KR102096677B1 - signal transmission Method, storage medium and network in a wide area positioning system(WAPS) - Google Patents

Abstract

The embodiment describes determining the location by selecting a set of digital pseudorandom sequences. The magnitude of the cross-correlation between any two sequences in the selected set is below a specified threshold. The subset of the digital pseudorandom sequence is selected from the set such that the magnitude of the autocorrelation function of each member of the subset is equal to or less than a specified value, in a specified region adjacent to the peak of the autocorrelation function. Each transmitter transmits a positioning signal, and at least a portion of the positioning signal is modulated by at least one member of the subset. At least two of the plurality of transmitters modulate each positioning signal by different members of a subset of the digital pseudorandom sequence.

Description

Signal transmission method, storage medium and network in a wide area positioning system (WAPS)}

inventor:

Norman Kressner

Arun Ragufasi

Related applications

This application claims the benefit of U.S. Patent Application No. 61 / 502,276 filed on June 28, 2011.

This application is a provisional application of U.S. Patent Application No. 13 / 535,626 filed on June 28, 2012.

This application is filed on U.S. Patent Application No. 13 / 412,487 filed on March 05, 2012, which is a continuing application for U.S. Patent Application No. 12 / 557,479 (currently U.S. Patent No. 8,130,141) filed on September 10, 2009 Some are still pending.

This application is filed on U.S. Patent Application No. 13 / 296,067 filed on November 14, 2011, which is a continuing part of U.S. Patent Application No. 12 / 557,479 (now patent 8,130,141) filed on September 10, 2009 Some are still pending.

This application relates to U.S. Patent Application No. 61 / 502,272 filed on June 28, 2011.

The present invention relates generally to positioning systems. Specifically, the present invention relates to a wide area positioning system.

Positioning systems, such as Global Positioning System (GPS), have been used for many years. However, in poor signal conditions, these conventional positioning systems can have degraded performance.

Inclusion by reference

Each patent, patent application, and / or publication referred to herein is incorporated by reference in its entirety to the same extent that each individual patent, patent application, and / or publication is specified and individually indicated.

1 is a block diagram of a wide area positioning system according to one embodiment.
2A and 2B (collectively FIG. 2) include a table of preferred gold codes of length 1023 at a level of -1 execution, according to one embodiment.
3 shows a plot of autocorrelation versus code phase for a preferred gold code, according to one embodiment.
FIG. 4 includes a table of sets of gold code pairs with long autocorrelation execution with amplitude −1, according to one embodiment.
5 shows a plot of autocorrelation magnitude versus code phase for a preferred gold code pair, according to one embodiment.
6 shows a diagram of transmitted symbol phase versus chip number for a preferred gold code pair, according to one embodiment.
7 is a table of sets of preferred maximum length codes with low cross-correlation values.
8 is a block diagram of a synchronized beacon according to one embodiment.
9 is a block diagram of a positioning system using a repeater configuration according to one embodiment.
10 is a block diagram of a positioning system using a repeater syntax according to one alternative embodiment.
11 illustrates tower synchronization according to one embodiment.
12 is a block diagram of a GPS trained PPS generator according to one embodiment.
13 is a GPS trained oscillator according to one embodiment.
14 is a signal diagram for counting the visual difference between a signal that allows an analog section of a PPS and a transmitter to transmit data according to one embodiment.
15 is a block diagram of a differential WAPS system according to an embodiment.
16 shows a common view time transmission according to one embodiment.
17 illustrates two-way time transmission according to one embodiment.
18 is a block diagram of a receiver unit according to one embodiment.
19 is a block diagram of an RF module according to an embodiment.
20 illustrates up-conversion and / or down-conversion of a signal according to an embodiment.
21 is a block diagram of a receiver system with multiple receive chains where one of the receive chains according to one embodiment may be used to temporarily receive and process WAPS signals.
22 is a block diagram illustrating clock sharing in a positioning system according to one embodiment.
23 is a block diagram of auxiliary transmission from WAPS to GNSS according to an embodiment.
24 is a block diagram illustrating transmission of auxiliary information from a GNSS receiver to a WAPS receiver according to one embodiment.
25 is an exemplary configuration in which WAPS assistance information according to an embodiment is provided from a WAPS server.
26 is a flow chart for estimating the earliest arrival route according to one embodiment.
27 is a flowchart for estimating a reference correlation function according to an embodiment.
28 is a flowchart for estimating a noise subspace according to an embodiment.
29 is a flow chart for estimating a noise subspace according to an alternative embodiment.
30 is a flowchart for estimating a noise subspace according to another alternative embodiment.
31 is a flowchart for estimating a noise subspace according to another alternative embodiment.
32 is a flow chart for estimating a noise subspace according to an alternative embodiment.
33 is a block diagram of a reference elevated pressure system according to one embodiment.
34 is a block diagram of a WAPS incorporating a reference elevated pressure system according to one embodiment.
35 is a block diagram of hybrid position estimation using range measurements from various systems according to one embodiment.
36 is a block diagram of hybrid position estimation using position estimation from various systems according to one embodiment.
37 is a block diagram of hybrid position estimation using a combination of range and position estimation from various systems, according to one embodiment.
38 is a hybrid position where the position / speed estimation from the WAPS / GNSS system according to one embodiment is fed back to help correct the drift bias of the sensor at a time when the quality of the GNSS / WAPS position and / or speed estimate is good. It is a flowchart for deciding a decision solution.
39 is a flow chart for determining a hybrid position solution in which sensor parameters (eg, bias, scale and drift) are estimated as part of position / velocity calculation in a GNSS and / or WAPS unit without explicit feedback according to one embodiment. to be.
40 is a flow chart for determining a hybrid positioning solution where sensor calibration according to one embodiment is separate from individual position calculation units.
41 is a flow chart for determining a hybrid positioning solution in which sensor parameter estimation is made as part of the state of an individual position calculation unit according to one embodiment.
42 illustrates the exchange of information between WAPS and other systems according to one embodiment.
43 is a block diagram illustrating the exchange of position, frequency, and time estimates between an FM receiver and a WAPS receiver according to one embodiment.
44 is a block diagram illustrating the exchange of location, time, and frequency estimates between a WLAN / BT transceiver and a WAPS receiver according to one embodiment.
45 is a block diagram illustrating the exchange of position, time, and frequency estimates between a cellular transceiver and a WAPS receiver according to one embodiment.
46 shows a parallel composite correlator architecture, according to one embodiment.
47 shows a 32-bit shift register implementation obtained from two 16-bit shift register primitives with parallel random access read capability according to one embodiment.
48 shows a shift operation and a readout operation rate according to an embodiment.
49 shows a structure for an adder tree implementing a 1023 × n-bit adder according to one embodiment.
50 is a block diagram of setting a session key according to an embodiment.
51 is a flow chart for encryption according to an embodiment.
52 is a block diagram of a security architecture for encryption according to an alternative embodiment.

Systems and methods are described for determining the location of a receiver. The positioning system of one embodiment includes a transmitter network that includes transmitters that broadcast positioning signals. The positioning system includes a remote receiver that acquires and tracks a positioning signal and / or a satellite signal. The satellite signal is a signal of a satellite-based positioning system. The first mode of the remote receiver uses terminal-based positioning, where the remote receiver calculates the location using a positioning signal and / or a satellite signal. The positioning system includes a server connected to a remote receiver. The second mode of operation of the remote receiver includes network-based positioning, where the server receives the positioning signal and / or satellite signal from the positioning signal and / or satellite signal, and Calculate the location of the remote receiver transmitting to the server.

The method of positioning in one embodiment includes receiving at least one of a positioning signal and a satellite signal at a remote receiver. The positioning signal is received from a transmitter network comprising a plurality of transmitters. The satellite signal is received from a satellite-based positioning system. The method includes determining a position of a remote receiver using one of terminal-based positioning and network-based positioning. The terminal-based positioning includes calculating a position of a remote receiver at a remote receiver using at least one of a positioning signal and a satellite signal. The network-based positioning includes calculating a position of a remote receiver at a remote server using at least one of a positioning signal and a satellite signal.

In addition to systems and methods for determining location, a spreading code and apparatus for wide area positioning is disclosed that provides an improved structure that enables multipath mitigation for wide area positioning systems. . Specifically, in addition to binary codes, quaternary and other non-binary spreading codes with very good autocorrelation and cross-correlation properties over a limited code phase range are described. Non-binary codes enable higher data rates than binary codes, such as data rates used in Global Positioning Systems (GPS). These codes can be used in systems using CDMA multiplexing, TDMA multiplexing, frequency offset multiplexing, or any combination thereof.

A system and method for determining a location by selecting a set of digital pseudorandom sequences is described. The size of the cross-correlation function between any two sequences in the selected set is below a certain threshold. The subset of the digital pseudorandom sequence is selected from the set such that the magnitude of the autocorrelation function of each member of the subset is less than or equal to a specified value within a specific range adjacent to the peak of the autocorrelation function. Each transmitter in the transmitter's network transmits a positioning signal, and at least a portion of the positioning signal is modulated according to at least one member of the subset. At least two of the network of transmitters modulate their respective positioning signals according to different members of a subset of the digital pseudorandom sequence.

Additionally, a system and method for determining location by selecting a set of digital pseudorandom sequences is described. The magnitude of the autocorrelation function of any two sequences of the selected set of digital pseudorandom sequences is below a certain threshold, within the region adjacent to the peak of the autocorrelation function. The subset of digital pseudorandom sequences is selected from the set such that the magnitude of the autocorrelation function of any sequence pair in the subset of digital pseudorandom sequences is less than or equal to a specified value. Each transmitter in the network of transmitters transmits a positioning signal, and at least a portion of the positioning signal is modulated according to at least one member of the subset. At least two of the network of transmitters modulate their positioning signals by different members of a subset of the digital pseudorandom sequence.

In the following description, the autocorrelation (or cross-correlation) function can be regarded as a set of time samples. Through this understanding, the term "region" means a set of contiguous time samples of a function within a time interval specified by this region. The term "adjacent" means nearby. When it is said that the autocorrelation function (or cross-correlation function) size within a region is below a threshold, this means that the size of each time sample of the autocorrelation function (or cross-correlation function) within this region is a threshold within one region. It means that If no region is specified, this means all time samples. Depending on the sequence used, the cross-correlation function can be a real or complex function. The autocorrelation function is a real function, but it can be a positive or negative function. In most cases, we are interested in the magnitude of these functions, and less of their polarity and / or phase. Since the autocorrelation function is symmetric about the peak value (which is a positive value), if these functions have a magnitude lower than some threshold within a region higher than the location corresponding to the peak location, the autocorrelation magnitude is also lower than this threshold. The region is necessarily symmetrically placed in the region below the peak location. In the case of cross-correlation functions, this is not usually the case.

