CN114615619A - Indoor positioning method based on signal reflection points - Google Patents
Indoor positioning method based on signal reflection points Download PDFInfo
- Publication number
- CN114615619A CN114615619A CN202210177544.XA CN202210177544A CN114615619A CN 114615619 A CN114615619 A CN 114615619A CN 202210177544 A CN202210177544 A CN 202210177544A CN 114615619 A CN114615619 A CN 114615619A
- Authority
- CN
- China
- Prior art keywords
- signal
- receiver
- reflection point
- excitation source
- signals
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 58
- 230000005284 excitation Effects 0.000 claims abstract description 126
- 238000001228 spectrum Methods 0.000 claims abstract description 51
- 238000012545 processing Methods 0.000 claims abstract description 19
- 230000001360 synchronised effect Effects 0.000 claims description 27
- 238000006243 chemical reaction Methods 0.000 claims description 18
- 238000001514 detection method Methods 0.000 claims description 18
- 239000002131 composite material Substances 0.000 claims description 9
- 230000007480 spreading Effects 0.000 claims description 9
- 230000005540 biological transmission Effects 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 7
- 238000003672 processing method Methods 0.000 claims description 7
- 238000004364 calculation method Methods 0.000 claims description 5
- 238000005516 engineering process Methods 0.000 description 16
- 238000010586 diagram Methods 0.000 description 11
- 238000010276 construction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/02—Services making use of location information
- H04W4/023—Services making use of location information using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B1/707—Spread spectrum techniques using direct sequence modulation
- H04B1/7073—Synchronisation aspects
- H04B1/7075—Synchronisation aspects with code phase acquisition
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/02—Services making use of location information
- H04W4/021—Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/30—Services specially adapted for particular environments, situations or purposes
- H04W4/33—Services specially adapted for particular environments, situations or purposes for indoor environments, e.g. buildings
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
- H04W64/006—Locating users or terminals or network equipment for network management purposes, e.g. mobility management with additional information processing, e.g. for direction or speed determination
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
Abstract
The invention relates to an indoor positioning method based on signal reflection points, which transmits signals through an excitation source, the transmitted signals are received by the signal reflection points, the signal reflection points perform spread spectrum processing on the received signals, finally, a receiver receives the signals of the excitation source and each signal reflection point, the received signals are processed to obtain the distance difference between each signal reflection point, and the TDOA algorithm is adopted for positioning, so that the target position can be obtained finally. The invention can realize mass deployment in an indoor positioning scheme by utilizing the characteristics of simple structure, lower cost and easy deployment of the signal reflection point.
Description
Technical Field
The invention relates to the technical field of indoor positioning, in particular to an indoor positioning method based on signal reflection points.
Background
With the rapid development of society and the modern construction of cities, more and more large buildings appear in the lives of people. The maturity of Global Navigation Satellite Systems (GNSS), such as the Global Positioning System (GPS) and the beidou satellite navigation system (BDS), has substantially satisfied the need for outdoor positioning in people's daily life. However, research shows that the time of people in an indoor environment in daily life accounts for 80% -90% of the total time, so when a user wants to position any object in a building or a closed environment, due to the limitation of GNSS and the complexity of the indoor environment, the user cannot realize accurate positioning to meet the user's requirement due to the influence of multipath effect, high-frequency change, shadow effect, non-line-of-sight interference and the like on signals, and thus the demand of indoor positioning service becomes stronger and stronger. For example, the market demand of indoor positioning technology in the fields of building management, intelligent hospital construction, personal service, vehicle position inquiry in parking lots, security and the like is large.
According to the placement position of the information source, the existing indoor positioning technology can be divided into two categories: the indoor positioning technology based on the natural information source and the indoor positioning technology based on the external information source. The indoor positioning technology based on the natural information source comprises inertial navigation, geomagnetic navigation and the like; the indoor positioning technology based on the external information source includes an infrared positioning technology, an ultrasonic positioning technology, a bluetooth positioning technology, a WiFi positioning technology, an Ultra Wideband (UWB) positioning technology, a Radio Frequency Identification (RFID) positioning technology, a positioning technology based on Frequency Modulated Continuous Wave (FMCW) and the like. The performance indexes of the indoor positioning system mainly include cost and positioning accuracy, and the current indoor positioning technology has deviation, but the two indexes are difficult to be considered, and how to control the cost while improving the positioning accuracy as much as possible is a great challenge. The trend in the future will be to combine technologies, fuse their advantages, and overcome their respective disadvantages. Therefore, the design of the indoor positioning system with high cost performance, easy realization and simple structure has practical significance.
Disclosure of Invention
Aiming at the defects of high cost and high power consumption of the existing indoor positioning technology, the invention aims to provide an indoor positioning method based on signal reflection points, which is low in cost, low in power consumption and easy to deploy.
In order to achieve the purpose, the invention adopts the technical scheme that:
an indoor positioning method based on signal reflection points is realized based on an indoor positioning system, wherein the indoor positioning system comprises an excitation source, a receiver and at least three signal reflection points;
the excitation source is used for continuously or discontinuously transmitting signals, linear modulation FMCW signals are adopted, and the signals are obtained by modulating the frequency of continuous waves;
the signal reflection points are composed of a receiving antenna, an amplifier, a spread spectrum module and a transmitting antenna, the signal reflection points amplify the received signals, each signal reflection point has a special spread spectrum code, the sequence is used for modulating the received signals, and finally the signals are sent to a receiver, and the spread spectrum codes can be used for identifying the identity information of the signals in the subsequent signal processing process;
the receiver captures signals of an excitation source and a plurality of signal reflection points by using the related reception of a spread spectrum code through a signal processing method by receiving the signals, obtains code phase offset and frequency offset estimation, separates out the reflection signal of each signal reflection point, can calculate the distance difference from each signal reflection point to the receiver, and obtains the position information of the receiver by using a TDOA (time difference of arrival) positioning method.
