Incoherent ranging method suitable for unidirectional channel dynamic simulation

Abstract

An incoherent ranging method suitable for one-way channel dynamic simulation adopts frame counting, intra-frame data bit counting, data bit inner spread spectrum chip counting and spread spectrum chip phase information to represent a virtual uplink signal, is simple in implementation method and low in resource consumption, can be realized in a full-digital manner, and can be applied to dynamic simulation of one-way channels. The distance measurement precision calculated by sampling the virtual uplink signal is equivalent to the distance measurement precision under a real channel dynamic state; according to the invention, incoherent ranging can be realized without depending on downlink channel dynamic simulation under the condition of uplink one-way channel dynamic simulation, and the problem that channel dynamic simulation cannot be carried out on downlink signals of satellite-borne equipment is solved. The method is simple and flexible in overall implementation, less in resource occupation, excellent in performance and widely applicable.

Description

Technical Field

[0001] The present invention belongs to the field of communication technologies, and particularly relates to a non-coherent ranging method applicable to dynamic simulation of unidirectional channels. Background Art

[0002] The TT&C transponder belongs to the satellite TT&C sub-system and is a key device for realizing space-ground remote control, telemetry and measurement. During the development of the TT&C transponder, it is necessary to simulate the dynamic environment of the TT&C channel on the ground to test and verify the measurement performance of the transponder. Non-coherent ranging is one of the commonly used measurement systems in satellite TT&C. The ranging principle is as follows: 1. The ground equipment generates measurement information. After coding, framing and spreading spectrum, it is sent to the on-board equipment (generally referring to the TT&C transponder) through the uplink. After receiving the uplink signal, the on-board equipment performs signal synchronization, demodulation, bit synchronization and frame synchronization, and then samples the uplink signal using the trailing edge of the downlink measurement frame synchronization formed by itself to extract the ranging information, obtaining the uplink pseudo-range. After putting the uplink pseudo-range and other measurement information into the downlink measurement frame in real time, it is sent to the ground equipment through the downlink. 2. After receiving the downlink signal, the ground equipment performs signal synchronization, demodulation, bit synchronization and frame synchronization. After extracting the downlink measurement frame synchronization signal, it samples the uplink signal formed by itself using the trailing edge of the downlink frame to extract the downlink pseudo-range and samples other measurement information. 3. The ground comprehensively calculates the space-ground distance based on the downlink pseudo-range transmitted by the satellite and the downlink pseudo-range measured on the ground.

[0003] Since the on-board equipment cannot simulate the channel dynamics of the downlink, the ground test equipment cannot directly calculate the space-ground distance based on the downlink pseudo-range. Therefore, during the development of the ground test equipment, a non-coherent ranging method applicable to dynamic simulation of the uplink unidirectional channel needs to be designed. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide a non-coherent ranging method applicable to dynamic simulation of unidirectional channels, so as to solve the problem that the on-board equipment cannot simulate the channel dynamics of the downlink, resulting in the ground test equipment being unable to directly calculate the space-ground distance based on the downlink pseudo-range.

[0005] To achieve the above purpose, the technical solutions adopted by the present invention include:

[0006] A non-coherent ranging method applicable to dynamic simulation of unidirectional channels, comprising the following steps:

[0007] S1, the ground equipment control unit sends configuration information to the ground equipment signal processing unit. After receiving the configuration information, the ground equipment signal processing unit initializes the internal working modules;

[0008] The configuration information includes the working parameters of the uplink and downlink signals, as well as the channel delay and dynamic simulation parameters;

[0009] S2. The configuration information is input into the uplink data framing module of the ground equipment signal processing unit, which outputs and generates a ground uplink data frame, and performs encoding, spread spectrum modulation, and frequency hopping modulation on the ground uplink data frame to obtain a spread-spectrum and frequency-hopping uplink baseband signal;

[0010] S3. The channel delay and dynamic simulation parameters and the pulse signal at the start time of the ground uplink data frame are input into the virtual channel dynamic simulation module of the ground equipment signal processing unit, and wait for T delay After time, it outputs the uplink virtual spread-spectrum chip phase accumulation valid flag P 1 , T delay is a preset parameter;

