A method for determining timing advance and a terminal

Abstract

The application discloses a method for determining timing advance and a terminal, and is used for providing a calculation mode of timing advance, improving the adaptability of different parameters of a satellite-ground communication scene, and avoiding the problems of excessive timing advance or introduction of inter-symbol interference due to improper experience value setting. The method comprises the following steps: determining the motion state of a satellite relative to a terminal; when the satellite is in a close state relative to the terminal, acquiring a last estimated Doppler frequency offset value, and determining the timing advance of a current time slot according to the last estimated Doppler frequency offset value.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a method and terminal for determining timing advance. Background Technology

[0002] In wireless communication between low-Earth orbit satellites and ground terminals, the distance between the satellite and the terminal changes significantly over time. During a single overhead pass of the satellite, the satellite-to-ground distance first shortens and then lengthens. Correspondingly, during the same overhead pass, the air interface propagation delay first shortens and then lengthens, causing continuous drift in the terminal's downlink timing.

[0003] Existing technical solutions rely on empirical values ​​to advance the timing during downlink timing operations at the terminal. However, empirical values ​​lack sufficient theoretical basis and may still result in ISI (Intermittent Separation Ingress) due to improper settings; furthermore, they have poor adaptability and lack unified empirical values ​​for different satellite-to-ground communication scenarios with varying parameters. Summary of the Invention

[0004] This invention provides a method and terminal for determining timing advance, which provides a way to calculate timing advance, improves the adaptability to different satellite-to-ground communication scenarios, and avoids problems such as excessive timing advance or the introduction of inter-symbol interference due to inappropriate empirical value settings.

[0005] In a first aspect, embodiments of the present invention provide a method for determining a timing advance, the method comprising:

[0006] Determine the satellite's motion state relative to the terminal;

[0007] When the satellite is close to the terminal, the previously estimated Doppler frequency offset value is obtained, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value.

[0008] This embodiment proposes a method to calculate the timing advance of the current time slot using the previously estimated Doppler frequency offset value, providing a method for real-time calculation of the timing advance of the current time slot. This avoids problems such as excessive timing advance or the introduction of inter-symbol interference due to inappropriate empirical value settings, and has better adaptability to satellite-to-ground communication scenarios with different parameters.

[0009] As an optional implementation, determining the satellite's motion state relative to the terminal includes:

[0010] Based on the satellite's ephemeris information, determine the satellite's motion state relative to the terminal; or,

[0011] The motion state of the satellite relative to the terminal is determined based on the Doppler frequency offset value.

[0012] As an optional implementation, determining the satellite's motion state relative to the terminal based on the satellite's ephemeris information includes:

[0013] Determine the satellite's direction of motion and position based on its ephemeris information; then determine the satellite's motion state relative to the terminal based on its direction of motion and position; or,

[0014] The Doppler frequency offset value is determined based on the satellite's ephemeris information, and the satellite's motion state relative to the terminal is determined based on the Doppler frequency offset value.

[0015] As an optional implementation, determining the satellite's motion state relative to the terminal based on the Doppler frequency offset value includes:

[0016] The Doppler frequency offset value is obtained by estimating the Doppler frequency offset using the reference signal. Based on the Doppler frequency offset value, the motion state of the satellite relative to the terminal is determined.

[0017] As an optional implementation, determining the satellite's motion state relative to the terminal based on the Doppler frequency offset value includes:

[0018] If the Doppler frequency offset value is positive, it is determined that the satellite is close to the terminal; or,

[0019] If the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

[0020] As an optional implementation, determining the timing advance of the current time slot based on the previously estimated Doppler frequency offset includes:

[0021] Based on the previously estimated Doppler frequency offset and carrier frequency, determine the timing offset per unit time period;

[0022] The time interval is determined based on the current time slot and the synchronization time of the last estimated Doppler frequency offset;

[0023] The timing advance of the current time slot is determined based on the timing offset of the unit time period and the time interval.