The positioning method specifically comprises the following steps:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Wherein mod (T, T) represents T modulo T, T is the sweep period, μ is the sweep rate (Hz/s), fcIs the carrier frequency;
step 2, neglecting the influence of channel multipath, the transmission signal is transmitted from the excitation source, and is received by a certain signal reflection point k (k is 1, 2.), each signal reflection point has a dedicated C/a code, and the modulated signal is
wherein ,dk(t) is a spread spectrum chip signal, and when different spreading methods are adopted, the values thereof are different: when OOK regime is adopted, dk(t) a pseudorandom signal having a value of 0 or 1; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1;is the channel gain from the excitation source to the reflection point, which is a complex number;for the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be taken into accountPerforming the following steps; w is ak(t) is noise;
step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, wherein the received signal is
wherein ,for the channel gain of the signal reflection point to the receiver,is the signal propagation delay, w0(t) is receiver noise;
step 4, carrying out synchronous down-conversion processing on the carrier signal received by the receiver to obtain a baseband signal
wb(t) is the equivalent low-pass noise after down-conversion;
step 5, the receiver locally synchronizes to generate an FMCW messagePhase tracking the baseband signal and phase locking toThe output after synchronous detection is
wd(t) noise after synchronous detection;
wherein ,is at a frequency ofThe sine term of (a) is,in order to be the initial phase of the signal,OOK/BPSK multiplication terms;
step 6, the receiver captures the signal by using the correlation reception of the spread spectrum code to obtain the code phase offset and the frequency offset estimation, and the receiver can know from which reflection point the signal comes; assuming that the distance from the excitation source to a certain reflection point is R1, the distance from the reflection point to the receiver is R2, and the distance from the excitation source to the receiver is R; to pairThe frequency estimation is performed to obtain the reflection point and the reception point of each signalThe distance difference between machines; the distance difference (R1+ R2) -R can be calculated according to the frequency offset, and the distance difference (R2-R) from the excitation source to the receiver and the reflection point to the receiver is calculated because R1 is known; and then, according to a plurality of distances and the positions of the signal reflection points, the TDOA positioning method is used for calculation to obtain the position information of the receiver, so that the positioning of the target is realized.
An indoor positioning method based on signal reflection points is realized based on an indoor positioning system, wherein the indoor positioning system comprises at least one excitation source, three signal reflection points and a receiver;
the excitation source is used for continuously or discontinuously transmitting signals, linear modulation FMCW signals are adopted, and the signals are obtained by modulating the frequency of continuous waves;
the signal reflection points are composed of a receiving antenna, an amplifier, a spread spectrum module and a transmitting antenna, the signal reflection points amplify the received signals, each signal reflection point has a special spread spectrum code, the sequence is used for modulating the received signals, and finally the signals are sent to a receiver, and the spread spectrum codes can be used for identifying the identity information of the signals in the subsequent signal processing process;
the receiver captures signals of an excitation source and a plurality of signal reflection points by using the related reception of a spread spectrum code through a signal processing method by receiving the signals, obtains code phase offset and frequency offset estimation, separates out the reflection signal of each signal reflection point, can calculate the distance difference from each signal reflection point to the receiver, and obtains the position information of the excitation source by using a TDOA (time difference of arrival) positioning method.
The positioning method specifically comprises the following steps:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Wherein mod (T, T) represents T modulo T, T is the sweep period, μ is the sweep rate (Hz/s), fcIs the carrier frequency;
step 2, neglecting the influence of channel multipath, the transmission signal is transmitted from the excitation source, and is received by a certain signal reflection point k (k is 1, 2.), each signal reflection point has a dedicated C/a code, and the modulated signal is
wherein ,dk(t) is a spread spectrum chip signal, and when different spreading methods are adopted, the values thereof are different: when OOK regime is adopted, dk(t) a pseudorandom signal having a value of 0 or 1; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1;is the channel gain from the excitation source to the reflection point, which is a complex number;for the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be consideredPerforming the following steps; w is ak(t) is noise;
step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, wherein the received signal is
wherein ,for the channel gain of the signal reflection point to the receiver,is the signal propagation delay, w0(t) is receiver noise;
step 4, carrying out synchronous down-conversion processing on the carrier signal received by the receiver to obtain a baseband signal
wb(t) is the equivalent low-pass noise after down-conversion;
step 5, the receiver generates an FMCW signal locally and synchronously, carries out phase tracking on the baseband signal and locks the phase toThe output after synchronous detection is
wd(t) noise after synchronous detection;
wherein ,is at a frequency ofThe sine term of (a) is,in order to be the initial phase of the signal,OOK/BPSK multiplication terms;
step 6, the receiver uses spread spectrumThe relevant receiving of the code captures the signal to obtain the code phase offset and frequency offset estimation, and the receiver can know from which reflection point the path of signal comes; assuming that the distance from the excitation source to a certain reflection point is R1, the distance from the reflection point to the receiver is R2, and the distance from the excitation source to the receiver is R; to pairThe distance difference between each signal reflection point and the receiver can be obtained by carrying out frequency estimation, the distance difference (R1+ R2) -R can be calculated according to the frequency offset, and the distance difference (R1-R) from the excitation source to the receiver and from the excitation source to the reflection point is calculated because R2 is known; and then, according to a plurality of distances and the positions of the signal reflection points, the TDOA positioning method is used for calculation to obtain the position information of the excitation source, so that the target is positioned.
An indoor positioning method based on signal reflection points is realized based on an indoor positioning system, wherein the indoor positioning system comprises at least four excitation sources, at least four receivers and a signal reflection point;
the excitation source is used for continuously or discontinuously transmitting signals, linear modulation FMCW signals are adopted, and the signals are obtained by modulating the frequency of continuous waves;
the signal reflection points are composed of four parts, namely a receiving antenna, an amplifier, a spread spectrum module and a transmitting antenna, the signal reflection points amplify the received signals, each signal reflection point has a special spread spectrum code, the sequence is used for modulating the received signals, and finally the signals are transmitted to a receiver, and the spread spectrum codes can be used for identifying identity information of the signals in the subsequent signal processing process;
the receiver captures signals of an excitation source and a plurality of signal reflection points by using the related reception of a spread spectrum code through a signal processing method by receiving the signals, obtains code phase offset and frequency offset estimation, separates out the reflection signal of each signal reflection point, can calculate the distance difference from each signal reflection point to the receiver, and obtains the position information of the signal reflection points by using a TDOA (time difference of arrival) positioning method.
