CN101630000B - System for estimating influence of interference signal on GPS performance - Google Patents

System for estimating influence of interference signal on GPS performance Download PDF

Info

Publication number
CN101630000B
CN101630000B CN 200810116830 CN200810116830A CN101630000B CN 101630000 B CN101630000 B CN 101630000B CN 200810116830 CN200810116830 CN 200810116830 CN 200810116830 A CN200810116830 A CN 200810116830A CN 101630000 B CN101630000 B CN 101630000B
Authority
CN
China
Prior art keywords
gps
signal
satellite
subsystem
receiver
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN 200810116830
Other languages
Chinese (zh)
Other versions
CN101630000A (en
Inventor
宁春林
施浒立
田炳丽
李圣明
胡超
胡正群
宁波
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National Astronomical Observatories of CAS
Original Assignee
National Astronomical Observatories of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by National Astronomical Observatories of CAS filed Critical National Astronomical Observatories of CAS
Priority to CN 200810116830 priority Critical patent/CN101630000B/en
Publication of CN101630000A publication Critical patent/CN101630000A/en
Application granted granted Critical
Publication of CN101630000B publication Critical patent/CN101630000B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Position Fixing By Use Of Radio Waves (AREA)

Abstract

本发明公开了一种基于GPS软件接收机评估干扰信号对GPS性能影响的系统，包括：GPS天线模块和射频模块子系统，用于将接收的GPS信号由射频下变频至中频，经过采样后得到数字中频信号输出给GPS软件接收机子系统；干扰信号仿真子系统，用于产生数字干扰信号，将产生的数字干扰信号输出给GPS软件接收机子系统；GPS软件接收机子系统，用于对输入的数字中频信号和数字干扰信号进行信号捕获、信号跟踪、位同步和帧同步、伪距计算，以及卫星位置和用户位置计算，将结果输出给GPS软件接收机评估子系统；GPS软件接收机评估子系统，用于对接收的结果进行误差分析，实现干扰信号对GPS性能影响的评估。利用本发明，能够确定干扰信号的哪方面是影响GPS性能的主要因素。

The invention discloses a system for evaluating the influence of interference signals on GPS performance based on a GPS software receiver. The digital intermediate frequency signal is output to the GPS software receiver subsystem; the interference signal simulation subsystem is used to generate digital interference signals, and the generated digital interference signals are output to the GPS software receiver subsystem; the GPS software receiver subsystem is used to process the input digital signals The intermediate frequency signal and digital interference signal are used for signal acquisition, signal tracking, bit synchronization and frame synchronization, pseudo-range calculation, satellite position and user position calculation, and the results are output to the GPS software receiver evaluation subsystem; GPS software receiver evaluation subsystem , which is used to analyze the error of the received result and realize the evaluation of the influence of the interference signal on the GPS performance. Using the present invention, it is possible to determine which aspect of the interfering signal is the main factor affecting GPS performance.