[0024] As an optional implementation, the method further includes:

[0025] If a satellite handover occurs, when the new satellite is close to the terminal, the previously estimated Doppler frequency offset value of the new satellite is determined, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value of the new satellite.

[0026] Secondly, an embodiment of the present invention provides a terminal, which includes a processor and a memory. The memory is used to store a program executable by the processor, and the processor is used to read the program in the memory and perform the following steps:

[0027] Determine the satellite's motion state relative to the terminal;

[0028] When the satellite is close to the terminal, the previously estimated Doppler frequency offset value is obtained, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value.

[0029] As an optional implementation, the processor is specifically configured to execute:

[0030] Based on the satellite's ephemeris information, determine the satellite's motion state relative to the terminal; or,

[0031] The motion state of the satellite relative to the terminal is determined based on the Doppler frequency offset value.

[0032] As an optional implementation, the processor is specifically configured to execute:

[0033] Determine the satellite's direction of motion and position based on its ephemeris information; then determine the satellite's motion state relative to the terminal based on its direction of motion and position; or,

[0034] The Doppler frequency offset value is determined based on the satellite's ephemeris information, and the satellite's motion state relative to the terminal is determined based on the Doppler frequency offset value.

[0035] As an optional implementation, the processor is specifically configured to execute:

[0036] The Doppler frequency offset value is obtained by estimating the Doppler frequency offset using the reference signal. Based on the Doppler frequency offset value, the motion state of the satellite relative to the terminal is determined.

[0037] As an optional implementation, the processor is specifically configured to execute:

[0038] If the Doppler frequency offset value is positive, it is determined that the satellite is close to the terminal; or,

[0039] If the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

[0040] As an optional implementation, the processor is specifically configured to execute:

[0041] Based on the previously estimated Doppler frequency offset and carrier frequency, determine the timing offset per unit time period;

[0042] The time interval is determined based on the current time slot and the synchronization time of the last estimated Doppler frequency offset;

[0043] The timing advance of the current time slot is determined based on the timing offset of the unit time period and the time interval.

[0044] As an optional implementation, the processor is further configured to execute:

[0045] If a satellite handover occurs, when the new satellite is close to the terminal, the previously estimated Doppler frequency offset value of the new satellite is determined, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value of the new satellite.

[0046] Thirdly, embodiments of the present invention also provide an apparatus for determining a timing advance, the apparatus comprising:

[0047] The status determination module is used to determine the motion status of the satellite relative to the terminal;

[0048] The timing advance module is used to obtain the previously estimated Doppler frequency offset value when the satellite is close to the terminal, and to determine the timing advance amount of the current time slot based on the previously estimated Doppler frequency offset value.

[0049] As an optional implementation, the state determination module is specifically used for:

[0050] Based on the satellite's ephemeris information, determine the satellite's motion state relative to the terminal; or,

[0051] The motion state of the satellite relative to the terminal is determined based on the Doppler frequency offset value.

[0052] As an optional implementation, the state determination module is specifically used for:

[0053] Determine the satellite's direction of motion and position based on its ephemeris information; then determine the satellite's motion state relative to the terminal based on its direction of motion and position; or,

[0054] The Doppler frequency offset value is determined based on the satellite's ephemeris information, and the satellite's motion state relative to the terminal is determined based on the Doppler frequency offset value.

[0055] As an optional implementation, the state determination module is specifically used for:

[0056] The Doppler frequency offset value is obtained by estimating the Doppler frequency offset using the reference signal. Based on the Doppler frequency offset value, the motion state of the satellite relative to the terminal is determined.

