A navigation signal enhancement method based on satellite communication signal

Abstract

The present invention discloses a method for enhancing navigation signals based on satellite communication signals, the method comprising the following steps: the satellite receives an access request from a user terminal in a service area, determines whether there is an application for navigation signal enhancement authorization user in a certain beam coverage area, and determines a navigation signal wireless resource configuration mode; the satellite generates a navigation signal based on the satellite communication signal, and modulates and transmits the navigation signal based on the satellite communication signal using an idle channel or a channel allocated according to the authorized user level; the user terminal captures, tracks and demodulates the navigation signal based on the satellite communication signal, obtains the pseudo-range measurement result and satellite navigation message between the user terminal and the satellite, and then determines the position and time information of the user terminal through a positioning algorithm. The present invention can provide multi-level navigation positioning and timing services for users with different permissions on demand through resource allocation.

Description

Technical Field

[0001] The invention belongs to the technical field of satellite navigation, and in particular relates to a navigation signal enhancement method based on satellite communication signals. Background Art

[0002] As an important space infrastructure, the Global Navigation Satellite System (GNSS) is playing a huge role in the application fields of national politics, economy, military, science and technology, and culture. At present, the four major global satellite navigation systems, namely the GPS system of the United States, the GLONASS system of Russia, the Galileo system of Europe, and the Beidou satellite navigation system of China, can provide basic navigation, positioning, and timing services for global navigation users. However, the landing power of GNSS signals is limited, and the satellite position, signal frequency, and structure are all easy-to-obtain information, which makes the GNSS system extremely vulnerable to electronic interference, blocking, and deception. In urban blocks, indoors, canyons, forests and other environments, due to the obstruction of trees and buildings, the number of visible navigation satellites may not meet the positioning requirements, and in extreme cases, the GNSS system will be unavailable. Therefore, it is very necessary and of great practical significance to study the navigation signal enhancement method in the environment where GNSS application is restricted.

[0003] The vigorous development of low-orbit communication constellations provides an opportunity for the integration of communication and navigation. It can take advantage of the global coverage of communication satellite systems and their differences with navigation constellations in orbit, signal frequency band and intensity. By integrating them into the communication system, navigation signal enhancement can be achieved and new space-based navigation nodes can be added efficiently and cost-effectively.

[0004] The first project to provide positioning and timing signals based on low-orbit mobile communication satellites was the High Integrity GPS Project (i.e., iGPS Project). It was planned to use the next-generation Iridium system to broadcast GPS-like signals and GPS-assisted enhancement information to improve navigation and positioning accuracy and anti-interference capabilities. iGPS has adaptively modified the original Iridium signal and used idle communication channel resources to broadcast dedicated navigation and ranging signals (patent number: US 7579987 B2). When the communication business is busy, the positioning and timing functions may be interrupted.

[0005] The actual iGPS project was not implemented in the next generation Iridium system. Instead, it was replaced by the STL (Satellite Time and Location) signal designed by Satelles. The STL signal independently occupies a paging channel and appears as a simple text message. The STL signal is a carefully arranged set of data that generates a spread spectrum RF signal pulse, including a CW, a PRN code sequence, and modulated data. The STL burst is broadcast once every 1.4 seconds on average, and is broadcast in time-division polling in multiple Iridium beams. Therefore, the STL signal is a pulse system, low duty cycle, narrowband (25kcps) high-power signal. Compared with GNSS signals, the signal has better penetration, but limited anti-interference ability.

[0006] China has also made some achievements in the field of communication and navigation fusion signal systems. The patent "Satellite navigation and communication integration method and system" (patent number: CN 201410514108.2) provides a satellite navigation and communication integration method, which performs multi-carrier modulation on the navigation signal and the communication signal, and sends the modulated signal after obtaining it. The patent "A communication method based on low-orbit mobile communication satellite" (patent number: CN 110208822 A) proposes a safe positioning and timing signal, which broadcasts a broadband spread spectrum signal in the idle frequency band outside the communication paging signal during the downlink paging period of the communication satellite. The patent "A low-orbit mobile communication satellite system based on frequency hopping and time hopping positioning and timing function" (patent number: CN 110557169 A) adds a frequency hopping system on the basis of the patent "A communication method based on low-orbit mobile communication satellite" (patent number: CN 110208822 A), realizes frequency hopping modulation in the idle frequency band outside the communication paging signal according to the designed frequency hopping pattern, and improves the signal anti-interference ability. The patent "A navigation method based on satellite communication signals" (patent number: CN 10906 1675 A) proposes using idle communication channel resources to broadcast dedicated navigation ranging signals.

