KR102323899B1 - Apparatus and method for selecting positioning signal - Google Patents

Abstract

The present invention provides a baseband signal acquisition unit for acquiring a baseband signal from each of the LTE signals transmitted from a plurality of base stations, extracting reference signals PSS and SSS from each of the baseband signals, and extracting the baseband signal and the extracted PSS and A reference signal extractor for obtaining a PSS correlation peak value and an SSS correlation peak value indicating a correlation value between each SSS, and a cell ID of a base station that transmits an LTE signal using the PSS and the SSS in a predetermined manner ID obtaining unit, RSRQ obtaining unit obtaining an RSRQ value calculated by the ratio of the signal strength obtained by demodulating the baseband signal to the strength ratio of the reference signal sequence, and PSS correlation peak value, SSS correlation peak value, and a plurality of based on the RSRQ value It is possible to provide a positioning signal selection apparatus and method capable of detecting a signal most suitable for positioning in a current signal reception environment, including a positioning signal selection unit for selecting an LTE signal to be used as a positioning signal among LTE signals transmitted from the base station.

Description

Positioning signal selection device and method {APPARATUS AND METHOD FOR SELECTING POSITIONING SIGNAL}

The present invention relates to an apparatus and method for selecting a positioning signal, and to an apparatus and method for selecting a positioning signal through quality evaluation of an LTE signal.

A current global navigation satellite system (hereinafter referred to as GNSS) can provide accurate location and time information and is considered as the most used positioning system due to its convenience. However, the GNSS may be degraded by abnormal ionospheric conditions, signal reflection and blocking, etc., and may be affected by interference, etc. because the strength of the GNSS signal is low, and there is a problem that power consumption is large.

Accordingly, when GNSS cannot be used, various alternative signals of opportunity (SOP) are being considered. As the opportunity signal, various RF signals that are not basically provided for the purpose of positioning may be used, and for example, Wi-Fi, TV, radio, and mobile phone signals may be used. Long-Term Evolution (LTE) signals among various RF signals are considered as one of the most suitable positioning signals due to their high bandwidth and data rate.

Korean Patent Registration No. 10-2034082 (Registered on October 14, 2019)

An object of the present invention is to provide an apparatus and method for selecting a positioning signal capable of detecting a signal most suitable for positioning of a user terminal among signals transmitted from a plurality of base stations.

Another object of the present invention is to extract two types of reference signals and reference signal reception quality from LTE signals transmitted from a plurality of base stations, and global demarcation and adaptive demarcation for the extracted reference signal and reference signal reception quality An object of the present invention is to provide an apparatus and method for selecting a positioning signal capable of detecting a signal most suitable for positioning in a current signal reception environment.

Positioning signal selection apparatus according to an embodiment of the present invention for achieving the above object is a baseband signal acquisition unit for acquiring a baseband signal from each LTE signal transmitted from a plurality of base stations; PSS (Primary Synchronization Sequence) and SSS (Secondary Synchronization Sequence), which are reference signals, are extracted from each of the baseband signals, and PSS correlation peak value and SSS correlation indicating a correlation value between the baseband signal and each of the extracted PSS and SSS a reference signal extraction unit for obtaining a peak value; A cell ID obtaining unit for obtaining a cell ID of a base station that has transmitted an LTE signal using the PSS and the SSS in a predetermined manner: a reference signal calculated as a ratio of the strength of the reference signal sequence to the signal strength obtained by demodulating the baseband signal RSRQ acquisition unit for acquiring a reception quality (Reference Signal Received Quality: hereinafter RSRQ) value; and a positioning signal selection unit for selecting an LTE signal to be used as a positioning signal among LTE signals transmitted from a plurality of base stations based on the PSS correlation peak value, the SSS correlation peak value, and the RSRQ value.

