Method and device for accessing low earth orbit satellite, and electronic equipment

Abstract

The invention provides a method and a device for accessing a low earth orbit satellite, and electronic equipment, which are used for improving the success rate of accessing the low earth orbit satellite by a terminal. The method comprises the following steps: determining fitting information; wherein the fitting information comprises the corresponding relation between the position information of the low-orbit satellite and the time, and the corresponding relation between the rate information and the time; determining an access parameter based on the fitting information, and initiating uplink random access to the low-orbit satellite based on the access parameter; wherein the access parameters comprise Doppler frequency offset and time delay.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a method, an apparatus, and an electronic device for accessing a low-earth orbit satellite. Background Art

[0002] Low-earth orbit satellite communication refers to a communication system composed of satellites with an orbital altitude of 500 - 1500 KM. Compared with geostationary satellite communication, low-earth orbit satellite communication is considered to be the most promising satellite communication system because of its advantages such as short transmission delay, low path loss, and being conducive to the miniaturization of satellites and terminals.

[0003] Also, because the orbital altitude of low-earth orbit satellites is low, there is a high-speed relative motion between the satellites and the ground, which results in a large Doppler frequency offset. At the same time, as the low-earth orbit satellite orbits the earth and the relative position between the satellite and the ground terminal changes, there is also a certain rate of change in the time delay and Doppler frequency offset of the satellite-ground link. The magnitude of this rate of change is mainly related to the altitude of the satellite and the elevation angle of the ground terminal with respect to the satellite. Taking the low-earth orbit satellite Iridium with an orbital altitude of 780 Km as an example, when the elevation angle is 20 degrees, the Doppler frequency offset is 380 KHz, and when the elevation angle is 80 degrees, the frequency offset rate of change reaches 2.7 KHz / s.

[0004] Especially in the 5G NR protocol system, with a subcarrier spacing of 120 KHz, the maximum Doppler frequency offset exceeds three times the subcarrier spacing. Therefore, before the terminal performs uplink random access, it is necessary to first obtain the ephemeris information of the local satellite from the broadcast message, and combine it with the Doppler frequency offset to pre-compensate the Doppler frequency offset.

[0005] However, in some cases, when the terminal is in the initial power-on state, or the ephemeris error is large, the calculated Doppler frequency offset based on this will have too large an error, resulting in the terminal being unable to complete the initial access process normally. Therefore, the current success rate of terminal initial access needs to be improved. Summary of the Invention

[0006] The present invention provides a method, an apparatus, and an electronic device for accessing a low-earth orbit satellite, so as to improve the success rate of a terminal accessing a low-earth orbit satellite.

[0007] In a first aspect, an embodiment of the present application provides a method for accessing a low-earth orbit satellite, including:

[0008] Determine fitting information; wherein, the fitting information includes the correspondence between the position information of the low-earth orbit satellite and time, and the correspondence between the rate information and time;

[0009] Based on the fitting information, determine access parameters, and initiate uplink random access to the low-earth orbit satellite based on the access parameters; wherein, the access parameters include Doppler frequency offset and time delay.

[0010] A possible implementation manner, the uplink random access to the LEO satellite based on the access parameters includes:

[0011] Based on the access parameters, determine the target time for initiating uplink random access;

[0012] At the target time, initiate uplink random access to the LEO satellite.

[0013] A possible implementation manner, the determination of the fitting information includes:

[0014] Obtain ephemeris information; wherein, the ephemeris information includes at least one of the ephemeris information of the current time slot, historical ephemeris information, and pre-stored ephemeris information;

[0015] Based on the ephemeris information, determine the fitting information.

[0016] A possible implementation manner, the determination of the access parameters based on the fitting information and the uplink random access to the LEO satellite based on the access parameters includes:

[0017] In response to the ephemeris information being composed of the pre-stored ephemeris information, determine the access parameters;

[0018] Based on the access parameters and the restricted set A / B random access mode, initiate uplink random access to the LEO satellite.

[0019] A possible implementation manner, the uplink random access to the LEO satellite based on the access parameters and the restricted set A / B random access mode includes:

[0020] Compensate the Doppler frequency offset and time delay in the access parameters by an integer multiple respectively to obtain the compensated access parameters;

[0021] Based on the compensated access parameters and the restricted set A / B random access mode, initiate uplink random access to the LEO satellite.

[0022] A possible implementation manner, the access parameters include the communication elevation angle at each moment;

[0023] Then the uplink random access to the LEO satellite based on the access parameters includes:

[0024] In response to the communication elevation angle being greater than or equal to the minimum communication elevation angle, initiate uplink random access to the LEO satellite based on the access parameters.

