CN202794533U

CN202794533U - Closed-loop testing system of GPS simulator and GPS receiver

Info

Publication number: CN202794533U
Application number: CN 201220094048
Authority: CN
Inventors: 纪元法; 孙希延; 符强; 王守华; 邓洪高; 严素清; 吴孙勇; 张瑞霞
Original assignee: Guilin University of Electronic Technology
Current assignee: Guilin University of Electronic Technology
Priority date: 2012-03-14
Filing date: 2012-03-14
Publication date: 2013-03-13
Anticipated expiration: 2022-03-14

Abstract

The utility model discloses a closed-loop testing system of a GPS simulator and a GPS receiver, which comprises the GPS simulator and the GPS receiver. The testing system is characterized in that the GPS simulator is mainly composed of a signal processing unit, a radio frequency signal outputting unit, a synchronous pulse signal outputting unit and a reference signal outputting unit. The radio frequency signal outputting unit, the synchronous pulse signal outputting unit and the reference signal outputting unit are respectively connected on the output end of the signal processing unit. The GPS receiver is mainly composed of an actual-measurement receiving unit and a positioning calculating unit. The radio frequency signal outputting unit and the synchronous pulse signal outputting unit of the GPS simulator are connected with the input end of the actual-measurement receiving unit of the GPS receiver. The output end of the actual-measurement receiving unit is further connected with one input end of the positioning calculating unit. The reference signal outputting unit of the GPS simulator is directly connected with the other input end of the positioning calculating unit of the GPS receiver. The two output ends of the positioning calculating unit of the GPS receiver are together connected to the input end of the signal processing unit of the GPS simulator.

Description

GPS simulator and receiver closed loop test system

Technical field

The utility model relates to the gps satellite navigation field, is specifically related to a kind of GPS simulator and receiver closed loop test system.

Background technology

The GPS of the U.S. (GPS) is the mark post of current satellite navigation system, and the GPS location has round-the-clock, precision high, and there is very widely application in the military-civil field of every country in the world.Present GPS receiver speed of development is very fast, is that the indexs such as volume, power consumption, sensitivity, precision all had very large lifting before 10 years.Except the technical development of receiver itself, on building, gps system also constantly updating the replacement.Following gps satellite will have higher time reference, higher power, the signal system of more optimizing, for the user provides more quality services.

In the GPS navigation System Development, the development of gps system construction and GPS receiver is interactional, especially in the development of receiver, need to consider respectively the impact of various observed quantities, various error sources, and take respectively corresponding measure, in the hope of obtaining higher measuring accuracy.In the research and development of GPS receiver, test, mainly measure measuring accuracy, the signal receiving sensitivity of receiver, to improve the applicability of receiver.Also to consider the location availability of receiver under the complex environments such as missile-borne.For under the static environment of laboratory, realizing easily these tests, according to relative motion principle, needn't be placed on receiver on the Space Facilities such as guided missile, star ship, only need simulator to simulate receiver received navigation satellite signal under these tracks, indoor to static receiver test, the positioning result of receiver is exactly the predefined track of simulator, can make things convenient for the locating effect of test receiver under high-altitude, high-speed motion condition, has saved like this testing cost of receiver.According to such application demand, the computing of GPS simulator grows up.

The gps satellite signal simulator is simulated exactly and is produced the gps satellite navigation signal, and for development, the test of GPS receiver provides simulated environment, it is the important testing tool of satellite navigation system and receiver (especially high dynamic receiver) development.The simulated environment environment that the gps signal simulator is simulated is more true to nature, then gets over as accurate for the performance measurement of GPS receiver.But generally speaking, receiver is independently to the signal measurement of simulator, and Measuring Time benchmark and simulator are irrelevant.The various observed quantity precision of receiver can't accurately be measured like this, and such as pseudo range observed quantity commonly used, general simulator is difficult to the pseudo range measurement precision of objective evaluation receiver.

The utility model content

Technical problem to be solved in the utility model provides a kind of GPS simulator and receiver closed loop test system, it can be on receiver and simulator unification to a time reference, and the observation to signal realizes closed loop test, thereby the quality of the technology of the links of precise evaluation receiver and algorithm more, signal imitation precision that conversely also can the Simulation device, and provide the mechanism of evaluation for the construction of navigational system.

For addressing the above problem, the utility model is realized by following scheme: a kind of GPS simulator and receiver closed loop test system comprise GPS simulator and GPS receiver.Described GPS simulator mainly is made of signal processing unit, radiofrequency signal output unit, synchronization pulse output unit and reference signal output unit; Wherein radiofrequency signal output unit, synchronization pulse output unit and reference signal output unit are connected on the output terminal of signal processing unit; Described GPS receiver is mainly by actual measurement receiving element and location Calculation cell formation; The radiofrequency signal output unit of GPS simulator links to each other with the input end of synchronization pulse output unit with the actual measurement receiving element of GPS receiver, and the output terminal of actual measurement receiving element connects one of them input end of location Calculation unit; The reference signal output unit of GPS simulator directly links to each other with another input end of the location Calculation unit of GPS receiver; 2 output terminals of the location Calculation unit of GPS receiver are connected to the input end of the signal processing unit of GPS simulator jointly.