The following description uses terms in which the signal is modulated according to a pseudorandom or other sequence. This means that the selection or modification of the waveform transmitted over a continuous (usually short) time interval is selected according to the successive elements of the sequence. In general (but essentially), a fixed mapping from the values of the sequence to the selection or modification of the waveform is done. An example of an embodiment includes a pseudorandom binary sequence with values used to phase shift the carrier by 0 or 180 degrees at regular intervals. An example of an alternative embodiment is a pseudorandom quaternary sequence with a value (one of four) used to phase shift the carrier by 0 degrees, 90 degrees, 180 degrees, or 270 degrees. However, embodiments herein are not limited to regular or irregular phase shifts, or regular or irregular intervals, and various modulation methods such as frequency shift, on-off keying, differential phase shift keying keying), pulse width modulation, and the like. In some cases, for brevity, a description is used that a pseudorandom sequence is used to "modulate" the signal. This nomenclature is synonymous with the description that the signal is modulated "according to" this sequence. In context, it will be apparent that the modulation type is binary phase reversal, or quaternary phase shift, or a more general modulation type. In the following description, when referring to a sequence used for pseudorandom modulation or spreading, the terms sequence and code are used interchangeably. It is distinct from data sequences that refer to information streams.

In the following description, many specific details are introduced to provide a complete understanding and description of the systems and methods described. However, one of ordinary skill in the art will recognize that these embodiments may be practiced without one or more of the specific details, or including other components, systems, or the like. In other instances, well-known structures or operations are not shown or described in detail, in order to avoid obscuring aspects of the disclosed embodiments.

1 is a block diagram of a positioning system according to one embodiment. The positioning system, also referred to herein as a wide area positioning system (WAPS) or "system", acquires and tracks a network of synchronized beacons, the beacon and global positioning system (GPS) satellites. The receiver unit (optionally has a location calculation engine), and a server including a tower index, a billing interface, a proprietary encryption algorithm (optionally has a location calculation engine) ). The system operates in the licensed / unlicensed operating band and the beacon transmits a proprietary waveform for location and navigation purposes. The WAPS system can be used in conjunction with other positioning systems or to assist with other positioning systems for better positioning solutions.

In the context of the present application, a positioning system is to locate one or more of latitude, longitude and altitude coordinates. Whenever 'GPS' is referred to, it is referred to as the Global Navigation Satellite System (GNSS), and other existing satellite positioning systems, such as Glonass, as well as future positioning. Systems, such as Galileo and Compass / Beidou.

As will be described in detail herein, one embodiment WAPS includes a plurality of towers that broadcast a synchronized positioning signal to a mobile receiver. The tower of one embodiment is terrestrial, but the embodiment is not limited thereto. A significant problem that arises particularly in terrestrial systems, especially terrestrial systems operating in urban environments, is the presence of multipath. In this situation, the mobile receiver can receive a plurality of signals from the transmitter in response to a plurality of direct and reflected paths. It is common for a range of delays, sometimes referred to as delay spreads, to be limited by geometrical circumstances. For example, a delay spread of 1 microsecond corresponds to a maximum differential path length of 300 meters and a diffusion of 6 microseconds corresponds to 1499 meters.

Conventional WAPS can obtain optical bandwidth using coded modulation, so-called spread spectrum modulation, or pseudonoise (PN) modulation. In such a system, the carrier signal is modulated by a broadband modulated signal (generally digital modulation) and this optical bandwidth enables accurate positioning by using a time-of-arrival measurement method. Mobile receivers process these signals using a de-spreading device, typically a matched filter or a series of correlators. These receivers produce a waveform called a cross-correlation function with narrow, strong peaks, which are ideally surrounded by low level energy. The arrival time of the peak represents the arrival time of the transmitted signal on the mobile. By performing this operation on a plurality of signals from a plurality of towers having exactly known positions, it is possible to determine the position of the mobile through a trilateration algorithm.

Assuming the use of a matched filter to process the received spread spectrum signal, when multipath is present, the matched filter output provides a series of overlapping sharp pulses of variable amplitude, delay, and phase. The mobile receiver attempts to estimate the arrival time of this earliest pulse. Various algorithms can be used for this purpose, for example, leading edge location algorithm, MUSIC algorithm, minimum mean square estimation algorithm, and the like.

However, the problem that arises is that the energy surrounding the peak generally includes a series of ancillary peaks, or “sidelobes”. In an ideal situation (ie no noise or multipath), the specification of the structure of this sidelobe is provided by a function called an “autocorrelation function”. In a multipath environment, these ancillary peaks can be confused with weak early signal arrival. For example, in a GPS system, in the case of C / A civilian code, a specific binary spreading code, a so-called "gold code" having a frame length of 1023 symbols, that is, a "chip" ( Gold Code) ". An ideal matched filter for receiving this gold code produces a set of sidelobes of -65/1023 times peak amplitude, 63/1023 times peak amplitude, and -1/1023 times peak amplitude amplitude. do. Therefore, the size of the largest sidelobe is about 0.06 times the peak amplitude or -24 dB. In general, these large amplitude sidelobes may be close to or close to the peak amplitude of the autocorrelation function. By selecting a code having a large area at the center of the peak of autocorrelation with a sidelobe value of -1/1023 times peak (for length 1023), improved multipath estimation can be achieved. This is referred to as -1 run length. In particular, in this case, the -1 execution length is defined as the number of contiguous chips on one side of the autocorrelation peak, the amplitude -1/1023 times the peak. The embodiment described herein is a selection of a set of Gold Codes with the largest -1 execution length. As described in detail herein, in various alternative embodiments, other classes of code sets may be used.

For the sake of brevity, in this application, strictly speaking, mainly for cyclic, i.e., "periodic" autocorrelation functions, which are applied when the transmitted code sequence is repeated two or more times, such as Focus is achieved. Thus, the autocorrelation and cross-correlation mentioned are, strictly speaking, synonymous with cyclic cross-correlation and cyclic autocorrelation. However, the application and advantages of the idea of this description are acyclic, i.e., "aperiodic" correlation, especially when attention is paid to the performance near the peak of the output of a matched filter (or set of correlators). Also applies to This is true because the aperiodic autocorrelation function is almost the same as the cyclic autocorrelation function near the peak output of the matched filter. Likewise, an aperiodic cross-correlation function can be similar to a cyclic aperiodic cross-correlation function when two correlated sequences are nearly aligned with their starting epoch.

A signal whose spread spectrum modulated signal is suitable for use in positioning has been described. However, it is generally the case that signals transmitted from various transmitters include data necessary for calculating the positioning position. For example, such data may include the geographic location of the transmitter, the time of transmission, environmental data, and the like. Another set of such slow data may include sequences for full signal synchronization. In any case, this data is usually transmitted at a rate much lower than the bandwidth of the spread signal. Often this data is further modulated in addition to the spread spectrum modulated signal used for positioning, and often the data epoch is ordered according to the epoch of spread spectrum modulation, eg, the beginning of a pseudorandom frame. Often, even if both spread spectrum modulation and data modulation are used to phase shift the signal carrier, this is not necessarily the case, and the embodiments herein are not limited thereto. Additionally, when a portion of the transmitted signal can include only a spread spectrum modulated carrier without any additional data, and another portion of the transmitted signal can include a spread spectrum signal and a carrier modulated by both data. Can be. Also, although both modulations may be provided in different parts of the transmitted signal, it may be the case that different pseudorandom sequences can be used in different parts of the transmission. In the following description, when terms such as data, data rate, data modulation, data bits, and information bits are used, these terms are generally used to refer to data types as referred to in this paragraph in contrast to spread modulation. .

As will be described in detail below, one embodiment includes coded modulation of four or more decimal digits for the modulation being transmitted. For systems using BPSK data modules and BPSK spreading, it is sufficient to select a good -1 run length for multipath mitigation. When quaternary spreading is used, it is necessary not only to have a good -1 run length for various tributaries, but also to have very good cross-correlation properties between tributary codes for code offsets matching -1 run length. Alternative embodiments of the methods described herein include selecting a pair or larger set of codes.

Many WAPS use binary coded modulation as a spreading method. One embodiment produces a quaternary coded modulation configured in a manner to minimize the effect of multipath, as described above. Another higher-order coding modulation is also disclosed and has similar advantages with respect to multipath mitigation.

In binary coded modulation, the transmitting source indicates a waveform corresponding to one of the two symbols, typically -1 and +1, or 0 and 1, in any case. To create. In general, the waveform is biphase coded, which means that the signal is transmitted, or by inverting the carrier, the inverse of the signal is transmitted. In order to achieve the binary coded signal, it is possible to use frequency shift keying, amplitude shift keying, and the like.

In quaternary coded modulation, the transmitter source transmits one of four possible symbols, which can be named A, B, C and D at any time. One embodiment includes a transmitter that maps these four symbols to one of four possible phases to produce a quadrature modulated signal. One way to generate such a quadrature modulated spread signal is to use two gold codes that modulate the in-phase and quadrature components of the transmitted carrier. The signal transmitted to any instance is again one of four symbols corresponding to the four carrier phases. The number of possible symbols transmitted at any time is sometimes referred to as the alphabet size. Therefore, in the case of the 4-value, the alphabet size is 4. Any alphabet size is possible, but by using a small alphabet size, system complexity can be reduced. There are well-known pseudorandom sequences with good autocorrelation and cross-correlation properties, where each sequence element is one of the M possible values. In other words, this value M is called the alphabetic size of the sequence. When transmitting signals according to this sequence, there is a mapping of each sequence element value to one appropriate waveform. For example, a sequence can have an alphabetic size of 16, and one possible mapping would be to map each of the 16 possible values to 16 possible phase shifted exponentials. It is not necessary to construct a sequence of higher digits from a sequence of lower digits, such as a Gold code (they can be configured directly). However, the example description currently provided illustrates this configuration.

By using quaternary coding of data rather than binary coding of the data, the data rate transmitted by the transmitter can be doubled without affecting the signal structure. For example, if the code length is N symbols, the entire spreading sequence of N transmitted (4-valued) symbols can be further phase shifted by 0, 90, 180 or 270 degrees, thereby biphase coding. As in the case of, it is possible to transmit 2 bits of data per code period, rather than 1 bit.

An additional advantage of spreading signal quaternary coding is that the method provides a means for distinguishing signals from another transmitter that has the same code and overlaps in time. A sequence of symbols transmitted from one transmitter may appear as A + jB, where A is a specific gold code (for example), B is another gold code, and j represents a 90 ° phase shift. The second transmitter can transmit A-jB. Both transmitters are transmitting quaternary symbols in a similar manner, but the relationship between the in-phase component and the quadrature component is changed and is easily determined by the receiver.