The positioning method specifically comprises the following steps:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Wherein mod (T, T) represents T modulo T, T is the sweep period, μ is the sweep rate (Hz/s), fcIs the carrier frequency;
step 2, neglecting the influence of channel multipath, the transmission signal is transmitted from the excitation source, and is received by a certain signal reflection point k (k is 1, 2.), each signal reflection point has a dedicated C/a code, and the modulated signal is
wherein ,dk(t) is a spread spectrum chip signal, and when different spreading methods are adopted, the values thereof are different: when OOK regime is adopted, dk(t) a pseudorandom signal having a value of 0 or 1; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1;is the channel gain from the excitation source to the reflection point, which is a complex number;for the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be taken into accountPerforming the following steps; w is ak(t) is noise;
step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, wherein the received signal is
Wherein,for the channel gain of the signal reflection point to the receiver,is the signal propagation delay, w0(t) is receiver noise;
step 4, carrying out synchronous down-conversion processing on the carrier signal received by the receiver to obtain a baseband signal
wb(t) is the equivalent low-pass noise after down-conversion;
step 5, the receiver generates an FMCW signal locally and synchronously, carries out phase tracking on the baseband signal and locks the phase toThe output after synchronous detection is
wd(t) noise after synchronous detection;
wherein ,is at a frequency ofThe sine term of (a) is,in order to be the initial phase of the signal,OOK/BPSK multiplication terms;
step 6, the receiver captures the signal by using the correlation reception of the spread spectrum code to obtain the code phase offset and the frequency offset estimation, and the receiver can know from which reflection point the signal comes; taking one transceiver as an excitation source, and the other transceivers can be used as receivers, wherein the distance from the transceiver as the excitation source to a certain reflection point is assumed to be R1, the distance from the reflection point to the transceiver as the receiver is assumed to be R2, and the distance from the excitation source to the receiver is assumed to be R; for is toThe distance difference between each signal reflection point and the receiver can be obtained by carrying out frequency estimation, the distance difference (R1+ R2) -R can be calculated according to the frequency offset, and the distance difference (R1+ R2) from the excitation source to the reflection point and from the reflection point to the receiver is calculated because R is known; and then, according to a plurality of the distances, the determined serial numbers of the signal transmitting points and the positions of the transceivers, calculating by using a TDOA (time difference of arrival) positioning method to obtain the position information of the signal reflecting points, thereby realizing the positioning of the target.
After the scheme is adopted, the signal is transmitted through the excitation source, the transmitted signal is received by the signal reflection points, the signal reflection points perform spread spectrum processing on the received signal, the receiver finally receives the signals of the excitation source and the signal reflection points, the distance difference between the signal reflection points can be obtained by processing the received signal, and the TDOA algorithm is adopted for positioning, so that the target position can be obtained finally. The invention can realize mass deployment in an indoor positioning scheme by utilizing the characteristics of simple structure, lower cost and easy deployment of the signal reflection point.
Drawings
FIG. 1 is a schematic diagram of a receiver positioning system of the present invention;
FIG. 2 OOK spread spectrum schematic diagram of signal reflection point of the present invention
FIG. 3 is a functional block diagram of the receiver positioning system of the present invention;
FIG. 4 is a schematic diagram of a receiver positioning distance relationship;
FIG. 5 is a schematic diagram of an excitation source positioning system of the present invention;
FIG. 6 is a functional block diagram of an excitation source positioning system;
FIG. 7 is a schematic diagram of the relationship between the positioning distances of the excitation sources;
FIG. 8 is a schematic diagram of a signal reflection point locating system;
FIG. 9 is a functional block diagram of a signal reflection point locating system;
fig. 10 is a diagram illustrating the relationship between the positioning distances of the signal reflection points.
Detailed Description
The invention discloses an indoor positioning method based on signal reflection points, which is realized based on an indoor positioning system, wherein the indoor positioning system comprises an excitation source, the signal reflection points and a receiver. The description is as follows:
the excitation source, i.e. the signal source, is used to continuously or intermittently transmit a signal, using a linearly modulated FMCW signal, which is obtained by modulating the frequency of the continuous wave. The frequency modulation mode of the FMCW signal comprises linear frequency modulation and nonlinear frequency modulation. In the scheme, a sawtooth wave modulation mode in linear frequency modulation is adopted. The frequency difference between the received signal and the transmitted signal is obtained by the mixer and the subsequent signal processing module. And calculating the time difference between the signal received by the receiver and the local signal according to the frequency difference.
The signal reflection point is a low-cost signal modulation and amplification unit, and consists of four parts, namely a receiving antenna, an amplifier, a spread spectrum module and a transmitting antenna. The signal reflection points amplify the received signals, each signal reflection point has a special spread spectrum code, the received signals are modulated by the sequence and finally sent to a receiver, and the spread spectrum codes can be used for identifying the identity information of the signals in the subsequent signal processing process.
The receiver captures signals of an excitation source and a plurality of signal reflection points by using the related reception of a spread spectrum code through a signal processing method, obtains code phase offset and frequency offset estimation, separates out the reflection signal of each signal reflection point, and can calculate the distance difference from each signal reflection point to the receiver.
The indoor positioning system can be divided into a receiver positioning system, a signal reflection point positioning system and an excitation source positioning system according to different positioning scenes, and the positioning system is specifically as follows:
as shown in fig. 1, the positions of the excitation source and the signal reflection point in the receiver positioning system are determined, and the position of the receiver is solved. The system at least needs one excitation source, three reflection points and one receiver. The positioning system application is similar to GPS positioning and can be used for positioning plant equipment.