Description

A kind of system that assesses undesired signal to the GPS performance impact
Technical field
The present invention relates to the satellite navigation technical field, relate in particular to a kind of based on the system of GPS software receiver assessment interference (artificial interference (jamming) or interference (interference)) signal to the GPS performance impact.
Background technology
GPS adopts direct sequence spread spectrum skill to have certain anti-interference capability, but the gps signal that arrives ground is very faint, to ground reception place gps signal power pact-160dBW, because when the receiver signal despreading is handled, processing gain just obtains after taking place in that pseudo-code is relevant, to such an extent as to receiver can be easy to be subjected to variously have a mind to, Radio frequency interference (RFI) unintentionally.Relevant influence can reduce the carrier noise density of all gps signals than (C/N0) to Radio frequency interference (RFI) to sign indicating number.If C/N0 drops to below the tracking thresholding of GPS receiver, just make GPS receiver losing lock, lose the ability that obtains measured value from gps signal.So the Anti-Jamming Technique of GPS receiver becomes the important component part of gps system interference protection measure.
Radio frequency interference (RFI) is divided into selective interference, broadband interference and ultra broadband and disturbs.The method that a lot of inhibition GPS undesired signals have been arranged at present, but a lot of methods are carried out on various GPS hardware receivers, be difficult to change the needs that all kinds of parameters of receiver are handled with adaptation signal when needing to increase hardware supported, the more important thing is the different of hardware and receiver architecture, be difficult to determine which aspect of undesired signal is the principal element that influences the GPS performance.
In recent years, software radio is used widely as a kind of new technology.The software wireless method for electrically has weakened the requirement to hardware greatly.Along with the fast development of computing machine, the calculated load that signal Processing causes weakens greatly, is easy to research and develop new interference removal method.The GPS software receiver only need be done less change just can express analysis, emulation, all kinds of algorithms of realization, particularly catch, follow the tracks of and locate what signal baseband was handled, be to realize fully by software, can accomplish under identical situation, to analyze and compare undesired signal, thereby which aspect that can determine undesired signal is the principal element that influences the GPS performance to the GPS Effect on Performance.
Summary of the invention
(1) technical matters that will solve
In view of this, it is a kind of based on the system of GPS software receiver assessment undesired signal to the GPS performance impact that fundamental purpose of the present invention is to provide, and is the principal element that influences the GPS performance with which aspect of determining undesired signal.
(2) technical scheme
For achieving the above object, the invention provides a kind ofly based on the system of GPS software receiver assessment undesired signal to the GPS performance impact, this system comprises:
Gps antenna module and radio-frequency module subsystem are used to receive the gps signal of gps satellite emission, with the gps signal that receives by radio frequency down-conversion to intermediate frequency, and behind over-sampling, obtain digital medium-frequency signal and export to GPS software receiver subsystem;
The Jamming Signal Simulation subsystem is used to produce the digital interference signal, and the digital interference signal that produces is exported to GPS software receiver subsystem;
GPS software receiver subsystem, be used for the digital medium-frequency signal and the digital interference signal of input are carried out signal capture, signal trace, bit synchronization and frame synchronization, its computation of pseudoranges, and satellite position and customer location calculating, and with signal capture, signal trace, its computation of pseudoranges, and satellite position and customer location result of calculation are exported to GPS software receiver evaluation subsystem;
GPS software receiver evaluation subsystem is used for signal capture, signal trace, its computation of pseudoranges to receiving, and satellite position and customer location result of calculation carries out error analysis, realizes the assessment of undesired signal to the GPS performance impact.
In the such scheme, described gps antenna module and radio-frequency module subsystem comprise gps antenna, radio-frequency front-end and digital collection card at least, gps antenna receives the gps signal of gps satellite emission, and the gps signal that receives amplified through low noise and bandpass filtering treatment after export to radio-frequency front-end; Gps signal is downconverted to Low Medium Frequency after entering radio-frequency front-end, and the output digital medium-frequency signal is to GPS software receiver subsystem after the sampling of digital collection card.
In the such scheme, described Jamming Signal Simulation subsystem is realized by the Matlab software in the computing machine, is used to generate the digital interference signal under the various situations, comprises at least: narrow-band digital undesired signal, wideband digital undesired signal and ultra-broadband digital undesired signal.
In the such scheme, described GPS software receiver subsystem carries out signal capture to the digital medium-frequency signal and the digital interference signal of input, be the first step that gps signal is handled, be used to obtain the roughly carrier frequency of satellite-signal and the code phase of C/A sign indicating number, for follow-up signal trace provides starting condition; And this signal capture be thick synchronously, be used for the signal that will receive and local signal phase differential narrow down to chip of pseudo-code or more among a small circle in.
