User position acquisition and synchronization method based on Beidou

Abstract

The invention discloses a Beidou-based user position acquisition and synchronization method. The method comprises the following steps: acquiring a range in which user mobile equipment is located in a mode of combining Doppler measurement and a beam coverage area; acquiring information of all base stations in the range, judging the distance between the user mobile equipment and each base station, and selecting a near-point base station closest to the user mobile equipment to acquire auxiliary information; further correcting the position of the user mobile equipment through the SPT packet message and the auxiliary information of the near-point base station to obtain an accurate position; according to the accurate position, emitting two beams of mutually conjugated sequences with the same length, and estimating integer frequency offset and timing offset at the same time, thereby realizing tracking of the user mobile device and recording the user position in real time; through cooperation of the Beidou and the base station, the rough position and the accurate position of the user can be rapidly obtained, tracking is carried out in real time, integer frequency offset and timing deviation can be estimated at the same time, and the position of the user is optimized and synchronized.

Description

Technical Field

[0001] The present invention relates to the field of Beidou communication technology, and in particular to a Beidou-based user position acquisition and synchronization method. Background Art

[0002] With the needs of social development, the Beidou industry has developed rapidly and has been popularized in all aspects of people's daily life, providing users with continuous, stable and reliable services. At present, my country's independently developed Beidou communication technology has realized functions such as positioning and communication. It can obtain positioning information in real time according to the signals sent by users and communicate with them; but once the customer signal is unstable, the user's location cannot be obtained accurately and quickly, affecting the user's real-time location tracking and emergency rescue. Therefore, we propose a user location acquisition and synchronization method based on Beidou. Summary of the invention

[0003] In view of the defects in the prior art, the present invention provides a user position acquisition and synchronization method based on Beidou.

[0004] On the one hand, the present invention provides a Beidou-based user location acquisition and synchronization method, the method comprising the following steps:

[0005] S1: Obtain the range of the user's mobile device by combining Doppler measurement and beam coverage area;

[0006] S2: Obtain information of all base stations within the range, determine the distance between the user's mobile device and each base station, and select the nearest base station to the user's mobile device to obtain auxiliary information;

[0007] S3: The user's mobile device position is further corrected through the SPT packet message and the auxiliary information of the nearby base station to obtain the precise position;

[0008] S4: Using the precise position, two sequences of equal length and conjugated to each other are emitted, and integer frequency deviation and timing deviation are estimated at the same time, so as to track the user's mobile device and record the user's position in real time.

[0009] Optionally, observability of the position in the direction of BeiDou line of sight changes is optimized by Doppler measurements.

[0010] Optionally, when the range of the user's mobile device is obtained by combining Doppler measurement and beam coverage area, the range of the user's mobile device may be further optimized by pseudorange measurement.

[0011] Optionally, the auxiliary information of the near-point base station includes: base station information, movement trajectory, longitude and latitude information, user location identification, and user signal information.

[0012] Optionally, the SPT packet message adopts a signal design that integrates navigation and communication, broadcasts a high-gain signal through a Beidou communication channel, and obtains the location of the user's mobile device.

[0013] The beneficial effects of the present invention are as follows: the present invention can quickly obtain the user's rough location and precise location through the cooperation of Beidou and base stations, and track them in real time, and can simultaneously estimate the integer frequency deviation and timing deviation, and optimize and synchronize the user's location. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0015] Figure 1 It is a flowchart of a Beidou-based user location acquisition and synchronization method of the present invention; DETAILED DESCRIPTION

[0016] In order to make the technical personnel in the technical field better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in combination with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, device, product or end including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units inherent to these processes, methods, products or ends.

[0018] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0019] At present, my country's independently developed Beidou communication technology has realized functions such as positioning and communication. It can obtain positioning information in real time and communicate with the user based on the signal sent by the user; but once the customer signal is unstable, the user's location cannot be obtained accurately and quickly, affecting the user's real-time location tracking and emergency rescue. Therefore, we propose a user location acquisition and synchronization method based on Beidou.

[0020] A specific embodiment of the present invention provides a Beidou-based user location acquisition and synchronization method, the method is as follows Figure 1 As shown, the following steps are included:

[0021] In step S1, the range where the user's mobile device is located is obtained by combining Doppler measurement and beam coverage area.

[0022] In this embodiment, the observability of the position in the direction of Beidou line of sight change is optimized by Doppler measurement; when the range of the user's mobile device is obtained by combining Doppler measurement and beam coverage area, the range of the user's mobile device can be further optimized by pseudorange measurement.

[0023] In step S2, information of all base stations within the range is obtained, the distance between the user's mobile device and each base station is determined, and the nearest base station to the user's mobile device is selected to obtain auxiliary information.