[0057] As an optional implementation, the state determination module is specifically used for:

[0058] If the Doppler frequency offset value is positive, it is determined that the satellite is close to the terminal; or,

[0059] If the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

[0060] As an optional implementation, the timing advance module is specifically used for:

[0061] Based on the previously estimated Doppler frequency offset and carrier frequency, determine the timing offset per unit time period;

[0062] The time interval is determined based on the current time slot and the synchronization time of the last estimated Doppler frequency offset;

[0063] The timing advance of the current time slot is determined based on the timing offset of the unit time period and the time interval.

[0064] As an optional implementation, the device further includes a switching module specifically used for:

[0065] If a satellite switch occurs, the previously estimated Doppler frequency offset value corresponding to the switched satellite is determined, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value corresponding to the switched satellite.

[0066] Fourthly, embodiments of the present invention also provide a computer storage medium having a computer program stored thereon, which, when executed by a processor, is used to implement the steps of the method described in the first aspect above.

[0067] Fifthly, this application provides a computer program product comprising: computer program code, which, when run on a computer, causes the computer to perform the method described in any one of the first aspects.

[0068] These or other aspects of this application will become more apparent in the following description of embodiments. Attached Figure Description

[0069] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0070] Figure 1 This is a schematic diagram illustrating the variation of satellite-to-ground distance according to an embodiment of the present invention;

[0071] Figure 2A-2BA schematic diagram illustrating continuous drift of downlink timing points provided in an embodiment of the present invention;

[0072] Figure 3 This is a schematic diagram illustrating a current method of using empirical values ​​to advance downlink timing, as provided in an embodiment of the present invention.

[0073] Figure 4 This is a schematic diagram illustrating an example of setting an empirical value for timing advance that is too small, provided by an embodiment of the present invention.

[0074] Figure 5 This is a schematic diagram illustrating an example of setting an excessively large empirical value for timing advance, as provided in an embodiment of the present invention.

[0075] Figure 6 A flowchart illustrating the implementation of a method for determining timing advance amount provided in an embodiment of the present invention;

[0076] Figure 7 This is a flowchart illustrating a method for determining timing advance in a terminal, as provided in an embodiment of the present invention.

[0077] Figure 8 A flowchart illustrating the specific implementation of another method for determining timing advance in a terminal, as provided in this embodiment of the invention.

[0078] Figure 9 A schematic diagram of a terminal provided in an embodiment of the present invention;

[0079] Figure 10 This is a schematic diagram of a device for determining timing advance amount provided in an embodiment of the present invention. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0081] In this embodiment of the invention, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0082] It should be noted that the terminal in this embodiment is a device with wireless communication capabilities, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on water (such as ships); and it can also be deployed in the air (e.g., on airplanes, balloons, and satellites). The terminal can be a mobile phone, tablet, computer with wireless transceiver capabilities, virtual reality (VR) terminal, augmented reality (AR) terminal, wireless terminal in industrial control, wireless terminal in self-driving, wireless terminal in remote medical care, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, etc.; it can also be various forms of UE, mobile station (MS), or terminal device.

[0083] The application scenarios described in the embodiments of this invention are for the purpose of more clearly illustrating the technical solutions of the embodiments of this invention, and do not constitute a limitation on the technical solutions provided by the embodiments of this invention. Those skilled in the art will understand that with the emergence of new application scenarios, the technical solutions provided by the embodiments of this invention are also applicable to similar technical problems. In the description of this invention, unless otherwise stated, "multiple" means two or more.

[0084] Before introducing the method for determining timing advance provided in the embodiments of this application, the technical background of the embodiments of this application will be described in detail below for ease of understanding.

[0085] In the wireless communication between low-Earth orbit satellites and ground terminals, the distance between the satellite and the terminal changes relatively significantly over time. For example... Figure 1 As shown in the diagram, this embodiment provides a schematic of the change in satellite-to-ground distance. During one satellite overpass, the satellite-to-ground distance first shortens and then lengthens. Correspondingly, during one satellite overpass, the air interface propagation delay first shortens and then lengthens, which causes the downlink timing point of the terminal to continuously drift.