The reference signal extraction unit generates all possible PSSs, correlates the generated PSS with the baseband signal in a predetermined manner to extract the PSS representing the largest PSS correlation peak value, and extracts the PSS correlation peak value corresponding to the extracted PSS. PSS extraction unit to obtain; and SSS extraction for generating all possible SSSs, correlating the generated SSS with the baseband signal in a predetermined manner to extract the SSS representing the largest SSS correlation peak value, and obtaining the SSS correlation peak value corresponding to the extracted SSS may include wealth.

The positioning signal selection unit determines whether each of the PSS correlation peak value, the SSS correlation peak value, and the RSRQ value is equal to or greater than the reference PSS correlation peak value, the reference SSS correlation peak value, and the reference RSRQ value preset as a global boundary, and the global boundary Among the LTE signals determined to be abnormal, an LTE signal previously selected as a positioning signal may be selected as a positioning signal.

If the number of LTE signals selected as the positioning signal is less than the predetermined reference number, the positioning signal selection unit is determined to be more than a global boundary, and the PSS correlation peak value and the SSS correlation peak value of the LTE signal not previously selected as the positioning signal and setting the LTE signal priority based on the RSRQ value, and sequentially selecting the LTE signal as the positioning signal until the number of positioning signals becomes a predetermined number according to the set priority.

The positioning signal selector may set each of the reference PSS correlation peak value, the reference SSS correlation peak value, and the reference RSRQ value differently according to the frequency channel of the LTE signal.

A positioning signal selection method according to another embodiment of the present invention for achieving the above object includes: obtaining a baseband signal from each of the LTE signals transmitted from a plurality of base stations; extracting PSS and SSS, which are reference signals, from each of the baseband signals, and obtaining a PSS correlation peak value and an SSS correlation peak value indicating a correlation value between the baseband signal and the extracted PSS and SSS, respectively; Obtaining the cell ID of the base station that has transmitted the LTE signal in a predetermined manner using the PSS and the SSS: a reference signal reception quality calculated by the ratio of the strength of the reference signal sequence to the signal strength obtained by demodulating the baseband signal ( Hereinafter, RSRQ) obtaining a value; and selecting an LTE signal to be used as a positioning signal from among LTE signals transmitted from a plurality of base stations based on the PSS correlation peak value, the SSS correlation peak value, and the RSRQ value.

Therefore, the positioning signal selection apparatus and method according to an embodiment of the present invention extracts two types of reference signals and reference signal reception quality from LTE signals transmitted from a plurality of base stations, and extracts the reference signal and the reference signal reception quality. It is possible to detect the most suitable signal for positioning in the current signal reception environment through global boundary and adaptive boundary for the current signal reception environment.

1 shows a schematic structure of a positioning signal selection apparatus according to an embodiment of the present invention.
2 shows an example of an LTE frame and slot structure in the time domain.
FIG. 3 shows an example of a PSS correlation value obtained by the PSS correlation peak value extractor of FIG. 1 .
4 shows a positioning signal selection method according to an embodiment of the present invention.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention may be embodied in various different forms, and is not limited to the described embodiments. In addition, in order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals in the drawings indicate the same members.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components unless otherwise stated. In addition, terms such as "... unit", "... group", "module", and "block" described in the specification mean a unit that processes at least one function or operation, which is hardware, software, or hardware. and a combination of software.

1 shows a schematic structure of a positioning signal selection apparatus according to an embodiment of the present invention, FIG. 2 shows an example of the LTE frame and slot structure in the time domain, and FIG. 3 is the PSS correlation peak value extraction unit of FIG. An example of an acquired PSS correlation value is shown.

Here, it is assumed that the positioning signal selection apparatus is a user equipment (UE) of an LTE system, but the present invention is not limited thereto.

The positioning signal selection apparatus according to the present embodiment includes a baseband signal acquisition unit 100 , a reference signal extraction unit 200 , a cell ID acquisition unit 300 , a demodulator 400 , an RSRQ acquisition unit 500 , and a positioning signal and a selection unit 600 .