Based on a receiver positioning system, the indoor positioning method comprises the following steps:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Wherein mod (T, T) represents T modulo T, T is the sweep period, μ is the sweep rate (Hz/s), fcIs the carrier frequency.
Step 2, neglecting the influence of channel multipath, the transmission signal is transmitted from the excitation source, and is received by a certain signal reflection point k (k is 1, 2.), each signal reflection point has a dedicated C/a code, and the modulated signal is
wherein ,dk(t) is a spread spectrum chip signal, and when different spreading methods are adopted, the values thereof are different: when OOK system (the schematic block diagram is shown in FIG. 2) is adopted, dk(t) takes the value 0 or 1A pseudo-random signal; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1.It is a complex number that is the channel gain from the excitation source to the reflection point.For the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be taken into accountIn (1). w is ak(t) is noise.
Step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, wherein the received signal is
wherein ,for the channel gain of the signal reflection point to the receiver,is the signal propagation delay, w0(t) is the noise of the receiver,andphase ratio w after multiplication0(t) is much smaller and can be directly ignored.
Step 4, the carrier signal received by the receiver is processed by synchronous down-conversion (assuming carrier synchronization is obtained and locked, that is to say) Thus obtained baseband signalIs composed of
wbAnd (t) is equivalent low-pass noise after down-conversion.
Step 5, the receiver generates an FMCW signal locally and synchronously, carries out phase tracking on the baseband signal and locks the phase toThe output after synchronous detection is
wdAnd (t) is noise after synchronous detection.
wherein ,is at a frequency ofThe sine term of (a) is,in order to be the initial phase of the signal,is OOK/BPSK multiplication term.
Step 6, the receiver captures the signal by using the correlation reception of the spread spectrum code to obtain the code phase deviationAnd (4) estimating the quantity and the frequency offset, and enabling a receiver to know from which reflection point the path signal comes. Assume that the distance from the excitation source to a certain reflection point is R1, the distance from the reflection point to the receiver is R2, and the distance from the excitation source to the receiver is R, as shown in fig. 4. To pairAnd the distance difference between each signal reflection point and the receiver can be obtained by carrying out frequency estimation. The distance difference (R1+ R2) -R can be calculated from the frequency offset, and since R1 is known, the distance difference (R2-R) from the excitation source to the receiver and from the reflection point to the receiver can be calculated. And then, according to a plurality of distances and the positions of the signal reflection points, the TDOA positioning method is used for calculation to obtain the position information of the receiver, so that the positioning of the target is realized.
As shown in fig. 5, the positions of the reflection points and the receivers in the excitation source positioning system are determined, and the positions of the excitation sources are solved. The positioning system requires at least one excitation source, three signal reflection points and one receiver. If the algorithm supports signals such as 4G/5G/WIFI and the like as excitation sources, positioning of a specific mobile phone can be realized.
As shown in fig. 6, the method for implementing indoor positioning based on the excitation source positioning system specifically includes the following steps:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Where mod (T, T) denotes T modulo T, T is time, T is sweep period, μ is sweep rate (Hz/s), fcIs the carrier frequency.
Step 2, ignoring the influence of channel multipath, the signal is emitted from an excitation source, received by a certain signal reflection point k (k is 1, 2), each signal reflection point has a special C/A code, and the modulated signal is
wherein dkAnd (t) is a spread spectrum chip signal, and values of the spread spectrum chip signal are different when different spreading methods are adopted. When OOK regime is adopted, dk(t) a pseudorandom signal having a value of 0 or 1; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1.It is a complex number that is the channel gain from the excitation source to the reflection point.For the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be taken into accountIn (1). w is ak(t) is noise.
Step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, wherein the received signal is
Here, theFor the channel gain of the signal reflection point to the receiver,is the signal propagation delay, alpha0,τ0Channel attenuation coefficient and propagation delay, w, from the excitation source to the receiver, respectively0(t) is the noise of the receiver,andphase ratio w after multiplication0(t) is smallMany, and can be directly ignored.
Step 4, the carrier signal received by the receiver is processed by synchronous down-conversion (assuming carrier synchronization is obtained and locked, i.e. carrier synchronization is performed) Then obtaining a baseband signal of
wbAnd (t) is equivalent low-pass noise after down-conversion.
Step 5, the receiver generates an FMCW signal locally and synchronously, carries out phase tracking on the baseband signal and locks the phase toThe output after synchronous detection is
wdAnd (t) is noise after synchronous detection. In thatThe region, i.e. within one sweep period, is available
wherein Is at a frequency ofThe sine term of (a) is,is the initial phase of the signal and is the initial phase of the signal,is OOK/BPSK multiplication term.
And 6, the receiver captures the signal by utilizing the related reception of the spread spectrum code to obtain the code phase offset and the frequency offset estimation, and the receiver can know from which reflection point the path of signal comes. Assume that the distance from the excitation source to a certain reflection point is R1, the distance from the reflection point to the receiver is R2, and the distance from the excitation source to the receiver is R, as shown in fig. 7.
For is toThe frequency estimation is carried out to obtain the distance difference between each signal reflection point and the receiver, the distance difference (R1+ R2) -R can be calculated according to the frequency offset, and the distance difference (R1-R) between the excitation source and the receiver and the distance difference between the excitation source and the reflection point can be calculated according to the known R2. And then, according to a plurality of distances and the positions of signal reflection points, calculating by using a TDOA (time difference of arrival) positioning method to obtain the position information of the excitation source, thereby realizing the positioning of the target.
As shown in fig. 8, the positions of the excitation source and the receiver in the signal reflection point positioning system are determined, and the positions of the signal reflection points are solved. Generally, in the system, an excitation source and a receiver are arranged in one device, namely one radar transceiver, and the system needs at least four transceivers, namely four excitation sources, four receivers and one signal reflection point. The system has the advantages that the signal reflection nodes are low in cost, support mass deployment and can replace UWB schemes.