[0086] like Figure 2A-2BAs shown in the diagram, this embodiment provides a schematic of continuous downlink timing point drift, where the gray box represents the wireless transmission delay between the satellite and the ground terminal. Assuming the terminal performs timing synchronization in slot 0, its timing position is represented by a dashed line. Assuming an OFDM waveform is used, its cyclic prefix is ​​denoted as CP, and its data portion is denoted as Data. Figure 2A As shown, during the satellite's approach phase, the air interface propagation delay between the satellite and the terminal gradually shortens. For the next slot, its timing point is shifted backward. If the timing point shifts beyond the start of the OFDM symbol data (timing lag), inter-symbol interference (ISI) is introduced, disrupting subcarrier orthogonality and drastically degrading reception performance. Figure 2B As shown, during the satellite departure phase, the air interface propagation delay between the satellite and the terminal gradually increases. For the next slot, its timing point is in a forward-moving state. When the terminal performs the next timing operation, if the timing point is within the CP range (timing ahead), ISI will not be introduced, and the inter-carrier orthogonality will still be preserved; if the timing point moves outside the CP range, to the end of the data of the previous OFDM symbol, ISI will also be introduced.

[0087] like Figure 3 As shown in the diagram, this embodiment also provides a schematic diagram of using empirical values ​​for downlink timing advance. In the downlink timing operation of the terminal, the terminal uses the empirical value T_adv to advance the timing to avoid timing lag. However, empirical values ​​lack sufficient theoretical basis and may still result in ISI due to unreasonable settings; furthermore, their adaptability is poor, and there is no unified empirical value for satellite-to-ground communication scenarios with different parameters. Figure 4 As shown in the diagram, this embodiment illustrates a scenario where the empirical value for timing lead is set too small. During the satellite approach phase (when the downlink timing point continues to shift backward), if the empirical value for timing lead is not set large enough, timing lag will still occur, resulting in ISI (Instant Interference). Figure 5 As shown in the diagram, this embodiment provides a schematic diagram of an excessively large empirical value for timing advance. During the satellite departure phase (downlink timing point is continuously advanced), if the empirical value for timing advance is set too large, it may lead to excessive timing advance and introduce ISI.

[0088] To address the issue of ISI caused by setting the empirical value of timing advance too small or too large, this application provides a method and terminal for determining timing advance. This method provides a way to calculate timing advance, improves adaptability to different satellite-to-ground communication scenarios, and avoids problems such as excessive timing advance or inter-symbol interference caused by inappropriate empirical value settings.

[0089] like Figure 6 As shown in the figure, this embodiment provides a method for determining timing advance, which can be applied to a terminal. The specific implementation steps of the method are as follows:

[0090] Step 600: Determine the motion state of the satellite relative to the terminal;

[0091] Optionally, the satellite's motion relative to the terminal includes, but is not limited to, approaching or moving away. It should be noted that when the satellite is approaching the terminal, the terminal's downlink timing point is shifted backward, requiring proactive advance of the downlink timing to determine the timing advance amount.

[0092] In some embodiments, the motion state of the satellite relative to the terminal is determined by any of the following methods:

[0093] Method 1) Determine the satellite's motion state relative to the terminal based on the satellite's ephemeris information.

[0094] During implementation, when the terminal receives satellite ephemeris information during downlink reception, it can determine whether the satellite is close to or far away from the terminal based on the ephemeris information.

[0095] In some embodiments, after obtaining the satellite's ephemeris information, the terminal's operating status is determined by any of the following methods:

[0096] Method 1a) Determine the satellite's motion direction and position based on the satellite's ephemeris information, and determine the satellite's motion state relative to the terminal based on the satellite's motion direction and position;

[0097] Method 1b) Determine the Doppler frequency offset value based on the satellite's ephemeris information, and determine the satellite's motion state relative to the terminal based on the Doppler frequency offset value.