The baseband signal acquisition unit 100 acquires a baseband signal by receiving LTE signals from a plurality of base stations (NB). Here, each of the plurality of base stations (NB) may be an LTE mobile communication base station, also called eNodeB, and the baseband signal acquisition unit 100 removes noise and frequency in a predetermined manner for LTE signals applied from the plurality of base stations (NB). A baseband signal may be obtained by performing preprocessing such as downconversion.

The reference signal extraction unit 200 extracts a Primary Synchronization Sequence (PSS) and a Secondary Synchronization Sequence (SSS) that are reference signals from the baseband signal obtained by the baseband signal acquisition unit 100 , and extracts the baseband signal. A PSS correlation peak value and an SSS correlation peak value indicating a correlation value between PSS and SSS, respectively, are obtained.

A baseband signal obtained from an LTE signal transmitted from each of a plurality of base stations (NB) has a frame structure having a predetermined length (here, 10 ms as an example), as shown in FIG. 2 . In addition, each frame is divided into a predetermined number (here, 10 as an example) of sub-frames having the same length (here, for example, 1 ms). Also, each subframe may be divided into two slots of the same length.

In the LTE system, in order to provide symbol timing so that a user terminal (UE) can coherently demodulate a baseband signal, as shown in FIG. 2 , PSS and SSS are inserted at a fixed timing of a frame as reference signals. .

The PSS may be transmitted as the last symbol of the 0th slot as shown in FIG. 2, and may be repeatedly transmitted again in the 10th slot. That is, it may be repeated again in the fifth subframe. PSS is based on a Zadoff-Chu sequence in the frequency domain, and has a property of zero cyclic autocorrelation at any non-zero delay. Here, the PSS _{may be transmitted in three possible sequences mapped to integer values (N ID} ⁽¹⁾ ∈ {0, 1, 2}).

On the other hand, the SSS is transmitted in the symbol immediately preceding the PSS, and based on the maximum length sequence (m-sequence), a pseudo that can be generated as a sequence of ^{length 2 m-1 by cycling all possible states of the shift register of length m} A random number is generated as a binary sequence. Here, there are 168 possible sequences that the SSS can generate, and each sequence _{can be mapped to an integer value (N ID} ⁽²⁾ ∈ {0, 1, ..., 167}).

The reference signal extractor 200 may include a PSS extractor 210 and an SSS extractor 220 .

The PSS extractor 210 extracts the PSS included in the baseband signal. The PSS extraction unit 210 generates all possible PSSs, and correlates the baseband signal r obtained by the baseband signal acquisition unit 100 with a plurality of generated PSSs as shown in Equation (1).

은 N 포인트 원형 컨볼루션(N-point circular convolution) 연산을 나타낸다.where r is a baseband signal, S _PSS is a PSS generated in the time domain, N represents the number of samples included in a single frame of the baseband signal, S _PSS ^* represents a complex conjugate of S _PSS , (??) _N represents a modulo N operation. and

denotes an N-point circular convolution operation.

The PSS extractor 210 may generate all possible PSSs in advance regardless of reception of the baseband signals and extract the PSSs of the baseband signals by correlating the generated PSSs with the baseband signals.

By correlating the baseband signal r with the plurality of PSSs as shown in Equation 1, as shown in FIG. 3 , a maximum correlation peak value can be derived from a specific sample.

When the correlation in the time domain of Equation 1 is transformed into a correlation in the frequency domain using Fast Fourier Transform (FFT) and inverse fast Fourier transform (IFFT)), Equation 2 is obtained may be expressed.

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In addition, the PSS included in the baseband signal r may be determined from the sample from which the maximum correlation peak value is derived. That is, the PSS extractor 210 generates all possible PSSs, and determines the PSS representing the maximum correlation peak value with the baseband signal r among the plurality of generated PSSs as the PSS included in the baseband signal r. can be extracted.

At this time, the PSS correlation peak value (N _PSS ) with respect to the extracted PSS may be defined by Equation (3).