[0007] The core of the protection of the above patent is the signal fusion design implementation method, which mainly includes time division, frequency division and other methods. The usual practice is to broadcast signals specially designed for navigation services while fixedly occupying or utilizing idle frequency domain resources of communication services. Although the characteristics of communication signals are taken into consideration, the navigation enhancement signal design is not implemented in a mode that is fully integrated into the communication system, and the navigation performance scalability of the fused signal is not considered. Summary of the invention

[0008] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide a navigation signal enhancement method based on satellite communication signals, to realize the navigation enhancement signal design by adopting a mode that is fully integrated into the communication system, to not change the communication service frame format, to give priority to using idle space-time-frequency resources to broadcast the navigation enhancement signal, and to have a flexible expansion capability similar to that of the communication signal, and to provide multi-level navigation positioning and timing services for users with different permissions as needed.

[0009] The object of the present invention is achieved through the following technical scheme: a navigation signal enhancement method based on satellite communication signals, the method comprising the following steps: step 1: the satellite determines whether there is an authorized user application for navigation signal enhancement in a certain beam coverage area by receiving an access request from a user terminal in a service area, and determines a navigation signal wireless resource configuration mode according to whether there is an authorized user application for navigation signal enhancement in a certain beam coverage area; wherein the navigation signal wireless resource configuration mode comprises an idle time slot loading navigation signal wireless resource configuration mode and an authorized user navigation signal wireless resource configuration mode; step 2: the satellite generates a navigation signal based on a satellite communication signal, and modulates and transmits the navigation signal based on the satellite communication signal using an idle channel in the idle time slot loading navigation signal wireless resource configuration mode or a channel allocated according to the authorized user level in the authorized user navigation signal wireless resource configuration mode; step 3: the user terminal obtains a pseudo-range measurement result and a satellite navigation message between the user terminal and the satellite by capturing, tracking and demodulating the navigation signal based on the satellite communication signal in step 2, and then determines the position and time information of the user terminal through a positioning algorithm.

[0010] In the above-mentioned navigation signal enhancement method based on satellite communication signals, in step one, the navigation signal wireless resource configuration mode is determined according to whether there is an authorized user application for navigation signal enhancement within a certain beam coverage area, including the following steps: (1) if there is no authorized user application for navigation signal enhancement within a certain beam coverage area, the navigation signal wireless resource configuration mode of loading in idle time slot is adopted, and the satellite calculates and analyzes whether there are idle channel resources in the next communication service basic time slot of the beam; (2) if there is an authorized user application for navigation signal enhancement within a certain beam coverage area, the authorized user navigation signal wireless resource configuration mode is adopted, and the satellite plans to allocate channel resources matching the authorized user level in the next basic time slot according to the authorized user level to broadcast the navigation signal based on the satellite communication signal, and sends the configuration information of the navigation enhancement signal to the authorized user through the communication control channel.

[0011] In the above-mentioned navigation signal enhancement method based on satellite communication signals, in step (1), the following steps are also included: (1-1) if there are no idle channel resources, the navigation signal based on the satellite communication signal is not broadcast in the next basic time slot; (1-2) if there are idle channel resources, the navigation signal based on the satellite communication signal is planned to be broadcast in the idle channel of the next basic time slot, and the configuration information of the navigation enhancement signal is broadcast through the communication control channel.

[0012] In the above-mentioned navigation signal enhancement method based on satellite communication signals, in step 2, the satellite uses the idle channel resources in step (1-2) or the channel allocated according to the authorized user level in step (2) to modulate and transmit the navigation signal based on the satellite communication signal.