[0098] In practice, the Doppler frequency offset value can be calculated using ephemeris information, and the satellite's motion state relative to the terminal can be determined based on the Doppler frequency offset value.

[0099] In some embodiments, the motion state of the satellite relative to the terminal is determined using the Doppler frequency offset value through one or more of the following methods:

[0100] Method b1) If the Doppler frequency offset value is positive, then it is determined that the satellite is close to the terminal;

[0101] Method b2) If the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

[0102] Method 2) Determine the satellite's motion state relative to the terminal based on the Doppler frequency offset value.

[0103] In practice, when the terminal does not obtain ephemeris information or the reliability of the ephemeris information is lower than the threshold during downlink reception, it can use the reference signal to calculate the downlink Doppler frequency offset value. The positive or negative sign of the downlink Doppler frequency offset value can be used to determine whether the satellite is close to or far away from the terminal.

[0104] In some embodiments, after the terminal calculates the Doppler frequency offset value, it can use the Doppler frequency offset value to determine the motion state of the satellite relative to the terminal, as follows:

[0105] Doppler frequency offset is estimated using a reference signal to obtain the Doppler frequency offset value. Based on the Doppler frequency offset value, the satellite's motion state relative to the terminal is determined. The reference signal is the signal sent by the base station to the terminal for Doppler frequency offset estimation. Examples of reference signals include, but are not limited to, the PSS (Primary Synchronization Signal).

[0106] In some embodiments, the motion state of the satellite relative to the terminal is determined using the Doppler frequency offset value through one or more of the following methods:

[0107] Method b1) If the Doppler frequency offset value is positive, then it is determined that the satellite is close to the terminal;

[0108] Method b2) If the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

[0109] Step 601: When the satellite is close to the terminal, obtain the previously estimated Doppler frequency offset value, and determine the timing advance of the current time slot based on the previously estimated Doppler frequency offset value.

[0110] In practice, when the satellite is close to the terminal, the downlink timing point of the terminal is shifted backward, requiring the downlink timing to be actively advanced to determine the timing advance amount.

[0111] In some embodiments, the previously estimated Doppler frequency offset value is obtained in the following manner, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value:

[0112] Step c1: Determine the timing offset per unit time period based on the previously estimated Doppler frequency offset and carrier frequency;

[0113] Step c2: Determine the time interval based on the current time slot and the synchronization time of the last estimated Doppler frequency offset;

[0114] Step c3: Determine the timing advance of the current time slot based on the timing offset of the unit time period and the time interval.

[0115] In practice, when the terminal determines that the satellite is in a close proximity state (i.e., a timing shift occurs), the terminal actively advances the downlink timing for the current time slot. The formula for calculating the timing advance is as follows:

[0116] T_adv=f_d0 / fc*Delta_T Formula (1);

[0117] In formula (1), f_d0 represents the previously estimated Doppler frequency offset value, fc represents the carrier frequency, and Delta_T represents the time interval between the current time slot and the synchronization time of the previously estimated Doppler frequency offset. The synchronization time of the previously estimated Doppler frequency offset refers to the terminal's previous downlink synchronization time T_0.

[0118] In some embodiments, if a satellite handover occurs, when the switched satellite is close to the terminal, the previously estimated Doppler frequency offset value corresponding to the switched satellite is determined, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value corresponding to the switched satellite.

[0119] During implementation, when a satellite launch is switched, the motion state of the switched satellite relative to the terminal is determined. When the switched satellite is close to the terminal, the previously estimated Doppler frequency offset value corresponding to the switched satellite is determined. Based on the previously estimated Doppler frequency offset value corresponding to the switched satellite, the timing advance of the current time slot after the switch is determined.

[0120] like Figure 7 As shown in the figure, this embodiment also provides a specific implementation process for a method for a terminal to determine timing advance, as follows:

[0121] Step 700: Obtain the satellite's ephemeris information;

[0122] Step 701: Determine the satellite's motion direction and position based on the ephemeris information; and determine the satellite's motion state relative to the terminal based on the satellite's motion direction and position.