Meanwhile, the SSS extractor 220 also generates all the SSSs that can be generated similarly to the PSS extractor 210 , and correlates the generated plurality of SSSs with the baseband signal r, so that the maximum correlation among the generated plurality of SSSs is Extract the SSS that outputs the peak value.

The SSS extractor 220 may also generate all possible SSSs in advance regardless of reception of the baseband signal, and extract the SSS of the baseband signal by correlating the generated SSS with the baseband signal.

Here, the SSS correlation peak value (N _SSS ) with respect to the extracted SSS may be defined by Equation (4).

The cell ID acquisition unit 300 receives the PSS and SSS extracted from the reference signal extraction unit 200 and acquires a cell ID corresponding to the base station NB that has transmitted the baseband signal.

_{The cell ID acquisition unit 300 converts the fixed integer values (N ID} ⁽¹⁾ , N _ID ⁽²⁾ ) mapped to each of the PSS and the SSS extracted by the reference signal extraction unit 200 into the converted fixed integers. _{A cell ID (N CID} ) may be obtained from the values (N _ID ⁽¹⁾ , N _ID ⁽²⁾ ) according to Equation (5).

Here, the cell ID (N _CID ) is, for example, N _CID ∈ {0, 1, … , 503}.

When the cell ID (N _CID ) is obtained by the cell ID obtaining unit 300 , the demodulating unit 400 demodulates the baseband signal in a predetermined manner. For example, the demodulator 400 may perform demodulation in an OFDM scheme according to an LTE communication technique.

Meanwhile, the RSRQ acquisition unit 500 acquires a reference signal received quality (RSRQ), which is a ratio of the strength of the reference signal to the strength of the demodulated signal.

The RSRQ obtaining unit 500 may obtain an RSRQ value (N _RSRQ ) according to Equation (6).

Here, N _RSRP is a reference signal received power (RSRP), and N _RSSI is a received signal strength indicator (RSSI).

Multipath propagation causes inter symbol interference (ISI) in LTE signals, and RSRQ can better identify the effect of ISI than RSRP or RSSI. Accordingly, in the present embodiment, RSRQ is calculated and obtained according to Equation 5.

The positioning signal selection unit 600 analyzes the _{PSS correlation peak value (N PSS} ) and the SSS correlation peak value (N _SSS ) and the RSRQ value (N _RSRQ ) obtained from the LTE signal transmitted from each of the plurality of base stations (NB). , selects a predetermined number of LTE signals to be used as positioning signals among the LTE signals transmitted from each of the plurality of base stations (NB).

The positioning signal selection unit 600 first determines whether the PSS correlation peak value (N _PSS ), the SSS correlation peak value (N _SSS ), and the RSRQ value (N _RSRQ ) extracted from each LTE signal is greater than or equal to a predetermined global boundary. Here, the positioning signal selection unit 600 is a reference PSS correlation peak value and a reference SSS preset as a global boundary for each of the _{PSS correlation peak value (N PSS} ), the SSS correlation peak value (N _SSS ), and the RSRQ value (N _{RSRQ )} It is determined whether the correlation peak value and the reference RSRQ value or more, and the PSS correlation peak value (N _PSS ), the SSS correlation peak value (N _SSS ), and the RSRQ value (N _RSRQ ) are all above the global boundary and LTE signal is selected.

Tables 1 and 2 show the PSS correlation peak value (N _PSS ), the SSS correlation peak value (N _SSS ), and the RSRQ value (N _RSRQ ) obtained from different cell IDs, respectively. _{Table 1 shows the PSS correlation peak value (N PSS} ) and the SSS correlation peak value (N _SSS ) and the RSRQ value (N _RSRQ ) for the LTE signal transmitted from the base station (NB) having a cell ID (N _{CID ) of 25, Table 2 shows the PSS correlation peak value (N PSS} ) and the SSS correlation peak value (N _SSS ) and the RSRQ value (N _RSRQ ) for the LTE signal transmitted from the base station (NB) having a cell ID (N _{CID ) of 499.}

Referring to Tables 1 and 2, compared to the base station (NB) having the _{cell ID (N CID ) of 499, the PSS correlation peak value (N PSS} ) of the LTE signal transmitted from the base _{station (NB) having the cell ID (N CID ) of 25} ) and the SSS correlation peak value (N _SSS ) and the RSRQ value (N _RSRQ ) are all higher. Therefore, it can be seen that the LTE signal transmitted from the base station NB _{with the cell ID (N CID} ) of 25 is more suitable for the positioning signal compared to the LTE signal transmitted from the base station NB with the cell ID (N _{CID ) of 499.} .