[0025] A possible implementation manner, the uplink random access to the LEO satellite based on the access parameters includes:

[0026] Determine the maximum communication elevation angle within a period;

[0027] Determine a target elevation angle based on the maximum communication elevation angle within the period;

[0028] In response to the communication elevation angle being greater than or equal to the target elevation angle, initiate uplink random access to the LEO satellite based on the access parameters.

[0029] In a possible implementation, the access parameters include a frequency offset change rate;

[0030] Then, the initiating uplink random access to the LEO satellite based on the access parameters includes:

[0031] In response to the frequency offset change rate being greater than or equal to a preset target threshold, initiate uplink random access to the LEO satellite based on the frequency offset change rate, the Doppler frequency offset, and the time delay in the access parameters.

[0032] In a second aspect, an embodiment of the present application provides a device for accessing a LEO satellite, including:

[0033] A fitting unit, configured to determine fitting information; wherein, the fitting information includes the correspondence between the position information of the LEO satellite and time, and the correspondence between the rate information and time;

[0034] A parameter unit, configured to determine access parameters based on the fitting information, and initiate uplink random access to the LEO satellite based on the access parameters; wherein, the access parameters include a Doppler frequency offset and a time delay.

[0035] In a possible implementation, the parameter unit is specifically configured to determine a target time for initiating uplink random access based on the access parameters; at the target time, initiate uplink random access to the LEO satellite.

[0036] In a possible implementation, the fitting unit is specifically configured to obtain ephemeris information; wherein, the ephemeris information includes at least one of the ephemeris information of the current time slot, historical ephemeris information, and pre-stored ephemeris information; determine the fitting information based on the ephemeris information.

[0037] In a possible implementation, the parameter unit is further configured to determine the access parameters in response to the ephemeris information being composed of the pre-stored ephemeris information; initiate uplink random access to the LEO satellite based on the access parameters and the restricted set A / B random access mode.

[0038] In a possible implementation, the parameter unit is further configured to perform integer multiple compensation on the Doppler frequency offset and the time delay in the access parameters respectively to obtain compensated access parameters; initiate uplink random access to the LEO satellite based on the compensated access parameters and the restricted set A / B random access mode.

[0039] A possible implementation manner, where the access parameter includes the communication elevation angle at each moment; then the parameter unit is specifically configured to initiate uplink random access to the low-earth orbit satellite based on the access parameter in response to the communication elevation angle being greater than or equal to the minimum communication elevation angle.

[0040] A possible implementation manner, where the parameter unit is further configured to determine the maximum communication elevation angle within a period; determine the target elevation angle based on the maximum communication elevation angle within the period; and initiate uplink random access to the low-earth orbit satellite based on the access parameter in response to the communication elevation angle being greater than or equal to the target elevation angle.

[0041] A possible implementation manner, where the access parameter includes the frequency offset change rate; then the parameter unit is specifically configured to initiate uplink random access to the low-earth orbit satellite based on the frequency offset change rate, the Doppler frequency offset, and the time delay in the access parameter in response to the frequency offset change rate being greater than or equal to a preset target threshold.

[0042] In a third aspect, an embodiment of the present application provides a readable storage medium, including:

[0043] A memory,

[0044] The memory is used to store a computer program, and when the computer program is executed by a processor, it causes the device including the readable storage medium to complete the method as described in the first aspect and any possible implementation manner.

[0045] In a fourth aspect, an embodiment of the present application provides an electronic device, including:

[0046] A memory for storing a computer program;

[0047] A processor for implementing the method as described in the first aspect and any possible implementation manner when executing the computer program stored on the memory.

[0048] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects:

[0049] In the access method provided in the embodiments of the present application, by using the periodic characteristic of the movement of the low-earth orbit satellite, the access parameters including the Doppler frequency offset and the time delay are determined through a fitting curve corresponding to the movement trajectory of the low-earth orbit satellite, so as to correct the access parameters such as the Doppler frequency offset through the fitting information, thereby improving the accuracy of the access parameters such as the Doppler frequency offset, and avoiding the problem that the terminal fails to successfully access due to excessive errors in the access parameters such as the Doppler frequency offset, thereby improving the success rate of the terminal accessing the low-earth orbit satellite.

[0050] In particular, when determining the fitting information based on the ephemeris information, a secondary correction is implemented for the estimated value obtained by prediction, thereby improving the accuracy of the access parameters, and thus effectively extending the extrapolation time.