[0123] Step 702: Determine the Doppler frequency offset value based on the satellite's ephemeris information, and determine the satellite's motion state relative to the terminal based on the Doppler frequency offset value;

[0124] In practice, if the Doppler frequency offset value is positive, it is determined that the satellite is close to the terminal; if the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

[0125] It should be noted that either step 701 or step 702 can be performed as needed.

[0126] Step 703: Determine whether the satellite is close to the terminal. If yes, proceed to step 704; otherwise, end.

[0127] Step 704: Obtain the previously estimated Doppler frequency offset value, the synchronization time of the previously estimated Doppler frequency offset value, and the carrier frequency;

[0128] Step 705: Determine the timing offset per unit time period based on the previously estimated Doppler frequency offset and carrier frequency;

[0129] Step 706: Determine the time interval based on the current time slot and the synchronization time of the last estimated Doppler frequency offset;

[0130] Step 707: The product of the timing offset per unit time period and the time interval is determined as the timing advance of the current time slot.

[0131] like Figure 8 As shown in the figure, this embodiment also provides another method for determining timing advance by the terminal, as follows:

[0132] Step 800: Use the reference signal to estimate the Doppler frequency offset and obtain the Doppler frequency offset value;

[0133] Step 801: Determine if the Doppler frequency offset value is positive. If yes, proceed to step 802; otherwise, end.

[0134] Step 802: Obtain the previously estimated Doppler frequency offset value, the synchronization time of the previously estimated Doppler frequency offset value, and the carrier frequency;

[0135] Step 803: Determine the timing offset per unit time period based on the previously estimated Doppler frequency offset and carrier frequency;

[0136] Step 804: Determine the time interval based on the current time slot and the synchronization time of the last estimated Doppler frequency offset;

[0137] Step 805: The product of the timing offset per unit time period and the time interval is determined as the timing advance of the current time slot.

[0138] In this embodiment, the terminal determines whether the satellite is close to the terminal, i.e., whether the current time slot is in the downlink timing point shift stage. When the satellite is close to the terminal (i.e., the terminal is in the downlink timing point shift stage), the timing advance of the current time slot can be calculated using the previously estimated Doppler frequency offset value, and the downlink timing of the current time slot can be advanced. This avoids the problem of excessive timing advance that may occur in the timing point advance stage of conventional methods, and avoids the problem of ISI that may occur due to inappropriate empirical value settings in conventional methods. It can better provide adaptability to satellite-to-ground communication scenarios with different parameters.

[0139] Based on the same inventive concept, this embodiment of the invention also provides a terminal. Since this terminal is the same as the terminal in the method of this embodiment of the invention, and the principle of the terminal in solving the problem is similar to that of the method, the implementation of the terminal can refer to the implementation of the method, and the repeated parts will not be described again.

[0140] like Figure 9 As shown, the terminal includes a processor 900 and a memory 901. The memory 901 stores programs executable by the processor 900. The processor 900 reads the programs from the memory 901 and performs the following steps:

[0141] Determine the satellite's motion state relative to the terminal;

[0142] When the satellite is close to the terminal, the previously estimated Doppler frequency offset value is obtained, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value.

[0143] As an optional implementation, the processor 900 is specifically configured to execute:

[0144] Based on the satellite's ephemeris information, determine the satellite's motion state relative to the terminal; or,

[0145] The motion state of the satellite relative to the terminal is determined based on the Doppler frequency offset value.

[0146] As an optional implementation, the processor 900 is specifically configured to execute:

[0147] Determine the satellite's direction of motion and position based on its ephemeris information; then determine the satellite's motion state relative to the terminal based on its direction of motion and position; or,

[0148] The Doppler frequency offset value is determined based on the satellite's ephemeris information, and the satellite's motion state relative to the terminal is determined based on the Doppler frequency offset value.

