A random access method with fixed partition beam steering and spot beam on-demand scheduling

Abstract

The present invention discloses an on-demand access method for fixed partition beam guidance and spot beam on-demand scheduling. The method comprises: processing the fixed partition beam to achieve full coverage of the satellite field of view; analyzing the system resource planning situation to obtain resource planning information, and allocating an uplink carrier for a signaling channel based on the resource planning information; allocating a ZC root sequence to each beam and accessing the signaling channel; processing the ZC root sequence by a cyclic shift method to obtain a first extended parallel access user access sequence; processing the ZC root sequence by a ZC root sequence extension model to obtain a second extended parallel access user access sequence; integrating the first extended parallel access user access sequence and the second extended parallel access user access sequence to obtain an extended parallel access user access sequence; processing the extended parallel access user access sequence to obtain user access information; and processing the user access information to obtain a multi-spot beam scheduling method.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to an on-demand access method for fixed partition beam guidance and spot beam on-demand scheduling. Background Art

[0002] Currently, mobile phone direct satellite connectivity has become a research and development priority within academia and industry both domestically and internationally. Future mobile phone direct satellite connectivity will feature mobile phones equipped with miniaturized built-in satellite antennas, supporting broadband data and communications services. Providing mobile phone direct satellite broadband services requires the deployment of ultra-large-aperture multi-beam array antennas on satellites. This results in extremely narrow single beamwidths and a large number of beams required within the satellite's field of view. To enable on-demand access for mobile phone users with direct satellite connectivity distributed over a large area within the satellite's field of view, research is needed on high-density, ultra-narrow beam agile control and on-demand scheduling methods. Currently, there are two main technical solutions for on-demand access in satellite mobile communication systems: one is to configure an access signaling channel in each spot beam. However, due to the large number of spot beams required within the field of view of a low-orbit satellite and the uneven distribution of services, resource utilization is extremely low and the implementation cost is high. The other is to configure a dedicated spot beam to carry the access signaling channel, using a polling scanning method to achieve full coverage of the satellite's field of view. While this is a low-cost solution, user access latency is significant due to the polling cycle.

[0003] A study has proposed a satellite-to-ground random access method and system, which can be used for terminals to access satellites at any time. However, the access channel is composed of fixed beams with low gain and full airspace coverage, which is difficult to meet the needs of large-scale group users to connect directly to satellites concurrently; the research on a space-based random access method and device for intelligent spacecraft is mainly aimed at scheduling geostationary orbit satellite resources and is applied to ground control centers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the problem of random access of directly connected satellite mobile phones distributed over a large area under the satellite field of view. Based on the flexible and agile characteristics of phased array beams on demand, combined with the random access link capability, system broadcast message capacity, random access latency requirements, etc., and considering the full-time coverage advantage of fixed-area beams, a random access method with fixed partitioned beam guidance and on-demand scheduling of point beams is proposed.

[0005] To solve the above technical problems, an embodiment of the present invention discloses an on-demand access method for fixed-segment beam steering and spot beam on-demand scheduling, the method comprising:

[0006] S1, processes fixed partitioned beams to achieve full coverage of the satellite field of view;

[0007] S2: Connect each fixed partition beam to the signaling channel and allocate one ZC root sequence to each fixed partition beam;

[0008] S3, processing the ZC root sequence to obtain an extended parallel access user access sequence;

[0009] S4, using the extended parallel access user access sequence to identify and distinguish different users and obtain user access information;

[0010] The user access information includes location information in the user access application, priority information in the user access application, statistical information on uneven service distribution in different zones, and real-time traffic distribution information of high-density and extremely narrow spot beams;

[0011] S5: Process the user access information to obtain a multi-spot beam scheduling method.

[0012] As an optional implementation manner, in an embodiment of the present invention, accessing each fixed partitioned beam to a signaling channel includes:

[0013] S21, analyzing the system resource planning situation to obtain resource planning information;

[0014] S22, allocating an uplink carrier for a signaling channel according to the resource planning information;

[0015] S23: Connect each fixed partition beam to a signaling channel according to the uplink carrier.