[0051] This method can ensure that the terminal can successfully access within a short satellite transit time. Therefore, the method provided by the embodiments of the present application has great advantages in the initial stage of system construction with a small number of low-earth orbit satellites.

[0052] Secondly, when there is less ephemeris information, for example, when the ephemeris information only consists of pre-stored ephemeris information during cold start, by compensating for the Doppler frequency offset and / or using the restricted set A / B random access mode, it is ensured that successful access can still be achieved when the rate of change of the frequency offset is large, thereby achieving the purpose of increasing the probability of successful access.

[0053] Furthermore, by controlling that the communication elevation angle must be greater than the minimum communication elevation angle before the low-earth orbit satellite starts to initiate random access when it is within the visible detection window, while ensuring a high access rate, it also has the advantage of low power consumption.

[0054] Finally, when the uplink random access is initiated when the communication elevation angle is greater than or equal to the target elevation angle near the maximum communication elevation angle, since within the aforementioned communication elevation angle range, the Doppler frequency is low and the signal attenuation is low due to being close to the ground, initiating the uplink random access when the communication elevation angle is greater than or equal to the target elevation angle can further significantly increase the success rate of the terminal accessing the low-earth orbit satellite.

[0055] Other features and advantages of the present application will be described in the subsequent specification, and part of them will become obvious from the specification, or will be understood by implementing the present application. The objectives and other advantages of the present application can be achieved and obtained through the structures specifically pointed out in the written specification, claims, and drawings. It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0057] Figure 1 It is a schematic flowchart of a method for accessing a low-earth orbit satellite provided by an embodiment of the present application;

[0058] Figure 2 It is a schematic diagram of a method for accessing a low-earth orbit satellite provided by an embodiment of the present application;

[0059] Figure 3 A schematic structural diagram of a device for accessing a low-earth orbit satellite provided by an embodiment of the present application;

[0060] Figure 4 A schematic structural diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0061] In view of the problem of low success rate of current terminals accessing low-earth orbit satellites, in the embodiments of the present application, the terminal utilizes the characteristic that the orbit of the low-earth orbit satellite is fixed and its motion is periodic. By determining the fitting information indicating the motion trajectory of the low-earth orbit satellite within one or more periods, the access parameters for initiating random uplink access are determined, and random uplink access is initiated. Thus, based on the fitting information, high-precision correction of access parameters such as Doppler frequency offset is achieved, effectively improving the accuracy of access parameters including Doppler frequency offset, time delay, etc., and further effectively improving the success rate of accessing low-earth orbit satellites.

[0062] To better understand the above technical solution, the technical solution of the present application will be described in detail below through the accompanying drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present application and the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. Without conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0063] The terms "first" and "second" in the specification, claims and drawings of the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the term "including" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices. "Multiple" in the present application may represent at least two, for example, it may be two, three or more, and the embodiments of the present application do not make limitations.

[0064] Please refer to Figure 1 , the present application proposes a method for accessing a low-earth orbit satellite. This method is applied to a terminal to improve the success rate of the terminal accessing the low-earth orbit satellite. The method specifically includes the following implementation steps:

[0065] Step 101: Determine the fitting information.

[0066] Wherein, the fitting information includes the correspondence between the position information of the low-earth orbit satellite and time, and the correspondence between the rate information and time.

[0067] The time granularity of the fitting information is less than a preset threshold. The preset threshold can be 1 second.

[0068] Then, in the correspondence between the above position information and time, and the correspondence between the speed information and time, the time interval between two adjacent moments is at least less than 1 second.

[0069] Then the time points in the fitting information can be continuous or discontinuous. The time length between two adjacent discontinuous time points is less than 1 second.

[0070] Therefore, the fitting information represents the motion characteristics of the low-earth orbit satellite within one cycle or m cycles. And m is less than a first preset value to ensure that the information accuracy in the fitting curve meets the requirements.

[0071] In some embodiments, the above fitting information is represented by a table or a curve, i.e., a fitting curve.

[0072] The fitting curve includes the position-time curve of the low-earth orbit satellite. The position-time curve can be a curve of the position coordinates (x, y, z) of the low-earth orbit satellite changing with time t.

[0073] The fitting curve may further include a speed-time curve. The speed-time curve can be a curve of the speed v of the low-earth orbit satellite changing with time t.

[0074] The fitting curve may include a continuous fitting curve and / or a discontinuous fitting curve.

[0075] Further, to determine the above fitting information, it is necessary to first obtain ephemeris information, and then perform filtering processing on the ephemeris information and then fitting to obtain the aforementioned fitting curve. The ephemeris information may include at least one of the current time slot ephemeris information, historical ephemeris information, and built-in pre-stored ephemeris information.