Higher decimal spread modulation can be configured in a variety of ways. For example, a code having an alphabet size of 8 may be constructed. Each symbol of the code can be mapped to the phase shift value of the carrier by a size kxπ / 4, k = 0,1, ..., 7. Alternatively, each symbol can be mapped to a combination of amplitude and phase shift. In this example of alphabet size 8, the transmitter calculates the code sequence and mapping (3 bit words for the transmitted symbol on the fly), or stores the entire sequence or entire frame of the symbol and needs this data. According to this, it can be read out from the memory.

In all the scenarios described above, assuming the same transmitted and received energy, the same spreading symbol shape, and the same spreading symbol rate, the performance of the system is the same in terms of range measurement. However, when more than two information bits are transmitted per PN frame length, there is less energy per information bit. In many terrestrial wide area positioning systems, there is good received signal energy, so this limitation can be trivial.

2A and 2B (all together referred to as FIG. 2) include a table 200 of preferred gold codes of length 1023 at a level of -1 execution length, according to one embodiment. In a more general case than described herein, “-1 execution length” refers to the number of concatenated code phases following a correlation peak with +/- 1 times the peak value divided by the code length. Each of the gold codes is constructed from the same pair of maximum length codes, and different gold codes are distinguished by delay, or code phase, difference between pairs. Table 200 also includes the initial filling of the shift register of the second PN code as an alternative to the delay, since the initial fill is generally more closely related to the way the sequence will be generated. do. The filling of the first PN code in the table is always all equal to one. The filling of the second PN code is as specified in the table. The fill reading from left to right represents the first 10 outputs of the second PN generator. Filling in the shift register is positioned back to the beginning of the shift register. PN code 1 has a feedback tap [3, 10], and code 2 has a tap [2,3,6,8,9,10]. The best code displayed in table 200 has 25 runs (each side of the autocorrelation peak). In addition to the codes shown in Table 200, each of the individual maximum length codes, i.e., code 1 and code 2, can be considered part of the gold code set (because they share the gold code set cross-correlation attribute with other members), With these alone, it can be used to augment the code of the table 200. In addition, these maximum length codes have a (cyclic) autocorrelation function of -1 except for the correlation peak. If these codes are included in the code in Table 200, their -1 execution length will be 1022, so they will be located at the head of the list.

It should be noted that other maximum length PN code pairs can be used to construct a set of gold codes with good -1 execution length. The code pairs selected herein are for illustrative purposes. In addition, the table can be constructed in a similar manner to the case of other code lengths where gold codes are present. In addition, a code set other than the gold code set can be selected, and a subset of these sets for a good -1 execution length. Such modifications are described in detail herein.

3 shows a plot 300 of autocorrelation versus code phase for a preferred Gold code, according to one embodiment. More specifically, the chart 300 shows the central portion of the autocorrelation of the first item having a -1 execution length of 25 in table 200 (preferred order is 1, delay between codes is 853, equivalent fill) is 1000100001, -1 sidelobe execution length is 25).

As described in detail above, by using two gold codes in orthogonal phase relationship, a quaternary coded signal can be constructed. In this case, the autocorrelation function will have four terms corresponding to the individual autocorrelation of the two gold codes and the cross correlation between the gold codes. That is, if the constituent gold codes are referred to as g and h, the entire code can be expressed as g + jh. The autocorrelation then becomes gⓧg + hⓧh-jgⓧh + jhⓧg, where ⓧ means correlation, and when correlating two complex quantities, this second amount It is a complex pair. The last two terms in this total autocorrelation are cross-correlated. In order to construct a good quaternary code with a large -1 execution length, as well as using a gold code with a good individual -1 execution length, their cross-correlation, the autocorrelation function of the individual gold code set the value -1 It is also essential to have negligible contributions in the vicinity of the same code phase spacing. Here, the interval of a low cross-correlation value is called a cross-correlation run. Selection of these pairs of codes can be achieved by utilizing the fact that relative code phases between gold codes can be selected to obtain good cross-correlation performance over the interval of code phases of interest. One embodiment includes a set of gold code pairs determined in this way, by examining all gold code pairs in table 200 and all relative code phases between these pairs. Correlation operations for quaternary codes (or any code higher than binary) include operations that are multiplied by a complex pair of ideal received signals.

4 includes a table 400 of a set of gold code pairs that can be used to construct a quaternary code with a long -1 execution length, according to one embodiment. The delay in the third column is applied to Gold Code 2 to obtain the full autocorrelation of the orthogonally modulated signal with a long -1 execution length as shown in the fourth column. In this case, if the constituent gold code sequence has amplitude +/- 1, the total autocorrelation during the run has amplitude -2 and the peak of autocorrelation is 2046. Since the -1 times peak value division code length is equal to -1 times 2046/1023 = -2, the execution length definition matches the previous definition. 5 shows a plot 500 of autocorrelation magnitude versus code phase for a preferred gold code pair according to one embodiment. More specifically, the chart 500 shows the second item of the table 500 (gold code 1 (PN delay) 714, gold code 2 (PN2 delay) 456, and central cross correlation run (to code 2). ) The inserted delay shows the central portion of the magnitude of the autocorrelation of 343, the total cross-correlation execution is 47), which adds the length of the -1 execution of 18 to either side of the autocorrelation peak. To compare this with the diagram 300 (FIG. 3), the size is divided by two. The insertion of a proper delay between the constituent gold codes is important for constructing a quaternary code with excellent autocorrelation properties. The autocorrelation function for the peak can have large and close side lobes.

FIG. 6 shows a diagram 600 of symbol phase versus (vs.) chip numbers transmitted for a preferred gold code pair, according to one embodiment. More specifically, the diagram 600 is the second item in the table 400 (gold code 1 (PN delay) 714, gold code 2 (PN2 delay) 456, the delay inserted up to the central cross correlation execution is 343, total The cross-correlation run shows the sample portion of the transmitted symbol phase angle (in degrees) versus the number of chips for 37). Table 600 shows a sequence of four phases representing a four-value code, +/- 45 degrees and +/- 180 degrees. The transmitter itself only needs to store a sequence of phase angles, or symbol designations (eg, A, B, C, and D) rather than implementing code using shift registers or similar methods.

Although the description herein focuses on gold code, the idea extends to other code classes. Many code classes suitable for use in spread spectrum multiplexing at first can be selected. For example, such a set may include Kasami code, Bent code, and Gold-like code, but embodiments are not limited thereto. In general, these sets have good (aperiodic) cross-correlation properties between pairs of members. So, according to one embodiment, a subset of such code can be selected to have cyclic autocorrelation with a long -1 execution length. Likewise, a code set having good cross-correlation attributes with an alphabet size greater than 2, such as 4, 8, or more, can be selected. Subsequently, a subset of them with good cyclic autocorrelation properties can be selected.

In the description herein, the primary measure of performance is the -1 run length of the autocorrelation function. This corresponds to the length of the autocorrelation function on either side of the peak of the function with the value of -1 times the peak value / code length. However, additional embodiments herein select a subset of codes having an autocorrelation magnitude level not greater than threshold A within a specified region around the peak autocorrelation value. It is defined as the A run length. As before, a set of sequences is selected such that the maximum size of the cross-correlation function between any pair of codes is less than a certain value. Subsequently, a subset of this code set is selected such that for each member of this subset, the autocorrelation function size is less than or equal to the value A, within a particular location region near the peak. For the binary and quaternary gold codes mentioned above, A has a value of 1, assuming that the gold code sequence has +1 and -1.

In another embodiment, a set of codes is selected to have good autocorrelation properties over a range centered on the peak location of the function. Subsequently, a subset of these codes is selected where the pairwise cross-correlation magnitude between members is less than a certain threshold C (optionally over a range of code phases). This can be applied to binary codes or codes with larger alphabets (eg 4 values). For example, a set of maximum length sequences of a given size, such as 2047, can be considered. In this case, 176 such codes exist. Of course, each has a very good autocorrelation property with -1 run length 1022. Cross-correlation between members will be quite variable. FIG. 7 is a table 700 of a subset of codes selected to have a bounded cross-correlation size between members, according to one embodiment. Excellent performance is obtained by limiting the size of the subset. For example, for code length 2047, a maximum cross-correlation size of 65 can be obtained when the set size is limited to 3, and a maximum cross-correlation size of 129 can be obtained when the set size is limited to 10.

In one embodiment, the code described herein is used to modulate the carrier wave and thus generate a positioning signal. The code can be repeated one or more times. Such signals may include other signaling elements in addition to or instead of these positioning signals. For example, as described herein, a portion of such a signal may include a positioning signal itself, and another portion may include a positioning signal that is further modulated by a lower rate data sequence, Other parts of the signal may include other signal elements that do not contain a spreading code at all. In another embodiment, the transmitted signal can be transmitted as a set of bursts in a time-division multiplexed manner rather than continuously. Individual transmitters may use the same code in each burst, or these codes may be different in one burst and the next. The embodiments herein apply to all of these situations when at least one portion of such transmission includes a pseudorandom or spreading code selected in the manner described herein.

In one embodiment, the selected code set may have a sequence length that is truncated shorter than the standard sequence length or extended to a longer length. For example, instead of using a standard gold code of length 2047, a code length of 2046 can be used instead by deleting one code member. This may enable simpler implementation in situations where multiple lengths are employed. For example, the system may operate at one rate, ie, the first rate, and in another situation, at a second rate that is twice the first rate. In the first case, if a code length of 1023 is used, in the second case, the system is operated with a code length of 2046 to maintain the same frame (ie, sequence) duration. In another embodiment, different transmitters using codes selected according to embodiments described herein transmit signals using slightly different carrier frequencies.

WAPS system and method

8 is a block diagram of a beacon synchronized under one embodiment. Referring to Figures 8 and 1, one embodiment of a synchronized beacon (also referred to herein as a beacon) forms a CDMA network and has a pseudo-random number (PRN) sequence with good cross-correlation properties, such as built-in assistance. Each beacon transmits a signal according to a gold code sequence having a data stream of data. Alternatively, the sequence from each beacon transmitter may be out of time with individual slots in TDMA format.

In terrestrial positioning systems, one of the main problems to overcome is the near-far problem that, at the receiver, a remote transmitter will be jammed by a nearby transmitter. To solve this problem, the beacon of one embodiment uses a combination of CDMA, TDMA techniques, and frequency offset techniques. Such a system is called a hybrid multiplexing system because it is a combination, not just one of these methods. For example, to mitigate the near-source problem, the local transmitter can use separate time slots (and optionally different codes (CDMA)). Rather distant transmitters will be allowed to use the same time slot while using different CDMA codes and / or frequency offsets. This enables wide-area scalability of the system. Time slots can be deterministic for guaranteed near-circle performance, or randomized to provide good average near-circle performance. As indicated herein, the carrier signal is also offset by a small frequency difference (e.g., about a gold code repetition frequency) to improve the cross-correlation performance of the code, and thus the 'near-far' problem. Can solve it. When two towers use the same time slot and different code and / or offset frequency, cross-correlation at the receiver can be further eliminated by using interference cancellation of the strong signal before detecting the weak signal. The hybrid positioning system described herein employs sophisticated planning methods, so that each transmitter can be assigned a combination of time slot, CDMA code, and frequency offset to maximize overall system performance. The number of combinations of these parameters is limited such that signal acquisition by the receiver is a practical value.

In addition, the beacon of one embodiment may use a preamble containing auxiliary data, and the information may be channel estimation and forward error detection and / or correction to help make the data robust. Correction). Ancillary data in one embodiment includes, but is not limited to, one or more of the following: precision system time at the rising and falling edges of a pulse or specified signal epoch of a waveform, tower Geocode data of (latitude, longitude and altitude), geocode information for adjacent towers and indexes of sequences used by various transmitters in the area, clock timing correction for transmitters (optional) and neighbor transmitters (clock timing correction), local atmospheric correction (optional), relationship of WAPS timing to GNSS (optional), city to assist the receiver with pseudorange resolution, Semi-urban, indication of the rural environment (optional), and offset from the base index of the PN sequence or index of the gold code sequence. In the transmitted data frame being broadcast, a field containing information for deactivating a single receiver or set of receivers may be included for safety and / or authorization management reasons.

The transmit waveform timings of transmissions from different beacons and towers in one embodiment are synchronized to a common timing reference. Alternatively, the timing difference between transmissions from different towers is known and must be transmitted. With the exception of timing messages to be incremented at regular intervals, the assist data is repeated at intervals determined by the number and size of data blocks. The auxiliary data may be encrypted using an encryption algorithm. The spreading code can also be encrypted for additional security. The signal is up-converted and broadcast at a specified frequency. The end-to-end delay at the transmitter is accurately corrected to ensure that the differential delay between beacons is less than approximately 3 nanoseconds. Using a differential WAPS receiver at the irradiated position listening to the transmitter set, relative clock correction for the transmitter of the set can be found.

에 관한 것이다: i=1,...,n에 대해, x_min<x<x_max, y_min<y<y_max, z_min<z<z_max 이때, x_min, y_min 및 z_min는 커버리지 공간의 하한이고, x_max, y_max 및 z_max는 커버리지 공간의 상한임. 최소화될 함수는, The tower device of one embodiment is optimized for coverage and locating accuracy. Tower arrangements are arranged in a manner to receive signals from three or more towers, inside the network and at most locations on the edge of the network, so geometric dilution of precision (GDOP) at each of these locations meets the precision requirements. It may be lower than the designated threshold based on. Software programs for RF planning research will be augmented to include analysis of GDOP in and around the network. GDOP is a function of receiver position and transmitter position. One way to include GDOP in network planning is to set the optimization as follows: The function to be minimized is the volume integral of the power of the GDOP over the coverage voulme. The volume integral relates to the (x, y, z) coordinates of the receiver position. Minimization is the coordinates of n transmitter positions in a given coverage area according to constraints in the coverage space.

For i = 1, ..., n, x _min <x <x _max , y _min <y <y _max , z _min <z <z _{max where} x _min , y _min and z _min are The lower limit of the coverage space, and x _max , y _max and z _max are the upper limits of the coverage space. The function to be minimized is

Can be written as

In addition, the function to be minimized can be weighted according to the importance of the coverage area R _j (ie, the required quality of performance).

를 출력할 것이다. The location of additional constraint elements on the tower may be based on the location of the already available tower in the specified area. Coordinatization of all coordinates can generally be achieved in a local level coordinate system that is average east as positive x, average north as positive y, and average vertical upward as positive z. Optimized transmitter position to minimize function f by software that solves the above constraint minimization problem

Will output

This technique can be applied to both wide area networks (such as in cities) or local deployments (such as in malls). In one exemplary configuration, the network of transmitters in a triangular / hexagonal arrangement around each metropolitan area is spaced by a distance of approximately 30 km. Each tower can radiate up to maximum power in the range of approximately 20W to 1kW EIRP through a corresponding antenna. In another embodiment, the location of the tower can be identified and transmitted at a power level as low as 1W. The frequency band of operation includes any licensed or unlicensed band in the radio spectrum. The transmit antenna of one embodiment includes an omni-directional antenna or multiple antennas / arrays capable of assisting in diversity, sectoring, and the like.

By transmitting using different sequences with good cross-correlation properties, or alternatively, using the same sequence at different times, adjacent towers are distinguished. These differentiation techniques can be combined and applied only to specific geographic areas. For example, the same sequence in different geographic areas can be reused over the network.

Local towers may be deployed in specific geographic areas to augment a wide area network tower in one embodiment. The local tower, when used, can improve the accuracy of positioning. The local towers may be deployed in a campus-like environment, or for public safety purposes, spaced from a few tens of meters up to several kilometers.

Towers would preferably be placed at various heights (not similar heights) to facilitate good quality altitude estimation in positioning solutions. In addition to transmitters of different latitudes / longitudes with different heights, another way to add height diversity to towers is to have different code sequences (with different code sequences) at different heights (with the same latitude and longitude). Is to have multiple WAPS transmitters. Different code sequences on the same physical tower can use the same slot because transmitters on the same tower do not cause near-circle problems.

WAPS transmitters can be deployed on existing or new towers used for one or more other systems (eg, cellular towers). The cost of deploying a WAPS transmitter can be minimized by sharing the same physical tower or location.

To improve performance within a local area (eg, warehouse or mall), additional towers can be placed in the area to enhance transmitters used for wide area coverage. Alternatively, a repeater may be placed in the region of interest to lower the cost of installing the entire transmitter.

The transmit beacon signal used for the above-mentioned positioning need not be a transmitter built exclusively in WAPS, and any other system originally synchronized with time synchrozation or a system with enhanced synchronization through an additional timing module It may be a signal from. Alternatively, the signal can be a signal from a system with relative synchronization that can be determined through a reference receiver. For example, these systems have additional synchronization capabilities and can be already deployed or newly deployed. Examples of such systems may be broadcast systems, such as digital and analog TV or MediaFlo.

When a WAPS network is constructed, some transmission locations may be superior to others within the network determined by design or by field measurements (beacon height higher than clutter, power level). Such a beacon can be identified at the receiver either directly or thereafter by encoding data bits representing the “quality” of the beacon that the receiver can use to weight the signal received from this beacon.

9 is a block diagram of a positioning system using a repeater configuration according to one embodiment. The repeater configuration includes the following components:

1) Common WAPS receiving antenna (antenna 1)

2) RF power amplifier and splitter / switch connected by various WAPS transmitter antennas (local antennas 1-4)

3) WAPS user receiver

Antenna 1 receives, amplifies, and distributes (switches) the local antennas 1-4. Switching should be done so that there is no overlap (collision) between transmissions from different repeaters at the user receiver (which should preferably be done). Collisions of transmissions can be avoided through the use of guard intervals. From the switch, by adding a delay at the repeater-amplifier-transmitter to equalize the total delay for all local repeaters, or by adjusting the estimated arrival time from a specific repeater by a cable delay at the user-receiver. The cable delay known as the transmit antenna must be compensated. When TDMA is used in a wide area WAPS network, a repeater slot switching rate is selected such that each wide area slot (each slot will contain one wide area WAPS tower) occurs in all repeater slots. One exemplary configuration will use a repeater slot duration equal to multiple times the duration of multiple wide area TDMA frames. In particular, when the wide area TDMA frame is 1 second, the repeater slot may be an integer second. This configuration is the simplest, but only suitable for deployment in small and limited areas due to the requirement of RF signal distribution on the cable. The user WAPS receiver can use the time-difference of arrival when listening to the repeater tower to calculate position and work under static (or quasi static) assumptions during the repeater slot period. By the fact that each WAPS tower signal shows the same timing difference (jump) between one repeater slot and the next repeater slot, the fact that the transmission comes from the repeater can be automatically detected.

10 is a block diagram of a positioning system using a repeater configuration in accordance with an alternative embodiment. In this configuration, each repeater includes a WAPS repeater-receiver and associated coverage-augmentation WAPS transmitter (eg, including a local antenna that may be indoors). The WAPS repeater receiver should be able to extract the WAPS data stream corresponding to one wide area WAPS transmitter as well as WAPS system timing information. The WAPS system timing and data corresponding to one wide area WAPS transmitter is passed to the corresponding local area WAPS transmitter, after which the local area WAPS transmitter replays the WAPS signal (eg, using different codes and the same slot). -You can send. The transmitter will include additional data in its transmission, such as latitude, longitude and altitude of the local antenna. In this configuration, WAPS user receiver operation (range measurement and position measurement) can be transparent to the fact that the signal comes from the repeater. The transmitter used in the repeater is cheaper than the entire WAPS beacon because it does not need to have a GNSS timing unit to extract GNSS timing.

Depending on the mode of operation of the receiver unit, terminal-based or network-based positioning is provided by the system. In terminal-based positioning, the receiver unit calculates the user's location on the receiver itself. This is useful in applications such as turn-by-turn directions and geo-fencing. In network-based positioning, the receiver unit can receive a signal from the tower and transmit the received signal to the server to calculate the user's location. This is useful in applications such as E911 by a centralized server, asset tracking and management. Location calculations at the server can be done in near real time, or post-processed by data from many sources (eg, GNSS, differential WAPS, etc.) to improve accuracy on the server. The WAPS receiver can also obtain information from the server (as well, for example, as a Secure User PLane server (SUPL)) to facilitate network-based positioning.

Towers of one embodiment maintain synchronization with each other autonomously or using network-based synchronization. 11 illustrates tower synchronization according to one embodiment. The following parameters are used when describing aspects of synchronization:

System transmitter time = t _WAPS-tx

Absolute time base = t _{WAPS_abs}

Vision adjustment = Δ _system = t _WAPS-tx -t _{WAPS_abs}

It is not necessary to synchronize the WAPS system time on an absolute time basis. However, all WAPS transmitters are synchronized to one common WAPS system time (ie, relative timing synchronization of all WAPS transmitters). The timing correction of each transmitter relative to the WAPS system time should be calculated (if any). Timing correction should be made available to the receiver, either directly over the air WAPS auxiliary transmission or indirectly through some other communication means. Assistance from a system (e.g., Iridium or digital TV or MediaFlo or a broadcast channel of a cellular system) to a WAPS receiver via a cellular (or other) modem or via broadcast data Data can be transferred. Alternatively, timing corrections can be sent to the server and used to calculate a location at the server. Following is a description of tower synchronization according to one embodiment.

According to network-based synchronization, towers in one local area are synchronized with each other. Synchronization between towers is generally the transmission of pulses (which can be modulated using any form of modulation over the carrier and / or spreading with spreading codes for better time resolution to modulate the carrier) and pulse edges at the receiver. Synchronization to furnace, which is described in detail herein.