[0011] The uplink virtual spread-spectrum chip phase accumulation valid flag P 1 is input into the spread-spectrum chip, data bit, and frame count module of the ground equipment signal processing unit to update the uplink virtual data frame count The uplink virtual data bit count within a frame The uplink virtual spread-spectrum chip count within a data bit and the uplink virtual spread-spectrum chip phase

[0012] S4. The channel delay and dynamic simulation parameters and the spread-spectrum and frequency-hopping uplink baseband signal are input into the channel delay and dynamic simulation module of the ground equipment signal processing unit to obtain a spread-spectrum and frequency-hopping signal after channel delay and dynamic simulation. Then, the spread-spectrum and frequency-hopping signal after channel delay and dynamic simulation is up-converted and digitally-to-analog converted to obtain an uplink signal, and the uplink signal is sent to the on-board equipment;

[0013] The on-board equipment captures, tracks, demodulates, decodes, and frame synchronizes the uplink signal to obtain the uplink data frame generated by S2; at the same time, the on-board equipment generates an on-board downlink data frame, samples the uplink signal at the trailing edge of the on-board downlink data frame synchronization to obtain the uplink pseudorange information at the on-board sampling time, and writes the uplink pseudorange information at the on-board sampling time into the on-board downlink data frame corresponding to the on-board sampling time. Then, the on-board equipment performs encoding, spread spectrum modulation, and frequency hopping modulation on the on-board downlink data frame to obtain a spread-spectrum and frequency-hopping downlink baseband signal, which is up-converted and digitally-to-analog converted to obtain a downlink signal, and the downlink signal is sent to the ground equipment;

[0014] The uplink pseudorange information at the on-board sampling time includes the ground uplink data frame count at the on-board sampling time The uplink data bit count within a frame The uplink spread-spectrum chip count within a data bit and the uplink spread-spectrum chip phase

[0015] In S5, the downlink signal is input into the signal processing unit of the ground equipment. After digital-to-analog conversion and down-conversion, the downlink baseband signal is obtained, and the downlink baseband signal is captured, tracked, demodulated, decoded, and frame synchronized to obtain the uplink pseudorange information in the up and downlink data frames of the satellite in S4 and the effective identification of the trailing edge of the up and downlink data frame synchronization of the satellite;

[0016] The effective identification of the trailing edge of the up and downlink data frame synchronization of the satellite is input into the spreading code chip, data bit, and frame count module. When the spreading code chip, data bit, and frame count module detect the effective identification of the trailing edge of the up and downlink data frame synchronization of the satellite, the updated data in the spreading code chip, data bit, and frame count module is sampled, and the downlink virtual pseudorange at the ground sampling moment is output;

[0017] The downlink virtual pseudorange at the ground sampling moment includes the data frame count at the ground sampling moment The data bit count within the frame The spreading code chip count within the data bit and the spreading code chip phase

[0018] In S6, the uplink pseudorange information in the up and downlink data frame of the satellite and the downlink virtual pseudorange at the ground sampling moment are input into the measurement information calculation module of the signal processing unit of the ground equipment, and the satellite-ground distance R is calculated through Equation (1);

[0019] R = (Δt(ΔΦ u ) - Δt 0 ) × c (1)

[0020] where c represents the speed of light, and Δt 0 represents the up and downlink processing time delay between the on-satellite equipment and the ground equipment, and Δt(ΔΦ u ) is as shown in Equation (2);

[0021] Δt(ΔΦ u ) = T delay - (t 0 (Φ u0 ) - t 1 (Φ u1 )) (2)

[0022] where t 0 (Φ u0 ) and t 1 (Φ u1 ) are as shown in Equation (3);

[0023]

[0024] where f c represents the spreading code chip rate, and max_N d represents the data bit count included in a data frame, and max_N cIndicates the number of spread - spectrum chips contained within a data bit, max_θ c Indicates the phase within a spread - spectrum chip The cumulative maximum value, max_θ c Determined by the measurement accuracy of the pseudo - code phase, represented by M bit Represented by an unsigned integer, i.e., max_θ c = 2 M-1 , The quantization unit of is: 1 / 2 M-1 Cycle, value range: 0 ~ 1 / 2 M-1 Corresponding to 0 ~ 360°.