[0076] The ephemeris information may further include the whole network ephemeris information and the satellite ephemeris information. Then the ephemeris information of the current time slot includes the whole network ephemeris information of the current time slot and the satellite ephemeris information of the current time slot; the historical ephemeris information includes the historical whole network ephemeris information and the historical satellite ephemeris information; the pre-stored ephemeris information is only composed of the pre-stored whole network ephemeris information.

[0077] The whole network ephemeris information and the satellite ephemeris information of the above ephemeris information can be distinguished by reading the identifiers therein. The identifier can be, for example, the message IP. The ephemeris information of the current time slot, the historical ephemeris information, and the pre-stored ephemeris information can be distinguished by different acquisition methods, positions, and / or acquisition times.

[0078] The following will detail how to obtain the ephemeris information and the obtained ephemeris information:

[0079] Ephemeris information can be obtained through broadcast messages. Specifically, the satellite payload periodically transmits broadcast messages. At the same time, according to the periodicity of ephemeris broadcast, the ephemeris information is also periodically transmitted through broadcast messages. Since the ephemeris broadcast period is usually longer than the broadcast period, not all broadcast messages contain ephemeris information.

[0080] Therefore, after receiving the broadcast message, it is first necessary to identify the ephemeris information in the broadcast message and extract it for filtering and fitting. The ephemeris information extracted from the broadcast message at this time is the ephemeris information of the current time slot. The ephemeris information obtained above includes the ephemeris information of the local satellite in the current time slot and / or the ephemeris information of the entire network in the current time slot, as well as historical ephemeris information.

[0081] If the broadcast message does not contain ephemeris information, the pre-stored ephemeris information built into the terminal can be directly extracted. The ephemeris information obtained above includes the pre-stored ephemeris information and historical ephemeris information.

[0082] The pre-stored ephemeris information can be the ephemeris information pre-stored at any time before the current moment. For example, it can be the ephemeris information built into the terminal during the production stage.

[0083] In some embodiments, if the terminal is in a cold start, the terminal has not yet generated historical ephemeris information. At this time, the ephemeris information is only the pre-stored ephemeris information built in.

[0084] Furthermore, after obtaining the ephemeris information, denoising and fitting can be performed according to the obtained ephemeris information to obtain the fitting information.

[0085] It should be noted that the fitting information in the embodiments of this application has the characteristic of small time granularity. In the fitting curve, it is manifested as a short distance between adjacent two time scales. In this way, the fitting avoids the high error caused by the superposition of continuous multiple estimation errors. That is to say, such fitting actually plays a role in correction.

[0086] The following describes the implementation manner for determining the fitting information when the ephemeris information includes the ephemeris of the local satellite and the ephemeris information of the entire network:

[0087] Based on the ephemeris of the local satellite and the ephemeris of the entire network in the obtained ephemeris information, the ephemeris information for the next cycle or subsequent m cycles is predicted respectively through methods such as modeling to obtain two sets of estimated values. Filtering processing is performed on the two sets of predicted estimated values respectively, that is, the two sets of estimated values are used as the processing objects respectively to calculate the noise variance of the current system.

[0088] Then, the noise variances of the above two sets of estimated values are used to update the corresponding estimated values respectively to minimize the noise variance, so as to obtain two sets of updated estimated values with high precision: the first estimated value and the second estimated value.

[0089] Finally, the first estimated value and the second estimated value are fused and fitted by interpolation or other means to obtain fitting information with a time granularity less than a preset threshold. Alternatively, the first estimated value and the second estimated value are fitted separately and then fused to obtain fitting information with a time granularity less than a preset threshold.

[0090] In the embodiment of the present application, confirmation of the fitting information includes but is not limited to the above-mentioned implementation mode. For example, the ephemeris information may be directly filtered and fitted before prediction to obtain the fitting information.

[0091] Step 102: Determine access parameters based on the fitting curve, and initiate uplink random access to the low-orbit satellite based on the access parameters.

[0092] Among them, the access parameters include Doppler frequency deviation and delay.

[0093] The Doppler frequency deviation can be calculated by the velocity-time curve in the above-mentioned fitting curve. The time delay can be calculated by the position-time curve in the above-mentioned fitting curve. Then, in the access parameters, the Doppler frequency deviation corresponds to time, and the time delay also corresponds to time.

[0094] Moreover, the time granularity of the access parameter is consistent with the time granularity of the fitting information, and both are smaller than a preset threshold.

[0095] Specifically, firstly, based on the access parameters, the target time for initiating uplink random access is predicted, that is, the target time for initiating uplink random access is determined.