In an autonomous synchronization mode of one embodiment, the towers are synchronized using local timing criteria. The timing criteria can be one of the following: a GPS receiver, a high-accuracy clock source (e.g., atomic time), a local time source (e.g., a GPS disciplined clock), and any of a reliable clock source. Other networks. Signals from precisely time-synchronized XM satellite radio, LORAN, eLORAN, TV signals can be used as a rough timing reference for the tower. In one embodiment, for example, FIG. 12 is used to train an accurate / stable timing source according to one embodiment, such as rubidium, cesium, or hydrogen master. Is a block diagram of a PPS pulse source from a GPS receiver. Alternatively, a GPS trained rubidium clock oscillator can be used as shown in FIG. 13.

Referring to FIG. 12, a sufficiently large number (e.g., 0.5 to 2 hours) in which the PLL's time constant at the correct clock source provides better short-term stability (or equivalently, filtering of short-term GPS PPS variations). And GPS-PPS provides long-term stability and wider 'coarse' synchronization. The transmitter system continuously monitors these two PSS pulses (from the GPS unit and the correct clock source) and reports any anomaly. The above is that after two PPS sources are locked for several hours, one of the PPS sources deviates from the remaining sources by a specific time-threshold determined by the tower network manager. A third local clock source can be used to detect anomalies. In case of anomalous behavior, a PPS signal showing correct behavior is selected by the transmitter system and reported back to the monitoring station. In addition, an instantaneous time difference between the PPS input and the PPS output of the correct time source (as reported by the time source) can be sent to the server for use when broadcast or post-processed by the transmitter.

In the transmitter system, the time difference between the rising edge of the PPS pulse input and the rising edge of the signal that allows the analog section of the transmitter to transmit data is measured using an internally generated high speed clock. 14 shows a signal diagram for counting the time difference between a signal that allows an analog section of a PPS and a transmitter to transmit data, according to one embodiment. The count representing the time difference is transmitted to each of the receivers as part of the data stream. By using a highly stable clock reference, such as a rubidium clock (the clock is stable for hours / days), the system makes this correction per tower on the device only if the device can no longer modulate specific tower data. Can be saved / sent. Also, this correction data, if available, can be transmitted to the device via a communication medium. Correction data from the tower can be monitored by a reference receiver or by a receiver mounted on a tower listening to broadcasts from other towers, and can be conveyed to a centralized server. The tower can also periodically send this count information to a centralized server, which then spreads this information to devices in the vicinity of these towers via a communication link to the device. Alternatively, the server may pass information from the tower (eg, within the locale) to the neighboring tower, which can be broadcast as auxiliary information for neighboring towers. Auxiliary information for neighboring towers may include location for neighboring towers (because the tower is static), and timing correction information.

Similar to transmitter timing correction in one embodiment, it can be used to estimate multipath bias and precise true range when true PPS is available. The receiver estimates the range using, for example, a sample of the signal from the ADC. The receiver of one embodiment uses a high speed clock to determine the difference between the appearance of the PPS and the first edge of the sample ADC clock. This allows the range estimated by the receiver based on the ADC sample to be corrected for the difference between when true PPS occurs and when the ADC samples the data, thus estimating the receiver's true range with greater precision than the ADC's sample clock resolution. It becomes possible to do. In the context of the description in the paragraph above, PPS refers to pulses with edges that are aligned with or known as a standard timing base (eg, GPS pulse-per-second (PPS) timing).

In another embodiment, a wide area differential positioning system can be used to correct timing errors from the tower. 15 is a block diagram of a differential WAPS system according to one embodiment. A reference receiver (located where previously investigated) is used to receive signals from all nearby towers. Although the principle of differential GPS is applied in this method, handling the effect of non-line-of-sight in the ground case makes this method special. The reference receiver's pseudorange (code phase) measurements for each tower are time-tagged and transmitted to the server. The received code phase-based range measured at the reference receiver for towers j and i can be written as:

는 타워 j의 지오메트릭 레인지(geometric range)를 송신하기 위한 기준 수신기이며,

및

는 각각, 공통 기준 시(즉, GPS 시)에 대한 그들 각자의 안테나를 지칭하는 기준 수신기 및 송신기 클록 오프셋이고,

는 빛의 속도이고,

는 측정 노이즈이다. here,

Is a reference receiver for transmitting the geometric range of tower j,

And

Is a reference receiver and transmitter clock offset, each referring to their respective antenna relative to a common reference time (ie GPS time),

Is the speed of light,

Is the measurement noise.

가 서버에서 계산된다. 이는 로버/모바일 스테이션(rover/mobile station) 측정치에서 송신기들 간의 타이밍 차이를 제거하는 것을 가능하게 한다. 송신 타워에서 사용되는 클록이 비교적 안정할 때, 시간차

의 더 우수한(가령, 노이즈이 적은) 추정치를 얻기 위해 시간의 흐름에 따른 평균내기가 사용될 수 있다. The difference in clock timing between towers i and j by subtracting the above two equations and using a known geometric range from the reference receiver to the transmission tower,

Is calculated on the server. This makes it possible to eliminate timing differences between transmitters in the rover / mobile station measurements. Time difference when the clock used in the transmission tower is relatively stable

Averaging over time can be used to obtain a better (eg, less noise) estimate of.

The rover / mobile station's pseudorange measurements are also time-tagged and sent to the server. The received code phase based range measured at the rover / mobile station can be written as:

By subtracting and rearranging the above two equations, the result is

이다.

to be.

및

가 측정량이고, 양

은 기준 수신기 측정치로부터 계산된다.

및

각각은 수신기의 알려지지 않은 좌표와 송신 타워 i 및 j의 알려진 좌표에 대해 써질 수 있다. 3개의 레인지 측정치를 이용해, 앞서와 같이 2개의 레인지 차이 수학식이 형성되어 2차원 위치 해법을 얻거나, 4개의 레인지 측정치를 이용해, 3개의 레인지 차이 수학식이 형성되어 3-차원 위치를 얻을 수 있다. 추가 측정치를 이용할 때, 노이즈량의

및

의 효과를 최소화하기 위해, 최소 제곱 해법이 사용될 수 있다.

And

Is the measurand, quantity

Is calculated from the reference receiver measurements.

And

Each can be written for the unknown coordinates of the receiver and the known coordinates of the transmission towers i and j. Using three range measurements, two range difference equations are formed as described above to obtain a two-dimensional position solution, or four range measurements are used to form three range difference equations to obtain a three-dimensional position. When using additional measurements,

And

In order to minimize the effect of the least squares solution can be used.

Alternatively, a timing difference correction can be sent back to the mobile station to correct the error in-situ and facilitate position calculation at the mobile station. Differential correction can be applied to as many transmitters as seen by both the reference and mobile stations. Conceptually, with this method, the system can operate without tower synchronization, or correct any residual clock error in a loosely synchronized system.

Another approach is a standalone timing approach as opposed to the differential approach mentioned above. One way to establish timing synchronization is to have a GPS timing receiver at each transmit tower in a specified area receive DGPS corrections from a DGPS reference receiver in the same area. A DGPS reference receiver installed at a known location considers its own clock as the reference clock and finds corrections to pseudorange measurements up to the GPS satellites it tracks. In general, DGPS correction for specific GPS satellites includes total error and clock error due to satellite location and iono- and convective delay. This total error will be the same for any pseudorange measurements made by other GPS receivers that are neighbors of the DGPS reference receiver (usually in an area of about 100 km radius where the DGPS receiver is centered), because the DGPS reference receiver This is because the direction of the line of sight between and GPS satellites does not change significantly within this neighborhood. Accordingly, a GPS receiver using DGPS correction transmitted by a DGPS reference receiver for a specific GPS satellite can use correction to remove this total error from its pseudorange measurements for the satellite. In the process, however, the clock bias of the DGPS reference receiver for GPS time will be added to its pseudorange measurements. However, since this clock bias is common to all DGPS pseudorange corrections, the effect on timing solutions of different GPS receivers will be a common bias. However, this common bias does not give any relative timing error to the timing of different GPS receivers. In particular, if these GPS receivers are timing GPS receivers (at known locations), they are all synchronized to the clock of the DGPS reference receiver. When these GPS timing receivers drive different transmitters, the transmissions are also synchronized.

Instead of using correction from a DGPS reference receiver, a similar correction transmitted by a Wide Area Augmentation System (WAAS) can be used by the GPS timing receiver to synchronize the transmissions of their driving transmitter. The advantage of WAAS is that the reference time is not that of the DGPS reference system, but the GPS time itself maintained by setting the correct atomic clock.

Another approach to achieving accurate time synchronization between towers across a wide area is to use a time transfer technique to establish timing between pairs of towers. One technique that can be applied is called "common view time transfer". 16 shows a common view time transmission according to one embodiment. A GPS receiver in the transmitter with a common satellite view is used for this purpose. Code phase and / or carrier phase measurements for satellites within their common view, from each of the towers, are time tagged by the GPS receiver periodically (eg, at least once every second), and these measurements Is sent to the server being analyzed.

(위성 "i"에 의해 발산되고 수신기 "p"에 의해 관측되는 신호)는 다음과 같이 써질 수 있다:GPS code observable

(The signal emitted by satellite "i" and observed by receiver "p") can be written as:

는

와 동일한 수신기-위성 지오메트릭 레인지(geometric range)이고,

는 신호 수신 시점에서의 수신기 안테나 위치이며,

는 신호 발산 시점에서의 위성 위치를 나타내고,

및

각각은 전리층 딜레이와 대류층 딜레이고,

및

는 수신기 및 위성 하드웨어 그룹 딜레이이다. 변수는 안테나, 안테나를 수신기로 연결하는 케이블, 및 수신기 장체 내에서의 딜레이가 미치는 영향을 포함한다. 덧붙여,

및

는 각각 GPS 시에 대한 수신기 및 위성 클록 오프셋이며, c는 빛의 속도이고,

는 측정 노이즈이다. 공통 뷰 시각 전송 방법(common view time transfer method)은 단일 차분(single difference) 코드 관측치

를 다음과 같이 계산하며, 이는 2개의 수신기(이른바 "p" 및 "q")에서 동시에 측정된 코드 관측치 간 차이이다:here,

The

Equal to the receiver-satellite geometric range,

Is the position of the receiver antenna at the time of signal reception,

Indicates the satellite position at the time of signal emission,

And

Each is an ionosphere delay and a convective delay,

And

Is a receiver and satellite hardware group delay. The parameters include the antenna, the cable connecting the antenna to the receiver, and the effect of the delay in the receiver cabinet. Incidentally,

And

Is the receiver and satellite clock offset for GPS time, c is the speed of light,

Is the measurement noise. The common view time transfer method is a single difference code observation.