In the such scheme, described GPS software receiver subsystem carries out signal trace to the digital medium-frequency signal and the digital interference signal of input, carries out after signal capture is finished, and is used to obtain navigation data; This signals tracking process will be caught the code phase of the roughly carrier frequency that obtains and C/A sign indicating number as starting condition, comprise two loops: follow the tracks of the sign indicating number loop of C/A sign indicating number and follow the tracks of the carrier loop of carrier frequency, the sign indicating number loop tracks adopts delay locked loop DLL, carrier loop is followed the tracks of and is adopted the Costas phaselocked loop, and these two loops are coupled; The correlation integral that tracking results is output as 1ms adds up; This signals tracking process is a fine synchronization, the phase change of local reference signal accurate tracking received signal.
In the such scheme, described GPS software receiver subsystem carries out bit synchronization and frame synchronization to the digital medium-frequency signal and the digital interference signal of input, is used for the result of signal trace is converted into navigation message; After the result of signal trace is converted into navigation message, carry out parity checking, this parity checking is divided into two verifications: first verification is that the 25th～30bit of each subframe is a parity check bit, satisfies parity arithmetic; Second verification is that the 29th～30bit is a parity code 00 in the 2nd character code HOW of each subframe; Behind bit synchronization, frame synchronization and checksum verification, in the 2nd character code HOW of each subframe, the 20th～22bit is the subframe sequence number; According to the form of subframe sequence number and navigation message, all satellite ephemeris, the satellite clock that navigation message comprises be can calculate and parameter and temporal information corrected, and the satellite position that calculates unit when any.
In the such scheme, described GPS software receiver subsystem is as follows to the digital medium-frequency signal and the digital interference signal process of carrying out its computation of pseudoranges of input: remove satellite star clock error, gps satellite sends identical subframe at synchronization, receiver is received identical subframe in the different moment, and same sub arrives the delay inequality of receiver antenna and represents the distance of satellite to receiver; Each subframe repetition time is 30s, and above-mentioned delay inequality is 19ms to the maximum, as long as delay inequality is in 19ms, can think that same sub is that synchronization at different satellites sends; Because in the software receiver image data is handled afterwards, there is not the local reference time, sample frequency information just becomes unique available temporal information, the interval of the sampled data points of the subframe starting point correspondence of each satellite can be arrived the delay inequality of antenna as satellite subframe starting point; The travel-time that gps satellite signal arrives ground receiver is generally 67～86ms, and a constant can artificially be set, and supposes that this constant is 68ms, and this constant is added the signal travel-time of delay inequality, and described pseudorange just equals this travel-time and multiply by the light velocity.
In the such scheme, described GPS software receiver subsystem is to the digital medium-frequency signal of input and the digital interference signal carries out satellite position and the customer location calculation process is as follows: utilize geocentric inertial coordinate system ECI to measure and determine the track of gps satellite, utilize the earth's core body-fixed coordinate system ECEF to calculate the position of GPS receiver; The numerical value of the satellite ephemeris in the navigation message is under the ECI, in order to calculate the position of GPS receiver, satellite ephemeris to be transformed to the ECEF coordinate system from ECI; And the time changes in ECEF, for the position of determining the user will provide a gps time t cAccording to gps time t cAnd satellite ephemeris, under the ECI coordinate system, try to achieve the position of satellite, utilize coordinate system transformation to try to achieve the position of satellite under the ECEF coordinate system then, try to achieve the position of receiver at last according to the location column system of equations of the pseudorange of receiver to four satellite and four satellites.
In the such scheme, described GPS software receiver evaluation subsystem comprises the assessment of following three partial contents at least: catch error analysis assessment, tracking error analysis and evaluation and the assessment of pseudorange analysis of Positioning Error.
In the such scheme, various narrow-band interference signals, wideband interferer signal and ultra broadband undesired signal that described GPS software receiver evaluation subsystem utilizes Matlab software to generate enter with the gps signal stack respectively carries out signal capture, signal trace and pseudorange positioning calculation process in the GPS software receiver, the situation of catching in this process, tracking situation and pseudorange are located situation and do not had the situation of catching, tracking situation and pseudorange location situation under the various disturbed conditions to compare analysis, obtain qualitative and quantitative result; For same type interference, also can under amplitude, frequency and the bandwidth situation of undesired signal, compare, obtain qualitative and quantitative results.
(3) beneficial effect
Provided by the invention this based on the system of GPS software receiver assessment undesired signal to the GPS performance impact, interface definition between each subsystem module is clear and definite, as long as satisfy interface requirement, the realization of inside modules just can have multiple implementation, also can not influence in the system other module.Can make like this under the situation of software design being changed seldom, just can test, and then can determine which aspect of undesired signal is the principal element that influences the GPS performance various dissimilar antenna structures, signal form, processing mode and analytical approach.