[0096] Then, at the target time, a random uplink access is initiated to the low-orbit satellite.

[0097] When the terminal is in a cold start, the only ephemeris information it obtains is the built-in pre-stored ephemeris information. In order to avoid the problem of insufficient access parameter accuracy due to insufficient ephemeris information and the pre-stored ephemeris has exceeded its validity period, which leads to a decrease in access success rate. In some embodiments, the A / B random access mode can be restricted to limit the number of root sequences for different relative motions, thereby achieving the purpose of limiting the number of preamble codes.

[0098] This can effectively avoid the low-orbit satellite from confusing the received preamble code, and effectively improve the success rate of the current terminal access. Specifically, in response to the ephemeris information of the current time slot, the ephemeris information of the local star and / or the full network ephemeris information of the current time slot, the access parameters are determined based on the ephemeris information. Then, according to the access parameters and the restricted set A / B random access mode, an uplink random access is initiated to the low-orbit satellite.

[0099] The Doppler frequency offset in the access parameters here can be the Doppler frequency offset directly obtained from the fitting information (such as the fitting curve), or the Doppler frequency offset obtained after further compensating the Doppler frequency offset obtained from the fitting information (such as the fitting curve). For example, the maximum Doppler frequency offset can be determined by modeling, the ratio between the maximum Doppler frequency offset and the subcarrier is calculated and rounded, and then this ratio is multiplied by the Doppler frequency offset obtained from the aforementioned fitting curve, thereby realizing the integer multiple compensation of the Doppler frequency offset. By adopting a compensation method consistent with the Doppler frequency offset for the time delay, the compensated access parameters can be obtained. Among them, the compensated access parameters include the compensated Doppler frequency offset and the compensated time delay. In some embodiments, it may also include the compensated frequency offset change rate obtained in the same way. Then, based on the compensated access parameters and the aforementioned restricted set A / B random access mode, an uplink random access is initiated to the low-earth orbit satellite.

[0100] Furthermore, the access parameters may further include the communication elevation angle at each moment within the motion period of the low-earth orbit satellite. This communication elevation angle can also be obtained through the aforementioned fitting curve, specifically through the position-time curve in the fitting curve. To avoid unnecessary signaling overhead and ensure the success rate of each uplink random access initiation, in some embodiments, the terminal will only consider initiating an uplink random access when the communication elevation angle is greater than or equal to the minimum communication elevation angle. Otherwise, the terminal enters the energy-saving mode, stops the action of periodically repeating the uplink random access initiation, and does not resume until the satellite enters the terminal's visible detection window, that is, when the communication elevation angle is greater than or equal to the minimum communication elevation angle or after that, and then the energy-saving mode is turned off. Specifically, in response to the communication elevation angle being greater than or equal to the minimum communication elevation angle, an uplink random access is initiated to the low-earth orbit satellite based on the access parameters. Or;

[0101] In response to the communication elevation angle being less than the communication elevation angle, it is determined to enter the energy-saving mode.

[0102] Among them, the communication elevation angle indicates the angle between the connection line of the low-earth orbit satellite and the terminal and the projection of this connection line on the horizontal plane. The minimum communication elevation angle is determined according to the height and frequency point of the low-earth orbit satellite, so the minimum communication elevation angle of the low-earth orbit satellite does not change due to the period change.

[0103] Furthermore, when the Doppler frequency offset is within a relatively small range, that is, when the communication elevation angle is relatively large, on the one hand, its impact on the success rate of the terminal's uplink random access is correspondingly reduced; especially under the action of the fitting information, and when the Doppler frequency offset is close to 0, the error in predicting the Doppler frequency offset is almost 0, so the impact of this Doppler frequency offset error on the success rate of the uplink random access will also be reduced to 0. On the other hand, when the low Doppler frequency offset means that the low-earth orbit satellite is at the perigee, correspondingly the signal attenuation is also at a low level.

[0104] It can be seen that based on the above two aspects, the success rate of terminal access can be further improved. Therefore, in some embodiments, the maximum communication elevation angle within a period can be determined first. Since the Earth rotates while the low-orbit satellite is moving, the relative position between the terminal on the Earth and the low-orbit satellite changes, so the maximum communication elevation angle may be different in each period. This period is the movement period of the low-orbit satellite, which refers to the time interval between two consecutive passes of the low-orbit satellite.

[0105] Then, based on this maximum communication elevation angle, a target elevation angle is determined. The target elevation angle can be calculated based on the maximum communication elevation angle and a second preset value. For example, if the second preset value is 5° and the maximum communication elevation angle is 80°, then the target elevation angle can be (80 ± 5)°, that is, the target elevation angle can be 75° - 85°.