As shown in fig. 9, based on the signal reflection point positioning system, the indoor positioning method is as follows:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Where mod (T, T) denotes T modulo T, T is time, and T is sweep periodMu is sweep rate (Hz/s), fcIs the carrier frequency.
Step 2, neglecting the influence of channel multipath, the signal is transmitted from the excitation source and received by a certain signal reflection point k (k is 1, 2.), each signal reflection point has a special C/A code, and the modulated signal is
wherein dkAnd (t) is a spread spectrum chip signal, and values of the spread spectrum chip signal are different when different spreading methods are adopted. When OOK regime is adopted, dk(t) a pseudorandom signal having a value of 0 or 1; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1.It is a complex number that is the channel gain from the excitation source to the reflection point.For the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be consideredIn (1). w is ak(t) is noise.
Step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, and the received signal is
Here, theFor the channel gain of the signal reflection point to the receiver,is the signal propagation delay, alpha0,τ0Channel attenuation coefficient and propagation delay, w, respectively, from the excitation source to the receiver0(t) is the noise of the receiver,andphase ratio w after multiplication0(t) is much smaller and can be directly ignored.
Step 4, the carrier signal received by the receiver is processed by synchronous down-conversion (assuming carrier synchronization is obtained and locked, that is to say) Then obtaining a baseband signal of
wbAnd (t) is equivalent low-pass noise after down-conversion.
Step 5, the receiver generates an FMCW signal locally and synchronously, carries out phase tracking on the baseband signal and locks the phase toThe output after synchronous detection is
wdAnd (t) is noise after synchronous detection. In that The area, i.e. within one sweep period, being available
wherein Is at a frequency ofThe sine term of (a) is,in order to be the initial phase of the signal,is OOK/BPSK multiplication term.
Step 6: the receiver captures the signal by using the correlation reception of the spread spectrum code to obtain the code phase offset and the frequency offset estimation, and the receiver can know from which reflection point the path of signal comes. In this scheme, one transceiver is taken as an excitation source, and the remaining transceivers can be taken as receivers, and it is assumed that the distance from the transceiver as the excitation source to a certain reflection point is R1, the distance from the reflection point to the transceiver as the receiver is R2, and the distance from the excitation source to the receiver is R, as shown in fig. 10.
To pairThe distance difference between each signal reflection point and the receiver can be obtained by carrying out frequency estimation, the distance difference (R1+ R2) -R can be calculated according to the frequency offset, and the distance difference (R1+ R2) between the excitation source and the reflection point and the receiver can be calculated because R is known. And then, according to a plurality of the distances, the determined serial numbers of the signal transmitting points and the positions of the transceivers, calculating by using a TDOA (time difference of arrival) positioning method to obtain the position information of the signal reflecting points, thereby realizing the positioning of the target.
In summary, in the present invention, a signal is transmitted through an excitation source, the transmitted signal is received by signal reflection points, the signal reflection points perform spread spectrum processing on the received signal, and finally, a receiver receives signals of the excitation source and each signal reflection point, and performs processing on the received signal to obtain a distance difference between each signal reflection point, and a TDOA algorithm is used to perform positioning, so as to finally obtain a target position. The invention can realize mass deployment in an indoor positioning scheme by utilizing the characteristics of simple structure, lower cost and easy deployment of the signal reflection point.
The above description is only exemplary of the present invention and is not intended to limit the technical scope of the present invention, so that any minor modifications, equivalent changes and modifications made to the above exemplary embodiments according to the technical spirit of the present invention are within the technical scope of the present invention.
Claims (6)
1. An indoor positioning method based on signal reflection points is characterized in that: the method is realized based on an indoor positioning system, wherein the indoor positioning system comprises an excitation source, a receiver and at least three signal reflection points;
the excitation source is used for continuously or discontinuously transmitting signals, linear modulation FMCW signals are adopted, and the signals are obtained by modulating the frequency of continuous waves;
the signal reflection points are composed of a receiving antenna, an amplifier, a spread spectrum module and a transmitting antenna, the signal reflection points amplify the received signals, each signal reflection point has a special spread spectrum code, the sequence is used for modulating the received signals, and finally the signals are sent to a receiver, and the spread spectrum codes can be used for identifying the identity information of the signals in the subsequent signal processing process;
the receiver captures signals of an excitation source and a plurality of signal reflection points by using the related reception of a spread spectrum code through a signal processing method by receiving the signals, obtains code phase offset and frequency offset estimation, separates out the reflection signal of each signal reflection point, can calculate the distance difference from each signal reflection point to the receiver, and obtains the position information of the receiver by using a TDOA (time difference of arrival) positioning method.
2. A reflection point based indoor positioning method according to claim 1, characterized in that: the positioning method specifically comprises the following steps:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Wherein mod (T, T) represents T modulo T, T is the sweep period, μ is the sweep rate (Hz/s), fcIs the carrier frequency;
step 2, neglecting the influence of channel multipath, the transmission signal is transmitted from the excitation source, and is received by a certain signal reflection point k (k is 1, 2.), each signal reflection point has a dedicated C/a code, and the modulated signal is
wherein ,dk(t) is a spread spectrum chip signal, and when different spreading methods are adopted, the values thereof are different: when OOK regime is adopted, dk(t) a pseudorandom signal having a value of 0 or 1; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1;is the channel gain from the excitation source to the reflection point, which is a complex number;for the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be taken into accountPerforming the following steps; w is ak(t) is noise;
step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, and the received signal is
wherein ,for the channel gain of the signal reflection point to the receiver,is the signal propagation delay, w0(t) is receiver noise;
step 4, carrying out synchronous down-conversion processing on the carrier signal received by the receiver to obtain a baseband signal
wb(t) is the equivalent low-pass noise after down-conversion;
step 5, the receiver generates a FMCW signal locally and synchronously, performs phase tracking on the baseband signal, and locks the phase toThe output after synchronous detection is
wd(t) noise after synchronous detection;
wherein ,is at a frequency ofThe term of the sine of (a) is,in order to be the initial phase of the signal,OOK/BPSK multiplication terms;
step 6, the receiver captures the signal by using the correlation reception of the spread spectrum code to obtain the code phase offset and the frequency offset estimation, and the receiver can know from which reflection point the signal comes; assuming that the distance from the excitation source to a certain reflection point is R1, the distance from the reflection point to the receiver is R2, and the distance from the excitation source to the receiver is R; to pairThe distance difference between each signal reflection point and the receiver can be obtained by carrying out frequency estimation; the distance difference (R1+ R2) -R can be calculated according to the frequency offset, and the distance difference (R2-R) from the excitation source to the receiver and the reflection point to the receiver is calculated because R1 is known; and then, according to a plurality of distances and the positions of the signal reflection points, the TDOA positioning method is used for calculation to obtain the position information of the receiver, so that the positioning of the target is realized.