However, even in the LTE signal transmitted from the same base station with the same cell ID (N _CID ), when the center frequency of the LTE signal is 1820 MHz, the PSS correlation peak value (N _PSS ) and the SSS correlation peak value (N _{SSS) than in the case of 879 MHz or 2665 MHz} ) and RSRQ value (N _RSRQ ) can be seen to appear higher. This indicates that even for LTE signals transmitted from the same base station, the PSS correlation peak value (N _PSS ), the SSS correlation peak value (N _SSS ), and the RSRQ value (N _RSRQ ) may appear significantly different depending on the frequency channel.

Therefore, the positioning signal selector 600 may set the reference PSS correlation peak value, the reference SSS correlation peak value, and the reference RSRQ value, which are global boundaries, differently depending on the frequency channel of each LTE signal.

Thereafter, the positioning signal selection unit 600 selects a positioning signal by applying an adaptive boundary to the selected LTE signal. The positioning signal selection unit 600 determines whether the LTE signal used as the previous positioning signal is included in the selected LTE signal. And if the LTE signal used as the previous positioning signal is included, the corresponding LTE signal is preferentially selected as the positioning signal. And if the number of LTE signals selected as the positioning signal is less than a predetermined number (eg, 4), the PSS correlation peak value (N _PSS ) and the SSS correlation peak value (N) of each of the remaining LTE signals that are not selected as the positioning signal _SSS ) and the RSRQ value (N _RSRQ ) by weighting and adding weights in a predetermined manner to determine the priority of the remaining LTE signals. Then, the positioning signal is sequentially selected according to the determined priority until the LTE signal selected as the positioning signal becomes a predetermined number.

The selected positioning signal may then be used to determine the location of the user terminal (UE) based on a time of arrival (TOA) at which a signal transmitted from the corresponding base station (NB) to the user terminal (UE) arrives. have.

Although the demodulator 400 and the RSRQ acquirer 500 have been separately described above for convenience of description, the demodulator 400 may be included in the RSRQ acquirer 500 and may be omitted in some cases.

4 shows a positioning signal selection method according to an embodiment of the present invention.

Referring to FIG. 1, the positioning signal selection method of FIG. 4 is described. First, a predetermined pre-processing is performed on an LTE signal transmitted from each of a plurality of base stations NB to obtain a baseband signal (S11).

Then, a reference signal included in the baseband signal is extracted by correlating all possible reference signals generated in advance with the acquired baseband signal in a predetermined manner, and a correlation peak value is extracted (S12). Since the reference signal includes PSS and SSS, all possible PSSs and all possible SSSs are generated, and all the generated PSSs and baseband signals are correlated as in Equation 1 to extract the PSS representing the largest PSS correlation peak value, , obtain the PSS correlation peak value at this time. Also, by correlating all the generated SSSs with the baseband signal, the SSS representing the largest SSS correlation peak value is extracted, and the SSS correlation peak value at this time is obtained.

When PSS and SSS are extracted, each of the extracted PSS and SSS is converted into mapped fixed integer values (N _ID ⁽¹⁾ , N _ID ⁽²⁾ ), and converted fixed integer values (N _ID ⁽¹⁾ , N _ID) ^{From (2)} ), a cell ID (N _CID ) is obtained according to Equation 5 (S13). That is, the base station (NB) that has transmitted the LTE signal is determined.

