阅读说明：本技术 一种再生式卫星信号转发器 (Regenerative satellite signal transponder ) 是由 饶勇 孟冲 张一� 强亚辉 张宇轩 史亚敬 于 2020-05-29 设计创作，主要内容包括：本发明公开了一种再生式卫星信号转发器,其采用全数字动态模拟技术对卫星导航信号进行了动态修正处理,使得本发明的卫星信号转发器在转发的卫星信号中包含的用户位置可变,实现了可控制的动态模拟的功能。(The invention discloses a regenerative satellite signal transponder, which adopts a full-digital dynamic simulation technology to dynamically modify satellite navigation signals, so that the user position contained in the retransmitted satellite signals by the satellite signal transponder of the invention is variable, and the controllable dynamic simulation function is realized.)

1. A regenerative satellite signal repeater, comprising: the satellite signal conversion device comprises a radio frequency channel module and a baseband board card, wherein the output end of the radio frequency channel module is connected with the input end of the baseband board card, and the radio frequency channel module is used for converting a received target satellite signal into a simulated intermediate frequency signal of a target satellite;

the baseband board card comprises an analog-digital conversion module, a clock module, a digital-analog conversion module, a baseband signal processing module, a navigation resolving module and a dynamic simulation module;

the input end of the analog-to-digital conversion module is connected with the output end of the radio frequency channel module and is used for converting the analog intermediate frequency signal of the target satellite into a digital intermediate frequency signal of the target satellite;

the baseband signal processing module comprises a capturing module and a tracking module;

the input end of the acquisition module is connected with the output end of the analog-to-digital conversion module and is used for judging whether a target satellite exists according to the digital intermediate frequency signal of the target satellite, and if the target satellite exists, tracking the carrier frequency of the target satellite, the carrier phase of the target satellite and the code phase of the target satellite through the tracking module to obtain the observation quantity value of the target satellite; the baseband signal processing module is also used for receiving the carrier frequency and code phase correction value output by the dynamic simulation module, and delaying and compensating the target satellite code phase and the target satellite carrier phase; after the code phase and the carrier phase after dynamic processing are subjected to intermediate frequency modulation and combination, digital intermediate frequency signals of each satellite are obtained; transmitting the digital intermediate frequency signals of each satellite to a digital-to-analog conversion module, and outputting the analog intermediate frequency signals of each satellite to a radio frequency channel module;

the input end of the navigation resolving module is connected with the output end of the tracking module and is used for reading navigation messages sent by a target satellite and original observed quantities such as carrier frequency, carrier phase, code phase and the like and resolving the navigation messages into the position, the speed and the time of the target satellite; the position and the speed of the antenna of the user receiver are calculated, and the position, the speed and the time information of the antenna are transmitted to the dynamic simulation module;

the input end of the dynamic simulation module is connected with the output end of the navigation resolving module and used for obtaining the expected position and motion trail of the receiver according to the observation quantity value of the resolved target satellite by combining the position and speed of the antenna of the receiver of the current user, the position and speed of the currently received target satellite and the dynamic control quantity preset by the user, further obtaining the carrier frequency and code phase correction value of the target satellite signal at each moment and transmitting the correction value to the baseband signal processing module for correcting the target satellite signal and modulating the medium frequency.

2. The regenerative satellite signal repeater according to claim 1, wherein the acquisition module searches the received signals for the presence of the signal of the target satellite through a short-time matched filter-FFT algorithm;

the capture module comprises: the device comprises a digital down-conversion module, a pseudo-random code generator, a matched filter, an FFT (fast Fourier transform) and a Tong detector;

the digital down-conversion module is used for multiplying the digital intermediate frequency signal of the target satellite obtained by the analog-to-digital conversion module by a local carrier to obtain a complex baseband signal;

the pseudo-random code generator is used for generating a pseudo-random code corresponding to a target satellite to be captured according to a satellite number set by preset control software;

the matched filter is used for carrying out correlation operation through a complex baseband signal and a pseudo-random code to obtain grouped short-time correlation values;

the FFT is used for carrying out spectrum analysis on the short-time correlation value to obtain a long integral value in the coherence time;

the Tong detector is used for traversing all long integral values output by the FFT, and if the integral values are larger than a preset threshold and reach a specified number of times, the existence of a target satellite is judged; otherwise, the target satellite is judged to be not present.