[0025] Compared with the prior art, the advantages of the present invention are as follows:

[0026] (1) A non - coherent ranging method applicable to one - way channel dynamic simulation in the present invention uses frame counting, in - frame data - bit counting, data - bit - internal spread - spectrum chip counting, and spread - spectrum chip phase information to characterize the virtual uplink signal. The implementation method is simple, with less resource consumption, and can be fully digitalized. The ranging accuracy calculated by sampling the virtual uplink signal is equivalent to the ranging accuracy under the dynamic conditions of the real channel; it can achieve non - coherent ranging without relying on the dynamic simulation of the downlink channel under the condition of one - way uplink channel dynamic simulation, solving the problem that the downlink signal of on - satellite equipment cannot be dynamically simulated for the channel.

[0027] (2) A non - coherent ranging method applicable to one - way channel dynamic simulation in the present invention is simple and flexible in overall implementation, with less resource occupation, excellent performance, and can be widely applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification, together with the following specific embodiments, to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0029] Figure 1 Is the ranging principle diagram of the non - coherent ranging method applicable to one - way channel dynamic simulation.

[0030] Figure 2 Is the block diagram for realizing the non - coherent ranging function of the spread - hopping frequency - modulation TT&C ground equipment.

[0031] Figure 3 Is the flow chart for parameter update within the spread - spectrum chip, data - bit, and frame - counting modules. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The invention is not limited to the following specific embodiments. Any equivalent transformation based on the technical solution of this application falls within the protection scope of the present invention. All components and devices in the present invention, unless otherwise specified, all use the components and devices known in the prior art.

[0033] Embodiment

[0034] This embodiment discloses a non - coherent ranging method applicable to one - way channel dynamic simulation, including the following steps:

[0035] S1. The ground equipment control unit sends configuration information to the ground equipment signal processing unit. After receiving the configuration information, the ground equipment signal processing unit initializes the internal working modules; the configuration information includes the working parameters of the uplink and downlink signals, as well as the channel delay and dynamic simulation parameters;

[0036] S2. The configuration information is input into the uplink data framing module of the ground equipment signal processing unit, and the generated ground uplink data frame is output. Then, the ground uplink data frame is encoded, spread - spectrum modulated, and frequency - hopping modulated to obtain the spread - frequency - hopping uplink baseband signal;

[0037] S3. The channel delay and dynamic simulation parameters and the pulse signal at the starting moment of the ground uplink data frame are input into the virtual channel dynamic simulation module of the ground equipment signal processing unit, and after waiting for T delay time, the uplink virtual spread - spectrum chip phase accumulation valid flag P 1 is output, where T delay is a preset parameter;

[0038] In this embodiment, the value of T delay is determined by the downlink data frame period T df and the maximum satellite - ground delay τ max . Generally, τ max <T delay <T df ;

[0039] The uplink virtual spread - spectrum chip phase accumulation valid flag P 1 is input into the spread - spectrum chip, data bit, and frame counting module of the ground equipment signal processing unit to update the uplink virtual data frame count the uplink virtual data bit count within the frame the uplink virtual spread - spectrum chip count within the data bit and the uplink virtual spread - spectrum chip phase

[0040] The update process of the spread - spectrum chip, data bit, and frame counting module in this embodiment is as shown in Figure 3 where max_N Figure 3 represents the data bit count included in a data frame, max_N d represents the number of spread - spectrum chips included in a data bit, max_θ c represents the maximum accumulation value of the phase c within a spread - spectrum chip, and max_θ represents the maximum accumulation value of the phase within a spread - spectrum chip, and max_θ cDetermined by the pseudo-code code phase measurement accuracy, generally represented by an Mbit unsigned integer, i.e., max_θ c = 2 M-1 , The quantization unit of is: 1 / 2 M-1 cycle, value range: 0 to 1 / 2 M-1 (corresponding to 0 to 360°).