When the cell ID (N _CID ) is obtained, the baseband signal is demodulated in a predetermined manner (S14). Then, RSRQ is obtained according to the ratio of the strength of the demodulated signal to the strength of the reference signal (S15).

Then, it is determined whether the obtained PSS correlation peak value (N _PSS ), SSS correlation peak value (N _SSS ), and RSRQ value (N _RSRQ ) are greater than or equal to a predetermined global boundary ( S16 ). Here, the global boundary is divided into a reference PSS correlation peak value, a reference SSS correlation peak value, and a reference RSRQ value for each of the PSS correlation peak value (N _PSS ), the SSS correlation peak value (N _SSS ), and the RSRQ value (N _{RSRQ ).} can be set. In addition, the reference PSS correlation peak value, the reference SSS correlation peak value, and the reference RSRQ value may be set differently depending on the frequency channel of the LTE signal.

If it is determined that it is less than the global boundary, the LTE signal is excluded from the positioning signal selection target (S17).

However, if it is determined that it is less than the global boundary, it is determined whether the signal is previously selected as a positioning signal. That is, it is determined whether it is a _{cell ID (N CID} ) previously selected as a positioning signal (S18). If it is determined that the signal has been previously selected as the positioning signal, the corresponding LTE signal is selected as the positioning signal as it is (S19).

However, if it is determined that the signal is not previously selected as the positioning signal, it is determined whether the number of the currently selected positioning signal is equal to or greater than a predetermined reference number (S20). In addition, if the number of currently selected positioning signals is equal to or greater than the reference number, additional positioning signals are not selected. However, if the number of currently selected positioning signals is less than the reference number, the PSS correlation peak value (N _PSS ) and the SSS correlation peak value (N _SSS ) and the RSRQ value (N _RSRQ ) are used to prioritize the LTE signal in a predetermined manner. set (S21). Here, the priority may be set based on a value obtained by weighting and summing a predetermined weight to each of the PSS correlation peak value (N _PSS ), the SSS correlation peak value (N _SSS ), and the RSRQ value (N _{RSRQ ), for example.}

And the LTE signal is selected as the positioning signal until the number of positioning signals selected according to the set priority becomes a predetermined number (S22).

The method according to the present invention may be implemented as a computer program stored in a medium for execution by a computer. Here, the computer-readable medium may be any available medium that can be accessed by a computer, and may include all computer storage media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, and read dedicated memory), RAM (Random Access Memory), CD (Compact Disk)-ROM, DVD (Digital Video Disk)-ROM, magnetic tape, floppy disk, optical data storage, and the like.

Although the present invention has been described with reference to the embodiment shown in the drawings, which is merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

Accordingly, the true technical protection scope of the present invention should be defined by the technical spirit of the appended claims.

100: baseband signal acquisition unit 200: reference signal extraction unit
210: PSS extraction unit 220: SSS extraction unit
300: cell ID acquisition unit 400: demodulator
500: RSRQ acquisition unit 600: positioning signal selection unit

Claims (10)