[0016] As an optional implementation manner, in an embodiment of the present invention, processing the ZC root sequence to obtain an extended parallel access user access sequence includes:

[0017] S31, processing the ZC root sequence using a cyclic shift method to obtain a first extended parallel access user access sequence;

[0018] S32, using a ZC root sequence extension model, processing the ZC root sequence to obtain a second extended parallel access user access sequence;

[0019] S33: Integrate the first extended parallel access user access sequence and the second extended parallel access user access sequence to obtain an extended parallel access user access sequence.

[0020] As an optional implementation manner, in an embodiment of the present invention, the processing of the ZC root sequence using a cyclic shift method to obtain a first extended parallel access user access sequence includes:

[0021] S311, processing the extremely narrow spot beam corresponding to the ZC root sequence to obtain a maximum round-trip delay difference of the fixed partitioned beam;

[0022] S312: Process the maximum round-trip delay difference to obtain the cyclic shift value C of the fixed partition beam. v ;

[0023] S313, the cyclic shift value C v Processing is performed to obtain a first extended parallel access user access sequence.

[0024] As an optional implementation manner, in an embodiment of the present invention, the ZC root sequence is processed using a ZC root sequence extension model to obtain a second extended parallel access user access sequence, including:

[0025] S321, divide the time into K time slots, where K is a positive integer;

[0026] S322: In each time slot, use a ZC root sequence extension model to process the ZC root sequence to obtain a second extended parallel access user access sequence.

[0027] As an optional implementation manner, in an embodiment of the present invention, the processing of the ZC root sequence using a ZC root sequence extension model in each time slot to obtain a second extended parallel access user access sequence includes:

[0028] S3221, in each time slot, performing ZC root sequence extension using a non-orthogonal multiple access method to obtain an extended ZC root sequence;

[0029] S3222: Process the extended ZC root sequence using a non-orthogonal interference cancellation method to obtain a second extended parallel access user access sequence.

[0030] As an optional implementation manner, in an embodiment of the present invention, the method of processing the extended ZC root sequence using a non-orthogonal interference cancellation method to obtain a second extended parallel access user access sequence includes:

[0031] S32221, performing time domain correlation on the extended ZC root sequence and the local root sequence to obtain relevant information;

[0032] S32222, performing power calculation on the relevant information to obtain a power delay spectrum;

[0033] S32223, processing the power delay spectrum to obtain a detection threshold;

[0034] S32224: Detect, based on the detection threshold, a user that exceeds the detection threshold and has the highest power, and reconstruct the time domain sequence of the detected user to obtain a second extended parallel access user access sequence.

[0035] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0036] This invention implements an on-demand access method that combines fixed-segment beam steering with spot beam on-demand scheduling. Fixed-segment beams are combined to achieve full coverage of the satellite's field of view. Each fixed-segment beam is then configured with an access signaling channel. Each beam is assigned a ZC root sequence, and different users use different cyclic shifts to generate access sequences. Non-orthogonal multiple access and non-orthogonal interference cancellation techniques are then used to expand the number of ZC root sequences, further increasing the number of users with concurrent access per time slot. S-ALOHA is also used to reduce the probability of multi-user collisions. Finally, an intelligent planning algorithm is used to rapidly generate a multi-spot beam scheduling strategy. This invention can meet the on-demand access needs of a large number of users directly connected to satellites via mobile phones, while minimizing user access latency and engineering costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 This is a flow chart of a random access method for fixed partition beam steering and spot beam on-demand scheduling disclosed in an embodiment of the present invention;

[0039] Figure 2 This is a flow chart of another random access method with fixed partition beam steering and spot beam on-demand scheduling disclosed in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of random access combining fixed partition beams and spot beams disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] The terms "first," "second," and so on, in the description and claims of the present invention and the accompanying drawings are used to distinguish between different objects, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product, or device comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or device.

[0043] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0044] The present invention discloses a random access method that combines fixed-segment beam steering and spot beam on-demand scheduling. The method comprises: processing fixed-segment beams to achieve full coverage of the satellite's field of view; connecting the fixed-segment beams to a signaling channel and assigning a ZC root sequence to each fixed-segment beam; processing the ZC root sequence to obtain an extended parallel access user access sequence; processing the extended parallel access user access sequence to identify and distinguish different users and obtain user access information; the user access information includes location information in user access requests, priority information in user access requests, statistical information on uneven partitioned services, and real-time traffic distribution information for high-density, ultra-narrow spot beams; and processing the user access information to obtain a multi-spot beam scheduling method. The present invention can meet the random access needs of a large number of users directly connected to satellites via mobile phones, with minimal user access latency and low engineering cost. Each of these is described in detail below.

[0045] Example 1

[0046] See also Figure 1 , Figure 1 This is a flow chart of a random access method for fixed partition beam steering and spot beam on-demand scheduling disclosed in an embodiment of the present invention. Figure 1 The described random access method of fixed partition beam steering and spot beam on-demand scheduling is applied in the field of satellite communication technology to realize the random access needs of a large number of mobile phone direct satellite users, which is not limited in the embodiment of the present invention. Figure 1 As shown, the random access method for fixed partition beam steering and spot beam on-demand scheduling may include the following operations:

[0047] S1, processes fixed partitioned beams to achieve full coverage of the satellite field of view;

[0048] Full coverage of the satellite field of view refers to coverage of all users within the satellite field of view;

[0049] S2: Analyze the system resource planning situation, obtain resource planning information, and use it to allocate uplink carriers for signaling channels;

[0050] S3: traverse all fixed partitioned beams according to the uplink carrier, assign a ZC root sequence to each beam, and access the signaling channel;

[0051] The ZC root sequence is a random orthogonal sequence.

[0052] S4, processing the ZC root sequence using a cyclic shift method to obtain a first extended parallel access user access sequence, including:

[0053] S41, processing the extremely narrow spot beam corresponding to the ZC root sequence to obtain a maximum round-trip delay difference of the fixed partitioned beam;

[0054] S42: Process the maximum round-trip delay difference to obtain the cyclic shift value C of the fixed partition beam. v ;

[0055] S43, the cyclic shift value C v Processing is performed to obtain a first extended parallel access user access sequence;

[0056] S5, using a ZC root sequence extension model, processing the ZC root sequence to obtain a second extended parallel access user access sequence, including:

[0057] S51, divide the time into K time slots, where K is a positive integer;

[0058] S52, in each time slot, using the ZC root sequence to extend the model and obtain an extended ZC root sequence;

[0059] S53, performing time domain correlation on the extended ZC root sequence and the local sequence to obtain relevant information;

[0060] S54, performing power calculation on the relevant information to obtain a power delay spectrum;

[0061] S55, processing the power delay spectrum to obtain a detection threshold;

[0062] S56, detecting, based on the detection threshold, a user that exceeds the detection threshold and has the highest power, and reconstructing the time domain sequence of the detected user to obtain a second extended parallel access user access sequence;

[0063] S6, integrating the first extended parallel access user access sequence and the second extended parallel access user access sequence to obtain an extended parallel access user access sequence;

[0064] S7, processing the extended parallel access user access sequence to obtain user access information; the user access information includes location information in the user access application, priority information in the user access application, zoned service unevenness statistics, and high-density ultra-narrow spot beam real-time traffic distribution information;

[0065] S8. Process the user access information to obtain a multi-spot beam scheduling method.

[0066] As can be seen, the present invention implements an on-demand access method that combines fixed-segment beam steering with on-demand spot beam scheduling. Fixed-segment beams are combined to achieve full coverage of the satellite's field of view. Each fixed-segment beam is then configured with an access signaling channel. Each beam is assigned a ZC root sequence, and different users use different cyclic shifts to generate access sequences. Non-orthogonal multiple access and non-orthogonal interference cancellation techniques are then used to expand the number of ZC root sequences, further increasing the number of users with concurrent access per time slot. The S-ALOHA method is also used to reduce the probability of multi-user collisions. Finally, a multi-spot beam scheduling strategy is rapidly generated using an intelligent planning algorithm. This invention can meet the on-demand access needs of a large number of users directly connected to satellites via mobile phones, while minimizing user access latency and engineering costs.

[0067] Example 2

[0068] See also Figure 2 , Figure 2 This is a flow chart of another random access method for fixed partition beam steering and spot beam on-demand scheduling disclosed in an embodiment of the present invention. Figure 2 The described random access method of fixed partition beam steering and spot beam on-demand scheduling is applied in the field of satellite communication technology to realize the random access needs of a large number of mobile phone direct satellite users, which is not limited in the embodiment of the present invention. Figure 2 As shown, the random access method for fixed partition beam steering and spot beam on-demand scheduling may include the following operations:

[0069] Step S1: Fixed partition beams are combined to achieve full coverage of the satellite field of view, such as Figure 3 As shown;

[0070] Step S2: Each fixed partitioned beam is configured with an access signaling channel, and each beam is assigned one Zadoff–Chu (ZC) root sequence.

[0071] Step S3: Different users use different cyclic shifts to generate access sequences;

[0072] Step S4: The user divides the time into different time slots using the S-ALOHA method. Different users use different cyclic shifts to generate access sequences, reducing the probability of multi-user collisions.

[0073] Step S5: The user uses non-orthogonal multiple access technology and non-orthogonal interference cancellation technology to expand the number of ZC root sequences, further increasing the number of users accessing the system in parallel in a single time slot.

[0074] Step S6: Use an intelligent planning algorithm to quickly generate a multi-point beam scheduling strategy.

[0075] Optionally, beam coverage is achieved by combining fixed partitioned beams and spot beams. The fixed partitioned beams are combined to achieve full coverage of the satellite field of view, and the spot beams are scheduled on demand.

[0076] Optionally, an access signaling channel is configured in each fixed partitioned beam. In the frequency domain, according to system resource planning, M uplink carriers are configured for the access signaling channel; each fixed partitioned beam is allocated 1 ZC root sequence.

[0077] Optionally, different users use different cyclic shifts to generate access sequences, and a cyclic shift value C that is not less than the maximum round-trip delay difference of the beam is selected. v , the access sequence used by different users is n*C of the root sequence v Cyclic shift. n is the index of the cyclic shift used by the user in the root sequence.

[0078] Calculation of the maximum round-trip delay difference of the beam: The closest and farthest distances to the satellite within the beam are Lmin and Lmax respectively, then the maximum round-trip delay difference of the satellite = (Lmax-Lmin) / c*2, where c is the speed of light.

[0079] Optional interference cancellation techniques include:

[0080] Step S51: When detecting an access sequence, the access sequence is correlated with the local root sequence in the time domain, the power of the correlation result is calculated to obtain a power delay spectrum, and the detection threshold is calculated using the power delay spectrum;

[0081] Step S52, when calculating the noise power required for the detection threshold, the noise estimation value is obtained by removing N maximum values from the power delay profile and then calculating the average power, where N is the number of cyclic shifts supported by the root sequence;

[0082] In step S52, peak detection is performed by processing the signals in order of power to obtain information such as the user ID and timing advance. First, the user with the highest power exceeding the detection threshold is detected. The time domain sequence of the detected user is reconstructed. After subtracting the reconstructed signal from the received time domain signal, other users are detected again to offset the effects of cross-correlation between different root sequences.