In the such scheme, the synchronizing pulse of described synchronization pulse output unit output is Millisecond.

In the such scheme, the synchronizing pulse of described synchronization pulse output unit output is 1 millisecond.

Design of the present utility model is: GPS simulator and GPS receiver use same clock source, retention time benchmark consistent; Traditional GPS simulator only provides radiofrequency signal to the GPS receiver when using, and in the GPS simulator and receiver closed loop test system that the utility model relates to, the GPS simulator not only provides the GPS radiofrequency signal, also export the corresponding synchronizing pulse of radiofrequency signal to the GPS receiver, and carrier phase information, pseudo-code phase information and the satellite position information of each corresponding gps signal.The GPS receiver not only can be processed the GPS radio-frequency information under synchronizing pulse control like this, carries out traditional signal capture and follows the tracks of, and carries out the decoding of pseudo range measurement and ephemeris, finishes positioning calculation again; Can also directly utilize phase information that simulator provides and satellite position to position resolves.By these two kinds of computation processes, pseudorange that can comparative analysis GPS receiver is that measuring accuracy, ephemeris error analysis, the positioning calculation method of pseudo-code phase or carrier phase is good and bad or detect the simulation precision of GPS simulator.

Compared with prior art, the utlity model has following features:

1, the GPS simulator has been exported synchronizing pulse, carrier phase, pseudo-code phase and satellite position information more on the basis of output GPS radiofrequency signal;

2 compare with common GPS receiver, GPS receiver in the utility model design not only can be processed traditional GPS radiofrequency signal, finish location Calculation, carrier phase, pseudo-code phase and the satellite position information that can also receive from the GPS simulator directly position calculating, obtain desirable positioning result;

3, can the various error sources of systematic analysis gps system, for Receiver Design and GPS navigation system Construction provide significant reference; Thereby can be widely used in the GPS navigation positioning field, and for navigating, the Chinese Big Dipper offers reference.

Description of drawings

Fig. 1 is a kind of GPS simulator of the utility model and receiver closed loop test system.

Embodiment

Referring to Fig. 1, a kind of GPS simulator of the utility model and receiver closed loop test system comprise GPS simulator and GPS receiver.Described GPS simulator mainly by signal processing unit, radiofrequency signal output unit, synchronization pulse output unit, reference signal output unit and as a result comparing unit consist of.Wherein radiofrequency signal output unit, synchronization pulse output unit and reference signal output unit are connected on the output terminal of signal processing unit, and comparing unit then links to each other with the input end of signal processing unit as a result.Described GPS receiver mainly is made of actual measurement receiving element, actual measurement location Calculation unit and origin reference location computing unit.The radiofrequency signal output unit of GPS simulator and synchronization pulse output unit all link to each other with the input end of the actual measurement receiving element of GPS receiver, and the output terminal of actual measurement receiving element connects the input end of actual measurement location Calculation unit; The reference signal output unit of GPS simulator links to each other with the input end of the origin reference location computing unit of GPS receiver; The actual measurement location Calculation unit of GPS receiver and the output terminal of origin reference location computing unit are connected to the as a result comparing unit of GPS simulator jointly.

Signal processing unit is set the GPS receiver movement locus of simulating at first according to user's request; According to default ephemeris parameter, be encoded to navigation message; Set emulation movement locus and satellite position information constantly according to the user, as seen whether the prediction gps satellite.Then at each synchronizing pulse constantly, for every visible star, according to the corresponding emulation with satellite position calculation of customer location signal carrier phase, pseudo-code phase and signal frequency constantly.Afterwards visible star is assigned to corresponding signal and generates passage; According to the parameter that 2. step is calculated, set original carrier phase place, code phase and the navigation message phase place of each satellite, generate corresponding carrier wave, code and telegraph signal according to frequency information again, and finish three's spread spectrum, modulation, obtain intermediate frequency GPS simulating signal.

The radiofrequency signal output unit upconverts to the standard radio frequency frequency of GPS with the intermediate frequency GPS simulating signal that signal processing unit produces, and exports to the GPS receiver.

The synchronization pulse output unit is cycle that signal generates to be cycle of pseudo-code to export to the GPS receiver with the synchronization pulse in the signal processing unit.The synchronizing pulse of synchronization pulse output unit output is the cycle that signal generates, and is the cycle length of pseudo-code.In the utility model, the cycle that generates owing to signal is Millisecond, so the synchronizing pulse of synchronization pulse output unit also is Millisecond.In the utility model preferred embodiment, the GPS simulator at every millisecond of synchronizing pulse constantly, all can be according to the corresponding emulation with satellite position calculation of customer location signal carrier phase, pseudo-code phase and signal frequency constantly, so the synchronizing pulse of synchronization pulse output unit output is 1 millisecond.