[0024] In this embodiment, the auxiliary information of the near-point base station includes: base station information, movement trajectory, longitude and latitude information, user location identification, and user signal information.

[0025] In step S3, the position of the user's mobile device is further corrected through the SPT packet message and the auxiliary information of the nearby base station to obtain an accurate position.

[0026] In an embodiment of the present invention, the SPT packet message adopts a signal design that integrates navigation and communication, broadcasts a high-gain signal through a Beidou communication channel, and obtains the location of the user's mobile device.

[0027] In terms of the SPT positioning principle, Doppler positioning uses the Doppler observations of different epochs before and after Beidou for solution. The receiver roughly confirms the position, and cannot converge when the error is greater than 80km. The positioning accuracy is improved by observing epochs more often. The SPT terminal is implemented using diffuse Kalman filtering. The measurement update consists of Doppler measurement and distance measurement. Doppler measurement is used for the observability of the position in the direction of Beidou's line of sight change, and distance measurement is used for the observability of the position of Beidou's line of sight. For dynamic users, additional states are used to simulate the user speed, assisted by the inertial measurement unit. The equation is in the form of a constant speed equation:

[0028]

[0029] where ρ k is the pseudorange rate, It is the speed of Beidou. is the receiver speed, l k The unit vector from the station to BeiDou, δt is the offset rate of the receiver clock, ε k is the combined error during the Beidou clock measurement interval, and the quantity to be estimated is [r b , δt].

[0030] In actual calculation, the station velocity is considered to be zero, then:

[0031]

[0032] In the positioning solution, the partial derivative matrix of the estimated parameters in the positioning equation is:

[0033]

[0034]

[0035] [r b ,δt]=(G T G) -1 G T b

[0036] Given the initial condition r b , δt; and calculate the observation matrix G, the observation residual b, and use the least squares method to find the position correction Δr b , and the receiver clock offset correction Δt; using the correction Δr b , Δt correction r b and δt, and then repeatedly calculate the matrix G, the observation residual b, and the position correction Δr b If the correction value meets the requirement of certain accuracy or the number of iterations reaches the upper limit of iteration, the station coordinates r are output. b and the receiver clock offset correction δt.

[0037] In step S4, two sequences of equal length and conjugated to each other are emitted through the precise position, and integer frequency deviation and timing deviation are estimated at the same time, so as to track the user's mobile device and record the user's position in real time.

[0038] In an embodiment of the present invention, two combined carrier tracking methods are adopted to track the phase of the Beidou communication system through a loop filter; wherein the combined carrier tracking method includes a loop filter, a phase detector, a voltage-controlled oscillator NCO, a state controller, and a frequency detector and phase detector.

[0039] The present invention designs a user position acquisition and synchronization method based on Beidou. Through the cooperation of Beidou and base stations, the rough position and precise position of the user can be quickly acquired and tracked in real time. The integer frequency deviation and timing deviation can be estimated simultaneously, and the position of the user can be optimized and synchronized.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions 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 they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A Beidou-based user location acquisition and synchronization method, characterized in that: The method comprises the following steps: S1: Obtain the range of the user's mobile device by combining Doppler measurement and beam coverage area; S2: Obtain information of all base stations within the range, determine the distance between the user's mobile device and each base station, and select the nearest base station to the user's mobile device to obtain auxiliary information; S3: The user's mobile device position is further corrected through the SPT packet message and the auxiliary information of the nearby base station to obtain the precise position; S4: Using the precise position, two sequences of equal length and conjugated to each other are emitted, and integer frequency deviation and timing deviation are estimated at the same time, so as to track the user's mobile device and record the user's position in real time.

2. The method according to claim 1, characterized in that The observability of the position in the direction of BeiDou line of sight changes is optimized through Doppler measurements.

3. The Beidou-based user location acquisition and synchronization method according to claim 1, characterized in that: When the range of the user's mobile device is obtained by combining Doppler measurement and beam coverage area, the range of the user's mobile device can be further optimized by pseudo-range measurement.

4. The Beidou-based user location acquisition and synchronization method according to claim 1, characterized in that: The auxiliary information of the near-point base station includes: base station information, movement trajectory, longitude and latitude information, user location identification, and user signal information.

5. The Beidou-based user location acquisition and synchronization method according to claim 1, characterized in that: The SPT packet message adopts a signal design that integrates navigation and communication, broadcasts high-gain signals through the Beidou communication channel, and obtains the location of the user's mobile device.

6. The Beidou-based user location acquisition and synchronization method according to claim 1, characterized in that: Two combined carrier tracking methods are adopted to track the phase of the Beidou communication system through a loop filter; wherein the combined carrier tracking method includes a loop filter, a phase detector, a voltage-controlled oscillator NCO, a state controller, and a frequency detector and phase detector.

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