3. The regenerative satellite signal repeater according to claim 1, wherein resolving the position, velocity and time of the target satellite from the navigation message and the original observations of the target satellite comprises:

performing parity check on the original telegraph text, and analyzing the error-free telegraph text to obtain an ephemeris of each satellite;

and resolving ephemeris reference time from the satellite ephemeris, and resolving the detailed orbit parameters of each satellite and the satellite position, speed and time of a signal generation time point according to the specification of each satellite navigation system user interface protocol by taking the time as a reference.

4. The regenerative satellite signal repeater according to claim 1, wherein the obtaining of the target position motion trajectory according to the calculation of the observed magnitude of the target satellite in combination with the current position and velocity of the receiver antenna, the current position and velocity of the satellite, and the dynamic control amount preset by the user comprises:

obtaining a dynamic compensation speed value within a period of time by using the speed of a certain moment point in the dynamic control quantity preset by a user and the integral of the acceleration at the moment to the time;

obtaining a target position in a period of time, namely a track of the moving target position, by using the position of the receiver antenna obtained by resolving and adding the integral of the velocity value of the dynamic compensation to the time;

calculating the true pseudo range of each satellite according to the true satellite position and the position of the receiver antenna, calculating the expected pseudo range of each satellite according to the true satellite position and the moving target position, and obtaining the difference between the expected pseudo range and the true pseudo range, namely the code phase correction value of dynamic compensation;

the Doppler frequency value of the generated Doppler effect can be calculated by the speed value of each dynamic compensation in combination with the carrier frequency and the satellite elevation angle, namely the carrier frequency correction value of the dynamic compensation;

the code phase compensation adopts a time delay method based on DDS, and realizes the time delay of the pseudo code by controlling the control word phase of a pseudo random code generator for driving the DDS;

the carrier frequency compensation is directly added with a carrier frequency correction value on a frequency control word of a local carrier DDS to realize frequency correction.

Technical Field

The invention relates to the field of satellite navigation positioning, in particular to a regenerative satellite signal transponder.

Background

The Beidou/GNSS satellite navigation application is increasingly popularized, the demand is continuously increased, and a satellite navigation product manufacturer inevitably needs to use a test instrument in the aspects of design, production, maintenance and the like. The current special instruments for testing health products are mainly divided into two types: navigation signal source, satellite signal transponder.

The navigation signal source establishes a complete model according to a space segment, an environment segment, a user segment and the like, simulates influences on links such as generation, transmission, receiving and the like of satellite signals, and has the advantages of high precision, good consistency, high cost, difference with actual signals and the like.

The satellite signal transponder receives and retransmits the analog signal, really and completely restores the actual satellite signal, but the retransmission antenna is fixed to limit the application scene, and the satellite signal transponder is only suitable for static test and cannot perform dynamic test.

Disclosure of Invention

The invention mainly solves the technical problem that the satellite signal transponder cannot be dynamically tested.

The invention provides a regenerative satellite signal transponder, comprising: the satellite signal conversion device comprises a radio frequency channel module and a baseband board card, wherein the output end of the radio frequency channel module is connected with the input end of the baseband board card, and the radio frequency channel module is used for converting a received target satellite signal into a simulated intermediate frequency signal of a target satellite;

the baseband board card comprises an analog-digital conversion module, a clock module, a digital-analog conversion module, a baseband signal processing module, a navigation resolving module and a dynamic simulation module;

the input end of the analog-to-digital conversion module is connected with the output end of the radio frequency channel module and is used for converting the analog intermediate frequency signal of the target satellite into a digital intermediate frequency signal of the target satellite;

the baseband signal processing module comprises a capturing module and a tracking module;

the input end of the acquisition module is connected with the output end of the analog-to-digital conversion module and is used for judging whether a target satellite exists according to the digital intermediate frequency signal of the target satellite, and if the target satellite exists, tracking the carrier frequency of the target satellite, the carrier phase of the target satellite and the code phase of the target satellite through the tracking module to obtain the observation quantity value of the target satellite; the baseband signal processing module is also used for receiving the carrier frequency and code phase correction value output by the dynamic simulation module, and delaying and compensating the target satellite code phase and the target satellite carrier phase; after the code phase and the carrier phase after dynamic processing are subjected to intermediate frequency modulation and combination, digital intermediate frequency signals of each satellite are obtained; transmitting the digital intermediate frequency signals of each satellite to a digital-to-analog conversion module, and outputting the analog intermediate frequency signals of each satellite to a radio frequency channel module;