3. An indoor positioning method based on signal reflection points is characterized in that: the method is realized based on an indoor positioning system, wherein the indoor positioning system comprises at least one excitation source, three signal reflection points and a receiver;
the excitation source is used for continuously or discontinuously transmitting signals, linear modulation FMCW signals are adopted, and the signals are obtained by modulating the frequency of continuous waves;
the signal reflection points are composed of a receiving antenna, an amplifier, a spread spectrum module and a transmitting antenna, the signal reflection points amplify the received signals, each signal reflection point has a special spread spectrum code, the sequence is used for modulating the received signals, and finally the signals are sent to a receiver, and the spread spectrum codes can be used for identifying the identity information of the signals in the subsequent signal processing process;
the receiver captures signals of an excitation source and a plurality of signal reflection points by using the related reception of a spread spectrum code through a signal processing method by receiving the signals, obtains code phase offset and frequency offset estimation, separates out the reflection signal of each signal reflection point, can calculate the distance difference from each signal reflection point to the receiver, and obtains the position information of the excitation source by using a TDOA (time difference of arrival) positioning method.
4. A reflection point based indoor positioning method according to claim 3, characterized in that: the positioning method specifically comprises the following steps:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Wherein mod (T, T) represents T modulo T, T is the sweep period, μ is the sweep rate (Hz/s), fcIs the carrier frequency;
step 2, neglecting the influence of channel multipath, the transmission signal is transmitted from the excitation source, and is received by a certain signal reflection point k (k is 1, 2.), each signal reflection point has a dedicated C/a code, and the modulated signal is
wherein ,dk(t) is a spread spectrum chip signal, and when different spreading methods are adopted, the values thereof are different: when OOK regime is adopted, dk(t) a pseudorandom signal having a value of 0 or 1; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1;the channel gain from the excitation source to the reflection point is a complex number;for the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be taken into accountPerforming the following steps; w is ak(t) is noise;
step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, wherein the received signal is
wherein ,for the channel gain of the signal reflection point to the receiver,is the signal propagation delay, w0(t) is receiver noise;
step 4, carrying out synchronous down-conversion processing on the carrier signal received by the receiver to obtain a baseband signal
wb(t) is the equivalent low-pass noise after down-conversion;
step 5, the receiver generates an FMCW signal locally and synchronously, carries out phase tracking on the baseband signal and locks the phase toThe output after synchronous detection is
wd(t) noise after synchronous detection;
wherein ,is at a frequency ofThe sine term of (a) is,in order to be the initial phase of the signal,for OOK/BPSK multiplicationAn item;
step 6, the receiver captures the signal by using the correlation reception of the spread spectrum code to obtain the code phase offset and the frequency offset estimation, and the receiver can know from which reflection point the signal comes; assuming that the distance from the excitation source to a certain reflection point is R1, the distance from the reflection point to the receiver is R2, and the distance from the excitation source to the receiver is R; to pairThe distance difference between each signal reflection point and the receiver can be obtained by carrying out frequency estimation, the distance difference (R1+ R2) -R can be calculated according to the frequency offset, and the distance difference (R1-R) from the excitation source to the receiver and from the excitation source to the reflection point is calculated because R2 is known; and then, according to a plurality of distances and the positions of the signal reflection points, the TDOA positioning method is used for calculation to obtain the position information of the excitation source, so that the target is positioned.
5. An indoor positioning method based on signal reflection points is characterized in that: the method is realized based on an indoor positioning system, wherein the indoor positioning system comprises at least four excitation sources, at least four receivers and a signal reflection point;
the excitation source is used for continuously or discontinuously transmitting signals, linear modulation FMCW signals are adopted, and the signals are obtained by modulating the frequency of continuous waves;
the signal reflection points are composed of a receiving antenna, an amplifier, a spread spectrum module and a transmitting antenna, the signal reflection points amplify the received signals, each signal reflection point has a special spread spectrum code, the sequence is used for modulating the received signals, and finally the signals are sent to a receiver, and the spread spectrum codes can be used for identifying the identity information of the signals in the subsequent signal processing process;
the receiver captures signals of an excitation source and a plurality of signal reflection points by using the related reception of a spread spectrum code through a signal processing method by receiving the signals, obtains code phase offset and frequency offset estimation, separates out the reflection signal of each signal reflection point, can calculate the distance difference from each signal reflection point to the receiver, and obtains the position information of the signal reflection points by using a TDOA (time difference of arrival) positioning method.