[0041] S4. The channel delay and dynamic simulation parameters and the channel delay of the spread-spectrum and frequency-hopping uplink baseband signal input to the signal processing unit of the ground equipment and the dynamic simulation module to obtain the spread-spectrum and frequency-hopping signal after channel delay and dynamic simulation. Then, the spread-spectrum and frequency-hopping signal after channel delay and dynamic simulation is up-converted and digitally-to-analog converted to obtain the uplink signal, and the uplink signal is sent to the on-board equipment;

[0042] The on-board equipment captures, tracks, demodulates, decodes, and frame synchronizes the uplink signal to obtain the uplink data frame generated by S2; at the same time, the on-board equipment generates the on-board downlink data frame, and samples the uplink signal at the trailing edge of the on-board downlink data frame synchronization to obtain the uplink pseudorange information at the on-board sampling moment, and writes the uplink pseudorange information at the on-board sampling moment into the on-board downlink data frame corresponding to the on-board sampling moment to obtain the on-board downlink data frame. Then, the on-board equipment encodes, spreadspectrum modulates, and frequency-hopping modulates the on-board downlink data frame to obtain the spread-spectrum and frequency-hopping downlink baseband signal, which is up-converted and digitally-to-analog converted to obtain the downlink signal, and the downlink signal is sent to the ground equipment;

[0043] The uplink pseudorange information at the on-board sampling moment includes the ground uplink data frame count at the on-board sampling moment The data bit count within the uplink frame The spread-spectrum chip count within the uplink data bit and the uplink spread-spectrum chip phase

[0044] S5. The downlink signal is input to the signal processing unit of the ground equipment, and after digital-to-analog conversion and down-conversion, the downlink baseband signal is obtained, and the downlink baseband signal is captured, tracked, demodulated, decoded, and frame synchronized to obtain the uplink pseudorange information in the on-board downlink data frame in S4 and the valid flag at the trailing edge of the on-board downlink data frame synchronization;

[0045] The valid flag at the trailing edge of the on-board downlink data frame synchronization is input to the spread-spectrum chip, data bit, and frame count module. When the spread-spectrum chip, data bit, and frame count module detects the valid flag at the trailing edge of the on-board downlink data frame synchronization, it samples the updated data in the spread-spectrum chip, data bit, and frame count module and outputs the downlink virtual pseudorange at the ground sampling moment;

[0046] The downlink virtual pseudorange at the ground sampling moment includes the data frame count at the ground sampling moment The data bit count within the frame Data bit inner spreading code chip count And spreading code chip phase

[0047] S6, the uplink pseudorange information in the satellite - to - ground uplink data frame and the downlink virtual pseudorange at the ground sampling time are input into the measurement information calculation module of the ground equipment signal processing unit, and the satellite - to - ground distance R is calculated through Equation (1);

[0048] R = (Δt(ΔΦ u ) - Δt 0 )×c (1)

[0049] Among them, c represents the speed of light, Δt 0 represents the uplink and downlink processing delays between the on - satellite equipment and the ground equipment, and Δt(ΔΦ u ) is as shown in Equation (2);

[0050] Δt(ΔΦ u ) = T delay - (t 0 (Φ u0 ) - t 1 (Φ u1 )) (2)

[0051] Among them, t 0 (Φ u0 ) and t 1 (Φ u1 ) are as shown in Equation (3);

[0052]

[0053] Among them, f c represents the spreading code chip rate, max_N d represents the data bit count included in a data frame, max_N c represents the number of spreading code chips included in a data bit, max_θ c represents the cumulative maximum value of the phase within a spreading code chip max_θ c is determined by the pseudocode code phase measurement accuracy and is represented by an unsigned integer M bit , that is, max_θ c = 2 M-1 , The quantization unit of M-1 is: 1 / 2 M-1 cycle, and the value range is: 0~1 / 2 M-1

[0054] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0055] In addition, it should be noted that, in the various specific technical features described in the above specific embodiments, they can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination methods. In addition, any combination can also be made between the various different embodiments disclosed in this solution, as long as it does not violate the idea of the present disclosure, it should also be regarded as the content invented by the present disclosure.

Claims

1. A non-coherent ranging method suitable for dynamic simulation of a one-way channel, characterized in that: The following steps are involved: S1, the ground equipment control unit sends configuration information to the ground equipment signal processing unit, and the ground equipment signal processing unit initializes the internal working module after receiving the configuration information; The configuration information includes uplink and downlink signal working parameters as well as channel delay and dynamic simulation parameters; S2, the configuration information is input into the uplink data framing module of the ground equipment signal processing unit, the ground uplink data frame is generated, and the ground uplink data frame is encoded, spread spectrum modulated and frequency hopping modulated to obtain a spread frequency hopping uplink baseband signal; S3, the channel delay and dynamic simulation parameters and the pulse signal of the starting time of the ground uplink data frame are input into the virtual channel dynamic simulation module of the ground equipment signal processing unit, and wait for T delay After time, the uplink virtual spread spectrum code chip phase accumulation valid mark P1 is output, and the T delay are preset parameters; The uplink virtual spread spectrum code chip phase accumulation valid mark P1 is input into the spread spectrum code chip, data bit and frame counting module of the ground equipment signal processing unit to update the uplink virtual data frame count Data bit count in the upstream virtual frame Spread spectrum chip count in uplink virtual data bit and uplink virtual spread spectrum chip phase S4, the channel delay and dynamic simulation parameters and the spread frequency hopping uplink baseband signal are input into the channel delay and dynamic simulation module of the signal processing unit of the ground equipment to obtain the spread frequency hopping signal after the channel delay and dynamic simulation, and then the channel delay and the spread frequency hopping signal after the dynamic simulation are up-converted and digital-to-analog converted to obtain the uplink signal, and the uplink signal is sent to the onboard equipment; The on-board device captures, tracks, demodulates, decodes and performs frame synchronization on the uplink signal to obtain the uplink data frame generated by S2; at the same time, the on-board device generates a satellite uplink and downlink data frame, and samples the uplink signal at the trailing edge of the satellite uplink and downlink data frame synchronization to obtain the uplink pseudorange information at the satellite sampling moment, and writes the uplink pseudorange information at the satellite sampling moment into the satellite uplink and downlink data frame corresponding to the satellite sampling moment, and then the on-board device encodes, spread spectrum modulates and frequency hopping modulates the satellite uplink and downlink data frame to obtain a spread frequency hopping downlink baseband signal, obtains a downlink signal through up-conversion and digital-to-analog conversion, and sends the downlink signal to the ground device; The uplink pseudorange information at the satellite sampling time includes the ground uplink data frame count at the satellite sampling time Data bit count in uplink frame Spread spectrum chip count within uplink data bit and uplink spread spectrum chip phase S5, the downlink signal is input into the signal processing unit of the ground equipment, and after digital-to-analog conversion and down-conversion, a downlink baseband signal is obtained, and the downlink baseband signal is captured, tracked, demodulated, decoded and frame synchronized to obtain the uplink pseudorange information in the satellite uplink and downlink data frame in S4 and the satellite uplink and downlink data frame synchronization trailing edge valid mark; The satellite uplink and downlink data frame synchronization trailing edge valid mark is input into the spread spectrum code chip, data bit and frame counting module. When the spread spectrum code chip, data bit and frame counting module detects the satellite uplink and downlink data frame synchronization trailing edge valid mark, the spread spectrum code chip, data bit and frame counting module samples the updated data in the spread spectrum code chip, data bit and frame counting module, and outputs the downlink virtual pseudorange at the ground sampling moment; The downlink virtual pseudorange at the ground sampling time includes the data frame count at the ground sampling time. Data bit count within a frame Spread spectrum chip count within data bit and the spreading code chip phase S6, the uplink pseudorange information in the satellite uplink and downlink data frames and the downlink virtual pseudorange at the ground sampling time are input into the measurement information solution module of the ground equipment signal processing unit, and the satellite-to-ground distance R is calculated by formula (1); R=(Δt(ΔΦ u )-Δt0)×c (1) Where c represents the speed of light, Δt0 represents the downlink processing delay between the satellite equipment and the ground equipment, and Δt(ΔΦ u ) as formula (2); Δt(ΔΦ u )=T delay -(t0(Φ u0 )-t1(Φ u1 )) (2) Among them, t0(Φ u0 ) and t1(Φ u1 ) as formula (3); Among them, f c Indicates the spreading code chip rate, max_N d Indicates the data bit count contained in a data frame, max_N c Indicates the number of spread spectrum chips contained in one data bit, max_θ c Indicates the phase within a spread spectrum code chip The maximum value of the accumulation, max_θ c Determined by the pseudo code phase measurement accuracy, and by M bit Unsigned integer representation, i.e. max_θ c =2 M-1 , The quantitative unit is: 1 / 2 M-1 Week, value range: 0~1 / 2 M-1 Corresponding to 0~360°.

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