the input end of the navigation resolving module is connected with the output end of the tracking module and is used for reading navigation messages sent by a target satellite and original observed quantities such as carrier frequency, carrier phase, code phase and the like and resolving the navigation messages into the position, the speed and the time of the target satellite; the position and the speed of the antenna of the user receiver are calculated, and the position, the speed and the time information of the antenna are transmitted to the dynamic simulation module;

the input end of the dynamic simulation module is connected with the output end of the navigation resolving module and used for obtaining the expected position and motion trail of the receiver according to the observation quantity value of the resolved target satellite by combining the position and speed of the antenna of the receiver of the current user, the position and speed of the currently received target satellite and the dynamic control quantity preset by the user, further obtaining the carrier frequency and code phase correction value of the target satellite signal at each moment and transmitting the correction value to the baseband signal processing module for correcting the target satellite signal and modulating the medium frequency.

Further, the acquisition module searches whether the signal of the target satellite exists in the received signals through a short-time matched filtering-FFT algorithm;

the capture module comprises: the device comprises a digital down-conversion module, a pseudo-random code generator, a matched filter, an FFT (fast Fourier transform) and a Tong detector;

the digital down-conversion module is used for multiplying the digital intermediate frequency signal of the target satellite obtained by the analog-to-digital conversion module by a local carrier to obtain a complex baseband signal;

the pseudo-random code generator is used for generating a pseudo-random code corresponding to a target satellite to be captured according to a satellite number set by preset control software;

the matched filter is used for carrying out correlation operation through a complex baseband signal and a pseudo-random code to obtain grouped short-time correlation values;

the FFT is used for carrying out spectrum analysis on the short-time correlation value to obtain a long integral value in the coherence time;

the Tong detector is used for traversing all long integral values output by the FFT, and if the integral values are larger than a preset threshold and reach a specified number of times, the existence of a target satellite is judged; otherwise, the target satellite is judged to be not present.

Further, according to the navigation message and the original observed quantity of the target satellite, the position, the speed and the time of the target satellite are calculated, and the method comprises the following steps:

performing parity check on the original telegraph text, and analyzing the error-free telegraph text to obtain an ephemeris of each satellite;

and resolving ephemeris reference time from the satellite ephemeris, and resolving the detailed orbit parameters of each satellite and the satellite position, speed and time of a signal generation time point according to the specification of each satellite navigation system user interface protocol by taking the time as a reference.

Further, obtaining a target position motion trajectory according to the calculated observation quantity value of the target satellite and by combining the position and the speed of the current receiver antenna, the position and the speed of the current satellite and a dynamic control quantity preset by a user, the method comprises the following steps:

obtaining a dynamic compensation speed value within a period of time by using the speed of a certain moment point in the dynamic control quantity preset by a user and the integral of the acceleration at the moment to the time;

obtaining a target position in a period of time, namely a track of the moving target position, by using the position of the receiver antenna obtained by resolving and adding the integral of the velocity value of the dynamic compensation to the time;

calculating the true pseudo range of each satellite according to the true satellite position and the position of the receiver antenna, calculating the expected pseudo range of each satellite according to the true satellite position and the moving target position, and obtaining the difference between the expected pseudo range and the true pseudo range, namely the code phase correction value of dynamic compensation;

the Doppler frequency value of the generated Doppler effect can be calculated by the speed value of each dynamic compensation in combination with the carrier frequency and the satellite elevation angle, namely the carrier frequency correction value of the dynamic compensation;

the code phase compensation adopts a time delay method based on DDS, and realizes the time delay of the pseudo code by controlling the control word phase of a pseudo random code generator for driving the DDS;

the carrier frequency compensation is directly added with a carrier frequency correction value on a frequency control word of a local carrier DDS to realize frequency correction.

Compared with the prior art, the invention has the following technical effects:

the satellite signal transponder of the invention can change the user position contained in the forwarded satellite signal by adopting the all-digital dynamic simulation technology to dynamically modify the satellite navigation signal, thereby realizing the controllable dynamic simulation function.

Drawings

FIG. 1 is a schematic diagram of a regenerative satellite signal repeater;

fig. 2 is a schematic block diagram of a baseband board card.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).