6. A reflection point based indoor positioning method according to claim 1, characterized in that: the positioning method specifically comprises the following steps:
step 1, generating FMCW signal by excitation source, and setting its emission signal as
Wherein mod (T, T) represents T modulo T, T is the sweep period, μ is the sweep rate (Hz/s), fcIs the carrier frequency;
step 2, neglecting the influence of channel multipath, the transmission signal is transmitted from the excitation source, and is received by a certain signal reflection point k (k is 1, 2.), each signal reflection point has a dedicated C/a code, and the modulated signal is
wherein ,dk(t) is a spread spectrum chip signal, and when different spreading methods are adopted, the values thereof are different: when OOK regime is adopted, dk(t) a pseudorandom signal having a value of 0 or 1; when BPSK regime is adopted, dk(t) a pseudorandom signal having a value of-1 or 1;is the channel gain from the excitation source to the reflection point, which is a complex number;for the signal propagation delay from the excitation source to the reflection point, the delay from the input antenna to the output antenna of the reflection point can be taken into accountPerforming the following steps; w is ak(t) is noise;
step 3, the receiver receives the composite signal from the excitation source and the signal reflection point, wherein the received signal is
wherein ,for the channel gain of the signal reflection point to the receiver,is the signal propagation delay, w0(t) is receiver noise;
step 4, carrying out synchronous down-conversion processing on the carrier signal received by the receiver to obtain a baseband signal
wb(t) is the equivalent low-pass noise after down-conversion;
step 5, the receiver generates an FMCW signal locally and synchronously, carries out phase tracking on the baseband signal and locks the phase toThe output after synchronous detection is
wd(t) noise after synchronous detection;
wherein ,is at a frequency ofThe sine term of (a) is,in order to be the initial phase of the signal,OOK/BPSK multiplication terms;
step 6, the receiver captures the signal by using the correlation reception of the spread spectrum code to obtain the code phase offset and the frequency offset estimation, and the receiver can know from which reflection point the signal comes; taking one transceiver as an excitation source, and the other transceivers can be used as receivers, wherein the distance from the transceiver as the excitation source to a certain reflection point is assumed to be R1, the distance from the reflection point to the transceiver as the receiver is assumed to be R2, and the distance from the excitation source to the receiver is assumed to be R; to pairThe distance difference between each signal reflection point and the receiver can be obtained by carrying out frequency estimation, the distance difference (R1+ R2) -R can be calculated according to the frequency offset, and the distance difference (R1+ R2) from the excitation source to the reflection point and from the reflection point to the receiver is calculated because R is known; then according to several such distances, the determined signal transmitting point serial number and transceiver positionAnd calculating by using a TDOA positioning method to obtain the position information of the signal reflection point so as to realize the positioning of the target.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202210177544.XA CN114615619B (en) | 2022-02-25 | 2022-02-25 | Indoor positioning method based on signal reflection points |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202210177544.XA CN114615619B (en) | 2022-02-25 | 2022-02-25 | Indoor positioning method based on signal reflection points |
Publications (2)
Publication Number | Publication Date |
---|---|
CN114615619A true CN114615619A (en) | 2022-06-10 |
CN114615619B CN114615619B (en) | 2023-08-04 |
Family
ID=81858948
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202210177544.XA Active CN114615619B (en) | 2022-02-25 | 2022-02-25 | Indoor positioning method based on signal reflection points |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN114615619B (en) |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002063327A2 (en) * | 2001-02-06 | 2002-08-15 | Itt Manufacturing Enterprises, Inc. | Method and apparatus for determining the position of a mobile communication device |
CA2446842A1 (en) * | 2002-10-30 | 2004-04-30 | Her Majesty The Queen In Right Of Canada As Represented By The Minister Of National Defence | Synthetic doppler system and method for locating cooperative transceivers |
CN101339238A (en) * | 2007-07-06 | 2009-01-07 | 展讯通信(上海)有限公司 | Position calculation method and device for wireless positioning based on multisystem combined measurement |
CN102724753A (en) * | 2012-06-13 | 2012-10-10 | 北京邮电大学 | Arrival time difference rectification based wireless positioning method and terminal |
US20140125521A1 (en) * | 2012-02-10 | 2014-05-08 | Centre National D'etudes Spatiales (Cnes) | Method for Estimating the Direction of Arrival of Navigation Signals at a Receiver After Reflection by Walls in a Satellite Positioning System |
CN104133191A (en) * | 2014-08-22 | 2014-11-05 | 电子科技大学 | Indoor positioning device and method based on frequency modulation continuous wave |
WO2015001552A1 (en) * | 2013-07-01 | 2015-01-08 | Elbit Systems Bmd And Land Ew - Elisra Ltd. | Mitigation of multipath distortions for tdoa-based geolocation |
CN107942285A (en) * | 2016-10-13 | 2018-04-20 | 中兴通讯股份有限公司 | A kind of reaching time-difference measuring method, device, control device and terminal |
CN109164441A (en) * | 2018-09-30 | 2019-01-08 | 厦门大学 | A kind of method of radar range finding |
CN110601717A (en) * | 2019-09-16 | 2019-12-20 | 中国人民解放军军事科学院国防科技创新研究院 | Communication and ranging integrated system and method based on code division multiplexing |
US20200116817A1 (en) * | 2018-10-16 | 2020-04-16 | The Regents Of The University Of Michigan | Low-power, long-range rf localization system and method |
US10841894B1 (en) * | 2020-01-31 | 2020-11-17 | Trakpoint Solutions, Inc. | Method for waking from energy-efficient hibernation |