[0149] As an optional implementation, the processor 900 is specifically configured to execute:

[0150] The Doppler frequency offset value is obtained by estimating the Doppler frequency offset using the reference signal. Based on the Doppler frequency offset value, the motion state of the satellite relative to the terminal is determined.

[0151] As an optional implementation, the processor 900 is specifically configured to execute:

[0152] If the Doppler frequency offset value is positive, it is determined that the satellite is close to the terminal; or,

[0153] If the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

[0154] As an optional implementation, the processor 900 is specifically configured to execute:

[0155] Based on the previously estimated Doppler frequency offset and carrier frequency, determine the timing offset per unit time period;

[0156] The time interval is determined based on the current time slot and the synchronization time of the last estimated Doppler frequency offset;

[0157] The timing advance of the current time slot is determined based on the timing offset of the unit time period and the time interval.

[0158] As an optional implementation, the processor 900 is further configured to perform:

[0159] If a satellite handover occurs, when the new satellite is close to the terminal, the previously estimated Doppler frequency offset value of the new satellite is determined, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value of the new satellite.

[0160] Based on the same inventive concept, this embodiment of the invention also provides a device for determining timing advance. Since this device is the same as the device in the method of this embodiment of the invention, and the principle of the device in solving the problem is similar to that of the method, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0161] like Figure 10 As shown, the device includes:

[0162] The status determination module 1000 is used to determine the motion state of the satellite relative to the terminal.

[0163] The timing advance module 1001 is used to obtain the previously estimated Doppler frequency offset value when the satellite is close to the terminal, and determine the timing advance amount of the current time slot based on the previously estimated Doppler frequency offset value.

[0164] As an optional implementation, the state determination module 1000 is specifically used for:

[0165] Based on the satellite's ephemeris information, determine the satellite's motion state relative to the terminal; or,

[0166] The motion state of the satellite relative to the terminal is determined based on the Doppler frequency offset value.

[0167] As an optional implementation, the state determination module 1000 is specifically used for:

[0168] Determine the satellite's direction of motion and position based on its ephemeris information; then determine the satellite's motion state relative to the terminal based on its direction of motion and position; or,

[0169] The Doppler frequency offset value is determined based on the satellite's ephemeris information, and the satellite's motion state relative to the terminal is determined based on the Doppler frequency offset value.

[0170] As an optional implementation, the state determination module 1000 is specifically used for:

[0171] The Doppler frequency offset value is obtained by estimating the Doppler frequency offset using the reference signal. Based on the Doppler frequency offset value, the motion state of the satellite relative to the terminal is determined.

[0172] As an optional implementation, the state determination module 1000 is specifically used for:

[0173] If the Doppler frequency offset value is positive, it is determined that the satellite is close to the terminal; or,

[0174] If the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

[0175] As an optional implementation, the timing advance module 1001 is specifically used for:

[0176] Based on the previously estimated Doppler frequency offset and carrier frequency, determine the timing offset per unit time period;

[0177] The time interval is determined based on the current time slot and the synchronization time of the last estimated Doppler frequency offset;

[0178] The timing advance of the current time slot is determined based on the timing offset of the unit time period and the time interval.

[0179] As an optional implementation, the device further includes a switching module specifically used for:

[0180] If a satellite handover occurs, when the new satellite is close to the terminal, the previously estimated Doppler frequency offset value of the new satellite is determined, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value of the new satellite.

[0181] Based on the same inventive concept, this disclosure provides a computer storage medium comprising: computer program code, which, when executed on a computer, causes the computer to perform any of the methods for determining timing advance discussed above. Since the principle by which the computer storage medium solves the problem is similar to that of the method for determining timing advance, the implementation of the computer storage medium can be referred to the implementation of the method, and repeated details will not be elaborated further.