Is calculated as follows, which is the difference between the code observations measured simultaneously on two receivers (so-called "p" and "q"):

단일 차분 관측치를 계산할 때, 위성에서의 그룹 딜레이뿐 아니라 위성의 클록 오류까지 상쇄된다. 또한 상기의 수학식에서, 대류층 및 전리층 교란요인(perturbation)이 상쇄된다(또는, 예를 들어, 수신기 이격거리가 큰 경우 모델링될 수 있다). 수신기들 간 그룹 딜레이 차이가 교정되면, 수신기 클록들 간 바람직한 시각 차분(time difference)

가 상기 수학식으로부터 발견될 수 있다. 추정된 시각 차분의 품질을 추가로 개선하기 위해 복수의 시각 간 신호 차이 및 위성 측정치가 조합될 수 있다.

When calculating a single difference observation, not only the group delay at the satellite, but also the clock error of the satellite is canceled out. Also in the above equation, the convective and ionosphere perturbation is canceled (or can be modeled, for example, if the receiver separation distance is large). Once the group delay difference between receivers is corrected, the desired time difference between the receiver clocks

Can be found from the above equation. Signal differences and satellite measurements between a plurality of times may be combined to further improve the quality of the estimated time difference.

In a similar manner, the single differential carrier phase equation for common view time transmission is

Can be written as

Since there is an initial phase ambiguity and an integer ambiguity in the above equation, a phase single difference cannot be used to directly determine time transfer. By combining-using code and phase observations, advantages can be taken for absolute information about the time difference between codes and precision information about the progress of the time difference from the carrier phase. The error variance of the carrier phase single difference is better than that of the code phase single difference, leading to good time transfer tracking.

The final error per tower for a particular satellite is sent back to the tower for correction and sent to the receiver via a communication link for further correction to be made to the tower and made by the receiver, or any other timing correction from the tower. It can be transmitted as an included broadcast message. In certain cases, measurements from towers and receivers can be post-processed for better location accuracy at the server. Single channel GPS timing receiver or multiple channel timing receiver to generate C / A code measurements and / or L1 and / or L2 or other satellite systems, such as carrier satellite measurements from Galileo / Glonass Can be used for this common view time transmission purpose. In a multi-channel system, information from multiple satellites in a common view is captured simultaneously by the receiver.

An alternative mechanism in “common view visual transmission” is that different timing GPS receivers in the local area (each supplying their corresponding receivers) use only common satellites in their timing pulse origin (eg, one pulse per second), but GPS ( Or UTC) seconds to ensure that no attempt was made to correct the timing pulse. The use of common-view satellites indicates that common errors in timing pulses (e.g., common GPS satellite position and clock errors and iono- and convective-delay compensation errors) result in timing pulse errors of the same magnitude and relative errors in timing pulses are reduced. Is guaranteed. In positioning, no server-based tie error correction is required, since only relative timing errors are an issue. However, the server can issue commands to different GPS receivers as to which GPS satellite will be used when extracting the timing pulse.

와 타워 j에서의

간 관계, 및 i의 클록과 j의 클록 간 시각 차분

는 An alternative method of time transmission is the "two way time transmission" technique. 17 illustrates two-way time transmission according to one embodiment. Two towers used to timing each other are contemplated. The transmitter PPS pulse from each of the two transmitters starts and a time interval counter is started in the receiving section of the transmission tower (WAPS receiver). The received signal is used to stop the time interval counter at either side. The results from the time interval counter are transmitted over the data modem link to the WAPS server, where these results are compared with the transmission time and timing errors between the two towers can be calculated. It can then be extended to any number of towers. In this way, counter measurements at tower i

And at tower j

Relationship, and time difference between clock of i and clock of j

The

및

는 타워의 송신기 딜레이이고,

및

는 타워의 수신기 딜레이이다. 송신기 및 수신기 딜레이가 교정되면 시각 차분이 추정될 수 있다. Can appear as, where,

And

Is the transmitter delay of the tower,

And

Is the receiver delay of the tower. When the transmitter and receiver delays are corrected, the visual difference can be estimated.

In addition to the time transmission between towers, the timing of the tower relative to the GPS time can be discovered by the GPS timing receiver used in the common view time transmission.

에 대한 로컬 클록의 시각 정정이 계산된다. 그룹 딜레이의 측정치에 의해 수신기의 딜레이

가 교정될 수 있다. (복조를 통해서 또는 서버로부터 얻어진) GPS 위성 항법 메시지가,

및

의 영향을 제거하는 위성 타이밍 정정을 계산하도록 사용될 수 있다. 마찬가지로, 외부 모델로부터의 정정을 이용해 대류층 및 전리층 딜레이 영향이 최소화된다. 예를 들어, 전리층 정정은 WAAS 메시지로부터 획득될 수 있다. 대안적으로, 클록 및 전리층/대류층 정정의 조합은, 이용가능할 때 의사레인지(pseudorange)에 대한 RTCM DGPS 정정으로부터 획득될 수 있다. GPS time after taking into account the delay of the receiver, satellite clock error and ionosphere / convection layer error using the same range measurement

The time correction of the local clock for is calculated. Delay of the receiver by the measurement of the group delay

Can be corrected. GPS satellite navigation messages (obtained via demodulation or from the server),

And

It can be used to calculate satellite timing correction to eliminate the effects of. Likewise, the effects of convective and ionosphere delays are minimized using corrections from external models. For example, ionosphere correction can be obtained from a WAAS message. Alternatively, a combination of clock and ionosphere / convection layer correction can be obtained from RTCM DGPS correction for pseudorange when available.

Also, an offset to GPS time can be transmitted as part of the data stream from the tower. This activates any WAPS receiver that has acquired a WAPS signal to provide accurate GPS time and frequency that helps to significantly reduce the GNSS search requirement at the GNSS receiver.

In one embodiment of the system, a broadcast transmitter can be used as an ad hoc to provide local indoor location determination. For example, in fire-safety applications, a WAPS transmitter will be located on three or more broadcast stations (eg, firefighting stations). The towers will be synchronized with each other by a broadcast signal with one of the many means described above. Bandwidth and chipping rates will be scaled based on spectral availability and accuracy requirements over a specified area, specific application, and specific time point. The receiver will be informed of the system parameters via the communication link to the device.

18 is a block diagram of a receiver unit according to an embodiment. The beacon signal is received, demodulated, unloaded and fed to the positioning engine at the antenna on the receiver unit. The receiver provides all the information to accurately reconstruct the signal. The receiving antenna may be one omni-directional antenna, or a plurality of antennas / arrays providing diversity. In another embodiment, mixing and down conversion may be performed in the digital domain. Each receiver unit contains or uses a unique hardware identification number and a computer-generated private key. Each receiver unit generally stores the last few locations in a non-volatile memory, and can query remotely for the last few stored locations later. Based on the availability of spectrum in a specified area, transmitters and receivers can adapt to available bandwidth and change chipping rate and filter bandwidth for better accuracy and multipath resolution.

In one embodiment, digital baseband processing of the received signal is accomplished using a commercialized GPS receiver by multiplexing / supplying signals from the GPS RF section by the WAPS RF module. 19 is a block diagram of a receiver of a WAPS RF module according to an embodiment. The RF module includes one or more low noise amplifiers (LNAs), filters, down-converters, and analog-to-digital converters. In addition to these components, the signal can be further conditioned to meet the input requirements of the GPS receiver using additional processing on a chip or custom ASIC or FPGA or DSP or microprocessor. Signal conditioning is digital filtering for in-band or out-of-band noise (eg ACI-adjacent channel interference), translating the input from the frequency of the WAPS receiver to the GPS IC ), Intermediate or baseband frequency, digital signal strength adjustment that allows the GPS IC to process WAPS signals, and automatic gain control (AGC) algorithm to control the WAPS front end. In particular, frequency translation is a very useful feature that allows the WAPS RF module to work with any commercially available GPS receiver. In another embodiment, the entire RF pro-end chain, including the signal conditioning circuitry for the WAPS system, can be integrated onto the existing GPS die including the GPS RF chain.

In another embodiment, if access to the digital baseband input is not available, the signal can be up-converted / down-converted to the GPS band in any open area and fed to the RF section of the GPS receiver. 20 illustrates signal up-conversion and / or down-conversion according to one embodiment.

In yet another embodiment, multiple RF chains or tunable RF chains can be added to both the transmitter and receiver of the WAPS system, allowing the use of a more effective frequency of operation in a specific area, whether wide or local. The choice of frequency can be determined by the cleanliness of the spectrum, propagation requirements, and the like.

Likewise, WAPS can temporarily use a receive chain in a receiver system that includes multiple receive chains. For example, a wideband CDMA (W-CDMA) receiver system includes two receive chains to improve receive diversity. Thus, when WAPS is used in a W-CDMA receiver system, one of the two native receive chains of W-CDMA can be temporarily used to receive and process WAPS signals. 21 is a block diagram of a receiver system with a plurality of receive chains where one of the receive chains according to one embodiment may be temporarily used to receive and process WAPS signals. In this example, a diversity receive chain can be used to temporarily receive and process WAPS signals. Alternatively, a GPS receive chain can be used to temporarily receive and process WAPS signals.

A radio front-end can be shared between WAPS and another applicator. Some parts of the frontend can be shared, and some can be used mutually exclusively. For example, if the die / system already has a TV (NTSC or ATSC or DVB-H, MediaFLO, etc.) tuner front end that includes an antenna, the TV tuner radio and antenna can be shared with the WAPS system. They can operate mutually exclusive in that either system receives a TV signal or a WAPS signal at any particular point in time. In another embodiment, if it is easy to add a WAPS RF section to such a system, the antenna can be shared between the TV tour and the WAP system, allowing both systems to operate simultaneously. If the system / die has a radio such as an FM radio, the RF-front-end can be modified to accommodate both WAPS systems and FM radios, and these radios can operate mutually exclusively. Similar modifications can be made to systems with some RF front end at frequencies close to the WAPS RF band.

The clock source reference used in GNSS sub-systems such as crystal, crystal oscillator (XO), voltage controlled temperature compensated crystal oscillator (VCTCXO), digital-controlled crystal oscillator (DCXO), and temperature compensated crystal oscillator (TCXO) is based on the WAPS receiver and It can be shared to provide a reference clock to the WAPS receiver. This sharing can be done on the die or off-chip. Alternatively, the TCXO / VCTCXO used by any other system on the cellular phone can be shared with the WAPS system. 22 is a block diagram illustrating clock sharing in a positioning system, in an embodiment. The transceiver or processor system block may refer to various systems. The transceiver system that shares the clock with the WAPS system can be a modem transceiver (eg, cellular or WLAN or BT modem) or a receiver (eg, GNSS, FM or DTV receiver). These transceiver systems can selectively control VCTCXO or DCXO for frequency control. Note that the transceiver system and the WAPS system can be integrated into a single die or can be separate die and not affect clock sharing. The processor can be any CPU system using a clock source (eg, ARM sub-system, digital signal processor system). In general, when VCTCXO / DCXO is shared, the frequency correction applied by other systems can be delayed as much as possible to facilitate WAPS operation. Specifically, frequency updates within the maximum integration time used for WAPS receivers can be limited to enabling better performance (ie minimizing SNR loss) for WAPS receivers. Information about the state of the WAPS receiver (specifically, the level of integration used, the acquisition and tracking state of the WAPS system) can be exchanged with other systems for better control of frequency updates. For example, the frequency update can be stopped during the WAPS acquisition phase, or the frequency update can be scheduled when the WAPS receiver is in a sleep state. The communication may be in the form of a control signal, or alternatively, in the form of a message exchanged between the transceiver system and the WAPS system.