-
2022
- 2022-02-25 CN CN202210177544.XA patent/CN114615619B/en active Active
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002063327A2 (en) * | 2001-02-06 | 2002-08-15 | Itt Manufacturing Enterprises, Inc. | Method and apparatus for determining the position of a mobile communication device |
CA2446842A1 (en) * | 2002-10-30 | 2004-04-30 | Her Majesty The Queen In Right Of Canada As Represented By The Minister Of National Defence | Synthetic doppler system and method for locating cooperative transceivers |
CN101339238A (en) * | 2007-07-06 | 2009-01-07 | 展讯通信(上海)有限公司 | Position calculation method and device for wireless positioning based on multisystem combined measurement |
US20140125521A1 (en) * | 2012-02-10 | 2014-05-08 | Centre National D'etudes Spatiales (Cnes) | Method for Estimating the Direction of Arrival of Navigation Signals at a Receiver After Reflection by Walls in a Satellite Positioning System |
CN102724753A (en) * | 2012-06-13 | 2012-10-10 | 北京邮电大学 | Arrival time difference rectification based wireless positioning method and terminal |
WO2015001552A1 (en) * | 2013-07-01 | 2015-01-08 | Elbit Systems Bmd And Land Ew - Elisra Ltd. | Mitigation of multipath distortions for tdoa-based geolocation |
CN104133191A (en) * | 2014-08-22 | 2014-11-05 | 电子科技大学 | Indoor positioning device and method based on frequency modulation continuous wave |
CN107942285A (en) * | 2016-10-13 | 2018-04-20 | 中兴通讯股份有限公司 | A kind of reaching time-difference measuring method, device, control device and terminal |
CN109164441A (en) * | 2018-09-30 | 2019-01-08 | 厦门大学 | A kind of method of radar range finding |
US20200116817A1 (en) * | 2018-10-16 | 2020-04-16 | The Regents Of The University Of Michigan | Low-power, long-range rf localization system and method |
CN110601717A (en) * | 2019-09-16 | 2019-12-20 | 中国人民解放军军事科学院国防科技创新研究院 | Communication and ranging integrated system and method based on code division multiplexing |
US10841894B1 (en) * | 2020-01-31 | 2020-11-17 | Trakpoint Solutions, Inc. | Method for waking from energy-efficient hibernation |
Non-Patent Citations (12)
Title |
---|
DMITRY V. IVANOV ET AL.: "Positioning of Dynamic Objects by Means of Systems of Multi-Frequency Sounding of HF Radio Paths with the use of FMCW Signals", 《2018 2ND URSI ATLANTIC RADIO SCIENCE MEETING (AT-RASC)》 * |
DMITRY V. IVANOV ET AL.: "Positioning of Dynamic Objects by Means of Systems of Multi-Frequency Sounding of HF Radio Paths with the use of FMCW Signals", 《2018 2ND URSI ATLANTIC RADIO SCIENCE MEETING (AT-RASC)》, 27 September 2018 (2018-09-27) * |
QI YANG ET AL.: "Location Based Joint Spectrum Sensing and Radio Resource Allocation in Cognitive Radio Enabled LTE-U Systems", 《IEEE TRANS. VEH. TECHNOL》 * |
XIANGYU SHEN ET AL.: "A Novel FMCW Radar-Based Scheme for Indoor Localization and Trajectory Tracking", 《2020 IEEE 6TH INTERNATIONAL CONFERENCE ON COMPUTER AND COMMUNICATIONS (ICCC)》 * |
XIANGYU SHEN ET AL.: "A Novel FMCW Radar-Based Scheme for Indoor Localization and Trajectory Tracking", 《2020 IEEE 6TH INTERNATIONAL CONFERENCE ON COMPUTER AND COMMUNICATIONS (ICCC)》, 12 February 2021 (2021-02-12) * |
刘泽龙 等: "基于LFMCW雷达测距的改进频域CFAR算法", 《信息与电子工程》 * |
刘泽龙 等: "基于LFMCW雷达测距的改进频域CFAR算法", 《信息与电子工程》, no. 06, 25 December 2012 (2012-12-25) * |
史小红: "基于TDOA的无线定位方法及其性能分析", 《东南大学学报(自然科学版)》, no. 02 * |
史小红: "基于TDOA的无线定位方法及其性能分析", 《东南大学学报(自然科学版)》, no. 02, 20 March 2013 (2013-03-20) * |
孟庆宝: "基于调频连续波的室内人员定位技术研究", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
孟庆宝: "基于调频连续波的室内人员定位技术研究", 《中国优秀硕士学位论文全文数据库 信息科技辑》, 15 March 2020 (2020-03-15) * |
陈杨毅 等: "基于最优几何的改进型多星座卫星选星算法", 《软件》 * |
Also Published As
Publication number | Publication date |
---|---|
CN114615619B (en) | 2023-08-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7039421B2 (en) | System for determining the position of an object | |
CN101208983B (en) | Methods, systems and devices for determining the location of a mobile device based on simulcast communication signals | |
CN1325927C (en) | A method of despreading GPS signals | |
US9851429B2 (en) | Terrestrial position and timing system | |
CN102171584B (en) | Method for processing combined navigation signals | |
EP2256511B1 (en) | Methods and apparatus for accurately determining signal time of arrival | |
WO2005098466A1 (en) | Position detection with frequency smoothing | |
JP2011237386A (en) | Navigation signal transmitting apparatus, navigation signal transmitting method and positional information supplying apparatus | |
US20150063426A1 (en) | Systems and methods for pseudo-random coding | |
CN105008951A (en) | Autonomous direction finding using differential angle of arrival | |
Pelka et al. | S-TDoA—Sequential time difference of arrival—A scalable and synchronization free approach forl positioning | |
US20230131074A1 (en) | Global navigation satellite system receiver | |
KR100448574B1 (en) | GPS Receiver and Method for Determining Position of a Wireless Terminal | |
US7110474B2 (en) | Method for determining a boundary of an information element, a system, and an electronic device | |
CN1954233B (en) | A GPS device | |
JPH08146110A (en) | Location measuring unit | |
CN114615619B (en) | Indoor positioning method based on signal reflection points | |
WO2021183067A9 (en) | A gnss repeater architecture and location finding method for indoor positioning systems using lower frequencies than gnss signals | |
CN103618560A (en) | Precise synchronization-unrequired coal mine underground spread spectrum accurate ranging method and device | |
US20230142169A1 (en) | Radar system and a radar method for compensating a carrier characteristic offset | |
CN100586042C (en) | Forward link repeater frequency watermarking scheme | |
CN108345013B (en) | Method for improving satellite navigation signal receiving sensitivity | |
CN114845386B (en) | Time synchronization and positioning method and system based on UWB base station secondary self-correction | |
US20230204788A1 (en) | Global navigation satellite system (gnss) signal output system supporting gnss shaded areas | |
CN215575686U (en) | Indoor and outdoor seamless positioning system based on pseudolite technology |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |