CN111722255A - A regional navigation and positioning system and method based on space-time modulation - Google Patents

Abstract

The invention provides a method and system for regional navigation and positioning based on space-time modulation, including: a navigation base station generates a digital navigation signal; time-modulated, and radiated into space by the antenna array; after receiving the navigation signal at the mobile terminal, the navigation signal is converted into a digital navigation signal by an analog-to-digital converter after low-noise amplification, down-conversion, filtering and drive amplification; Demodulate the digital navigation signal in the digital domain to obtain the position information of the current navigation base station; analyze the fundamental wave and harmonic components in the received digital navigation signal, and calculate the azimuth and pitch angle of the mobile terminal relative to the navigation base station; obtain multiple navigation The position of the base station and the azimuth and pitch angles of the mobile terminal relative to the navigation base station are used to calculate the current three-dimensional coordinates of the mobile terminal. The present invention is especially suitable for a system in which a large number of users perform positioning and navigation at the same time.

Description

A regional navigation and positioning system and method based on space-time modulation

technical field

The present invention relates to the technical field of radio navigation and positioning engineering, in particular, to a regional navigation and positioning system and method based on space-time modulation, and more particularly, to a method of passively receiving radio signals transmitted by a base station to realize navigation and positioning. positioning system.

Background technique

Radio navigation and positioning technology has a wide range of applications in military defense and national life. Before the birth of the global positioning system, radio navigation was the main navigation method for aircraft, such as radio Roland C, Tacan and other navigation systems. After the deployment of global positioning systems such as GPS and Beidou, as a safety backup, radio navigation is still widely used in civil aviation and other fields. For example, the VOR/DME (pointing station) navigation technology requires a large loop antenna array to transmit navigation signals, and the technology is very complex.

Patent document CN106842263A (application number: 201710046067.2) discloses a satellite navigation method based on the combination of space-time processing of navigation signals and vector tracking, including the following steps: establishing a coordinate system; receiving satellite navigation signals by a receiver; space-time processing of satellite signals; space-time coherence constraints, using coherent local composite carrier and spread spectrum signals to achieve coherent steering constraints of the array, the data after coherent steering constraints are sent to the filter bank, and finally the observation data is extracted. Navigation solution is realized at the back end; for satellite navigation signal acquisition tracking and vector tracking, using space-time joint coherence constraints, the satellite signal relative to the origin of the carrier coordinate system is obtained. From the ephemeris data of the satellite signal, the carrier and code phase are further obtained by using the EPL data of this channel to form the observation quantity, and the positioning operation can be realized.

SUMMARY OF THE INVENTION

In view of the defects in the prior art, the purpose of the present invention is to provide a method and system for regional navigation and positioning based on space-time modulation.

According to a method for regional navigation and positioning based on space-time modulation provided by the present invention, the method includes:

Step M1: the navigation base station generates a digital navigation signal, which is subjected to periodic space-time modulation by a modulation switch module after including digital-to-analog conversion, drive amplification, up-conversion, filtering and power amplification;

Step M2: the periodic space-time modulated navigation signal is radiated into space by the antenna array;

Step M3: After the mobile terminal receives the navigation signal, after including low-noise amplification, down-conversion, filtering and drive amplification, the analog-to-digital converter converts the navigation signal into a digital navigation signal;

Step M4: demodulate the digital navigation signal in the digital domain to obtain the position information of the current navigation base station; analyze the fundamental wave and harmonic components in the received digital navigation signal at the same time, and estimate the azimuth angle and pitch angle of the mobile terminal relative to the navigation base station ;

Step M5: After obtaining the positions of multiple navigation base stations and the azimuth and pitch angles of the mobile terminal relative to the navigation base stations, the current three-dimensional coordinates of the mobile terminal are solved by the method of angle cross positioning, so as to realize the navigation and positioning of the mobile terminal.

Preferably, the step M1 includes: an antenna array 1, a modulation switch module 2, a power amplifier 3, a band-pass filter 4, a mixer 5, a radio frequency local oscillator 6, a low-pass filter 7, a digital-to-analog converter 8 and Transmitter signal processing module 9;

Step M1.1: the transmitter signal processing module 9 generates a digital navigation signal;

Step M1.2: the digital-to-analog converter 8 converts the digital navigation signal into an analog navigation signal;

Step M1.3: filter out high-frequency components in the analog navigation signal through the low-pass filter 7;

Step M1.4: the RF local oscillator 6 combines with the mixer 5 to convert the intermediate frequency navigation signal in the analog navigation signal to a high frequency;

Step M1.5: select the mixed high-frequency navigation signal through the bandpass filter 4;

Step M1.6: Power amplify the high-frequency navigation signal through the power amplifier 3;

Step M1.7: The transmitter signal processing module 9 controls the modulation switch module 2 to perform periodic space-time modulation on the power amplified high-frequency navigation signal.

Preferably, the antenna array includes an antenna array composed of three antenna elements or an antenna array composed of multiple antenna elements; the antenna array composed of the three antenna elements is arranged in an L-shape; The arrangement of the antenna array is circular.