[0013] In the above-mentioned navigation signal enhancement method based on satellite communication signals, in step 2, the satellite uses a certain communication service frame format to generate a navigation signal frame based on the satellite communication signal.

[0014] In the above-mentioned navigation signal enhancement method based on satellite communication signals, the certain communication service frame format can be selected and determined in the downlink service frame format of the communication satellite carrying the navigation enhancement service according to navigation measurement and communication requirements.

[0015] In the above-mentioned navigation signal enhancement method based on satellite communication signals, the navigation signal frame is realized by filling two sections of special data in the data field of the communication service frame according to the protocol regulations; wherein, the first section of data is filled with a fixed character string for realizing the measurement function; the second section of data is filled with the basic navigation message of the local satellite, which is used to broadcast the latest local satellite predicted orbit, predicted clock error and other message information required for user positioning solution.

[0016] In the above-mentioned navigation signal enhancement method based on satellite communication signals, step three specifically includes the following steps: (31) the user terminal receives the navigation signal based on the satellite communication signal broadcasted in step two, and extracts the received data according to the communication service frame format adopted by the navigation signal based on the satellite communication signal; (32) the user terminal locally generates a pseudo-random code using a scrambling code generator defined by the communication system, and performs XOR processing with a fixed character string filled according to the protocol to form local data for pseudo-range measurement; (33) the user terminal uses the local data for pseudo-range measurement to perform correlation processing with the first segment of the received navigation signal frame, and uses the autocorrelation characteristics of the scrambling code to realize the correlation tracking and capture processing of the navigation enhancement signal, and obtains the pseudo-range measurement results of the user terminal and the satellite; (34) the user terminal demodulates the received data and obtains the satellite navigation message carried in the second segment of the navigation signal frame; (35) the user terminal uses the obtained pseudo-range measurement results of the user terminal and the satellite, as well as the obtained satellite navigation message, to determine its own position and time information through a positioning algorithm, thereby realizing navigation signal enhancement based on satellite communication signals.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention generates a navigation signal frame based on a satellite communication signal by adopting a certain communication service frame format and realizes the measurement function by utilizing the autocorrelation characteristics of the communication system scrambling code, thereby realizing the navigation enhancement signal design that is fully integrated into the communication system, and the system complexity is low;

[0019] (2) The present invention generates a navigation signal frame based on a satellite communication signal by adopting a certain communication service frame format, and utilizes the inherent high-speed information transmission advantage of the communication system to realize rapid broadcasting of navigation messages;

[0020] (3) The idle time slot designed by the present invention loads the navigation signal wireless resource configuration mode, which uses the idle resources of the communication satellite to broadcast the navigation enhancement signal, and can maximize the utilization rate of satellite resources;

[0021] (4) The wireless resource configuration mode for authorized user navigation signals designed in the present invention can fully utilize the flexibility of the frequency, time slot and multi-beam resources of satellite communication signals to provide multi-level navigation, positioning and timing services for users with different permissions on demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0023] Figure 1 It is a schematic diagram of the basic frame time domain structure of satellite communication signals;

[0024] Figure 2 is a schematic diagram of the frequency domain structure of a satellite communication signal;

[0025] Figure 3 A schematic diagram of a correlation processing result obtained by utilizing the autocorrelation characteristics of a communication system scrambling code;

[0026] Figure 4 A schematic diagram of a navigation signal format based on a communication service signal format disclosed in the present invention;

[0027] Figure 5 A schematic diagram of wireless resource configuration in an idle time slot loading mode;

[0028] Figure 6 Schematic diagram of wireless resource configuration for authorized user configuration mode. DETAILED DESCRIPTION

[0029] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] This embodiment provides a navigation signal enhancement method based on satellite communication signals, comprising the following steps:

[0031] Step 1: The satellite determines the navigation signal radio resource configuration mode based on the satellite communication signal in the next communication service basic frame, which is divided into two modes: idle time slot loading and authorized user configuration.

[0032] Specifically, the satellite determines whether there is a navigation signal enhancement authorization user application within a certain beam coverage area by receiving an access request from a user terminal within the service area.

[0033] (1) If there is no user application for navigation signal enhancement authorization within the coverage area of ​​a certain beam, the navigation signal wireless resource configuration mode is adopted to load the idle time slot, and the satellite calculates and analyzes whether there is idle channel resource in the next basic time slot of the communication service of the beam.

[0034] (1-1) If there are no idle channel resources, the navigation signal based on the satellite communication signal will not be broadcast in the next basic time slot;

[0035] (1-2) If there are idle channel resources, it is planned to broadcast the navigation signal based on the satellite communication signal on the idle channel of the next basic time slot, and broadcast the configuration information of the navigation enhancement signal through the communication control channel.

[0036] (2) If there is an authorized user applying for navigation signal enhancement within a certain beam coverage area, the authorized user navigation signal wireless resource configuration mode is adopted. The satellite planning allocates corresponding channel resources in the next basic time slot according to the authorized user level to broadcast the navigation signal based on the satellite communication signal, and sends the configuration information of the navigation enhancement signal to the authorized user through the communication control channel. Specifically, the channel resources are used to broadcast the navigation signal based on the satellite communication signal; the communication control channel is used to inform the user of the configuration information of the navigation enhancement signal: such as the carrier frequency, broadcast time slot and other prior information, to assist the user in rapid capture.

[0037] Step 2: The satellite generates and utilizes the idle channel in step 1 (1-2) or the channel allocated in (2) to modulate and transmit a navigation signal based on the satellite communication signal.

[0038] Specifically, the satellite uses a certain communication service frame format to generate a navigation signal frame based on the satellite communication signal. The certain communication service frame format can be selected and determined in the downlink service frame format of the communication satellite carrying the navigation enhancement service according to the navigation measurement and communication requirements. The navigation signal frame is realized by filling two sections of special data in the data field of the communication service frame according to the protocol; wherein the first section of data is filled with a fixed character string for realizing the measurement function; the second section of data is filled with the basic navigation message of the satellite, which is used to broadcast the latest predicted orbit of the satellite, predicted clock error and other message information required for user positioning solution.

[0039] Step 3: The user terminal captures, tracks, and demodulates the navigation signal based on the satellite communication signal broadcast in step 2, obtains the pseudo-range measurement results between it and the satellite and the satellite navigation message, and then determines its own position and time information through the positioning algorithm.

[0040] The detailed processing flow of step three is as follows:

[0041] (31) The user terminal receives the navigation signal based on the satellite communication signal broadcasted in step 2, and extracts and forms received data according to the communication service frame format adopted by the navigation signal based on the satellite communication signal;

[0042] (32) The user terminal generates a pseudo-random code locally using a scrambling code generator defined by the communication system, and performs an XOR process with the fixed character string filled according to the protocol to form local data for pseudo-range measurement;

[0043] (33) The user terminal uses the local data used for pseudorange measurement to perform correlation processing with the first segment of the received navigation signal frame, and uses the autocorrelation characteristics of the scrambling code to implement correlation tracking and capture processing of the navigation enhancement signal to obtain the pseudorange measurement results between the user terminal and the satellite;

[0044] (34) The user terminal demodulates the received data to obtain the satellite navigation message carried in the second segment of the navigation signal frame;

[0045] (35) The user terminal uses the pseudo-range measurement results between the user terminal and the satellite, as well as the obtained satellite navigation message, to determine its own position and time information through a positioning algorithm, thereby achieving navigation signal enhancement based on the satellite communication signal.

[0046] Specifically, the present invention belongs to the field of satellite navigation, and in particular relates to a navigation signal generation method based on a satellite communication service frame format, and a wireless resource management and receiving tracking processing method for the signal.

[0047] To achieve the above-mentioned purpose, the present invention discloses a navigation signal design method based on satellite communication signals, and discloses a receiving and processing method of the signal.

