CN112327251B - Unattended signal time difference positioning method under low-rate communication condition - Google Patents
Unattended signal time difference positioning method under low-rate communication condition Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
- G01S5/06—Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
- G01S5/0294—Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering
Abstract
The invention discloses an unattended signal time difference positioning method under a low-rate communication condition, which comprises the following specific steps: in a set time, the master station sends a broadcast cooperation signaling to search for potential auxiliary stations; after receiving the broadcast cooperation signaling, the potential auxiliary station sends a response signaling to the main station; after receiving the response signaling of the potential auxiliary station, if the master station judges that the auxiliary station is in compliance, determining that the auxiliary station is a cooperative auxiliary station and configuring general working parameters for the auxiliary station; when the number of the auxiliary stations establishing the cooperative relationship is zero, the main station independently executes direction-finding positioning and broadband signal target positioning, otherwise, the main station is configured to enter a multi-station joint positioning and tracking mode, and the auxiliary stations are scheduled to perform cooperative positioning and tracking. The connection establishment and the work cooperation between the main station and the auxiliary station are automatically completed, the automation degree of the system is improved, the system has strong robustness, the reconnaissance and identification difficulty of the opposite side to the network of the system is increased, and the survival capability of the system is improved.
Description
Technical Field
The invention belongs to the field of ad hoc network type unmanned signal passive positioning in communication countermeasure, and particularly relates to an unattended signal time difference positioning method under a low-rate communication condition.
Background
For communication signals with low transmission rate, although the signal bandwidth is narrow, the communication signals generally have higher utilization significance, such as ultrashort wave narrowband continuous wave communication signals. At present, a direction-finding positioning mode is basically adopted for narrow-band continuous wave signals, and is limited by factors such as an algorithm, wavelength characteristics and the like, so that the direction-finding precision is low, and the corresponding positioning precision is reduced. In the field of passive positioning, time difference positioning has the characteristics of high positioning precision, high positioning speed and the like, and can be used for positioning low-speed communication signals. The time difference positioning needs the cooperation of a plurality of measuring stations, and the target signal is sampled simultaneously on the basis of time synchronization of each station, so that the position of the target signal is positioned according to the arrival time difference of the signal, the precision of the time difference positioning is far higher than that of a direction finding mode, and the time difference positioning mode is the development trend of a future passive positioning system.
The traditional time difference positioning system is composed of a plurality of independent stations, equipment of each positioning station is simple to assemble, all the stations need manual maintenance and operation, meanwhile, a plurality of positioning stations are connected through wired optical fiber links, time synchronization and data return are provided, deployment cost is high, an application mode is inflexible, and rapid deployment is difficult to achieve.
Disclosure of Invention
Aiming at the defects of weak flexible expansion capability, incapability of full-automatic operation, need of optical fiber wired connection and need of manual maintenance in the traditional passive positioning technology, the invention provides an unattended signal time difference positioning method under the condition of low-speed communication, which comprises the following steps:
s1, the attribute values of the main and auxiliary stations of the equipment are preset when the equipment leaves a factory, the attributes of the main and auxiliary stations of the equipment are manually modified according to task requirements when the equipment is laid out, and the attributes of the main and auxiliary stations of the equipment are automatically identified when the equipment is started;
s2, in the set time, the main station sends a broadcast cooperation signaling to search for potential auxiliary stations;
the method comprises the steps that a main station sends a broadcast cooperation signaling to search for potential auxiliary stations, wherein the broadcast cooperation signaling used by the main station is divided into a restart cooperation signaling and an accumulation cooperation signaling; restarting the cooperation signaling requires that each auxiliary station which receives the signaling and keeps the cooperation relationship with the main station needs to interrupt the cooperation relationship, and after the initial state is recovered, the cooperation relationship is established with the main station again; the accumulated cooperation signaling is aimed at the secondary station which has not established cooperation with the primary station, and the secondary station which has established cooperation with the primary station does not respond to the signaling any more. The restart cooperative signaling and the accumulated cooperative signaling both include the following information:
the cooperative signaling identifier is flag information for distinguishing two signaling types.
And the time number is a time unified information number generated by the main and auxiliary stations for recording time system information, and the time system information is provided by a GPS or a Beidou system.
The method comprises the steps that a master station first ID (first serial number), namely a master station first number, is used for distinguishing the identities of the master stations when multi-user communication is carried out among a plurality of master stations within a beyond visual range, the ID base of each master station is configured when the master stations leave a factory, each master station has a plurality of IDs available for the master station, and each master station randomly selects one ID in the ID base as a master station first ID when a restarting cooperation signaling is generated by the master station;
the response channel information specifies the wireless channel information which is required to be used when the secondary station transmits signals back to the main station, and the wireless channel information comprises frequency points, bandwidth, sampling rate, modulation mode and the like.
And the response information format identifier is used for indicating the auxiliary station to select a corresponding response information format from a preset response signaling structure template and fill corresponding information content for response, and a plurality of response signaling formats are preset when the auxiliary station equipment leaves a factory.
And receiving response starting time and response ending time, wherein the response starting time and the response ending time are used for indicating a time range of the secondary station for sending the response signaling, and the time range takes the time system information as reference.
And the ID mapping mode number is used for indicating the master station to select a corresponding mapping function from a preset ID mapping function set according to the ID mapping mode number, the ID mapping mode number and the mapping function are in one-to-one correspondence, the mapping function is a monotonically increasing or monotonically decreasing function, and the ID mapping function set is preset when the equipment leaves a factory.
And the signaling transmission power is used for setting the transmission power of the cooperative signaling sent by the main station.
S3, after receiving the broadcast cooperation signaling, the potential secondary station sends a response signaling to the primary station; the method comprises the following specific steps:
and S31, before the potential secondary station receives the accumulated response signaling containing the self mapping ID, the potential secondary station continuously receives and screens the broadcast cooperation signaling of the primary station, and sorts the screened primary stations according to the time and power information, and the secondary station selects the primary station with the highest sorting and sends the response signaling for response.
The potential auxiliary station receives and screens the broadcast cooperation signaling of the main station, namely the potential auxiliary station judges the time number in the received main station broadcast signaling and the first ID information of the main station, the judgment rule is that the time information of the time for the potential auxiliary station to receive the broadcast cooperation signaling and the time information interval represented by the time number carried in the broadcast cooperation signaling are smaller than a certain threshold value, and the first ID of the main station is required to be in a main station ID information list preset when the auxiliary station leaves a factory.
Sorting the screened main stations according to the time and power information, wherein the first ID is the sorting value P of the main station with iiThe calculation formula of (2) is as follows:
wherein, Ptx,iBroadcast signalling transmission power, P, for a primary station having a first ID of irx,i,jReceiving power t of j-th broadcast signaling of a primary station with a first ID i received by a secondary station in a preset time periodiThe method comprises the steps that time numbers of a main station broadcast signaling with a latest first ID i received by an auxiliary station are numbered, N is the number of times of the main station broadcast signaling with the first ID i received by the auxiliary station in a preset time period, and beta is a weight value adjustment coefficient; the larger the ranking value, the higher the ranking.
The response signaling specifically includes a response signaling identifier, a time number, a secondary station first ID, and a primary station first mapping ID. The first ID of the secondary station is the ID randomly selected by the secondary station from the ID library of the secondary station, and the first ID of the secondary station is kept unchanged during the period that the secondary station establishes a cooperative relationship with the main station and the time from the transmission of a response signaling by the secondary station to the target main station to the reception of the response of the main station; the first mapping ID of the master station is obtained by calculation according to the first ID of the master station and a mapping function represented by an ID mapping mode number carried in the broadcast cooperation signaling by the master station, and the calculation formula is as follows:
Bid,i＝f(Kid,i,0)+tm，
wherein, tmTime number, K, corresponding to the transmission of response messages for the secondary stationid,iFirst ID, B, representing the Master station iid,iA first mapping ID representing the primary station i, f () is a mapping function of the first ID to the first mapping ID. The mapping function being a monotonically increasing or decreasing function, mappingThe expression of the function of the ray is:
f(x，j)＝A(Qx+j),j＝0,1,...,N-1，
a is any integer, Q is the total number of IDs in the ID library of a secondary station, and x, j are input parameters.
S32, the potential secondary station measures the signal azimuth angle after receiving the broadcast cooperation signaling, and adjusts the antenna directional diagram according to the azimuth angle, aims at the primary station signal to reach the direction, and according to the received signal power, calculates and adjusts the transmitting power of the response signaling, the transmitting power calculation formula of the response signaling of the secondary station is:
wherein, Pytx,kFor the response signalling transmission power of the secondary station numbered k, PbtxA base transmit power for the response signaling; n is the number of the primary station broadcast signaling with the first ID i received by the secondary station in a preset time period; ptx,iTransmitting power of broadcast cooperation signaling for a master station with a first ID of i; prx,i,jThe power value of the j-th broadcast cooperative signaling of the primary station with the first ID i received by the secondary station in a preset time period.
S4, after receiving the response signaling of the potential secondary station, the primary station determines that the secondary station is a cooperative secondary station if the primary station can correctly analyze and judge the compliance;
the judgment compliance means that the first mapping ID of the primary station carried in the received response signaling is consistent with the result calculated by the primary station according to the mapping function, and the time interval between the time represented by the time number in the response signaling of the secondary station and the time for receiving the response signaling by the primary station does not exceed a certain threshold value.
And S5, the primary station responds to the response information of the cooperative auxiliary station, the primary station sends an accumulated response signaling to configure general working parameters for the cooperative auxiliary station, and the cooperative auxiliary station recognizes that a cooperative relationship is established with the primary station after receiving the compliant accumulated response signaling containing the self information and waits for the primary station to dispatch tasks.
And the main station sends an accumulated response signaling, wherein the accumulated response signaling comprises an accumulated response signaling identifier, a time number, a first ID of the main station, task feedback channel configuration information and a second mapping ID list of the auxiliary station.
The task feedback channel configuration information is radio channel information that needs to be used when the secondary station sends a signal to the primary station, such as channel frequency, bandwidth, sampling rate, transmission format, modulation mode, synchronization code, and the like.
The secondary station second mapping ID list is a list formed by second mapping IDs of secondary stations establishing a cooperative relationship with the primary station, and a calculation formula of the secondary station second mapping ID is as follows:
Sid,i＝R(f(Uid,i))+tm，
wherein, tmTime number, U, corresponding to the time when the master station sends the cumulative response signallingid,iFirst ID, S, representing secondary station iid,iA second mapping ID representing the secondary station i, the function R () representing randomly taking one of the plurality of input results as output, the function f () being the same mapping function used by the primary station first mapping ID. The meaning of this formula is that all the mapping IDs available to the secondary station are calculated from the first ID of the secondary station, and then one of the mapping IDs is randomly selected and summed with the time number to obtain the second mapping ID.
After the secondary station sends the response signaling, the secondary station continuously monitors the accumulated response signaling of the primary station, calculates all mapping IDs of the secondary station by using the same mapping function as the primary station, compares the mapping IDs with a second mapping ID of the secondary station in the received accumulated response signaling, and determines that the current accumulated response signaling contains the self information of the secondary station when the results are consistent.
S6, after the set time is counted, the main station judges the number of the auxiliary stations which establish the cooperation relationship with the main station;
s7, when the number of the auxiliary stations which have established cooperation with the main station is zero, the main station enters a single-station positioning working mode, and performs direction finding positioning and broadband signal target positioning independently; and when the number of the auxiliary stations establishing the cooperative relationship with the main station is nonzero, the main station enters a multi-station joint positioning and tracking mode, and schedules the auxiliary stations to perform cooperative positioning and tracking.
Step S7 includes, for single station positioning work, the main station firstly receives signals according to preset parameters such as time, space, frequency band, etc., searches and matches target signals according to preset matching conditions, and executes positioning and tracking processing after detecting the target signals;
for multi-station joint positioning and tracking, the specific steps are as follows:
the method comprises the following steps that a main station selects a plurality of auxiliary stations from all auxiliary stations which have a cooperative relationship with the main station through a wireless channel, and then tasks are assigned to the auxiliary stations through work task signaling; the task signaling comprises a time number, a first ID of a main station, task information and a third mapping ID list of the auxiliary station, wherein the task information comprises receiving time information, receiving configuration information and returning configuration information, the receiving time information comprises the starting time and the receiving duration of a received target signal, the receiving configuration information comprises the direction, the frequency, the bandwidth and the sampling rate required by the received target signal, and the returning configuration information comprises wireless channel information required to be used when the auxiliary station returns the signal to the main station, the returning time, the channel frequency, the bandwidth, the transmission format, the modulation mode and the like. The master station sends signaling to all the auxiliary stations connected with the master station in a broadcasting mode, and indicates all the auxiliary stations participating in the target positioning and tracking task to receive target signals simultaneously; after receiving the work task signaling, the auxiliary station firstly carries out compliance judgment, only the signaling of which the time number and the first ID of the main station meet the compliance judgment requirement belongs to the compliance signaling, and for the compliance signaling, the auxiliary station firstly detects whether a third mapping ID list of the auxiliary station contained in the auxiliary station comprises the auxiliary station per se, and the auxiliary station which is not in the third mapping ID list of the auxiliary station does not execute subsequent tasks.
The third mapping ID of the secondary station is the same as the calculation formula used by the second mapping ID of the secondary station, and the difference is that a plurality of ID results calculated by the mapping function need to firstly remove the first ID of the secondary station and the second mapping ID of the secondary station, and then carry out random selection operation and time numbering operation.
And after the starting time of receiving the target signal is reached, the main station starts to receive and store the target signal data, the auxiliary stations participating in the multi-station joint positioning tracking configure parameters such as an antenna directional pattern, frequency, bandwidth and sampling rate of a receiving link according to the requirement of a work task signaling, and start to acquire data with specific duration at the starting time of the signaling requirement. After the receiving duration is over, the secondary station compresses the acquired data according to the requirement of the return configuration information to reduce the communication transmission rate, and returns the compressed acquired data to the primary station at the appointed return time.
The main station decompresses the data received from the secondary stations, locates the target with the decompressed data collected from the secondary stations by using the multi-station time difference location method to obtain the instantaneous position of the target signal, and the main station and the secondary stations cooperate continuously to perform multi-station joint location to complete the estimation of multiple instantaneous positions of the target continuously, thereby realizing the track tracking of the target.
The auxiliary station compresses the acquired data to reduce the communication transmission rate according to the requirement of the returned configuration information, and for the compression of the acquired data, the original sampling sequence C { } is subjected to data processing once at every M points to obtain a compressed sampling point sequence D { }, wherein the data processing formula is as follows:
Dkrepresenting the kth element, C, in a sequence of compressed samplesMk+iRepresenting the (Mk + i) th element, f, in the original sample sequencedFor guard band spacing, which is greater than the target signal bandwidth, TsIs the original sampling time interval.
After receiving the returned data of each auxiliary station, the primary station respectively performs decompression processing, specifically: the primary station performs Fourier transform in the frequency domain according to fdAnd splitting the returned data of each auxiliary station into M independent frequency spectrum interval signal components at intervals, then respectively carrying out inverse Fourier transform on the M independent frequency spectrum interval signal components, respectively mixing the obtained M time domain sequences in the time domain according to the sampling time sequence of the sampling points, and merging the time domain sequence data, thereby completing the recovery of the original sampling sequence.
The mixing is carried out in the time domain, and the time domain sequence data are mergedIn one embodiment, the master station receives the compressed sequence of one of the cooperating secondary stations as D' ═ D1′,D′2,D′3,...,D′NObtaining M independent time domain sequences after inverse Fourier transform processing
The decompressed sequence obtained after merging the time domain sequence data should be:
and the main and auxiliary stations establish connection by adopting a low-cost short-wave ionosphere scattering communication transmission link and transmit forwarding data required by time difference positioning.
Compared with the prior art, the invention has the following advantages:
1. the invention gets rid of the fiber link connection between the traditional main and auxiliary stations, and replaces the wireless link connection, especially the scattering transmission link connection, and the transmission distance is more distant than the fiber and can reach hundreds of kilometers level while keeping the safe bearing of the data and the control signaling, thereby having the advantages which can not be compared with the traditional fiber multi-station mode.
2. The connection establishment and the work cooperation between the main station and the auxiliary station are automatically completed, and the main station controls the connection establishment and the work cooperation through wireless signaling, so that the use amount of personnel can be greatly reduced. The main stations and the auxiliary stations are in wireless connection, new auxiliary stations can be added or the auxiliary stations can be quitted at any time, and the passive positioning system has strong robustness.
3. The cooperation mode of each station becomes more flexible, the main station and the auxiliary station verify each other to avoid external smart countermeasure interference, and meanwhile, the ID of the partner is mapped and covered when the main station and the auxiliary station interact signaling, namely the ID is not directly interacted, so that the reconnaissance and identification difficulty of the partner on a system network is greatly increased, and the survival capability of the system is improved;
4. under the background that the traditional time difference positioning uses a high sampling rate far higher than a signal bandwidth to ensure the positioning accuracy, the compression method is used for realizing the reduction of the transmission data volume by times, thereby realizing the low rate and being more suitable for the over-the-horizon wireless transmission mode.
Drawings
Fig. 1 is a flowchart of an unattended signal time difference positioning method under a low-rate communication condition according to the present invention.
Detailed Description
For a better understanding of the present disclosure, an example is given here.
The invention provides an unattended signal time difference positioning method under a low-rate communication condition, and a flow chart of the unattended signal time difference positioning method is shown in figure 1, and the unattended signal time difference positioning method comprises the following steps:
s1, the attribute values of the main and auxiliary stations of the equipment are preset when the equipment leaves a factory, the attributes of the main and auxiliary stations of the equipment are manually modified according to task requirements when the equipment is laid out, and the attributes of the main and auxiliary stations of the equipment are automatically identified when the equipment is started;
s2, in the set time, the main station sends a broadcast cooperation signaling to search for potential auxiliary stations;
the method comprises the steps that a main station sends a broadcast cooperation signaling to search for potential auxiliary stations, wherein the broadcast cooperation signaling used by the main station is divided into a restart cooperation signaling and an accumulation cooperation signaling; restarting the cooperation signaling requires that each auxiliary station which receives the signaling and keeps the cooperation relationship with the main station needs to interrupt the cooperation relationship, and after the initial state is recovered, the cooperation relationship is established with the main station again; the accumulated cooperation signaling is aimed at the secondary station which has not established cooperation with the primary station, and the secondary station which has established cooperation with the primary station does not respond to the signaling any more. The restart cooperative signaling and the accumulated cooperative signaling both include the following information:
the cooperative signaling identifier is flag information for distinguishing two signaling types.
And the time number is a time unified information number generated by the main and auxiliary stations for recording time system information, and the time system information is provided by a GPS or a Beidou system.
The method comprises the steps that a master station first ID (first serial number), namely a master station first number, is used for distinguishing the identities of the master stations when multi-user communication is carried out among a plurality of master stations within a beyond visual range, the ID base of each master station is configured when the master stations leave a factory, each master station has a plurality of IDs available for the master station, and each master station randomly selects one ID in the ID base as a master station first ID when a restarting cooperation signaling is generated by the master station;
the response channel information specifies the wireless channel information which is required to be used when the secondary station transmits signals back to the main station, and the wireless channel information comprises frequency points, bandwidth, sampling rate, modulation mode and the like.
And the response information format identifier is used for indicating the auxiliary station to select a corresponding response information format from a preset response signaling structure template and fill corresponding information content for response, and a plurality of response signaling formats are preset when the auxiliary station equipment leaves a factory.
And receiving response starting time and response ending time, wherein the response starting time and the response ending time are used for indicating a time range of the secondary station for sending the response signaling, and the time range takes the time system information as reference.
And the ID mapping mode number is used for indicating the master station to select a corresponding mapping function from a preset ID mapping function set according to the ID mapping mode number, the ID mapping mode number and the mapping function are in one-to-one correspondence, the mapping function is a monotonically increasing or monotonically decreasing function, and the ID mapping function set is preset when the equipment leaves a factory.
And the signaling transmission power is used for setting the transmission power of the cooperative signaling sent by the main station.
The organization of the restart cooperative signaling and the accumulated cooperative signaling is shown in table 1.
TABLE 1 information organization of restart cooperative signaling and cumulative cooperative signaling
S3, after receiving the broadcast cooperation signaling, the potential secondary station sends a response signaling to the primary station; the method comprises the following specific steps:
and S31, before the potential secondary station receives the accumulated response signaling containing the self mapping ID, the potential secondary station continuously receives and screens the broadcast cooperation signaling of the primary station, and sorts the screened primary stations according to the time and power information, and the secondary station selects the primary station with the highest sorting and sends the response signaling for response.
The potential auxiliary station receives and screens the broadcast cooperation signaling of the main station, namely the potential auxiliary station judges the time number in the received main station broadcast signaling and the first ID information of the main station, the judgment rule is that the time information of the time for the potential auxiliary station to receive the broadcast cooperation signaling and the time information interval represented by the time number carried in the broadcast cooperation signaling are smaller than a certain threshold value, and the first ID of the main station is required to be in a main station ID information list preset when the auxiliary station leaves a factory.
Sorting the screened main stations according to the time and power information, wherein the first ID is the sorting value P of the main station with iiThe calculation formula of (2) is as follows:
wherein, Ptx,iBroadcast signalling transmission power, P, for a primary station having a first ID of irx,i,jReceiving power t of j-th broadcast signaling of a primary station with a first ID i received by a secondary station in a preset time periodiThe method comprises the steps that time numbers of a main station broadcast signaling with a latest first ID i received by an auxiliary station are numbered, N is the number of times of the main station broadcast signaling with the first ID i received by the auxiliary station in a preset time period, and beta is a weight value adjustment coefficient; the larger the ranking value, the higher the ranking.
The response signaling specifically includes a response signaling identifier, a time number, a secondary station first ID, and a primary station first mapping ID. The first ID of the secondary station is the ID randomly selected by the secondary station from the ID library of the secondary station, and the first ID of the secondary station is kept unchanged during the period that the secondary station establishes a cooperative relationship with the main station and the time from the transmission of a response signaling by the secondary station to the target main station to the reception of the response of the main station; the first mapping ID of the master station is obtained by calculation according to the first ID of the master station and a mapping function represented by an ID mapping mode number carried in the broadcast cooperation signaling by the master station, and the calculation formula is as follows:
Bid,i＝f(Kid,i,0)+tm，
wherein, tmTime number, K, corresponding to the transmission of response messages for the secondary stationid,iFirst ID, B, representing the Master station iid,iA first mapping ID representing the primary station i, f () is a mapping function of the first ID to the first mapping ID. The mapping function is a monotone increasing or decreasing function, and the expression of the mapping function is as follows:
f(x，j)＝A(Qx+j),j＝0,1,...,N-1，
a is any integer, Q is the total number of IDs in the ID library of a secondary station, and x, j are input parameters. The expression of f () is f (x, j) ═ kx (Qx + j), where K is a constant parameter, or f () uses a more complex function, as long as the characteristic of monotone increasing or monotone decreasing is satisfied, if the function f () is a discontinuous function, a better anti-reactance effect can be achieved.
S32, the potential secondary station measures the signal azimuth angle after receiving the broadcast cooperation signaling, and adjusts the antenna directional diagram according to the azimuth angle, aims at the primary station signal to reach the direction, and according to the received signal power, calculates and adjusts the transmitting power of the response signaling, the transmitting power calculation formula of the response signaling of the secondary station is:
wherein, Pytx,kFor the response signalling transmission power of the secondary station numbered k, PbtxA base transmit power for the response signaling; n is the number of the primary station broadcast signaling with the first ID i received by the secondary station in a preset time period; ptx,iTransmitting power of broadcast cooperation signaling for a master station with a first ID of i; prx,i,jThe power value of the j-th broadcast cooperative signaling of the primary station with the first ID i received by the secondary station in a preset time period.
S4, after receiving the response signaling of the potential secondary station, the primary station determines that the secondary station is a cooperative secondary station if the primary station can correctly analyze and judge the compliance;
the judgment compliance means that the first mapping ID of the primary station carried in the received response signaling is consistent with the result calculated by the primary station according to the mapping function, and the time interval between the time represented by the time number in the response signaling of the secondary station and the time for receiving the response signaling by the primary station does not exceed a certain threshold value.
And S5, the primary station responds to the response information of the cooperative auxiliary station, the primary station sends an accumulated response signaling to configure general working parameters for the cooperative auxiliary station, and the cooperative auxiliary station recognizes that a cooperative relationship is established with the primary station after receiving the compliant accumulated response signaling containing the self information and waits for the primary station to dispatch tasks.
And the main station sends an accumulated response signaling, wherein the accumulated response signaling comprises an accumulated response signaling identifier, a time number, a first ID of the main station, task feedback channel configuration information and a second mapping ID list of the auxiliary station.
The task feedback channel configuration information is radio channel information that needs to be used when the secondary station sends a signal to the primary station, such as channel frequency, bandwidth, sampling rate, transmission format, modulation mode, synchronization code, and the like.
The secondary station second mapping ID list is a list formed by second mapping IDs of secondary stations establishing a cooperative relationship with the primary station, and a calculation formula of the secondary station second mapping ID is as follows:
Sid,i＝R(f(Uid,i))+tm，
wherein, tmTime number, U, corresponding to the time when the master station sends the cumulative response signallingid,iFirst ID, S, representing secondary station iid,iA second mapping ID representing the secondary station i, the function R () representing randomly taking one of the plurality of input results as output, the function f () being the same mapping function used by the primary station first mapping ID. The meaning of this formula is that all the mapping IDs available to the secondary station are calculated from the first ID of the secondary station, and then one of them is randomly selected and summed with the time number to obtain the second mapping ID.
After the secondary station sends the response signaling, the secondary station continuously monitors the accumulated response signaling of the primary station, calculates all mapping IDs of the secondary station by using the same mapping function as the primary station, compares the mapping IDs with a second mapping ID of the secondary station in the received accumulated response signaling, and determines that the current accumulated response signaling contains the self information of the secondary station when the results are consistent.
S6, after the set time is counted, the main station judges the number of the auxiliary stations which establish the cooperation relationship with the main station;
s7, when the number of the auxiliary stations which have established cooperation with the main station is zero, the main station enters a single-station positioning working mode, and performs direction finding positioning and broadband signal target positioning independently; and when the number of the auxiliary stations establishing the cooperative relationship with the main station is nonzero, the main station enters a multi-station joint positioning and tracking mode, and schedules the auxiliary stations to perform cooperative positioning and tracking.
Step S7 includes, for single station positioning work, the main station firstly receives signals according to preset parameters such as time, space, frequency band, etc., searches and matches target signals according to preset matching conditions, and executes positioning and tracking processing after detecting the target signals;
for multi-station joint positioning and tracking, the specific steps are as follows:
the method comprises the following steps that a main station selects a plurality of auxiliary stations from all auxiliary stations which have a cooperative relationship with the main station through a wireless channel, and then tasks are assigned to the auxiliary stations through work task signaling; the task signaling comprises a time number, a first ID of a main station, task information and a third mapping ID list of the auxiliary station, wherein the task information comprises receiving time information, receiving configuration information and returning configuration information, the receiving time information comprises the starting time and the receiving duration of a received target signal, the receiving configuration information comprises the direction, the frequency, the bandwidth and the sampling rate required by the received target signal, and the returning configuration information comprises wireless channel information required to be used when the auxiliary station returns the signal to the main station, the returning time, the channel frequency, the bandwidth, the transmission format, the modulation mode and the like. The master station sends signaling to all the auxiliary stations connected with the master station in a broadcasting mode, and indicates all the auxiliary stations participating in the target positioning and tracking task to receive target signals simultaneously; after receiving the work task signaling, the auxiliary station firstly carries out compliance judgment, only the signaling of which the time number and the first ID of the main station meet the compliance judgment requirement belongs to the compliance signaling, and for the compliance signaling, the auxiliary station firstly detects whether a third mapping ID list of the auxiliary station contained in the auxiliary station comprises the auxiliary station per se, and the auxiliary station which is not in the third mapping ID list of the auxiliary station does not execute subsequent tasks.
The third mapping ID of the secondary station is the same as the calculation formula used by the second mapping ID of the secondary station, and the difference is that a plurality of ID results calculated by the mapping function need to firstly remove the first ID of the secondary station and the second mapping ID of the secondary station, and then carry out random selection operation and time numbering operation.
And after the starting time of receiving the target signal is reached, the main station starts to receive and store the target signal data, the auxiliary stations participating in the multi-station joint positioning tracking configure parameters such as an antenna directional pattern, frequency, bandwidth and sampling rate of a receiving link according to the requirement of a work task signaling, and start to acquire data with specific duration at the starting time of the signaling requirement. After the receiving duration is over, the secondary station compresses the acquired data according to the requirement of the return configuration information to reduce the communication transmission rate, and returns the compressed acquired data to the primary station at the appointed return time.
The main station decompresses the data received from the secondary stations, locates the target with the decompressed data collected from the secondary stations by using the multi-station time difference location method to obtain the instantaneous position of the target signal, and the main station and the secondary stations cooperate continuously to perform multi-station joint location to complete the estimation of multiple instantaneous positions of the target continuously, thereby realizing the track tracking of the target.
The auxiliary station compresses the acquired data to reduce the communication transmission rate according to the requirement of the returned configuration information, and for the compression of the acquired data, the original sampling sequence C { } is subjected to data processing once at every M points to obtain a compressed sampling point sequence D { }, wherein the data processing formula is as follows:
Dkrepresenting the kth element, C, in a sequence of compressed samplesMk+iRepresenting the (Mk + i) th element, f, in the original sample sequencedFor guard band spacing, which is greater than the target signal bandwidth, TsIs the original sampling time interval.
The primary station receives the returned data of each secondary stationAnd then, respectively carrying out decompression processing, specifically: the primary station performs Fourier transform in the frequency domain according to fdAnd splitting the returned data of each auxiliary station into M independent frequency spectrum interval signal components at intervals, then respectively carrying out inverse Fourier transform on the M independent frequency spectrum interval signal components, respectively mixing the obtained M time domain sequences in the time domain according to the sampling time sequence of the sampling points, and merging the time domain sequence data, thereby completing the recovery of the original sampling sequence.
The mixing is performed in the time domain, and the time domain sequence data are merged, specifically, the compressed sequence received by the primary station as one of the cooperative secondary stations is D '═ D'1,D′2,D′3,...,D′NObtaining M independent time domain sequences after inverse Fourier transform processing
The decompressed sequence obtained after merging the time domain sequence data should be:
and the main and auxiliary stations establish connection by adopting a low-cost short-wave ionosphere scattering communication transmission link and transmit forwarding data required by time difference positioning.
The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.
Claims (10)
1. An unattended signal time difference positioning method under a low-rate communication condition is characterized by comprising the following steps:
s1, the attribute values of the main and auxiliary stations of the equipment are preset when the equipment leaves a factory, the attributes of the main and auxiliary stations of the equipment are manually modified according to task requirements when the equipment is laid out, and the attributes of the main and auxiliary stations of the equipment are automatically identified when the equipment is started;
s2, in the set time, the main station sends a broadcast cooperation signaling to search for potential auxiliary stations;
s3, after receiving the broadcast cooperation signaling, the potential secondary station sends a response signaling to the primary station;
s4, after receiving the response signaling of the potential secondary station, the primary station determines that the secondary station is a cooperative secondary station if the primary station can correctly analyze and judge the compliance;
s5, the primary station responds to the response information of the cooperative auxiliary station, the primary station sends an accumulated response signaling to configure general working parameters for the cooperative auxiliary station, and the cooperative auxiliary station recognizes that a cooperative relationship is established with the primary station after receiving the compliant accumulated response signaling containing the self information and waits for the primary station to dispatch a task;
s6, after the set time is counted, the main station judges the number of the auxiliary stations which establish the cooperation relationship with the main station;
s7, when the number of the auxiliary stations which have established cooperation with the main station is zero, the main station enters a single-station positioning working mode, and performs direction finding positioning and broadband signal target positioning independently; and when the number of the auxiliary stations establishing the cooperative relationship with the main station is nonzero, the main station enters a multi-station joint positioning and tracking mode, and schedules the auxiliary stations to perform cooperative positioning and tracking.
2. The method according to claim 1, wherein in step S2, the primary station sends broadcast cooperation signaling to search for potential secondary stations, and specifically, the broadcast cooperation signaling used by the primary station is divided into restart cooperation signaling and cumulative cooperation signaling, wherein the restart cooperation signaling requires that each secondary station receiving the signaling and maintaining cooperation with the primary station should interrupt cooperation, and after the initial state is recovered, establish cooperation with the primary station again; the accumulated cooperation signaling is aimed at the auxiliary station which has not established the cooperation relationship with the main station, and the auxiliary station which has established the cooperation relationship with the main station does not respond to the signaling any more; the restart cooperative signaling and the accumulated cooperative signaling both include the following information:
the cooperation signaling identifier is mark information used for distinguishing two signaling types;
the time number is a time unified information number generated by the main and auxiliary stations for recording time system information, and the time system information is provided by a GPS or a Beidou system;
the method comprises the steps that a master station first ID (first serial number), namely a master station first number, is used for distinguishing the identities of the master stations when multi-user communication is carried out among a plurality of master stations within a beyond visual range, the ID base of each master station is configured when the master stations leave a factory, each master station has a plurality of IDs available for the master station, and each master station randomly selects one ID in the ID base as a master station first ID when a restarting cooperation signaling is generated by the master station;
the response channel information specifies wireless channel information which is required to be used when the secondary station transmits signals back to the main station, and comprises frequency points, bandwidth, sampling rate and a modulation mode;
the response information format identifier is used for indicating the auxiliary station to select a corresponding response information format from a preset response signaling structure template and fill corresponding information content for response, and a plurality of response signaling formats are preset when the auxiliary station equipment leaves a factory;
receiving response starting and ending moments, wherein the response starting and ending moments are used for indicating a time range of the secondary station for sending a response signaling, and the time range takes the time system information as reference;
the ID mapping mode numbers are used for indicating the master station to select corresponding mapping functions from a preset ID mapping function set according to the ID mapping mode numbers, the ID mapping mode numbers and the mapping functions are in one-to-one correspondence, the mapping functions are monotonically increasing or monotonically decreasing functions, and the ID mapping function set is preset when the equipment leaves a factory;
and the signaling transmission power is used for setting the transmission power of the cooperative signaling sent by the main station.
3. The method for locating the time difference of an unattended signal in a low-rate communication condition according to claim 1, wherein the step S3 includes the following steps:
s31, before the potential secondary station receives the accumulated response signaling containing the self mapping ID, the potential secondary station continuously receives and screens the broadcast cooperation signaling of the primary station, and sorts the screened primary stations according to the time and power information, the secondary station selects the primary station with the highest sorting, and sends the response signaling for response;
s32, the potential secondary station measures the signal azimuth angle after receiving the broadcast cooperation signaling, and adjusts the antenna directional diagram according to the azimuth angle, aims at the primary station signal to reach the direction, and according to the received signal power, calculates and adjusts the transmitting power of the response signaling, the transmitting power calculation formula of the response signaling of the secondary station is:
wherein, Pytx,kFor the response signalling transmission power of the secondary station numbered k, PbtxA base transmit power for the response signaling; n is the number of the primary station broadcast signaling with the first ID i received by the secondary station in a preset time period; ptx,iTransmitting power of broadcast cooperation signaling for a master station with a first ID of i; prx,i,jThe power value of the j-th broadcast cooperative signaling of the primary station with the first ID i received by the secondary station in a preset time period.
4. The method as claimed in claim 3, wherein the step of receiving and screening the broadcast cooperative signaling of the primary station by the potential secondary station means that the potential secondary station determines the time number and the first ID information of the primary station in the received broadcast signaling of the primary station according to a determination rule that the time information of the time when the potential secondary station receives the broadcast cooperative signaling is recorded, the time information interval between the time information and the time number carried in the broadcast cooperative signaling is smaller than a certain threshold, and the first ID of the primary station must be in a primary station ID information list preset by the secondary station from the factory.
5. The method as claimed in claim 3, wherein the master station passing the screen is ranked according to time and power informationOrder value P of master station with first ID of iiThe calculation formula of (2) is as follows:
wherein, Ptx,iBroadcast signalling transmission power, P, for a primary station having a first ID of irx,i,jReceiving power t of j-th broadcast signaling of a primary station with a first ID i received by a secondary station in a preset time periodiThe method comprises the steps that time numbers of a main station broadcast signaling with a latest first ID i received by an auxiliary station are numbered, N is the number of times of the main station broadcast signaling with the first ID i received by the auxiliary station in a preset time period, and beta is a weight value adjustment coefficient; the larger the ranking value, the higher the ranking.
6. The method according to claim 3, wherein the response signaling specifically includes a response signaling identifier, a time number, a secondary station first ID, and a primary station first mapping ID; the first ID of the secondary station is the ID randomly selected by the secondary station from the ID library of the secondary station, and the first ID of the secondary station is kept unchanged during the period that the secondary station establishes a cooperative relationship with the main station and the time from the transmission of a response signaling by the secondary station to the target main station to the reception of the response of the main station; the first mapping ID of the master station is obtained by calculation according to the first ID of the master station and a mapping function represented by an ID mapping mode number carried in the broadcast cooperation signaling by the master station, and the calculation formula is as follows:
Bid,i＝f(Kid,i,0)+tm，
wherein, tmTime number, K, corresponding to the transmission of response messages for the secondary stationid,iFirst ID, B, representing the Master station iid,iA first mapping ID representing the primary station i, f () being a mapping function of the first ID to the first mapping ID; the mapping function is a monotone increasing or decreasing function, and the expression of the mapping function is as follows:
f(x，j)＝A(Qx+j),j＝0,1,...,N-1，
a is any integer, Q is the total number of IDs in the ID library of a secondary station, and x, j are input parameters.
7. The method as claimed in claim 1, wherein the decision compliance means that the first mapping ID of the primary station carried in the received response signaling is consistent with the result calculated by the primary station itself according to the mapping function, and the time interval between the time represented by the time number in the secondary station response signaling and the time when the primary station receives the response signaling does not exceed a certain threshold.
8. The method as claimed in claim 1, wherein the primary station sends an accumulated response signaling in step S5, and the accumulated response signaling includes an accumulated response signaling identifier, a time number, a primary station first ID, task feedback channel configuration information, and a secondary station second mapping ID list;
the task feedback channel configuration information is wireless channel information which is required to be used when the auxiliary station sends a signal to the main station, and is channel frequency, bandwidth, sampling rate, transmission format, modulation mode and synchronous code;
the secondary station second mapping ID list is a list formed by second mapping IDs of secondary stations establishing a cooperative relationship with the primary station, and a calculation formula of the secondary station second mapping ID is as follows:
Sid,i＝R(f(Uid,i))+tm，
wherein, tmTime number, U, corresponding to the time when the master station sends the cumulative response signallingid,iFirst ID, S, representing secondary station iid,iA second mapping ID representing the secondary station i, the function R () representing randomly taking one of the plurality of input results as output, the function f () being the same mapping function used by the primary station first mapping ID.
9. The method as claimed in claim 1, wherein the step S7 comprises, for single-station positioning, the primary station first receiving signals according to preset parameters of time, space and frequency band, searching and matching target signals according to preset matching conditions, and performing positioning and tracking processing after detecting the target signals.
10. The method as claimed in claim 1, wherein the step S7 specifically includes, for multi-station joint location tracking, the specific steps of: the method comprises the following steps that a main station selects a plurality of auxiliary stations from all auxiliary stations which have a cooperative relationship with the main station through a wireless channel, and then tasks are assigned to the auxiliary stations through work task signaling; the task signaling comprises a time number, a first ID of a main station, task information and a third mapping ID list of the auxiliary station, wherein the task information comprises receiving time information, receiving configuration information and returning configuration information, the receiving time information comprises the starting time and the receiving duration of a received target signal, the receiving configuration information comprises the direction, the frequency, the bandwidth and the sampling rate required by the received target signal, and the returning configuration information comprises wireless channel information required to be used when the auxiliary station returns the signal to the main station, the wireless channel information comprises the returning time, the channel frequency, the bandwidth, the transmission format and the modulation mode; the master station sends signaling to all the auxiliary stations connected with the master station in a broadcasting mode, and indicates all the auxiliary stations participating in the target positioning and tracking task to receive target signals simultaneously; after receiving a work task signaling, the auxiliary station firstly carries out compliance judgment, only the signaling of which the time number and the first ID of the main station meet the compliance judgment requirement belongs to the compliance signaling, and for the compliance signaling, the auxiliary station firstly detects whether a third mapping ID list of the auxiliary station contained in the auxiliary station comprises the auxiliary station per se, and the auxiliary station not in the third mapping ID list of the auxiliary station does not execute subsequent tasks;
after the starting time of receiving the target signal is reached, the main station starts to receive and store the target signal data, the auxiliary stations participating in the multi-station joint positioning tracking are configured with the antenna directional pattern, the frequency, the bandwidth and the sampling rate parameters of the receiving link according to the signaling requirements of the work task, and the data with specific duration are collected at the starting time of the signaling requirements; after the receiving duration is over, the secondary station compresses the acquired data according to the requirement of the return configuration information to reduce the communication transmission rate, and returns the compressed acquired data to the primary station at the specified return time;
the main station decompresses the data received from the secondary stations respectively after receiving the data returned from the secondary stations, and then performs target positioning on the decompressed data collected from the secondary stations by using a multi-station time difference positioning method to obtain the instantaneous position of a target signal;
the auxiliary station compresses the acquired data to reduce the communication transmission rate according to the requirement of the returned configuration information, and for the compression of the acquired data, the original sampling sequence C { } is subjected to data processing once at every M points to obtain a compressed sampling point sequence D { }, wherein the data processing formula is as follows:
Dkrepresenting the kth element, C, in a sequence of compressed samplesMk+iRepresenting the (Mk + i) th element, f, in the original sample sequencedFor guard band spacing, which is greater than the target signal bandwidth, TsIs the original sampling time interval;
after receiving the returned data of each auxiliary station, the primary station respectively performs decompression processing, specifically: the primary station performs Fourier transform in the frequency domain according to fdAnd splitting the returned data of each auxiliary station into M independent frequency spectrum interval signal components at intervals, then respectively carrying out inverse Fourier transform on the M independent frequency spectrum interval signal components, respectively mixing the obtained M time domain sequences in the time domain according to the sampling time sequence of the sampling points, and merging the time domain sequence data, thereby completing the recovery of the original sampling sequence.
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