Description of drawings
Fig. 1 is provided by the invention based on the structural representation of GPS software receiver assessment undesired signal to the system of GPS performance impact;
Fig. 2 is provided by the invention based on the functional schematic of GPS software receiver assessment undesired signal to the system of GPS performance impact.
Embodiment
For making the purpose, technical solutions and advantages of the present invention clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in more detail.
Provided by the invention this based on the system of GPS software receiver assessment undesired signal to the GPS performance impact, comprise gps antenna module and radio-frequency module subsystem, Jamming Signal Simulation subsystem, GPS software receiver subsystem and GPS software receiver evaluation subsystem.
Structurally, as shown in Figure 1, the present invention can be divided into input, handles and analyze three parts, wherein the importation comprises gps antenna module and radio-frequency module subsystem, and Jamming Signal Simulation subsystem, GPS software receiver subsystem belongs to the processing section, and analysis part is a GPS software receiver evaluation subsystem.Gps antenna module and radio-frequency module subsystem belong to hardware components, and Jamming Signal Simulation subsystem, GPS software receiver subsystem and GPS software receiver evaluation subsystem are based on the software section of PC.
Wherein, gps antenna module and radio-frequency module subsystem are used to receive the gps signal of gps satellite emission, with the gps signal that receives by radio frequency down-conversion to intermediate frequency, and behind over-sampling, obtain digital medium-frequency signal and export to GPS software receiver subsystem.The Jamming Signal Simulation subsystem is used to produce the digital interference signal, and the digital interference signal that produces is exported to GPS software receiver subsystem.GPS software receiver subsystem, be used for the digital medium-frequency signal and the digital interference signal of input are carried out signal capture, signal trace, bit synchronization and frame synchronization, its computation of pseudoranges, and satellite position and customer location calculating, and with signal capture, signal trace, its computation of pseudoranges, and satellite position and customer location result of calculation are exported to GPS software receiver evaluation subsystem.GPS software receiver evaluation subsystem is used for signal capture, signal trace, its computation of pseudoranges that receives, and satellite position and customer location result of calculation carries out error analysis, realizes the assessment of undesired signal to the GPS performance impact.
Described gps antenna module and radio-frequency module subsystem comprise gps antenna, radio-frequency front-end and digital collection card at least, gps antenna receives the gps signal of gps satellite emission, and the gps signal that receives amplified through low noise and bandpass filtering treatment after export to radio-frequency front-end; Gps signal is downconverted to Low Medium Frequency after entering radio-frequency front-end, and the output digital medium-frequency signal is to GPS software receiver subsystem after the sampling of digital collection card.
Described Jamming Signal Simulation subsystem is realized by the Matlab software in the computing machine, is used to generate the digital interference signal under the various situations, comprises at least: narrow-band digital undesired signal, wideband digital undesired signal and ultra-broadband digital undesired signal.
On function, as shown in Figure 2, the gps signal of launching from gps satellite is received by gps antenna, through radio-frequency front-end with its by radio frequency down-conversion to intermediate frequency, exist on the hard disk through the form with file behind the over-sampling.Utilize the Matlab software on the PC to produce digital interference signal miscellaneous simultaneously, also the form with file exists on the hard disk.Matlab software among the PC is handled the input of back as GPS software receiver subsystem with the signal and the signal in the digital interference file of digital intermediate frequency file.The GPS software receiver to input signal catch, tracking and its computation of pseudoranges, obtain positioning result at last.GPS software receiver evaluation subsystem to catch, the error of tracking and its computation of pseudoranges and positioning result analyzes.
Below to constituting provided by the invention thisly be described in detail respectively based on GPS software receiver assessment undesired signal each ingredient to GPS performance impact system.
1) Anneta module and radio-frequency module subsystem
Anneta module and radio-frequency module subsystem are based on hard-wired, and the kind of antenna is a lot, and the signal that receives is handled through low noise amplifier and bandpass filter, outputs to radio-frequency module.Signal is down-converted to Low Medium Frequency after entering radio-frequency module, output digital medium-frequency signal after the sampling of digital collection card, and data are stored in the hard disc of computer temporarily.
Only at the L1 wave band 1575.42MHz of GPS, the structure of tube antenna is not how in the present invention, and the centre frequency of antenna all will satisfy above-mentioned frequency.The effect of the down coversion in the radio-frequency module is exactly that the radiofrequency signal of 1575.42MHz is become the Low Medium Frequency signal, and the typical frequency of the signal of this Low Medium Frequency is 4.309MHz.The selection of capture card sampling rate needs only the intermediate frequency carrier according to radio-frequency module output, and satisfying is to lose this special law of sampling, and considers the design of simplifying frequency synthesizer simultaneously, should reduce sampling rate as far as possible, so that improve the reliability of system, reduce requirement to hardware, typical sample frequency is 12MHz.