WAPS broadcasts broadcast signals and messages from the tower, so the baseband hardware of a conventional GPS receiver need not be modified to support both WAPS and conventional GPS systems. The importance of this is that although the WAPS system has only half the available bandwidth (which affects the chip rate) of the GPS C / A system, the WAPS broadcast signal is within the bounds of a commercial grade C / A code GPS receiver. It is configured to work on. Moreover, the algorithm will determine whether a GPS signal should be used or a WAPS signal or a combination of them to obtain the most accurate location based on signal availability.

Data transmitted from the top of the gold code on the WAPS system can be used to send assistance information for the GNSS in the case of a hybrid GNSS-WAPS usability scenario. This ancillary data may be in the form of SV orbit parameters (eg, ephemeris and almanac). In addition, the assist can be specialized in the SV visible in the local area.

In addition, timing information obtained from the WAPS system can be used as a fine time to support the GNSS system. Because the WAOS system timing is aligned in GPS (or GNSS) time, aligning the code and bits of the WAPS signal and reading the data stream from any tower provides coarse knowledge of GNSS time. In addition, the location solution (the clock bias of the receiver is a by-product of the location solution) accurately determines the WAPS system time. Once the WAPS system time is known, the supported precision time can be provided to the GNSS receiver. Timing information can be transmitted using a single hardware signal pulse with the edge bound to the internal visual base of the WAPS. Note that the WAPS system time is mapped directly on the GPS time (more generally, the time base of the GNSS system is directly related to the GNSS time). Upon receiving this edge, the GNSS can latch its internal GNSS time base coefficient. Alternatively, the GNSS system can generate pulses, the edges of which are aligned to the internal time base, and the WAPS system should be able to latch its internal WAPS tie base. The WAPS receiver can then send a message with this information to the GNSS receiver and have the GNss receiver map the time base to the WAPS time base.

Likewise, frequency estimation for the local clock can be used to provide frequency support for the GNSS receiver. Note that the frequency estimation from the WAPS receiver can be used to refine the frequency estimation of the GNSS receiver regardless of whether they share a common clock. When the two receivers have separate clocks, additional calibration hardware or software blocks are required to measure the clock frequency of one system relative to another. The hardware or software block can be in the WAPS receiver section or the GNSS receiver section. Then, frequency estimation from the WAPS receiver can be used to refine the frequency estimation of the GNSS receiver.

In addition, information that can be sent from the WAPS system to the GNSS system may include estimation of the location. The estimation of the location can be approximated (eg, determined by the PN code of the WAPS tower) or more accurately approximated based on the actual location estimation in the WAPS system. The possible location estimation from the WAPS system, combined with another estimate of the location from other systems (eg, macroscopic location estimation from cellular ID based positioning), can be used to better support the GNSS system. You can provide an estimate. 23 is a block diagram of the transmission of ancillary data from a WAPS to a GNSS receiver in an embodiment.

In addition, the GNSS receiver is used to improve the performance of the WAPS receiver in terms of time-to-first-fix (TTFF), sensitivity, and location quality by providing location, frequency, and GNSS time estimates to the WAPS receiver. It can help. For example, FIG. 24 is a block diagram illustrating transmission of support information from a GNSS receiver to a WAPS receiver in an embodiment. The GNSS system can be replaced with a LORN, e-LORN or similar terrestrial positioning system. The position estimate can be partial (eg, altitude or 2-D position), or complete (eg, 3-D position) or raw range / pseudo-range data. Range / pseudo range data is provided along with the position of the SV (or a means for calculating the position of the SV, such as SV trajectory parameters) to enable the use of this range information in a hybrid solution. Positioning support information is provided along with a metric indicating its quality. When providing GNSS time information (which can be sent to the WAPS system using a hardware signal), the offset (if any) of the GNSS time to GPS time is provided to activate the use of the WAPS receiver. The frequency estimate is provided as an estimate of the clock frequency along a confidence metric (eg, indicating the estimated quality that estimates the maximum expected error of the estimate). When the GNSS system and WAPS system share the same clock source, this is enough. When the GNSS system and the WAPS system use separate clocks, the GNSS clock is also provided to the WAPS system so that the WAPS system is calibrated (i.e., an estimate of the relative clock bias of the WAPS relative to the GNSS clock) or, alternatively, the WAPS system The clock is provided to the GNSS system, and the GNSS system provides a calibration estimate (ie, an estimate of the clock bias relative to the WAPS relative to the GNSS clock).

To improve the sensitivity and TTFF of the WAPS receiver, auxiliary information (such as others decoded from the information transmitted by the tower) can be provided to the WAPS receiver from the WAPS server by different communication media (cellular phones, WiFi, SMS, etc.). Can be. While "almanac" information is already available, the work of the WAPS receiver is simplified because the receiver only needs time to align with the transmit waveform (without the requirement of bit alignment or decoding). Eliminating the need to decode data bits reduces TTFF, thus reducing power because the receiver does not need to supply voltage to decode all bits in succession. 25 is an example configuration in which, in an embodiment, WAPS assistance information is provided from a WAPS server.

Beacons can be added to the receiver to further improve local positioning. The beacon may include a low power RF transmitter that periodically transmits a waveform with a signature based on the device ID. For example, the signature can be a code that uniquely identifies the transmitter. The associated receiver will be able to locate the transmitter with higher accuracy through signal energy peak detection, such as scanning in all directions, or direction detection (using signals from multiple antenna elements to determine the direction of signal arrival). .

Resolution of multipath signals

Multipath resolution is important in positioning systems. The wireless channel is often characterized by a series of randomly varying multipath components with arbitrary phases and amplitudes. For accurate positioning, it is essential for the receiver algorithm to decompose the visible line (LOS) path (which will be the first arrival path), or to decompose the first arrival path (which is not necessarily an LOS component). Often, the conventional method is implemented as follows. (1) The received signal is correlated with the transmitted pseudo-random sequence (eg, gold code sequence, which is known at the receiver), and (2) the receiver finds the first peak of the resulting cross-correlation function, and the first It is assumed that the timing of the arrival route is the same as the timing indicated by the position of this peak. These methods work efficiently only when the lowest multipath separation is much longer than the inverse of the available bandwidth, but this is not often the case. Bandwidth is valuable, and a method that can resolve multipaths with minimal bandwidth is very desirable for improving the efficiency of the system.

Depending on the channel environment (including multipath and signal strength), an appropriate method of obtaining an estimate of the earliest arrival path is used. For the highest resolution, a higher resolution method is used, while for a reasonable performance at low SNR, a more conventional method is applied that directly uses a correlation peak sample and some characteristic of the correlation function around the peak.

으로 주어진 속도 f_s에서 샘플링된 양자화된 수신 신호 y[n]를 상정하라. 여기서, y[n]은 전송된 의사-랜덤 시퀀스 x[n]과 유효 채널

의 콘볼루션인 수신된 신호이고, h _tx [n]은 송신 필터이며, h _rx [n]는 수신 필터이고, h[n]은 다중경로 채널이다.

Suppose a quantized received signal y [n] sampled at a given rate f _s . Where y [n] is the transmitted pseudo-random sequence x [n] and the effective channel

Is a received signal that is a convolution of, h _tx [n] is a transmit filter, h _rx [n] is a receive filter, and h [n] is a multipath channel.

One way to find the peak position is by peak interpolation, using values around the apparent peak position. Interpolation can be quadratic using one value on either side of the peak, high-dimensional polynomial using two or more samples around the peak, or using a best fit for the actual pulse shape. In the case of quadratic interpolation, the quadratic is fitted to the peak value and the values immediately around the peak. The secondary peak determines the peak position used to determine the range. The method is very robust and performs very well at low SNR.

Alternate embodiments may use values other than the peak position as the reference position. Note that the DLL uses the peak position as a reference position in the correlation function, while the method uses a point different from the peak. The method is motivated by the fact that the early edge of the correlation peak is less affected by multipath than the trailing edge. For example, 75% point of the chip Tc from the peak on the uncorrugated (no channel effect) correlation function can be used as a reference point. In this case, the potion of the interpolated z [n] function matching this 75% point is selected, and the peak is dropped 25% of Tc from this point. A method based on another alternative peak correlation function can use the peak shape (such as measuring the peak's circumference, such as peak width). Starting at the peak location and based on the shape of the peak, corrections for the peak location are determined to estimate the earliest arrival path.

The high resolution method is a kind of effective multipath-resolving method that uses Eigen-space decomposition to find a multipath configuration. Methods like MUSIC and ESPIRIT are decomposition schemes of this kind. These are very powerful schemes with respect to the configuration of spaced multipaths, because they can resolve much more effectively than conventional methods, given the same bandwidth. High resolution of arrival method The earliest time attempts to estimate the arrival time of the earliest route directly instead of inferring the peak position from the peak value. The following assumes that the coarse-acquitsiton of the transmitted signal is already available at the receiver, and the start of the pseudo-random sequence is roughly known at the receiver.

26 is a flowchart for estimating the earliest arrival route at h [n], in an embodiment. The method for determining the earliest route includes, but is not limited to, operations described below.

로 기재된다. 이 수학식은

로 다시 기재될 수 있다. 여기서,

는 의사-랜덤 시퀀스의 자기상관 함수(autocorrelation function)이다.1. To obtain the result z [n], the received sample y [n] is cross-correlated with the transmission sequence x [n]. When cross-correlation is described as convolution,

It is described as. This equation

It can be written again. here,

Is the autocorrelation function of the pseudo-random sequence.

2. Find the first peak of z [n] and denote it as n _peak . The left side of the peak of z [n] is extracted with the wL sample and the right side of the peak of z [n] with the wR sample, and this vector is expressed as pV.

