equal to the second threshold, the i-th sampling point is determined as the target sampling point; Here, i takes values ​​of 1, 2, 3, ... in sequence until the target sampling point is determined.

3. The method according to claim 2, characterized in that When a first signal-to-noise ratio of a sampling point in the SSB after the i-th sampling point is greater than or equal to the second threshold, determining the i-th sampling point as the target sampling point includes: Determine a k-th sampling point corresponding to the SSB whose time domain position is after the i-th sampling point; Determining a first noise power of the k-th sampling point; determining a first signal power according to the first noise power; determining the first signal-to-noise ratio according to the first noise power and the first signal power; When the first signal-to-noise ratio is greater than or equal to the second threshold, the i-th sampling point is determined as the target sampling point.

4. The method according to claim 3, characterized in that Determining a k-th sampling point corresponding to an SSB whose time domain position is located after the i-th sampling point includes: Acquire indication information, where the indication information includes a preset interval; According to the preset interval and the i-th sampling point, the k-th sampling point is determined among the M sampling points.

5. The method according to claim 4, characterized in that The preset interval is greater than or equal to jW and less than or equal to jW+D, where D is the number of orthogonal frequency division multiplexing technology OFDM symbols occupied by SSB, W is the interval between the starting positions of any two SSBs among the multiple SSBs, and j is a positive integer less than the number of the multiple SSBs.

6. The method according to any one of claims 3 to 5, characterized in that: Determining the first noise power of the k-th sampling point includes: Determine, according to the synchronization sequence and the local sequence, a plurality of first correlation values ​​corresponding to a plurality of sampling points between the k+θ1th sampling point and the k+θ2th sampling point, and a plurality of second correlation values ​​corresponding to the sampling points between the k-θ1th sampling point and the k-θ2th sampling point; determining an average of a plurality of the first correlation values ​​and a plurality of the second correlation values ​​as the first noise power; Among them, θ1 is not equal to θ2, and θ1 and θ2 are positive integers.

7. The method according to claim 6, characterized in that Determining a first signal power according to the first noise power includes: Obtaining the correlation value of the k-th sampling point; The first signal power is determined according to a difference between the correlation value of the kth sampling point and the first noise power.

8. A timing synchronization device, characterized in that: include: An acquisition module, configured to acquire a synchronization sequence, wherein the synchronization sequence includes data of M sampling points, wherein the data of the M sampling points includes signal values ​​of multiple synchronization signal blocks SSB, and M is a positive integer; A first determination module is used to determine a target sampling point among the M sampling points according to a signal-to-noise ratio of a sampling point among the M sampling points and a signal-to-noise ratio of a corresponding sampling point in an SSB whose time domain position is after the sampling point; The second determining module is used to determine the target sampling point as a synchronization position.

9. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 7 when executed by a processor.

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