2) Jamming Signal Simulation subsystem
Radio frequency interference (RFI) is divided into selective interference, broadband interference and ultra broadband and disturbs.Utilize Matlab software can generate digital interference signal under the various situations.
3) GPS software receiver subsystem
Widely used common receiver is based on special IC (Application SpecificIntegrated Circuit at present, ASIC) receiver of structure, and ASIC has limited dirigibility, the research staff is difficult to new algorithm is tested, analyzed and uses, and software receiver then is a kind of fine selection of receiver design.Software receiver is not the processing of carrying out signal capture and tracking in hardware but in software, with respect to common receiver, software receiver exploitation new algorithm does not need corresponding new hardware supported, so have that structure is general, a flexible function, advantage such as system improves and upgrading is convenient.
3.1 signal capture
Signal capture is the first step in gps signal is handled, and purpose is to obtain the roughly carrier frequency of satellite-signal and the code phase of C/A sign indicating number, for follow-up signal trace provides starting condition.Catch be thick synchronously, received signal and local signal phase differential can be narrowed down to chip of pseudo-code or more among a small circle in.
3.2 signal trace
In a single day signal captures with regard to entering signal and follows the tracks of link, and this link purpose is to obtain navigation data.Follow the tracks of processing from catching the roughly carrier frequency that obtains and the code phase of C/A sign indicating number as starting condition.Need two loops in order to follow the tracks of gps signal: follow the tracks of the sign indicating number loop of C/A sign indicating number and follow the tracks of the carrier loop of carrier frequency.Traditional sign indicating number loop tracks employing delay locked loop (Delay Lock Loop, DLL), the general normal classical Costas phaselocked loop that adopts of carrier track, these two loops are coupled.The correlation integral that tracking results is output as 1ms adds up.Tracking is a fine synchronization, allows the phase change of local reference signal accurate tracking received signal.
3.3 bit synchronization and frame synchronization
According to tracking results, just can recover navigation message through bit synchronization and frame synchronization.Next step is parity checking, and this parity checking is divided into two verifications, and first verification is that the 25th～30bit of each subframe is a parity check bit, satisfy parity arithmetic; Second verification is in the 2nd character code of each subframe (HOW), and bit29～30 are parity code (00).Behind bit synchronization, frame synchronization and checksum verification, in the 2nd character code of each subframe (HOW), bit20～22 are the subframe sequence number.According to the form of subframe sequence number and navigation message, just can calculate all satellite ephemeris, the satellite clock that navigation message comprises and correct parameter and temporal information etc., can calculate the satellite position of unit when any.
3.4 its computation of pseudoranges
Gps satellite sends identical subframe at synchronization (removing satellite star clock error), and receiver is received identical subframe in the different moment, and same sub arrives the delay inequality of receiver antenna and represents the distance of satellite to receiver.Each subframe repetition time is 30s, and above-mentioned delay inequality is 19ms to the maximum.In other words, as long as delay inequality is in 19ms, just can think that same sub is in the synchronization transmission of different satellites.Because in the software receiver image data is handled afterwards, there is not the local reference time, sample frequency information just becomes unique available temporal information, can arrive the interval of the sampled data points of the subframe starting point correspondence of each satellite as satellite subframe starting point the delay inequality of antenna.In addition, the travel-time that gps satellite signal arrives ground receiver is generally 67～86ms, constant hypothesis 68ms can artificially be set add the signal travel-time of delay inequality, and pseudorange just equals this travel-time and takes advantage of the light velocity.
3.5 satellite position and customer location calculate
Measure and the track of definite gps satellite, utilize geocentric inertial coordinate system (Earth-CenteredInteria, ECI); Calculate the position of GPS receiver, utilize the earth's core body-fixed coordinate system (Earth-Centered, Earth-Fixed, ECEF).The numerical value of the satellite ephemeris in the navigation message is under the ECI, in order to calculate the position of GPS receiver, satellite ephemeris must be transformed to the ECEF coordinate system from ECI.And the time changes in ECEF, so will provide a gps time t for the position of determining the user cAccording to gps time t cAnd satellite ephemeris, under the ECI coordinate system, try to achieve the position of satellite, utilize coordinate system transformation to try to achieve the position of satellite under the ECEF coordinate system then.Try to achieve at last the position of receiver according to the location column system of equations of the pseudorange of receiver to four satellite and four satellites.
4) GPS software receiver evaluation subsystem
GPS software receiver evaluation subsystem comprises the assessment of three partial contents: catch error analysis assessment, tracking error analysis and evaluation and the assessment of pseudorange analysis of Positioning Error.
Processes such as various narrow-band interference signals, wideband interferer signal and the ultra broadband undesired signal of utilizing Matlab software to generate enters in the GPS software receiver with the gps signal stack respectively and catch, tracking and pseudorange location Calculation, the situation of catching, tracking situation and the pseudorange of this process are located situation and do not had the situation of catching, tracking situation and pseudorange location situation under the various disturbed conditions to compare analysis, obtain qualitative and quantitative result.
For same type interference, can under the various situations such as amplitude, frequency and bandwidth of undesired signal, compare, thereby also can obtain qualitative and quantitative results.
Above-described specific embodiment; purpose of the present invention, technical scheme and beneficial effect are further described; institute is understood that; the above only is specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any modification of being made, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1.一种基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，该系统包括：1. A system based on GPS software receiver evaluation interference signal to GPS performance impact, it is characterized in that, this system comprises: GPS天线模块和射频模块子系统，用于接收GPS卫星发射的GPS信号，将接收的GPS信号由射频下变频至中频，并经过采样后得到数字中频信号输出给GPS软件接收机子系统；The GPS antenna module and radio frequency module subsystem are used to receive GPS signals transmitted by GPS satellites, down-convert the received GPS signals from radio frequency to intermediate frequency, and obtain digital intermediate frequency signals after sampling and output them to the GPS software receiver subsystem; 干扰信号仿真子系统，用于产生数字干扰信号，并将产生的数字干扰信号输出给GPS软件接收机子系统；The interference signal simulation subsystem is used to generate digital interference signals and output the generated digital interference signals to the GPS software receiver subsystem; GPS软件接收机子系统，用于对输入的数字中频信号和数字干扰信号进行信号捕获、信号跟踪、位同步和帧同步、伪距计算，以及卫星位置和用户位置计算，并将信号捕获、信号跟踪、伪距计算，以及卫星位置和用户位置计算结果输出给GPS软件接收机评估子系统；The GPS software receiver subsystem is used for signal capture, signal tracking, bit synchronization and frame synchronization, pseudo-range calculation, satellite position and user position calculation for the input digital intermediate frequency signal and digital interference signal, and signal capture, signal tracking , Pseudo-range calculation, and satellite position and user position calculation results are output to the GPS software receiver evaluation subsystem; GPS软件接收机评估子系统，用于对接收的信号捕获、信号跟踪、伪距计算，以及卫星位置和用户位置计算结果进行误差分析，实现干扰信号对GPS性能影响的评估。The GPS software receiver evaluation subsystem is used for error analysis of the received signal acquisition, signal tracking, pseudo-range calculation, and satellite position and user position calculation results, so as to realize the evaluation of the influence of interference signals on GPS performance. 2.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述GPS天线模块和射频模块子系统至少包括GPS天线、射频前端和数字采集卡，GPS天线接收GPS卫星发射的GPS信号，并将接收的GPS信号经过低噪声放大和带通滤波处理后输出给射频前端；GPS信号进入射频前端后被下变频至低中频，经数字采集卡采样后输出数字中频信号至GPS软件接收机子系统。2. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described GPS antenna module and radio frequency module subsystem comprise GPS antenna, radio frequency front-end and digital acquisition card at least, The GPS antenna receives the GPS signal transmitted by the GPS satellite, and outputs the received GPS signal to the RF front-end after low-noise amplification and band-pass filtering; the GPS signal enters the RF front-end and is down-converted to a low-intermediate frequency, and is sampled by a digital acquisition card Output the digital intermediate frequency signal to the GPS software receiver subsystem. 3.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述干扰信号仿真子系统由计算机中的Matlab软件实现，用于生成各种情况下的数字干扰信号，至少包括：窄带数字干扰信号、宽带数字干扰信号和超宽带数字干扰信号。3. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described interference signal simulation subsystem is realized by the Matlab software in the computer, is used for generating various situations digital interference signals, at least including: narrowband digital interference signals, wideband digital interference signals and ultra-wideband digital interference signals. 4.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述GPS软件接收机子系统对输入的数字中频信号和数字干扰信号进行信号捕获，是GPS信号处理的第一步，用于获得卫星信号的大致载波频率和C/A码的码相位，为后续的信号跟踪提供初始条件；且该信号捕获是粗同步，用于将接收的信号和本地信号相位差缩小到伪码的一个码片或更小范围内。4. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described GPS software receiver subsystem carries out signal acquisition to the digital intermediate frequency signal of input and digital interference signal, is The first step of GPS signal processing is used to obtain the approximate carrier frequency of the satellite signal and the code phase of the C/A code, which provides initial conditions for subsequent signal tracking; and the signal acquisition is coarse synchronization, which is used to combine the received signal and The local signal phase difference is reduced to within one chip or less of the pseudocode. 5.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述GPS软件接收机子系统对输入的数字中频信号和数字干扰信号进行信号跟踪，是在信号捕获完成后进行的，用于获得导航数据；该信号跟踪过程将捕获得到的大致载波频率和C/A码的码相位作为初始条件，包括两个环路：跟踪C/A码的码环路和跟踪载波频率的载波环路，码环路跟踪采用延迟锁定环路DLL，载波环路跟踪采用Costas锁相环，且这两个环路耦合在一起；跟踪结果的输出为1ms的相关积分累加；该信号跟踪过程是精细同步，本地参考信号精确跟踪接收信号的相位变化。5. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described GPS software receiver subsystem carries out signal tracking to the digital intermediate frequency signal of input and digital interference signal, is It is carried out after the signal acquisition is completed, and is used to obtain navigation data; the signal tracking process takes the acquired approximate carrier frequency and the code phase of the C/A code as initial conditions, including two loops: tracking the code of the C/A code Loop and carrier loop tracking carrier frequency, code loop tracking uses delay-locked loop DLL, carrier loop tracking uses Costas phase-locked loop, and the two loops are coupled together; the output of the tracking result is a correlation of 1ms Integral accumulation; the signal tracking process is fine synchronization, and the local reference signal accurately tracks the phase change of the received signal. 6.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述GPS软件接收机子系统对输入的数字中频信号和数字干扰信号进行位同步和帧同步，用于将信号跟踪的结果转化为导航电文；信号跟踪的结果转化为导航电文后，进行奇偶校验，该奇偶校验分为两个校验：第一校验是每个子帧的第25～30bit为奇偶校验位，满足奇偶校验算法；第二校验是在每个子帧第2个字码HOW中，第29～30bit为奇偶检验码00；通过位同步、帧同步和奇偶校验验证后，在每个子帧第2个字码HOW中，第20～22bit为子帧序号；根据子帧序号和导航电文的格式，可计算导航电文包含的所有卫星星历、卫星时钟改正参数以及时间信息，以及计算任意时元的卫星位置。6. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described GPS software receiver subsystem carries out bit synchronization and frame to the digital intermediate frequency signal of input and digital interference signal Synchronization, used to convert the result of signal tracking into navigation message; after the result of signal tracking is converted into navigation message, perform parity check, which is divided into two checks: the first check is the first check of each subframe 25~30bit is the parity check bit, which satisfies the parity check algorithm; the second check is in the second word HOW of each subframe, and the 29th~30bit is the parity check code 00; through bit synchronization, frame synchronization and parity After verification and verification, in the second word HOW of each subframe, the 20th to 22bits are the subframe serial number; according to the subframe serial number and the format of the navigation message, all satellite ephemeris and satellite clock corrections included in the navigation message can be calculated Parameters and time information, and calculate the satellite position for any epoch. 7.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述GPS软件接收机子系统对输入的数字中频信号和数字干扰信号进行伪距计算的过程如下：7. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described GPS software receiver subsystem carries out pseudo-range calculation to input digital intermediate frequency signal and digital interference signal The process is as follows: 除去卫星星钟误差，GPS卫星在同一时刻发送相同的子帧，接收机在不同的时刻收到相同的子帧，相同子帧到达接收机天线的时延差代表卫星到接收机的距离；每个子帧重复时间为30s，而上述的时延差最大为19ms，只要时延差在19ms以内，可认为相同子帧是在不同卫星的同一时刻发送的；因为软件接收机中对采集数据进行事后处理，没有本地参考时间，采样频率信息就成为唯一可用的时间信息，可将各卫星的子帧起点对应的采样数据点的间隔作为卫星子帧起点到达天线的时延差；GPS卫星信号到达地面接收机的传播时间一般为67～86ms，可以人为设置一常量，将该常量加上时延差作为信号的传播时间，所述伪距就等于该传播时间乘以光速。Except for the satellite clock error, the GPS satellite sends the same subframe at the same time, and the receiver receives the same subframe at different times, and the delay difference between the arrival of the same subframe at the receiver antenna represents the distance from the satellite to the receiver; The repetition time of each subframe is 30s, and the above-mentioned delay difference is at most 19ms. As long as the delay difference is within 19ms, it can be considered that the same subframe is sent at the same time of different satellites; Processing, without a local reference time, the sampling frequency information becomes the only available time information, and the interval between the sampling data points corresponding to the starting point of each satellite subframe can be used as the delay difference between the starting point of the satellite subframe and the antenna; the GPS satellite signal reaches the ground The propagation time of the receiver is generally 67-86 ms. A constant can be set artificially, and the constant plus the delay difference is used as the propagation time of the signal. The pseudo-range is equal to the propagation time multiplied by the speed of light. 8.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述GPS软件接收机子系统对输入的数字中频信号和数字干扰信号进行卫星位置和用户位置计算的过程如下：8. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described GPS software receiver subsystem carries out satellite position and user to the digital intermediate frequency signal of input and digital interference signal The process of position calculation is as follows: 利用地心惯性坐标系ECI测量和确定GPS卫星的轨道，利用地心地固坐标系ECEF计算GPS接收机的位置；导航电文中的卫星星历的数值是ECI下的，为了计算GPS接收机的位置，将卫星星历从ECI变换到ECEF坐标系；而时间在ECEF中是变化的，为了确定用户的位置要给出一个GPS时间tc；根据GPS时间tc和卫星星历，在ECI坐标系下求得卫星的位置，然后利用坐标系变换求得卫星在ECEF坐标系下的位置，最后根据接收机到四颗卫星的伪距和四颗卫星的位置列方程组求得接收机的位置。Use the earth-centered inertial coordinate system ECI to measure and determine the orbit of the GPS satellite, and use the earth-centered earth-fixed coordinate system ECEF to calculate the position of the GPS receiver; the value of the satellite ephemeris in the navigation message is under the ECI, in order to calculate the position of the GPS receiver , transform the satellite ephemeris from ECI to the ECEF coordinate system; while the time is changing in ECEF, a GPS time t c is given in order to determine the user's position; according to the GPS time t c and the satellite ephemeris, in the ECI coordinate system Calculate the position of the satellite, then use the coordinate system transformation to obtain the position of the satellite in the ECEF coordinate system, and finally obtain the position of the receiver according to the pseudo-range from the receiver to the four satellites and the position of the four satellites. 9.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述GPS软件接收机评估子系统至少包括以下三部分内容的评估：捕获误差分析评估、跟踪误差分析评估和伪距定位误差分析评估。9. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described GPS software receiver evaluation subsystem at least comprises the evaluation of following three parts content: acquisition error analysis evaluation , Tracking error analysis and evaluation and pseudo-range positioning error analysis and evaluation. 10.根据权利要求1所述的基于GPS软件接收机评估干扰信号对GPS性能影响的系统，其特征在于，所述GPS软件接收机评估子系统利用Matlab软件生成的各种窄带干扰信号、宽带干扰信号和超宽带干扰信号分别与GPS信号叠加进入GPS软件接收机中进行信号捕获、信号跟踪和伪距定位计算过程，将该过程中的捕获情况、跟踪情况和伪距定位情况与没有各种干扰情况下的捕获情况、跟踪情况和伪距定位情况进行比较分析，得到定性和定量结果；对于同一种类型的干扰，也可从干扰信号的幅度、频率以及带宽情况下进行对比，得到定性和定量的结果。10. the system based on GPS software receiver evaluation interference signal to GPS performance impact according to claim 1, is characterized in that, described GPS software receiver evaluation subsystem utilizes various narrowband interference signals, broadband interference generated by Matlab software The signal and ultra-wideband interference signal are superimposed with the GPS signal and entered into the GPS software receiver for signal acquisition, signal tracking and pseudo-range positioning calculation process. The capture situation, tracking situation and pseudo-range positioning situation under different conditions can be compared and analyzed to obtain qualitative and quantitative results; for the same type of interference, it can also be compared from the amplitude, frequency and bandwidth of the interference signal to obtain qualitative and quantitative results. the result of.
CN 200810116830 2008-07-18 2008-07-18 System for estimating influence of interference signal on GPS performance Expired - Fee Related CN101630000B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 200810116830 CN101630000B (en) 2008-07-18 2008-07-18 System for estimating influence of interference signal on GPS performance