[0048] (1) Communication signal system

[0049] The satellite communication signal based on the present invention adopts a time division / frequency division / space division hybrid system, that is, a TDMA+FDMA+multi-beam system, specifically:

[0050] (1.1) Time domain structure.

[0051] The uplink and downlink signals adopt the time division multiplexing system in the time domain, and the service configuration is carried out in time slots and frames, which is realized in the following ways:

[0052] ① The signal time-division structure completely inherits the communication signal system, with the frame as the basic unit, and the frame length is defined as T f , T f >0;

[0053] ② A frame is divided into N t time slots of equal length, N t >1;

[0054] ③The length of each time slot is

[0055] ④The first time slot of each frame is fixed as the paging signal broadcasting time slot.

[0056] The specific implementation example of the present invention is f =100ms, N t =5, such as Figure 1 shown.

[0057] (1.2) Frequency domain structure.

[0058] The uplink and downlink signals use frequency division multiplexing in the frequency domain. The structures of the two are the same, and fixed frequency bands are divided for control service signals and communication service signals. This is achieved in the following ways:

[0059] ① The total bandwidth occupied is BW, BW>0;

[0060] ② Divide into N f sub-bands with equal bandwidth BW sub , N f >1,

[0061] ③The low-frequency part is used as the control service channel, occupying the bandwidth BW b ; The remaining high frequency part is used for communication services, occupying bandwidth BW c ; BW b +BW c =BW.

[0062] The specific implementation example of the present invention takes BW=10MHz, N f=80, BW b =1MHz,BW c =9MHz, such as Figure 2 shown.

[0063] (1.3) Multi-beam antenna multi-color multiplexing system. The communication satellite signal is a multi-beam multi-color multiplexing system. Each beam uses one or more sub-bands as needed, while satisfying the multi-color multiplexing of adjacent beams to reduce interference between beams.

[0064] (2) Navigation signal based on communication service frame format

[0065] The present invention is based on the communication service frame format, utilizes the autocorrelation characteristics of the communication system scrambling code to realize the measurement function, and utilizes the natural information transmission advantage of the communication system to realize the rapid transmission of the navigation message, specifically:

[0066] (2.1) Communication service frame structure.

[0067] The coded output after modulation of the communication service frame consists of four parts: protection period, unique code, public information and data field.

[0068] The specific implementation example of the present invention adopts the modulation of the unique code, public information and data domain respectively. Among them, the unique code and public information adopt QPSK modulation; the data domain first performs CRC calculation, then performs data encoding, rate matching, interleaving and scrambling, and finally adopts π / 4QPSK modulation.

[0069] The specific implementation example of the present invention adopts a protection period length T pp =2.5 bits; unique code length T uc =54 bits; public information length T pi =54 bits; data field length T da =847 bits.

[0070] (2.2) Communication system scrambling code.

[0071] The scrambling code uses a pseudo-random code of a certain order.

[0072] The specific implementation example of the present invention uses a 15th-order pseudo-random code, which is generated according to the following polynomial:

[0073] p(x)=1+D+D 15

[0074] The initial state of the shift register is:

[0075] I(D)=1+D+D3+D6+D9+D14

[0076] (2.3) Navigation measurement function.

[0077] By filling a fixed character string in the data field of the communication service frame, the measurement function is realized by using the autocorrelation performance of the scrambling code. The specific steps are as follows:

[0078] ① The user terminal receives the navigation signal based on the satellite communication signal, and extracts and forms the received data according to the communication service frame format adopted by the navigation signal based on the satellite communication signal;

[0079] ② The user terminal generates a pseudo-random code locally using the scrambling code generator defined by the communication system, and performs XOR processing with the fixed string filled according to the protocol to form local data for pseudo-range measurement;

[0080] ③ The user terminal uses the local data used for pseudorange measurement to perform correlation processing with the first segment of the received navigation signal frame, and uses the autocorrelation characteristics of the scrambling code to implement the correlation tracking and capture processing of the navigation enhancement signal to obtain the pseudorange measurement results between the user terminal and the satellite.

[0081] The specific implementation example of the present invention fills the first 600 bits of the communication service frame data field with a fixed "010101......" string, and the simulated distance delay is 420 characters. The signal generation and receiving processing flow are verified according to the above steps. The local data and the received data can be well correlated, such as Figure 3 shown.

[0082] (2.4) Navigation message transmission function.

[0083] By filling the satellite's predicted orbit, clock error and other navigation message information in the communication service frame data field, the natural information transmission advantage of the communication system is utilized to achieve rapid transmission of navigation messages.

[0084] In a specific implementation example of the present invention, the last 232 bits of the communication service frame data field are filled with navigation message information such as the predicted orbit and clock error of the satellite.

[0085] According to the design parameters of the above specific implementation examples, the navigation signal format based on the communication service signal format disclosed in the present invention is as follows: Figure 4 shown.

[0086] (3) Navigation signal wireless resource configuration mode

[0087] The present invention designs two navigation signal wireless resource configuration modes, namely, idle time slot loading and authorized user configuration. It mainly utilizes the configurability of satellite communication signal frequency, time slot and multi-beam resources to provide multi-level navigation positioning and timing services for users with different permissions on demand, specifically:

[0088] (3.1) Idle time slot loading mode

[0089] This mode utilizes the idle frequency channel resources of the downlink communication service in the current time slot to modulate and transmit the aforementioned navigation signal based on the communication service signal system.

[0090] The specific implementation of the present invention takes one of the beams i of the communication satellite as an example. In one of the basic frames, 5 communication service sub-bands are allocated, and there is an idle sub-band in the 2nd, 4th and 5th time slots respectively, which can be used to carry the navigation signal broadcasting function. The satellite autonomously broadcasts the navigation signal based on the communication service signal system according to the current idle sub-band. The wireless resource configuration diagram of the idle time slot loading mode is shown in FIG. Figure 5 shown.

[0091] (3.2) Authorized User Configuration Mode

[0092] In this mode, authorized users of different levels interact with satellites or communication ground systems through control channels. Users send navigation service applications, and the satellite confirms the user's identity autonomously or through the ground. It then responds to the user's application through wireless resource configuration management and sends down navigation signal enhancement configuration information through the control channel. During the validity period of the application, authorized users can independently occupy part or all of the downlink communication service channel resources for satellite modulation and transmission of the aforementioned navigation signals based on the communication service signal system. The user terminal uses coherent joint processing through multiple sub-band signals to effectively improve the measurement performance.

[0093] The specific implementation of the present invention takes the case where the authorized user is located in the coverage area of ​​one of the beams i of the communication satellite as an example. According to the navigation service application submitted by the user, after the two-way authentication is realized, the beam is fixedly divided into 4 sub-bands, which are used to modulate and transmit the navigation signal based on the communication service signal system within the application time. The wireless resource configuration diagram of the authorized user configuration mode is shown in FIG. Figure 6 shown.

[0094] The present invention adopts a certain communication service frame format to generate a navigation signal frame based on a satellite communication signal, utilizes the autocorrelation characteristics of the communication system scrambling code to realize the measurement function, realizes the navigation enhancement signal design that is fully integrated into the communication system, and has low system complexity; the present invention adopts a certain communication service frame format to generate a navigation signal frame based on a satellite communication signal, utilizes the natural high-speed information transmission advantage of the communication system to realize the rapid broadcasting of navigation messages; the idle time slot loading navigation signal wireless resource configuration mode designed by the present invention utilizes the idle resources of the communication satellite to broadcast the navigation enhancement signal, and can maximize the utilization rate of satellite resources; the authorized user navigation signal wireless resource configuration mode designed by the present invention can fully utilize the flexibility of the frequency, time slot and multi-beam resources of the satellite communication signal, and provide multi-level navigation positioning and timing services for users with different permissions on demand.

[0095] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A navigation signal enhancement method based on satellite communication signals, characterized in that: The method comprises the following steps: Step 1: The satellite receives an access request from a user terminal in the service area, determines whether there is an application for navigation signal enhancement authorization in a certain beam coverage area, and determines a navigation signal wireless resource configuration mode according to whether there is an application for navigation signal enhancement authorization in a certain beam coverage area; wherein the navigation signal wireless resource configuration mode includes an idle time slot loading navigation signal wireless resource configuration mode and an authorized user navigation signal wireless resource configuration mode; Step 2: The satellite generates a navigation signal based on the satellite communication signal, and modulates and transmits the navigation signal based on the satellite communication signal by using an idle time slot to load an idle channel in the navigation signal wireless resource configuration mode or a channel allocated according to the authorized user level in the authorized user navigation signal wireless resource configuration mode; Step 3: The user terminal acquires the pseudo-range measurement result and satellite navigation message between the user terminal and the satellite by capturing, tracking and demodulating the navigation signal based on the satellite communication signal in step 2, and then determines the position and time information of the user terminal through the positioning algorithm; In step 1, determining the navigation signal wireless resource configuration mode according to whether there is a navigation signal enhancement authorized user application in a certain beam coverage area includes the following steps: (1) If there is no user application for navigation signal enhancement authorization within the coverage area of ​​a certain beam, the navigation signal wireless resource configuration mode is adopted to load the navigation signal in the idle time slot, and the satellite calculates and analyzes whether there is an idle channel resource in the next basic time slot of the communication service for the beam; (2) If there is an authorized user applying for navigation signal enhancement within a certain beam coverage area, the authorized user navigation signal wireless resource configuration mode is adopted. The satellite planning allocates channel resources matching the authorized user level in the next basic time slot to broadcast navigation signals based on satellite communication signals, and sends the configuration information of the navigation enhancement signal to the authorized user through the communication control channel; In step (1), the following steps are also included: (1-1) If there are no idle channel resources, the navigation signal based on the satellite communication signal will not be broadcast in the next basic time slot; (1-2) If there are idle channel resources, plan to broadcast the navigation signal based on the satellite communication signal on the idle channel of the next basic time slot, and broadcast the configuration information of the navigation enhancement signal through the communication control channel; In step 2, the satellite generates a navigation signal frame based on the satellite communication signal using a certain communication service frame format; Step 3 specifically includes the following steps: (31) The user terminal receives the navigation signal based on the satellite communication signal broadcasted in step 2, and extracts and forms received data according to the communication service frame format adopted by the navigation signal based on the satellite communication signal; (32) The user terminal generates a pseudo-random code locally using a scrambling code generator defined by the communication system, and performs an XOR process with the fixed character string filled according to the protocol to form local data for pseudo-range measurement; (33) The user terminal uses the local data used for pseudorange measurement to perform correlation processing with the first segment of the received navigation signal frame, and uses the autocorrelation characteristics of the scrambling code to implement correlation tracking and capture processing of the navigation enhancement signal to obtain the pseudorange measurement results between the user terminal and the satellite; (34) The user terminal demodulates the received data to obtain the satellite navigation message carried in the second segment of the navigation signal frame; (35) The user terminal uses the pseudo-range measurement results between the user terminal and the satellite, as well as the obtained satellite navigation message, to determine its own position and time information through a positioning algorithm, thereby achieving navigation signal enhancement based on the satellite communication signal.

2. The method for enhancing navigation signals based on satellite communication signals according to claim 1, characterized in that: In step 2, the satellite utilizes the idle channel resources in step (1-2) or the channel allocated according to the authorized user level in step (2) to modulate and transmit a navigation signal based on the satellite communication signal.

3. The method for enhancing navigation signals based on satellite communication signals according to claim 1, characterized in that: The certain communication service frame format can be selected and determined from the downlink service frame format of the communication satellite carrying the navigation enhancement service according to navigation measurement and communication requirements.

4. The method for enhancing navigation signals based on satellite communication signals according to claim 1, characterized in that: The navigation signal frame is realized by filling two sections of special data in the data field of the communication service frame according to the protocol regulations; the first section of data is filled with a fixed character string for realizing the measurement function; the second section of data is filled with the basic navigation message of the local satellite, which is used to broadcast the latest local satellite predicted orbit, predicted clock error user positioning solution required message information.

Images