[0182] In specific implementation, computer storage media can include: Universal Serial Bus Flash Drive (USB), portable hard drive, Read-Only Memory (ROM), Random Access Memory (RAM), magnetic disk or optical disk, and other storage media that can store program code.

[0183] Based on the same inventive concept, this disclosure also provides a computer program product, which includes computer program code that, when executed on a computer, causes the computer to perform any of the methods for determining timing advance discussed above. Since the principle by which the above-described computer program product solves the problem is similar to that of the method for determining timing advance, the implementation of the above-described computer program product can be referred to the implementation of the method, and repeated details will not be elaborated further.

[0184] Computer program products may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0185] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0186] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 Devices that specify the functions in one or more boxes.

[0187] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction device, which is implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0188] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0189] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for determining timing advance, characterized in that, The method includes: Determine the satellite's motion state relative to the terminal; When the satellite is close to the terminal, the previously estimated Doppler frequency offset value is obtained, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value. The step of determining the timing advance of the current time slot based on the previously estimated Doppler frequency offset value includes: determining the timing offset per unit time period based on the previously estimated Doppler frequency offset value and carrier frequency; determining the time interval based on the synchronization time of the current time slot and the previously estimated Doppler frequency offset; and determining the timing advance of the current time slot based on the timing offset per unit time period and the time interval.

2. The method according to claim 1, characterized in that, Determining the satellite's motion state relative to the terminal includes: Based on the satellite's ephemeris information, determine the satellite's motion state relative to the terminal; or, The satellite's motion state relative to the terminal is determined based on the Doppler frequency offset value.

3. The method according to claim 2, characterized in that, Determining the satellite's motion state relative to the terminal based on the satellite's ephemeris information includes: Determine the satellite's direction of motion and position based on its ephemeris information; then determine the satellite's motion state relative to the terminal based on its direction of motion and position; or, The Doppler frequency offset value is determined based on the satellite's ephemeris information, and the satellite's motion state relative to the terminal is determined based on the Doppler frequency offset value.

4. The method according to claim 2, characterized in that, The process of determining the satellite's motion state relative to the terminal based on the Doppler frequency offset value includes: The Doppler frequency offset value is obtained by estimating the Doppler frequency offset using the reference signal. Based on the Doppler frequency offset value, the motion state of the satellite relative to the terminal is determined.

5. The method according to any one of claims 2 to 4, characterized in that, The process of determining the satellite's motion state relative to the terminal based on the Doppler frequency offset value includes: If the Doppler frequency offset value is positive, it is determined that the satellite is close to the terminal; or, If the Doppler frequency offset value is negative, it is determined that the satellite is far away from the terminal.

6. The method according to claim 1, characterized in that, The method also includes: If a satellite handover occurs, when the new satellite is close to the terminal, the previously estimated Doppler frequency offset value of the new satellite is determined, and the timing advance of the current time slot is determined based on the previously estimated Doppler frequency offset value of the new satellite.

7. A terminal, characterized in that, The terminal includes a processor and a memory, the memory being used to store programs executable by the processor, and the processor being used to read the programs from the memory and perform the following steps: Determine the satellite's motion state relative to the terminal; When the satellite is close to the terminal, determine the previously estimated Doppler frequency offset value, and determine the timing advance of the current time slot based on the previously estimated Doppler frequency offset value. The processor is specifically configured to perform the following: determining the timing offset per unit time period based on the previously estimated Doppler frequency offset value and carrier frequency; determining the time interval based on the current time slot and the synchronization time of the previously estimated Doppler frequency offset; and determining the timing advance of the current time slot based on the timing offset per unit time period and the time interval.

8. The terminal according to claim 7, characterized in that, The processor is specifically configured to execute: Based on the satellite's ephemeris information, determine the satellite's motion state relative to the terminal; or, The motion state of the satellite relative to the terminal is determined based on the Doppler frequency offset value.

9. A computer storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the method as described in any one of claims 1 to 6.

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