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 200810116830 CN101630000B (en) 2008-07-18 2008-07-18 System for estimating influence of interference signal on GPS performance

Publications (2)

Publication Number Publication Date
CN101630000A CN101630000A (en) 2010-01-20
CN101630000B true CN101630000B (en) 2011-11-09

Family

ID=41575176

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 200810116830 Expired - Fee Related CN101630000B (en) 2008-07-18 2008-07-18 System for estimating influence of interference signal on GPS performance

Country Status (1)

Country Link
CN (1) CN101630000B (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104977592B (en) * 2015-07-20 2017-11-14 北京航空航天大学 A kind of navigation satellite signal interference simulation and Performance Analysis Platform and its method based on PXI buses
CN107576975B (en) * 2017-08-14 2019-07-30 北京航空航天大学 The treating method and apparatus of the model of error evaluation applied to satellite navigation system
CN109743102B (en) * 2019-01-28 2021-03-05 西安玄黄通信技术有限公司 Time reference synchronization method of micro-nano satellite and networking control method thereof
CN110018441A (en) * 2019-04-12 2019-07-16 相维(北京)科技有限公司 A kind of appraisal procedure of TOA
CN111175697B (en) * 2019-12-31 2023-09-19 中国电子科技集团公司第三十六研究所 Unmanned aerial vehicle self-positioning precision evaluation method and device
CN111385046B (en) * 2020-04-14 2024-10-01 北京航天广通科技有限公司 Amplitude modulation broadcast interference assessment method and device
CN111766612A (en) * 2020-07-09 2020-10-13 广东电网有限责任公司电力科学研究院 Method, device and equipment for evaluating influence degree of electromagnetic interference on positioning result
CN113655503A (en) * 2021-07-27 2021-11-16 西安广和通无线通信有限公司 Method, device and system for testing positioning function and storage medium
CN114152957B (en) * 2021-11-26 2024-11-22 中国电子科技集团公司第五十四研究所 A portable satellite navigation regional service quality comprehensive evaluation device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001103099A (en) * 1999-09-30 2001-04-13 Fujitsu General Ltd Reception data reproducing device
CN1897486A (en) * 2006-05-12 2007-01-17 西安电子科技大学 Satellite figured antenna anti-intrusion based on high-resolution algorithm
CN101029923A (en) * 2007-01-19 2007-09-05 电子科技大学 Software receiver for indoor position and navigation technology of global positioning system
CN101158718A (en) * 2007-11-16 2008-04-09 上海伽利略导航有限公司 Global position system real-time software receiving machine and real-time processing method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001103099A (en) * 1999-09-30 2001-04-13 Fujitsu General Ltd Reception data reproducing device
CN1897486A (en) * 2006-05-12 2007-01-17 西安电子科技大学 Satellite figured antenna anti-intrusion based on high-resolution algorithm
CN101029923A (en) * 2007-01-19 2007-09-05 电子科技大学 Software receiver for indoor position and navigation technology of global positioning system
CN101158718A (en) * 2007-11-16 2008-04-09 上海伽利略导航有限公司 Global position system real-time software receiving machine and real-time processing method thereof

Non-Patent Citations (15)

* Cited by examiner, † Cited by third party
Title
冯青
卢丹
卢丹;冯青;吴仁彪.基于空时自适应处理的GPS宽带干扰抑制技术.《中国民航大学学报》.2007,第25卷(第4期),1-4. *
吴仁彪.基于空时自适应处理的GPS宽带干扰抑制技术.《中国民航大学学报》.2007,第25卷(第4期),1-4.
孙希延
孙希延;纪元法;施浒立.GPS软件基带信号处理与定位实现.《系统仿真学报》.2007,第19卷(第24期),5832-5836. *
宁春林
宁春林;施浒立;李圣明;崔君霞;胡超.GPS软件接收机信号捕获频率分辨率的研究.《计算机工程与应用》.2008,第44卷(第6期),14-16,171. *
崔君霞
施浒立
施浒立.GPS软件基带信号处理与定位实现.《系统仿真学报》.2007,第19卷(第24期),5832-5836.
李圣明
章勇.GPS信号模拟技术及软件接收机的研究.《中国优秀硕士学位论文全文数据库》.2008,(第6期),1-64. *
纪元法
胡超.GPS软件接收机信号捕获频率分辨率的研究.《计算机工程与应用》.2008,第44卷(第6期),14-16，171.

Also Published As

Publication number Publication date
CN101630000A (en) 2010-01-20

Similar Documents

Publication Publication Date Title
CN101630000B (en) System for estimating influence of interference signal on GPS performance
CN107121685A (en) A kind of miniature spaceborne high-dynamic GNSS receiver and its air navigation aid
CN103033828B (en) High-sensitivity compass-assisted time servicing device, time service receiver and time service method
CN107728172A (en) A kind of spaceborne receiver of the Big Dipper/GPS dual-mode and its navigation locating method
CN110673177A (en) A highly dynamic GNSS receiver based on flexible substrate and its navigation method
CN103954977B (en) A kind of GNSS cheating interference cognitive method and system
CN106415314A (en) Method and apparatus for processing radionavigation signals for atmospheric monitoring
CN101710180A (en) Structure of base band circuit for realizing double frequency GPS satellite signal receiver and method thereof
US20150204981A1 (en) Signal processing method for ultra-fast acquisition and tracking of severely attenuated spread spectrum signals with doppler frequency and apparatus thereof
CN101246210A (en) A GPS positioning method and a GPS software receiver based on a dual-core processor
CN103592662A (en) Carrier wave tracking method and loop for GPS signal receiver
CN101520505B (en) Adaptive coherent accumulation joint acquisition method under GNSS weak signal
CN114609652B (en) A multi-frequency open-loop receiver tracking method and system under extreme ionospheric anomaly
US20170285173A1 (en) Method and apparatus for gnss signal tracking
CN113411141B (en) ELORAN signal period identification method and device based on sky wave reconstruction
US8847819B2 (en) Clock drift profile determination in navigation system receivers
CN101498784A (en) Apparatus and method for tracking satellite signal
CN106291612B (en) A kind of aeronautical satellite inter-satellite link wireless signal high-performance prize judgment method
EP2243035B1 (en) Measurement of energy potential (signal-to-noise ratio) in digital global navigation satellite systems receivers
CN102508265B (en) Signal separation estimation theory-based satellite navigation signal multipath interference suppression method
CN110780320B (en) Software and hardware integrated satellite navigation signal processing method
CN106338748A (en) Kalman filtering based GPS receiver tracking loop
CN102565822A (en) Capture method of GPS L5 signal and apparatus thereof
KR101032735B1 (en) GPS receiver for real-time GPS signal tracking through software type CPU processor module
JP2005148005A (en) Satellite positioning method and satellite positioning system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20111109