[0106] In response to the communication elevation angle being greater than or equal to the target elevation angle, an uplink random access is initiated to the low-orbit satellite based on the access parameters. Or;

[0107] In response to the communication elevation angle being less than the target elevation angle, the frequency at which the terminal initiates uplink random access can be made lower than the preset minimum value, or the energy-saving mode can be directly enabled, so as to maximize the success rate of the terminal's successful access.

[0108] Furthermore, the above access parameters may further include a frequency offset change rate. The frequency offset change rate can be calculated through the aforementioned fitting curve, specifically through the rate-time curve in the fitting curve.

[0109] In some embodiments, based on the frequency offset change rate, Doppler frequency offset, and time delay in the access parameters, the timing for initiating uplink random access to the low-orbit satellite is determined, and uplink random access is initiated based on this timing.

[0110] In some embodiments, when the low-orbit satellite is in the first period, the frequency offset change rate is not required, and the moment for initiating random access is predicted directly through the Doppler frequency offset and time delay in the access parameters, and uplink random access is initiated.

[0111] In some embodiments, in response to the frequency offset change rate being greater than or equal to a preset target threshold, based on the frequency offset change rate, Doppler frequency offset, and time delay in the access parameters, the timing for initiating uplink random access to the low-orbit satellite is determined, and uplink random access is initiated based on this timing. Or;

[0112] In response to the frequency offset change rate being less than the preset target threshold, based on the Doppler frequency offset and time delay in the access parameters, the timing for initiating uplink random access to the low-orbit satellite is determined, and uplink random access is initiated based on this timing.

[0113] Further, when determining the access parameters, the time interval between downlink cell search and the initiation of uplink random access may also be determined according to a protocol or preset rules, and the access parameters and the target time for indicating the initiation of uplink random access may be determined according to this time interval. For example, the time interval is 0.5 seconds, and the time of downlink cell search is the 0.1 second, then the access parameters and the target time should be calculated starting from the 0.6 second. This can avoid the influence of the time error between downlink cell search and uplink random access on the uplink random access success rate under high-frequency deviation change rate.

[0114] According to the method for accessing a low-earth orbit satellite described in steps 101-102, the following is an example in combination with Figure 2 For example:

[0115] First, the terminal receives the broadcast message sent by the satellite payload and reads it to determine whether it includes the local ephemeris or the full-network ephemeris.

[0116] If the broadcast message includes the local ephemeris and / or the full-network ephemeris, then the local ephemeris and / or the full-network ephemeris in the broadcast message are the local ephemeris and / or the full-network ephemeris of the current time slot. At this time, the local ephemeris and / or the full-network ephemeris contained in the broadcast message, as well as the historical ephemeris information, can be filtered and fitted to generate a fitting curve. And the access parameters such as Doppler frequency offset, time delay, and frequency offset change rate can be obtained accordingly. The access parameters are the Doppler frequency offset, time delay, frequency offset change rate, etc. corresponding to different times.

[0117] If the broadcast message includes neither the local ephemeris nor the full-network ephemeris, then the terminal obtains the pre-stored ephemeris built-in. And the fitting curve is generated based on this and the historical ephemeris information, and the access parameters such as Doppler frequency offset, time delay, and frequency offset change rate are calculated.

[0118] Then, according to the above access parameters, calculate the timing when uplink random access can be initiated, and select the best timing, and initiate uplink random access when the best timing arrives.

[0119] At the same time, according to the change of the communication elevation angle, when the low-earth orbit satellite is not in the visible detection window, the terminal is made to enter the energy-saving mode and stop initiating uplink random access. Wait until the low-earth orbit satellite enters the visible detection window and then turn off the energy-saving mode.

[0120] Based on the same inventive concept, an apparatus for accessing a low-earth orbit satellite is provided in an embodiment of the present application. The apparatus can be used for a terminal, and this apparatus corresponds to the Figure 1 method for accessing a low-earth orbit satellite shown above. The specific implementation manner of this apparatus can refer to the description in the method embodiment part above. For the repeated parts, they will not be elaborated again. Refer to Figure 3 , this apparatus includes:

[0121] A fitting unit 301, configured to determine fitting information.

[0122] Among them, the fitting information includes the correspondence between the position information of the low-earth orbit satellite and time, and the correspondence between the speed information and time.

[0123] The fitting unit 301 is specifically configured to obtain ephemeris information; among them, the ephemeris information includes at least one of the ephemeris information of the current time slot, historical ephemeris information, and pre-stored ephemeris information; based on the ephemeris information, determine the fitting information.

[0124] The parameter unit 302 is configured to determine access parameters based on the fitting information, and initiate uplink random access to the low-earth orbit satellite based on the access parameters; among them, the access parameters include Doppler frequency offset and time delay.

[0125] The parameter unit 302 is specifically configured to determine the target time for initiating uplink random access based on the access parameters; at the target time, initiate uplink random access to the low-earth orbit satellite.

[0126] Further, the parameter unit 302 is further configured to determine the access parameters in response to the ephemeris information being composed of the pre-stored ephemeris information; initiate uplink random access to the low-earth orbit satellite based on the access parameters and the restricted set A / B random access mode.

[0127] Further, the access parameters include the communication elevation angle at each moment;

[0128] Then the parameter unit 302 is specifically configured to initiate uplink random access to the low-earth orbit satellite based on the access parameters in response to the communication elevation angle being greater than or equal to the minimum communication elevation angle.

[0129] Further, the parameter unit 302 is further configured to perform integer multiple compensation on the Doppler frequency offset and time delay in the access parameters respectively to obtain the compensated access parameters; initiate uplink random access to the low-earth orbit satellite based on the compensated access parameters and the restricted set A / B random access mode.

[0130] Further, the parameter unit 302 is further configured to determine the maximum communication elevation angle within a period; determine the target elevation angle based on the maximum communication elevation angle within the period; initiate uplink random access to the low-earth orbit satellite based on the access parameters in response to the communication elevation angle being greater than or equal to the target elevation angle.

[0131] Further, the access parameters include the frequency offset change rate; then the parameter unit 301 is specifically configured to initiate uplink random access to the low-earth orbit satellite based on the frequency offset change rate, the Doppler frequency offset, and the time delay in the access parameters in response to the frequency offset change rate being greater than or equal to a preset target threshold.

[0132] Based on the same inventive concept, an embodiment of the present application further provides a readable storage medium, including:

[0133] a memory,

[0134] The memory is used to store a computer program, and when the computer program is executed by a processor, it enables the device including the readable storage medium to complete the method of accessing a low-earth orbit satellite as described above.

[0135] Based on the same inventive concept as the above method of accessing a low-earth orbit satellite, an embodiment of the present application further provides an electronic device, which can implement the functions of the foregoing method of accessing a low-earth orbit satellite. Please refer to Figure 4 , the electronic device includes:

[0136] At least one processor 401, and a memory 402 connected to at least one processor 401. In the embodiment of the present application, the specific connection medium between the processor 401 and the memory 402 is not limited. Figure 4 In, it is taken as an example that the processor 401 and the memory 402 are connected through a bus 400. The bus 400 is represented by a thick line in Figure 4 . The connection manners between other components are only for illustrative purposes and are not limiting. The bus 400 can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 4 only a thick line is used to represent it in, but it does not mean that there is only one bus or one type of bus. Alternatively, the processor 401 can also be called a controller, and the name is not limited.

[0137] In the embodiment of the present application, the memory 402 stores instructions executable by at least one processor 401. By executing the instructions stored in the memory 402, at least one processor 401 can execute the method of accessing a low-earth orbit satellite described above. The processor 401 can implement Figure 3 the functions of each module in the device shown.

[0138] Among them, the processor 401 is the control center of the device, and can connect various parts of the entire control device through various interfaces and lines. By running or executing the instructions stored in the memory 402 and calling the data stored in the memory 402, various functions of the device and process data, so as to monitor the device as a whole.

[0139] In a possible design, the processor 401 may include one or more processing units. The processor 401 may integrate an application processor and a modem processor. Among them, the application processor mainly processes the operating system, user interface, application programs, etc., and the modem processor mainly processes wireless communications. It can be understood that the above-mentioned modem processor may not be integrated into the processor 401. In some embodiments, the processor 401 and the memory 402 may be implemented on the same chip, and in some embodiments, they may also be separately implemented on independent chips.

[0140] The processor 401 may be a general-purpose processor, such as a central processing unit (CPU), a digital signal processor, an application-specific integrated circuit, a field-programmable gate array, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method for accessing a low-earth orbit satellite disclosed in combination with the embodiments of the present application may be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0141] As a non-volatile computer-readable storage medium, the memory 402 can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The memory 402 may include at least one type of storage medium. For example, it may include flash memory, a hard disk, a multimedia card, a card-type memory, a random access memory (RAM), a static random access memory (SRAM), a programmable read-only memory (PROM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic memory, a magnetic disk, an optical disk, etc. The memory 402 is any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 402 in the embodiments of the present application may also be a circuit or any other device capable of implementing a storage function, for storing program instructions and / or data.