The signal carrier phase that the reference signal output unit calculates signal processing unit, pseudo-code phase information and satellite position are exported to the GPS receiver.

The actual measurement receiving element gathers the radiofrequency signal of GPS simulator emission under synchronizing pulse control, carry out traditional signal capture tracking, pseudo range measurement and ephemeris decoding.

The result of calculation that actual measurement location Calculation unit is exported according to the actual measurement receiving element, and carry out location Calculation.

The origin reference location computing unit directly receives signal carrier phase, pseudo-code phase information and the satellite position of reference signal output unit output, directly positions and resolves.

The comparing unit positioning calculation result that will survey the output of location Calculation unit and origin reference location computing unit compares as a result, and comparison result is sent in the signal processing unit analyze.

The GPS simulator and the receiver closed loop test method that adopt said system to realize comprise the steps:

1. the GPS simulator is set the GPS receiver movement locus of simulating according to user's request; According to default ephemeris parameter, be encoded to navigation message; Set emulation movement locus and satellite position information constantly according to the user, as seen whether the prediction gps satellite;

2. the GPS simulator is in each synchronizing pulse moment, for every visible star, according to the corresponding emulation with satellite position calculation of customer location signal carrier phase, pseudo-code phase and signal frequency constantly;

3. the GPS simulator is assigned to corresponding signal to visible star and generates passage; According to the parameter that 2. step is calculated, set original carrier phase place, code phase and the navigation message phase place of each satellite, generate corresponding carrier wave, code and telegraph signal according to frequency information again, and finish three's spread spectrum, modulation, obtain intermediate frequency GPS simulating signal;

4. the radio-frequency module of GPS simulator upconverts to the standard radio frequency frequency of GPS with step intermediate frequency GPS simulating signal 3., and exports to the GPS receiver;

5. simultaneously, the GPS simulator is with step synchronization pulse 2., and the signal carrier phase, pseudo-code phase information and the satellite position that calculate are exported to the GPS receiver;

The synchronizing pulse of GPS simulator output is the cycle that signal generates, and is the cycle length of pseudo-code.In the utility model, the cycle that generates owing to signal is Millisecond, so the synchronizing pulse of GPS simulator output also is Millisecond.In the utility model preferred embodiment, the GPS simulator at every millisecond of synchronizing pulse constantly, all can be according to the corresponding emulation with satellite position calculation of customer location signal carrier phase, pseudo-code phase and signal frequency constantly, so the synchronizing pulse of GPS simulator output is 1 millisecond.

6. the GPS receiver gathers the radiofrequency signal of GPS simulator emission under synchronizing pulse control, carries out traditional signal capture tracking, pseudo range measurement and ephemeris decoding, finishes positioning calculation again;

7. simultaneously, the GPS receiver receives signal carrier phase, pseudo-code phase information and the satellite position from the emission of GPS simulator, directly positions and resolves;

8. 6. the GPS receiver all feeds back to the GPS simulator with two kinds of positioning results that 7. step goes on foot gained with step, can detect the positioning calculation effect of GPS receiver and/or the signal imitation precision of GPS simulator by contrasting two kinds of positioning results.

Step positioning result 7. is the desirable information of GPS simulator output, and the customer location that this desired position result and simulator are simulated is in full accord.Therefore, under the prerequisite of the signal imitation precision that guarantees the GPS simulator, 7. the desired position result who obtains when the actual location result who 6. obtains according to step and step more near the time, the location reception of GPS receiver is better, and namely the pseudorange of GPS receiver is that the measuring accuracy of pseudo-code phase or carrier phase is higher, ephemeris error is less, the positioning calculation method is more outstanding; Otherwise then the location reception of GPS receiver is poorer.In addition, under the prerequisite of the positioning calculation effect that guarantees the GPS receiver, the desired position result who 7. obtains when the actual location result who 6. obtains according to step and step more near the time, the signal imitation precision of GPS simulator is higher; Otherwise the signal imitation precision of GPS simulator is lower.

Claims

1.GPS simulator and receiver closed loop test system comprise GPS simulator and GPS receiver, it is characterized in that:

Described GPS simulator mainly is made of signal processing unit, radiofrequency signal output unit, synchronization pulse output unit and reference signal output unit; Wherein radiofrequency signal output unit, synchronization pulse output unit and reference signal output unit are connected on the output terminal of signal processing unit;

Described GPS receiver is mainly by actual measurement receiving element and location Calculation cell formation;

The radiofrequency signal output unit of GPS simulator links to each other with the input end of synchronization pulse output unit with the actual measurement receiving element of GPS receiver, and the output terminal of actual measurement receiving element connects one of them input end of location Calculation unit; The reference signal output unit of GPS simulator directly links to each other with another input end of the location Calculation unit of GPS receiver; 2 output terminals of the location Calculation unit of GPS receiver are connected to the input end of the signal processing unit of GPS simulator jointly.