a baseband signal acquisition unit for acquiring a baseband signal from each of the LTE signals transmitted from a plurality of base stations;
PSS (Primary Synchronization Sequence) and SSS (Secondary Synchronization Sequence), which are reference signals, are extracted from each of the baseband signals, and PSS correlation peak value and SSS correlation indicating a correlation value between the baseband signal and each of the extracted PSS and SSS a reference signal extraction unit for obtaining a peak value;
A cell ID obtaining unit for obtaining a cell ID of a base station that has transmitted an LTE signal using the PSS and the SSS in a predetermined manner:
an RSRQ acquisition unit configured to acquire a reference signal received quality (RSRQ) value calculated as a ratio of the strength of the reference signal sequence to the signal strength obtained by demodulating the baseband signal; and
A positioning signal selection unit for selecting an LTE signal to be used as a positioning signal among LTE signals transmitted from a plurality of base stations based on the PSS correlation peak value, the SSS correlation peak value, and the RSRQ value,
The positioning signal selection unit
Determine whether each of the PSS correlation peak value, the SSS correlation peak value, and the RSRQ value is greater than or equal to the reference PSS correlation peak value, the reference SSS correlation peak value, and the reference RSRQ value preset as a global boundary, LTE determined to be above the global boundary Select the LTE signal previously selected as the positioning signal among the signals as the positioning signal,
The positioning signal selection unit
If the number of LTE signals selected as the positioning signal is less than the predetermined reference number, it is determined that it is more than the global boundary, and the PSS correlation peak value and the SSS correlation peak value and the RSRQ value of the LTE signal not previously selected as the positioning signal Positioning signal selection device that sets the LTE signal priority based on, and sequentially selects the LTE signal as the positioning signal according to the set priority until the number of positioning signals reaches a predetermined number.
The method of claim 1, wherein the reference signal extractor
A PSS extraction unit that generates all possible PSSs, correlates the generated PSSs with the baseband signal in a predetermined manner to extract the PSS representing the largest PSS correlation peak value, and obtains the PSS correlation peak value corresponding to the extracted PSS ; and
An SSS extraction unit that generates all possible SSSs, correlates the generated SSS with the baseband signal in a predetermined manner, extracts the SSS representing the largest SSS correlation peak value, and obtains the SSS correlation peak value corresponding to the extracted SSS. Positioning signal selection device including. delete delete The method of claim 1, wherein the positioning signal selection unit
Positioning signal selection device for setting each of the reference PSS correlation peak value, the reference SSS correlation peak value, and the reference RSRQ value differently according to the frequency channel of the LTE signal. obtaining a baseband signal from each of the LTE signals transmitted from a plurality of base stations;
extracting PSS and SSS, which are reference signals, from each of the baseband signals, and obtaining a PSS correlation peak value and an SSS correlation peak value indicating a correlation value between the baseband signal and the extracted PSS and SSS, respectively;
Using the PSS and the SSS to obtain a cell ID of a base station that has transmitted an LTE signal in a predetermined manner:
obtaining a reference signal reception quality (hereinafter, RSRQ) value calculated as a ratio of the strength of the reference signal sequence to the signal strength obtained by demodulating the baseband signal; and
Selecting an LTE signal to be used as a positioning signal among LTE signals transmitted from a plurality of base stations based on the PSS correlation peak value, the SSS correlation peak value, and the RSRQ value,
The step of selecting the signal
determining whether each of the PSS correlation peak value, the SSS correlation peak value, and the RSRQ value is equal to or greater than a reference PSS correlation peak value, a reference SSS correlation peak value, and a reference RSRQ value preset as a global boundary; and
Comprising the step of selecting an LTE signal previously selected as a positioning signal among the LTE signals determined to be above the global boundary as a positioning signal,
The step of selecting the signal
If the number of LTE signals selected as the positioning signal is less than the predetermined reference number, it is determined that it is more than the global boundary, and the PSS correlation peak value and the SSS correlation peak value and the RSRQ value of the LTE signal not previously selected as the positioning signal setting LTE signal priority based on; and
Positioning signal selection method further comprising the step of sequentially selecting LTE signals as positioning signals according to the set priority until the number of positioning signals becomes a predetermined number.
The method of claim 6, wherein the obtaining of the correlation peak value comprises:
generating all possible PSSs, correlating the generated PSSs with the baseband signal in a predetermined manner to extract a PSS representing the largest PSS correlation peak value, and obtaining a PSS correlation peak value corresponding to the extracted PSS; and
generating all possible SSSs, correlating the generated SSS with the baseband signal in a predetermined manner to extract the SSS representing the largest SSS correlation peak value, and obtaining the SSS correlation peak value corresponding to the extracted SSS. How to select a positioning signal. delete delete 7. The method of claim 6, wherein selecting the signal comprises:
Positioning signal selection method for setting each of the reference PSS correlation peak value, the reference SSS correlation peak value, and the reference RSRQ value differently according to the frequency channel of the LTE signal.

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