Preferably, the composition of the modulation switch module 2 includes a single-pole multi-throw RF switch or a combination of a single-pole single-throw RF switch and a power divider;

The power amplifier 3 is to power amplify the navigation signal;

The bandpass filter 4 selects the mixed high-frequency navigation signal to suppress unwanted sidebands;

The mixer 5 converts the intermediate frequency navigation signal to a high frequency;

The radio frequency local oscillator 6 provides a local oscillation signal for the mixer;

The low-pass filter 7 filters out the high-frequency components in the pilot signal after the digital-to-analog conversion;

The digital-to-analog converter 8 converts the digital navigation signal into an analog navigation signal;

The transmitter signal processing module 9 generates a digital navigation signal, and controls the modulation switch module to perform periodic space-time modulation on the navigation signal.

Preferably, the step M3 includes: a receiving antenna 10, a low-noise amplifier 11, a mixer 12, a radio frequency local oscillator 13, a low-pass filter 14, a drive amplifier 15, and an analog-to-digital converter 16;

Step M3.1: the receiving antenna 10 receives the navigation signal sent by the navigation base station; the low-noise amplifier 11 performs low-noise amplification on the received navigation signal;

Step M3.2: the RF local oscillator 13 combines with the mixer 12 to mix the navigation signal amplified by the low noise amplifier to an intermediate frequency;

Step M3.3: filter out the high-frequency components in the mixed navigation signal through the low-pass filter 14;

Step M3.4: the driving amplifier 15 drives and amplifies the navigation signal filtered by the low-pass filter;

Step M3.5: The analog-to-digital converter 16 converts the drive-amplified analog navigation signal into a digital navigation signal.

Preferably, the receiving antenna 10 can receive the navigation signal sent by the navigation base station;

The low-noise amplifier 11 can perform low-noise amplification on the received navigation signal;

The mixer 12 can mix the radio frequency navigation signal to the intermediate frequency;

The radio frequency local oscillator 13 can provide a local oscillation signal for the receiving mixer;

The low-pass filter 14 can filter out high-frequency components in the mixed navigation signal;

The drive amplifier 15 can drive and amplify the mixed navigation signal, so that the output signal satisfies the input range of the analog-to-digital converter 16;

The digital-to-analog converter 16 is capable of converting the received analog navigation signal into a digital signal.

Preferably, the step M4 includes: using the mobile terminal signal processing module 17 to demodulate the digital navigation signal in the digital domain to obtain the current navigation base station location information; Wave and harmonic components, calculate the azimuth angle and pitch angle of the mobile terminal relative to the navigation base station;

Preferably, the step M5 includes: using a single antenna at the mobile terminal to perform radio direction finding on the received navigation signal to achieve angular cross positioning.

A space-time modulation-based regional navigation and positioning system provided according to the present invention includes:

Antenna array 1, modulation switch network 2, transmit chain 18, transmit end signal processing module 9, receive antenna 10, receive chain 19 and mobile end signal processing module 17;

The transmitter signal processing module 9 is connected to the transmitter link 18 and the modulation switch module 2, the transmitter link 18 is connected to the modulation switch module 2, and the modulation switch module 2 is connected to the antenna array 1;

The mobile terminal signal processing module 17 is connected to the receiving link 19; the receiving link 19 is connected to the receiving antenna 10;

The transmitter signal processing module 9 generates a digital navigation signal, and controls the modulation switch module 2 to perform periodic space-time modulation on the analog navigation signal;

The transmitting link 18 can convert the digital navigation signal into an analog navigation signal, and perform operations including drive amplification, frequency up-conversion, band-pass filtering, and power amplification;

The modulation switch module 2 can perform periodic space-time modulation on the input analog navigation signal, and feed the modulated navigation signal into each unit of the antenna array 1;

The antenna array 1 can radiate a navigation signal subjected to periodic space-time modulation to space;

The receiving antenna 10 can receive the navigation signal sent by the navigation base station;

The receiving link 19 can perform operations including low-noise amplification, down-conversion, low-pass filtering, and analog-to-digital conversion on the received navigation signal, so as to convert the analog navigation signal into a digital navigation signal;

The mobile terminal signal processing module 17 can analyze the harmonic spectrum of the received navigation signal, calculate the direction of the mobile terminal relative to the base station terminal; direction to solve the current position of the mobile terminal to achieve navigation and positioning.

Preferably, the transmit chain 18 includes a power amplifier 3, a band-pass filter 4, a mixer 5, a radio frequency local oscillator 6, a low-pass filter 7 and a digital-to-analog converter 8;

The digital-to-analog converter 8 is connected to the low-pass filter 7; the low-pass filter 7 is connected to the mixer 5; the mixer 5 is connected to the radio frequency local oscillator 6 and the band The pass filter 4 is connected; the band pass filter 4 is connected with the power amplifier 3; the power amplifier 3 is connected with the modulation switch module 2;

The power amplifier 3 can amplify the power of the navigation signal;

The bandpass filter 4 selects the mixed high-frequency navigation signal to suppress unwanted sidebands;

The mixer 5 converts the intermediate frequency navigation signal to a high frequency;

The radio frequency local oscillator 6 provides a local oscillation signal for the mixer;

The low-pass filter 7 filters out the high-frequency components in the pilot signal after the digital-to-analog conversion;

The digital-to-analog converter 8 converts the digital navigation signal into an analog navigation signal;

The receiving chain 19 includes: a low noise amplifier 11, a mixer 12, a radio frequency local oscillator 13, a low pass filter 14, a driving amplifier 15 and an analog-to-digital converter 16;

The analog-to-digital converter 16 is connected to the drive amplifier 15; the drive amplifier 15 is connected to the low-pass filter 14; the low-pass filter 14 is connected to the mixer 12; The device 12 is connected to the radio frequency local oscillator 13 and the low noise amplifier 11; the low noise amplifier 11 is connected to the receiving antenna 10;

The low-noise amplifier 11 can perform low-noise amplification on the received navigation signal;

The mixer 12 can mix the radio frequency navigation signal to the intermediate frequency;

The radio frequency local oscillator 13 can provide a local oscillation signal for the receiving mixer;

The low-pass filter 14 can filter out high-frequency components in the mixed navigation signal;

The drive amplifier 15 can drive and amplify the mixed navigation signal, so that the output signal satisfies the input range of the analog-to-digital converter 16;

The digital-to-analog converter 16 is capable of converting the received analog navigation signal into a digital signal.

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

1. The present invention does not require a large and precise navigation base station, and at the same time does not require two-way communication between the navigation base station and the mobile terminal;

2. The mobile terminal in the present invention performs two-dimensional direction finding with respect to the navigation base station. Compared with the existing two-station VOR direction finding positioning, only one-dimensional azimuth is measured. Therefore, the present invention can measure the three-dimensional coordinates of the mobile terminal, and its expected positioning accuracy is higher;

3. The present invention performs periodic space-time modulation on the navigation at the navigation base station, so that the transmitted navigation signal carries the spatial orientation information, and the mobile terminal does not need to use multiple antennas for orientation measurement, and the relative position of the mobile terminal to the navigation base station can be obtained. the orientation of the end;

4. The present invention is especially suitable for a system in which a large number of users perform positioning and navigation at the same time.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

Fig. 1 is the structural block diagram of the base station end and the mobile end of the regional navigation and positioning system provided by the present invention;

Fig. 2 is the structural block diagram of the base station end and the mobile end of the regional navigation and positioning system provided by the present invention;

Fig. 3 is the frequency spectrum of the navigation signal received by the mobile terminal in embodiment 3;

Fig. 4 is the root mean square value of the azimuth angle and pitch angle error estimated by the mobile end relative to the base station end under different signal-to-noise ratio conditions in Embodiment 3;

5 is a schematic diagram of the result of positioning the mobile terminal using two navigation base stations in Embodiment 2;

FIG. 6 shows the positioning error results of 100 positionings performed in Example 3. FIG.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the inventive concept. These all belong to the protection scope of the present invention.

Example 1

According to a method for regional navigation and positioning based on space-time modulation provided by the present invention, the method includes: as shown in FIG. 1 ,

Step M1: the navigation base station generates a digital navigation signal, which is subjected to periodic space-time modulation by a modulation switch module after including digital-to-analog conversion, drive amplification, up-conversion, filtering and power amplification;

Step M2: the periodic space-time modulated navigation signal is radiated into space by the antenna array;

Step M3: After the mobile terminal receives the navigation signal, after including low-noise amplification, down-conversion, filtering and drive amplification, the analog-to-digital converter converts the navigation signal into a digital navigation signal;

Step M4: demodulate the digital navigation signal in the digital domain to obtain the position information of the current navigation base station; analyze the fundamental wave and harmonic components in the received digital navigation signal at the same time, and estimate the azimuth angle and pitch angle of the mobile terminal relative to the navigation base station ;

Step M5: After obtaining the positions of multiple navigation base stations and the azimuth and pitch angles of the mobile terminal relative to the navigation base stations, the current three-dimensional coordinates of the mobile terminal are solved by the method of angle cross positioning, so as to realize the navigation and positioning of the mobile terminal.

Specifically, the step M1 includes: an antenna array 1, a modulation switch module 2, a power amplifier 3, a band-pass filter 4, a mixer 5, a radio frequency local oscillator 6, a low-pass filter 7, a digital-to-analog converter 8 and Transmitter signal processing module 9;

Step M1.1: the transmitter signal processing module 9 generates a digital navigation signal;

Step M1.2: the digital-to-analog converter 8 converts the digital navigation signal into an analog navigation signal;

Step M1.3: filter out high-frequency components in the analog navigation signal through the low-pass filter 7;

Step M1.4: the RF local oscillator 6 combines with the mixer 5 to convert the intermediate frequency navigation signal in the analog navigation signal to a high frequency;

Step M1.5: select the mixed high-frequency navigation signal through the bandpass filter 4;

Step M1.6: Power amplify the high-frequency navigation signal through the power amplifier 3;

Step M1.7: The transmitter signal processing module 9 controls the modulation switch module 2 to perform periodic space-time modulation on the power amplified high-frequency navigation signal.

Specifically, the antenna array includes an antenna array composed of three antenna units or an antenna array composed of multiple antenna units; the antenna array composed of the three antenna units is arranged in an L-shape; The arrangement of the antenna array is circular.

Specifically, the composition of the modulation switch module 2 includes a single-pole multi-throw RF switch or a combination of a single-pole single-throw RF switch and a power divider;

The power amplifier 3 is to power amplify the navigation signal;

The bandpass filter 4 selects the mixed high-frequency navigation signal to suppress unwanted sidebands;

The mixer 5 converts the intermediate frequency navigation signal to a high frequency;

The radio frequency local oscillator 6 provides a local oscillation signal for the mixer;

The low-pass filter 7 filters out the high-frequency components in the pilot signal after the digital-to-analog conversion;

The digital-to-analog converter 8 converts the digital navigation signal into an analog navigation signal;

The transmitter signal processing module 9 generates a digital navigation signal, and controls the modulation switch module to perform periodic space-time modulation on the navigation signal.

Specifically, the step M3 includes: a receiving antenna 10, a low-noise amplifier 11, a mixer 12, a radio frequency local oscillator 13, a low-pass filter 14, a drive amplifier 15, and an analog-to-digital converter 16;

Step M3.1: the receiving antenna 10 receives the navigation signal sent by the navigation base station; the low-noise amplifier 11 performs low-noise amplification on the received navigation signal;

Step M3.2: the RF local oscillator 13 combines with the mixer 12 to mix the navigation signal amplified by the low noise amplifier to an intermediate frequency;

Step M3.3: filter out the high-frequency components in the mixed navigation signal through the low-pass filter 14;

Step M3.4: the driving amplifier 15 drives and amplifies the navigation signal filtered by the low-pass filter;

Step M3.5: The analog-to-digital converter 16 converts the drive-amplified analog navigation signal into a digital navigation signal.

Specifically, the receiving antenna 10 can receive the navigation signal sent by the navigation base station;

The low-noise amplifier 11 can perform low-noise amplification on the received navigation signal;

The mixer 12 can mix the radio frequency navigation signal to the intermediate frequency;

The radio frequency local oscillator 13 can provide a local oscillation signal for the receiving mixer;

The low-pass filter 14 can filter out high-frequency components in the mixed navigation signal;

The drive amplifier 15 can drive and amplify the mixed navigation signal, so that the output signal satisfies the input range of the analog-to-digital converter 16;

The digital-to-analog converter 16 is capable of converting the received analog navigation signal into a digital signal.

Specifically, the step M4 includes: using the mobile terminal signal processing module 17 to demodulate the digital navigation signal in the digital domain to obtain the position information of the current navigation base station; at the same time analyzing the base station in the digital navigation signal received by the mobile terminal signal processing module 17 Wave and harmonic components, calculate the azimuth angle and pitch angle of the mobile terminal relative to the navigation base station;

Specifically, the step M5 includes: using a single antenna at the mobile terminal to perform radio direction finding on the received navigation signal to achieve angular cross positioning.

A regional navigation and positioning system based on space-time modulation provided according to the present invention includes: as shown in FIG. 2 ,

Antenna array 1, modulation switch network 2, transmit chain 18, transmit end signal processing module 9, receive antenna 10, receive chain 19 and mobile end signal processing module 17;

The transmitter signal processing module 9 is connected to the transmitter link 18 and the modulation switch module 2, the transmitter link 18 is connected to the modulation switch module 2, and the modulation switch module 2 is connected to the antenna array 1;

The mobile terminal signal processing module 17 is connected to the receiving link 19; the receiving link 19 is connected to the receiving antenna 10;

The transmitter signal processing module 9 generates a digital navigation signal, and controls the modulation switch module 2 to perform periodic space-time modulation on the analog navigation signal;

The transmitting link 18 can convert the digital navigation signal into an analog navigation signal, and perform operations including drive amplification, frequency up-conversion, band-pass filtering, and power amplification;

The modulation switch module 2 can perform periodic space-time modulation on the input analog navigation signal, and feed the modulated navigation signal into each unit of the antenna array 1;

The antenna array 1 can radiate a navigation signal subjected to periodic space-time modulation to space;

The receiving antenna 10 can receive the navigation signal sent by the navigation base station;

The receiving link 19 can perform operations including low-noise amplification, down-conversion, low-pass filtering, and analog-to-digital conversion on the received navigation signal, so as to convert the analog navigation signal into a digital navigation signal;

The mobile terminal signal processing module 17 can analyze the harmonic spectrum of the received navigation signal, calculate the direction of the mobile terminal relative to the base station terminal; direction to solve the current position of the mobile terminal to achieve navigation and positioning.

Specifically, the transmit chain 18 includes a power amplifier 3, a band-pass filter 4, a mixer 5, a radio frequency local oscillator 6, a low-pass filter 7 and a digital-to-analog converter 8;

The digital-to-analog converter 8 is connected to the low-pass filter 7; the low-pass filter 7 is connected to the mixer 5; the mixer 5 is connected to the radio frequency local oscillator 6 and the band The pass filter 4 is connected; the band pass filter 4 is connected with the power amplifier 3; the power amplifier 3 is connected with the modulation switch module 2;

The power amplifier 3 can amplify the power of the navigation signal;

The bandpass filter 4 selects the mixed high-frequency navigation signal to suppress unwanted sidebands;

The mixer 5 converts the intermediate frequency navigation signal to a high frequency;

The radio frequency local oscillator 6 provides a local oscillation signal for the mixer;

The low-pass filter 7 filters out the high-frequency components in the pilot signal after the digital-to-analog conversion;

The digital-to-analog converter 8 converts the digital navigation signal into an analog navigation signal;

The receiving chain 19 includes: a low noise amplifier 11, a mixer 12, a radio frequency local oscillator 13, a low pass filter 14, a driving amplifier 15 and an analog-to-digital converter 16;

The analog-to-digital converter 16 is connected to the drive amplifier 15; the drive amplifier 15 is connected to the low-pass filter 14; the low-pass filter 14 is connected to the mixer 12; The device 12 is connected to the radio frequency local oscillator 13 and the low noise amplifier 11; the low noise amplifier 11 is connected to the receiving antenna 10;

The low-noise amplifier 11 can perform low-noise amplification on the received navigation signal;

The mixer 12 can mix the radio frequency navigation signal to the intermediate frequency;

The radio frequency local oscillator 13 can provide a local oscillation signal for the receiving mixer;

The low-pass filter 14 can filter out high-frequency components in the mixed navigation signal;

The drive amplifier 15 can drive and amplify the mixed navigation signal, so that the output signal satisfies the input range of the analog-to-digital converter 16;

The digital-to-analog converter 16 is capable of converting the received analog navigation signal into a digital signal.

Example 2

Example 2 is a modification of Example 1

The basic principle of the present invention is to perform periodic space-time modulation on navigation at the base station. The periodic space-time modulated navigation signal contains fundamental and harmonic components, and is radiated into space through the antenna array at the base station. In different spatial orientations, the fundamental and harmonic components in the received navigation signals are different. Therefore, by analyzing the signals of fundamental wave components and harmonic components in the received navigation signal at the mobile terminal, the azimuth angle and pitch angle relative to the navigation base station can be estimated. If the mobile terminal simultaneously measures its azimuth and pitch angles relative to two or more navigation base stations, under the condition that the positions of the navigation base stations are known, the three-dimensional coordinates of the mobile terminal can be measured by using the angle cross positioning method to realize navigation. and positioning.

An area navigation and positioning system based on space-time modulation, the working process of which is as follows: a navigation base station generates a digital navigation signal, which contains information such as the position of the navigation base station. After digital-to-analog conversion, frequency up-conversion, filtering and power amplification, periodic space-time modulation is performed by the modulation switch module. The periodic space-time modulated navigation signal contains fundamental and harmonic components, and is radiated into space by the antenna array. At the mobile terminal, after receiving the navigation signal, it is converted into a digital navigation signal by an analog-to-digital converter after low-noise amplification, down-conversion, filtering and drive amplification. In the digital domain, on the one hand, the navigation signal is demodulated to obtain information such as the position of the current navigation base station; on the other hand, the fundamental wave and harmonic components in the received navigation signal are analyzed to estimate the azimuth and pitch of the mobile terminal relative to the navigation base station. horn. After obtaining the positions of two or more navigation base stations, as well as the azimuth and pitch angles of the mobile terminal relative to the navigation base stations, the current three-dimensional coordinates of the mobile terminal are solved through the azimuth of the angle cross positioning to realize the navigation and positioning of the mobile terminal.

Assuming that the navigation base station adopts a three-element antenna array and is arranged in an L-shape, the analysis of the navigation and positioning process is as follows:

Let the three antenna elements of the antenna array be E1, E2, and E3 respectively, and their positions are:

E1[D1,0,0], E2[0,0,0], E3[0,D2,0]; the modulation switch network controls the transmitted navigation signal to periodically turn on the three antenna units. In one modulation period T _p , E1 is turned on within (0, T _p /3], E2 is turned on within (T _p /3, 2T _p /3], and E2 is turned on within (2T _p /3, T _p ]. E3. The transmitted navigation signal is a narrow-band signal with a carrier frequency of _Fc . For the convenience of analysis, it is regarded as a point frequency signal, and the transmitted navigation signal is:

Among them, A is the amplitude of the transmitted navigation signal, and m is the cycle number, which is an integer. Δφ _i , i=1, 2, 3 is the phase of the navigation signal due to space-time modulation, and its value can be calculated by the following formula:

为方位角。λ表示波长，在导航基站端，第i个天线单元上发射的信号为：Wherein, x _i , y _i , z _i , i=1, 2, 3 are the coordinates of the three antenna elements. θ is the pitch angle of the mobile terminal relative to the navigation base station,

is the azimuth angle. λ represents the wavelength. At the navigation base station, the signal transmitted by the i-th antenna unit is:

The periodic signal S _i (t) can be expanded by Fourier series, assuming that the Fourier coefficients of its fundamental component and the first and second harmonic components are a _i,0 , a _i,1 , a _i respectively _,2 ,i=1,2,3. At the mobile terminal, Fourier transform is performed on the received navigation signal to obtain the fundamental component γ ₀ , and the first and second harmonic components γ ₁ and γ ₂ in the navigation signal. The fundamental and harmonic components in the received navigation signal can be regarded as the superposition in space of the fundamental and harmonic components emitted by the three antenna units at the navigation base station, so there are the following linear equations:

Among them, _Ar is the loss caused by the propagation path. Since the matrix on the left side of the above equation is a known quantity related to the modulation timing, the vector on the right side of the above equation can be obtained by performing Fourier transform on the received navigation signal, so the linear equations are solved as follows:

和俯仰角θ的值。Among them, D ₁ represents the abscissa of the antenna element E ₁ , and D ₂ represents the ordinate of the antenna element E ₂ . The vector on the left side of the equation contains the azimuth and pitch angle information; the matrix on the right side of the equation can be calculated from the modulation timing and is a known quantity; the vector on the right side of the equation can be obtained by Fourier transforming the received navigation signal. Therefore, by solving the system of linear equations shown in Eq., the azimuth angle can be obtained

and the value of the pitch angle θ.

At the same time, the mobile terminal demodulates the received navigation signal to obtain information such as the location of the navigation base station. If the mobile terminal receives signals from two or more sets of navigation base stations, and performs direction finding to obtain the pitch and azimuth angles of the mobile terminal relative to the navigation base stations. At the same time, the mobile terminal demodulates the navigation signal to obtain the position energy information of two or more sets of navigation base stations, and then the three-dimensional position coordinates of the mobile terminal can be solved by the method of angle cross positioning to realize the navigation and positioning of the mobile terminal, as shown in Figure 5. Show.

Example 3

Example 3 is a variation of Example 2 and/or Example 1

The mobile terminal measures the azimuth and pitch angles relative to the navigation base station

It is assumed that the navigation base station transmits a narrowband signal with a carrier frequency of 1 GHz. The antenna array of the navigation base station includes three antenna units and is distributed in an L shape, and the three antenna units are E1, E2 and E3. Wherein, the distances between E1 and E2, and E2 and E3 are all 15 cm (half wavelength). The transmitted navigation signal undergoes periodic space-time modulation, and is then radiated into space by the antenna array. Among them, the modulation period is 1us. In the first third of the period, the navigation signal is fed into the E1 unit; in the middle one third of the period, the navigation signal is fed into the E2 unit; in the last third of the period, the navigation signal is fed into the E2 unit. Unit E3. The navigation signal with 10 modulation cycles is radiated in the co-directional space, and the signal-to-noise ratio is 20dB.

Assume that the azimuth angle of the mobile terminal relative to the base station terminal is 65°, and the pitch angle is 20°. At the mobile terminal, the antenna receives the space-time modulated navigation signal, and its frequency spectrum is shown in Figure 3. As can be seen from the figure, the fundamental component of the received navigation signal is at 1 GHz, and the first and second harmonic components are at 1.001 GHz and 1.002 GHz, respectively. Substitute the obtained fundamental wave component and the first and second harmonic components into the formula and calculate the azimuth angle and pitch angle of the mobile terminal relative to the base station terminal, and the azimuth angle is 65.05° and the pitch angle is 20.00 degrees.

It is still set that the azimuth angle of the mobile terminal relative to the base station terminal is 65°, and the pitch angle is 20 degrees. Set the SNR from -10dB to +20dB in 2dB steps. Under each signal-to-noise ratio condition, 1000 times of Monte Carlo simulations were performed to calculate the mean square error of the estimated azimuth and pitch angles. The simulation results obtained are shown in Figure 4. It can be seen from Figure 4 that when the SNR increases from -10dB to +20dB, the mean square estimation errors of both the azimuth and pitch angles decrease from about 1.2° to 0.1°.

The mobile terminal uses the signals of the two navigation base stations to achieve navigation and positioning

The positions of the two navigation base stations are set as [0,-500m,0], [0,500m,0] respectively, and the real position of the mobile station is [100m, 200m, 80m]. The antenna array of the first navigation base station is a three-unit L-shaped, the distance between the units is half a wavelength, and the carrier frequency of the transmitted narrow-band navigation signal is 1GHz. The modulation switch network controls the navigation signal to turn on the three antenna units periodically, and its modulation period is 1us. In the first 1/3us, the navigation signal is connected to the antenna unit 1; in the middle 1/3us, the navigation signal is connected to the antenna unit 2; in the last 1/3us, the navigation signal is connected to the antenna unit 3. In the same position, the position signal of the navigation base station is coded and modulated by BPSK, and the symbol period is 10us. In one symbol period, a total of 10 modulation periods of navigation signals are transmitted.

Similarly, for the second navigation base station, the antenna array configuration, the transmitted navigation signal and the modulation method are the same as those of the first navigation base station, the difference is that the carrier frequency of the transmitted navigation signal is 1.1GHz, which is used for mobile The terminal realizes frequency division simultaneous reception.

Assuming that the signal-to-noise ratio of the received navigation signal is 20dB, the spectrum analysis of the received pilot signal is performed and the azimuth and pitch angles of the mobile terminal relative to the two navigation base stations are calculated. The simulation results obtained are as follows. The actual value of the pitch angle and azimuth angle of the mobile terminal relative to the first navigation base station is (83.55°, 81.87°), and the measured value is (83.91°, 81.86°); the pitch angle and azimuth angle relative to the second navigation base station are The true value of the angle is (75.80°, -71.57°) and the measured value is (75.87°, -71.59°). Assuming that the mobile terminal can correctly demodulate the positions of the two navigation base stations, the three-dimensional coordinates of the current mobile terminal can be calculated by using the angle cross positioning azimuth to be [99.67m, 203.84m, 77.13m]. Compared with the true value, the spatial distance error is 4.8m.

Under the above conditions, 100 Monte Carlo simulations were performed. The resulting positioning errors are shown in Figure 6. The root mean square value of the positioning error is calculated to be 2.55m.

In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", The orientation or positional relationship indicated by "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying the indicated device. Or elements must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present application.

Those skilled in the art know that, in addition to implementing the system, device and each module provided by the present invention in the form of pure computer readable program code, the system, device and each module provided by the present invention can be completely implemented by logically programming method steps. The same program is implemented in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, and embedded microcontrollers, among others. Therefore, the system, device and each module provided by the present invention can be regarded as a kind of hardware component, and the modules used for realizing various programs included in it can also be regarded as the structure in the hardware component; A module for realizing various functions can be regarded as either a software program for realizing a method or a structure within a hardware component.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essential content of the present invention. The embodiments of the present application and features in the embodiments may be combined with each other arbitrarily, provided that there is no conflict.

Claims (10)

1. a regional navigation and positioning method based on space-time modulation, is characterized in that, comprises: Step M1: the navigation base station generates a digital navigation signal, which is subjected to periodic space-time modulation by a modulation switch module after including digital-to-analog conversion, drive amplification, up-conversion, filtering and power amplification; Step M2: the periodic space-time modulated navigation signal is radiated into space by the antenna array; Step M3: After the mobile terminal receives the navigation signal, after including low-noise amplification, down-conversion, filtering and drive amplification, the analog-to-digital converter converts the navigation signal into a digital navigation signal; Step M4: demodulate the digital navigation signal in the digital domain to obtain the position information of the current navigation base station; analyze the fundamental wave and harmonic components in the received digital navigation signal at the same time, and estimate the azimuth angle and pitch angle of the mobile terminal relative to the navigation base station ; Step M5: After obtaining the positions of multiple navigation base stations and the azimuth and pitch angles of the mobile terminal relative to the navigation base stations, the current three-dimensional coordinates of the mobile terminal are solved by the method of angle cross positioning, so as to realize the navigation and positioning of the mobile terminal. 2. The regional navigation and positioning method based on space-time modulation according to claim 1, wherein the step M1 comprises: an antenna array (1), a modulation switch module (2), a power amplifier (3), a band-pass a filter (4), a mixer (5), a radio frequency local oscillator (6), a low-pass filter (7), a digital-to-analog converter (8) and a transmitter signal processing module (9); Step M1.1: the transmitter signal processing module (9) generates a digital navigation signal; Step M1.2: the digital-to-analog converter (8) converts the digital navigation signal into an analog navigation signal; Step M1.3: filter out high-frequency components in the analog navigation signal through a low-pass filter (7); Step M1.4: the radio frequency local oscillator (6) combined with the mixer (5) converts the intermediate frequency navigation signal in the analog navigation signal to a high frequency; Step M1.5: select the mixed high-frequency navigation signal through the bandpass filter (4); Step M1.6: performing power amplification on the high-frequency navigation signal through the power amplifier (3); Step M1.7: The modulation switch module (2) is controlled by the transmitter signal processing module (9) to perform periodic space-time modulation on the power-amplified high-frequency navigation signal. 3. The regional navigation and positioning method based on space-time modulation according to claim 1, wherein the antenna array comprises an antenna array composed of three antenna elements or an antenna array composed of multiple antenna elements; The antenna array formed by the antenna units is arranged in an L-shape; the antenna array formed by the plurality of antenna units is arranged in a circle. 4. The regional navigation and positioning method based on space-time modulation according to claim 2, wherein the modulation switch module (2) is composed of a single-pole multi-throw radio frequency switch or a single-pole single-throw radio frequency switch and a power divider the combined form of the device; The power amplifier (3) is used to amplify the power of the navigation signal; The bandpass filter (4) selects the mixed high-frequency navigation signal to suppress unwanted sidebands; The mixer (5) converts the intermediate frequency navigation signal to a high frequency; The radio frequency local oscillator (6) provides a local oscillation signal for the mixer; The low-pass filter (7) filters out high-frequency components in the pilot signal after digital-to-analog conversion; The digital-to-analog converter (8) converts the digital navigation signal into an analog navigation signal; The transmitter signal processing module (9) generates a digital navigation signal, and controls the modulation switch module to perform periodic space-time modulation on the navigation signal. 5. The regional navigation and positioning method based on space-time modulation according to claim 1, wherein the step M3 comprises: a receiving antenna (10), a low noise amplifier (11), a frequency mixer (12), a radio frequency A local oscillator (13), a low-pass filter (14), a drive amplifier (15) and an analog-to-digital converter (16); Step M3.1: the receiving antenna (10) receives the navigation signal sent by the navigation base station; low-noise amplification is performed on the received navigation signal through the low-noise amplifier (11); Step M3.2: the radio frequency local oscillator (13) combines with the mixer (12) to mix the navigation signal amplified by the low noise amplifier to an intermediate frequency; Step M3.3: filter out high-frequency components in the mixed navigation signal through a low-pass filter (14); Step M3.4: the driving amplifier (15) drives and amplifies the navigation signal filtered by the low-pass filter; Step M3.5: The analog-to-digital converter (16) converts the analog navigation signal amplified by the drive into a digital navigation signal. 6. The regional navigation and positioning method based on space-time modulation according to claim 5, wherein the receiving antenna (10) can receive the navigation signal sent by the navigation base station; The low-noise amplifier (11) can perform low-noise amplification on the received navigation signal; The mixer (12) can mix the radio frequency navigation signal to an intermediate frequency; The radio frequency local oscillator (13) can provide a local oscillation signal for the receiving mixer; The low-pass filter (14) can filter out high-frequency components in the mixed navigation signal; The drive amplifier (15) can drive and amplify the mixed navigation signal, so that the output signal satisfies the input range of the analog-to-digital converter (16); The digital-to-analog converter (16) is capable of converting the received analog navigation signal into a digital signal. 7. The regional navigation and positioning method based on space-time modulation according to claim 1, is characterized in that, described step M4 comprises: utilize mobile terminal signal processing module (17) to demodulate digital navigation signal in digital domain, obtain The position information of the current navigation base station; at the same time, the fundamental wave and harmonic components in the digital navigation signal received by the mobile terminal signal processing module (17) are analyzed, and the azimuth angle and the pitch angle of the mobile terminal relative to the navigation base station are calculated. 8. The regional navigation and positioning method based on space-time modulation according to claim 1, wherein the step M5 comprises: using a single antenna at the mobile terminal to perform radio direction finding on the received navigation signal to realize the method for cross-angle positioning . 9. A regional navigation and positioning system based on space-time modulation, characterized in that, comprising: Antenna array (1), modulation switch network (2), transmit chain (18), transmit end signal processing module (9), receive antenna (10), receive chain (19) and mobile end signal processing module (17) ; The transmitting end signal processing module (9) is connected to a transmitting link (18) and a modulation switch module (2), the transmission link (18) is connected to the modulation switch module (2), and the modulation switch module (2) is connected to the modulation switch module (2). The antenna array (1) is connected; The mobile terminal signal processing module (17) is connected with the receiving link (19); the receiving link (19) is connected with the receiving antenna (10); The transmitter signal processing module (9) generates a digital navigation signal, and controls the modulation switch module (2) to perform periodic space-time modulation on the analog navigation signal; The transmitting chain (18) can convert digital navigation signals into analog navigation signals, and perform operations including drive amplification, frequency up-conversion, band-pass filtering, and power amplification; The modulation switch module (2) is capable of performing periodic space-time modulation on the input analog navigation signal, and feeding the modulated navigation signal into each unit of the antenna array (1); The antenna array (1) is capable of radiating navigation signals subjected to periodic space-time modulation to space; The receiving antenna (10) can receive the navigation signal sent by the navigation base station; The receiving link (19) can perform operations including low-noise amplification, down-conversion, low-pass filtering, and analog-to-digital conversion on the received navigation signal, so as to convert the analog navigation signal into a digital navigation signal; The mobile terminal signal processing module (17) can analyze the harmonic spectrum of the received navigation signal, calculate the direction of the mobile terminal relative to the base station terminal; The direction of the base station is used to calculate the current position of the mobile terminal to realize navigation and positioning. 10. The area navigation and positioning system based on space-time modulation according to claim 9, wherein the transmission chain (18) comprises a power amplifier (3), a band-pass filter (4), a frequency mixer ( 5), a radio frequency local oscillator (6), a low-pass filter (7) and a digital-to-analog converter (8); The digital-to-analog converter (8) is connected to the low-pass filter (7); the low-pass filter (7) is connected to the mixer (5); the mixer (5) is connected to The radio frequency local oscillator (6) is connected to the bandpass filter (4); the bandpass filter (4) is connected to the power amplifier (3); the power amplifier (3) is connected to the modulation The switch module (2) is connected; The power amplifier (3) is capable of power amplifying the navigation signal; The bandpass filter (4) selects the mixed high-frequency navigation signal to suppress unwanted sidebands; The mixer (5) converts the intermediate frequency navigation signal to a high frequency; The radio frequency local oscillator (6) provides a local oscillation signal for the mixer; The low-pass filter (7) filters out high-frequency components in the pilot signal after digital-to-analog conversion; The digital-to-analog converter (8) converts the digital navigation signal into an analog navigation signal; The receiving chain (19) includes: a low noise amplifier (11), a mixer (12), a radio frequency local oscillator (13), a low-pass filter (14), a driving amplifier (15) and an analog-to-digital converter ( 16); The analog-to-digital converter (16) is connected to the drive amplifier (15); the drive amplifier (15) is connected to the low-pass filter (14); the low-pass filter (14) is connected to the low-pass filter (14) A mixer (12) is connected; the mixer (12) is connected to the radio frequency local oscillator (13) and the low noise amplifier (11); the low noise amplifier (11) is connected to the receiving antenna ( 10) Connection; The low-noise amplifier (11) can perform low-noise amplification on the received navigation signal; The mixer (12) can mix the radio frequency navigation signal to an intermediate frequency; The radio frequency local oscillator (13) can provide a local oscillation signal for the receiving mixer; The low-pass filter (14) can filter out high-frequency components in the mixed navigation signal; The drive amplifier (15) can drive and amplify the mixed navigation signal, so that the output signal satisfies the input range of the analog-to-digital converter (16); The digital-to-analog converter (16) is capable of converting the received analog navigation signal into a digital signal.

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