[0083] Optionally, based on the location, priority and other attributes in the user access application, as well as the uneven statistical characteristics of the partitioned services and the real-time traffic distribution of high-density ultra-narrow beams, an intelligent planning algorithm is used to quickly generate a multi-beam scheduling strategy to achieve on-demand scheduling of ultra-narrow beams that support user access at will. The method is as follows: Figure 3 Location and priority are reported by users, and the satellite side records the uneven statistical characteristics of partitioned services and the real-time traffic distribution of high-density, extremely narrow spot beams. Figure 3 It represents the entire framework of fixed partition beam coverage and spot beam on-demand scheduling.

[0084] The device embodiments described above are merely illustrative. Modules described as separate components may or may not be physically separate, and components shown as modules may or may not be physical modules, i.e., they may be located in one place or distributed across multiple network modules. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0085] Through the detailed description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus the necessary general hardware platform, or of course, by means of hardware. Based on this understanding, the above technical solution, in essence, or the portion that contributes to the prior art, can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, including a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0086] Finally, it should be noted that the random access method with fixed partitioned beam guidance and spot beam on-demand scheduling disclosed in the embodiment of the present invention is only a preferred embodiment of the present invention, and is only used to illustrate the technical solution of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A random access method with fixed partition beam steering and spot beam on-demand scheduling, characterized in that: The method comprises: S1, processes fixed partitioned beams to achieve full coverage of the satellite field of view; S2: Analyze the system resource planning situation, obtain resource planning information, and use it to allocate uplink carriers for signaling channels; S3: traverse all fixed partitioned beams according to the uplink carrier, assign a ZC root sequence to each beam, and access the signaling channel; S4, processing the ZC root sequence using a cyclic shift method to obtain a first extended parallel access user access sequence, including: S41, processing the extremely narrow spot beam corresponding to the ZC root sequence to obtain a maximum round-trip delay difference of the fixed partitioned beam; The maximum round-trip delay difference is calculated as follows: Maximum round-trip satellite delay difference = (Lmax-Lmin) / c*2 Wherein, the closest and farthest distances to the satellite within the beam are Lmin and Lmax respectively, and c is the speed of light; S42: Process the maximum round-trip delay difference to obtain the cyclic shift value C of the fixed partition beam. v ; S43, the cyclic shift value C v Processing is performed to obtain a first extended parallel access user access sequence; Different users use different cyclic shifts to generate access sequences, and the cyclic shift value C is selected to be no less than the maximum round-trip delay difference of the beam. v , the access sequence used by different users is n*C of the root sequence v Cyclic shift, n is the index of the cyclic shift used by the user in the root sequence; S5, using a ZC root sequence extension model, processing the ZC root sequence to obtain a second extended parallel access user access sequence, including: S51, divide the time into K time slots, where K is a positive integer; S52, in each time slot, using the ZC root sequence to extend the model and obtain an extended ZC root sequence; S53, when detecting the access sequence, performing time domain correlation on the access sequence and the local root sequence, calculating the power of the correlation result to obtain a power delay spectrum, and using the power delay spectrum to calculate the detection threshold; S54, when calculating the noise power required for the detection threshold, obtain a noise estimate by removing N maximum values from the power delay profile and then calculating the average power, where N is the number of cyclic shifts supported by the root sequence; S55, during peak detection, the signal power is processed in order to obtain the user ID and timing advance information of the access user; S56, detecting the user with the highest power that exceeds the detection threshold, reconstructing the time domain sequence of the detected user, subtracting the reconstructed signal from the received time domain signal, and re-detecting other users to offset the influence of the cross-correlation of different root sequences, thereby obtaining a second extended parallel access user access sequence; S6, integrating the first extended parallel access user access sequence and the second extended parallel access user access sequence to obtain an extended parallel access user access sequence; S7, processing the extended parallel access user access sequence to obtain user access information; the user access information includes location information in the user access application, priority information in the user access application, zoned service unevenness statistics, and high-density ultra-narrow spot beam real-time traffic distribution information; S8, using an intelligent planning algorithm to process the user access information, quickly generate a multi-point beam scheduling strategy, and implement on-demand scheduling of extremely narrow beams that supports random user access.

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