[0142] By programming the design of the processor 401, the code corresponding to the method for accessing a low-earth orbit satellite introduced in the foregoing embodiments can be solidified into the chip, so that the chip can execute when running Figure 1Steps of the method for accessing a low-earth orbit satellite. How to design and program the processor 401 is a well-known technology to those skilled in the art and will not be elaborated here.

[0143] Those skilled in the art can clearly understand that, for the convenience and conciseness of description, only the above division of each functional module is used as an example. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here.

[0144] In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0145] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0146] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0147] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage medium includes: various media that can store program codes, such as Universal Serial Bus flash disks, mobile hard disks, Read-Only Memory (ROM), Random Access Memory (RAM), magnetic disks, or optical discs.

[0148] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these changes and modifications.

Claims

1. A method for accessing a low-earth orbit satellite, characterized in that, it includes: Determine fitting information; wherein, the fitting information includes the correspondence between the position information of the low-earth orbit satellite and time, and the correspondence between the rate information and time; Based on the fitting information, determine access parameters, and initiate uplink random access to the low-earth orbit satellite based on the access parameters; wherein, the access parameters include Doppler frequency offset and time delay.

2. The method according to claim 1, characterized in that, the initiating uplink random access to the low-earth orbit satellite based on the access parameters includes: Based on the access parameters, determine the target time for initiating uplink random access; At the target time, initiate uplink random access to the low-earth orbit satellite.

3. The method according to claim 1 or 2, characterized in that, the determining the fitting information includes: Obtain ephemeris information; wherein, the ephemeris information includes at least one of the ephemeris information of the current time slot, historical ephemeris information, and pre-stored ephemeris information; Based on the ephemeris information, determine the fitting information.

4. The method according to claim 3, characterized in that, the determining access parameters based on the fitting information and initiating uplink random access to the low-earth orbit satellite based on the access parameters includes: In response to the ephemeris information being composed of the pre-stored ephemeris information, determine the access parameters; Based on the access parameters and the restricted set A / B random access mode, initiate uplink random access to the low-earth orbit satellite.

5. The method according to claim 4, characterized in that, the initiating uplink random access to the low-earth orbit satellite based on the access parameters and the restricted set A / B random access mode includes: Perform integer multiple compensation on the Doppler frequency offset and time delay in the access parameters respectively to obtain the compensated access parameters; Based on the compensated access parameters and the restricted set A / B random access mode, initiate uplink random access to the low-earth orbit satellite.

6. The method according to any one of claims 1-2, 4-5, characterized in that, the access parameters include the communication elevation angle at each moment; then the initiating uplink random access to the low-earth orbit satellite based on the access parameters includes: In response to the communication elevation angle being greater than or equal to the minimum communication elevation angle, initiate uplink random access to the low-earth orbit satellite based on the access parameters.

7. The method according to claim 6, characterized in that, the initiating uplink random access to the low-earth orbit satellite based on the access parameters includes: Determine the maximum communication elevation angle within a period; Based on the maximum communication elevation angle within the period, determine the target elevation angle; In response to the communication elevation angle being greater than or equal to the target elevation angle, initiate uplink random access to the low-earth orbit satellite based on the access parameters.

8. The method according to any one of claims 1-2, 4-5, 7, characterized in that, the access parameters include the rate of change of frequency offset; then the initiating uplink random access to the low-earth orbit satellite based on the access parameters includes: In response to the rate of change of frequency offset being greater than or equal to a preset target threshold, initiate uplink random access to the low-earth orbit satellite based on the rate of change of frequency offset, the Doppler frequency offset, and the time delay in the access parameters.

9. An apparatus for accessing a low-earth orbit satellite, It is characterized in that it includes: a fitting unit for determining fitting information; wherein, the fitting information includes the correspondence between the position information of the low-earth orbit satellite and time, and the correspondence between the rate information and time; a parameter unit for determining access parameters based on the fitting information and initiating uplink random access to the low-earth orbit satellite based on the access parameters; wherein, the access parameters include Doppler frequency offset and time delay.

10. A readable storage medium It is characterized in that it includes a memory The memory is used to store a computer program, and when the computer program is executed by a processor, the device including the readable storage medium completes the method described in any one of claims 1 to 8.

11. An electronic device It is characterized in that it includes: a memory for storing a computer program; a processor for implementing the method described in any one of claims 1 to 8 when executing the computer program stored on the memory.

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