의 피크의 왼쪽과 오른쪽 각각에 존재하도록 선택하는 것이다. wL과 wR의 선택에서 또 다른 생각은 충분히 상관되지 않은 노이즈 샘플을 선택하여 노이즈 서브공간(noise sub-space)과 관련하여 충분한 정보를 얻는 것이다. 또한, 정수 wL과 wR은 모든 가능한 다중경로 구성, 특히 파-아웃(far-out) 다중경로 구성을 분해하는데 도움을 주는 왼쪽 사이드(즉, wL을 선택하여)를 포함하기 위하여 선택되어야 한다. f_sT_c 이상의 너무 많은 샘플을 포함하는 것은 pV 벡터에 도입된 노이즈의 양을 증가시켜서 축소시켜야한다. 시뮬레이션과 실험을 통하여 wL과 wR에 대한 종래세트의 값은 각각 3f_sT_c 와 3f_sT_c 이다. z[n](및 그 다음에 pV)가 채널 효과 h[n], 송신 필터 h_tx[n], 수신 필터 h_rx[n] 및 의사-랜덤 시퀀스의 자기상관 함수

를 포함한다는 것을 주목하라. 채널에서 가장 이른 도착 경로를 추정하기 위하여, 다른 효과는 제거될 필요가 있다. 많은 경우에, 송신 및 수신 펄스-모양은 최고의 노이즈 성능을 위해 매치되나, 이 알고리즘이 작동하기에 제한이 요구되지는 않는다. 기준 상관 함수는

와 같이 정의되고, 이는 추정될 필요가 있고, pV가 가장 이른 도착 경로의 추정을 위해 사용되기 전에 제거된다.The vector pV represents a useful part of the cross-correlation result z [n]. In the ideal case, when there is no channel distortion and channel BW is not limited, selecting wL = wR = f _s T _c will be sufficient to determine the timing of the received signal. In the presence of limited BW, when the pseudo-random code x [n] is a sequence of + 1 / -1, the best way to select wL and wR is to set them to non-zero values (or generally as part of the peak value). Any set threshold is greater than the selected one)

Is to choose to exist on each of the left and right sides of the peak. Another idea in the selection of wL and wR is to select enough noise samples to get enough information about the noise sub-space. In addition, the integers wL and wR should be selected to include all possible multipath configurations, especially the left side (ie, by choosing wL) to help decompose the far-out multipath configuration. Including too many samples above f _s T _c should be reduced by increasing the amount of noise introduced into the pV vector. Through simulation and experiment, the values of the conventional set for wL and wR are 3f _s T _c and 3f _s T _c, respectively. z [n] (and then pV) is the channel effect h [n], transmit filter h _tx [n], receive filter h _rx [n] and auto-correlation function of pseudo-random sequence

Note that it includes. In order to estimate the earliest arrival route in the channel, other effects need to be removed. In many cases, the transmit and receive pulse-shapes are matched for best noise performance, but there are no restrictions required for this algorithm to work. The reference correlation function

It is defined as, which needs to be estimated, and is removed before pV is used for estimation of the earliest arrival path.

가 이후에 추정된다.3. Reference correlation function

Is estimated after.

의 유용한 샘플을 포함한다. 도 27은 실시예에서, 기준 상관 함수를 추정하기 위한 흐름도이다.One way to obtain a reference cross-correlation is as follows. Perform steps 1-2 on the 'abnormal' channel (so-called "cable link") to get the corresponding peak vector pV _Ref . The peak vector pV _Ref is the reference correlation function

Contains useful samples. 27 is a flowchart for estimating a reference correlation function in an embodiment.

The "cable link" method sends a modulated signal from the transmitter front-end (power-amplifier and transmitting antenna passing) to the receiver front-end (passing the receiving antenna) through the 'abnormal' channel (eg cable). Steps. Note that the 'abnormal' channel may have some delay or attenuation, but other distortions should not be added and have a high SNR. For best performance, 'cable' criteria need to be generated separately for each pseudo-random sequence since they have different criteria because they have different correlation functions. It is also important to select the appropriate PRN for the best autocorrelation function (specifically, their proximity at the autocorrelation side-lobe should be very suppressed relative to the peak), which is an autocorrelation sidelobe. If is not sufficiently attenuated, mistakes will occur for multipaths, which will result in optimal overall performance of the timing-resolving method.

Assuming that the transmit filter response is controlled, one calibration of the response to the cable link will be required per receiver in production. If the receiver filter feature is controlled (eg, a large number of receivers), the calibration on the response's cable link can be further reduced to one calibration measurement for the receiver set.

를 결정하기 위한 대안적인 방법은 각각의 구성

, htx[n] 및 hrx[n]을 분석적으로 계산하고, 이들을 콘볼루션하여 기준 상관 함수

에 도달한다. 이 방법은 송신 및 수신 필터 임펄스 응답이 실제 실행에서 제어될 수 있는 한도에 의존한다.Reference correlation function

Alternative methods for determining

, htx [n] and hrx [n] are analytically calculated, and convoluted them to a reference correlation function

To reach This method relies on the limits that the transmit and receive filter impulse responses can be controlled in actual execution.

4. Improves SNR by continuing averaging across multiple gold codes and even multiple bits in the estimation of pV. Averaging across a plurality of bits may continue to be done after determining that individual bits are to be transmitted. In other words, decision feedback is used before integration across bits. Equivalently improved SNR can be obtained by performing averaging on the cross-correlation function estimate of step 1.

5. N _fft - calculating a padding (zero padding) and N _fft length and fast Fourier change in pV _Ref (FFT) with zero in the pV (wL + wR), the length N _fft vector pV _Freq and pV _{Ref, Freq} Each gets. The optimum value for Nfft is obtained by confirming the resolution of multipath through simulation using both synthesized and actual measured channels. The conventional value of Nfft is found in 4096 directors.

를 계산하여 채널 h[n]의 주파수 도메인 추정(노이즈으로 손상된)을 얻는다. 수신된 시퀀스 y[n]가 Nos(즉,+/-1/Tc로 대역-제한된 송신 펄스 모양에 대한

)에 의하여 오버샘프되고, 송신 및 수신 펄스-모양 필터가 완전히 BW = 1/Tc로 대역-제한된다면, 이제, H_full[k]의 DC 주위의

양성 및 음성 샘플은 실제 채널, H_real[k]의 추정에 대하여 정확히 논-제로(즉, 사용가능)이다. 우리의 연구로부터, 우리는 DC의 양 사이드 상의

샘플(여기서, α>1는 송신기, 수신기 및 자기상관 함수

에서 사용되는 실제 펄스-모양 필터에 기초하여 선택됨)은 분해 알고리즘의 최고의 성능을 위해 선택되어야 한다고 결론 지었다.

의 주파수 천이 대역을 포함하는 것은 노이즈 증가를 유발하고, α는 선택된 샘플에서 이들 주파수를 제거하는데 충분히 크게 선택된다. 그러나, α를 너무 크게 선택하는 것은 신호 정보의 손실을 유발할 것이다. 작은 초과 대역폭을 가진 올림 코사인 필터(raised cosine filter) 모양에 기초한 실제 대역-제한된 함수에 대하여, α = 1.25의 바람직한 선택이 실행에서 사용되어 왔다.6.

Calculate to obtain the frequency domain estimation (noise damaged) of channel h [n]. The received sequence y [n] is Nos (ie +/- 1 / Tc for band-limited transmit pulse shape)

), And if the transmit and receive pulse-shaped filters are completely band-limited to BW = 1 / Tc, now around DC of H _full [k]

Positive and negative samples are exactly non-zero (ie, usable) for the estimation of the _real channel, H _real [k]. From our research, we have both sides of DC

Sample (where α> 1 is the transmitter, receiver and autocorrelation function

It was concluded that the selected based on the actual pulse-shape filter used in A) should be chosen for the best performance of the decomposition algorithm.

Including the frequency shift band of causes noise increase, and α is chosen large enough to remove these frequencies from the selected sample. However, selecting α too large will cause loss of signal information. For real band-limited functions based on the shape of a raised cosine filter with a small excess bandwidth, a preferred choice of α = 1.25 has been used in practice.

7. If the DC configuration of H _full [k] is index 0, the reduced H vector, H [], is defined as follows.

8. Construct the matrix P from the reduced channel estimation vector H [k].

Here, 1 <M <2N is a parameter, and () `represents a conjugate of complex numbers.

로 정의한다. M이 너무 작게 선택되면(1에 가깝게), R의 고유값이 합계로 매우 제한되고, 그 결과, 고분해능 알고리즘은 신호와 노이즈 사이를 기술할 수 없다. M이The estimated covariance matrix R of the reduced channel estimate vector H [k] is

Is defined as If M is selected too small (close to 1), the eigenvalues of R are very limited to the sum, and as a result, a high resolution algorithm cannot describe between signal and noise. M this

If too large is selected (close to 2N), the covariance matrix estimate R is unreliable as the amount of averaging in obtaining covariance is incorrect, and the resulting covariance matrix R is rank-deficient. Accordingly, the value of M is exactly the middle of the allowed range, that is, M = N is a good choice. In addition, it was confirmed experimentally.

9. Perform a singular value decomposition (SVD) such as R = UDV` on R. Here, U is the matrix of the left singular vector, V is the matrix of the right singular vector, and D is the diagonal matrix of singular values.

10. sV = constructs a vector of classified singular values sV, such as the diagonal elements of D classified by descending order.

은 노이즈에 대응된다. 노이즈 특이값의 벡터를 sV_noise로 정의한다.11. The next important step is to separate the signal and noise subspaces. In other words, select the index ns of the vector sV and singular value

Corresponds to noise. The vector of noise singular values is defined as sV _noise .

There are several ways to separate singular values corresponding to the noise subspace and find the expression for the basis vector of the noise subspace.

보다 작은 모든 특이값(여기서, T₁은 신호 대 노이즈비(가령, 칩 상의 SNR)의 함수인 임계치, T₁ = f(SNR)).a)

All smaller singular values, where T ₁ is the threshold as a function of signal to noise ratio (eg, SNR on the chip), T ₁ = f (SNR).

28 is a flowchart for estimating a noise subspace in an embodiment.

보다 작은 모든 특이값(여기서, L은 지연-확산(가령, N/2)보다 크게 선택될 수 있는 파라미터이고, T₂는 실험적으로 결정된 또 다른 임계치이다(일반적으로 값은 1000일 수 있음).b)

All smaller singular values (where L is a parameter that can be chosen greater than the delay-diffusion (eg, N / 2), and T ₂ is another experimentally determined threshold (generally the value can be 1000).

29 is a flowchart for estimating a noise subspace in an embodiment.

Another method involves determining a noise subspace by iteratively estimating SNRs for different partitions of the noise and signal-plus-noise subspace and including another estimate of the SNR. 30 is a flow diagram for estimating a noise subspace in another alternative embodiment.

  1) The estimated calculation of SNR is as follows.

에 의해 표현된다고 가정하고, 노이즈 분산은

로 계산한다.i. Noise is

Is assumed to be, and the noise variance is

Is calculated as

으로 계산한다.ii. Signal power

Is calculated as

iii. Estimation of SNR:

  2) Alternative estimates of the SNR are obtained through different methods (eg, on-chip SNR). One way to estimate the SNR directly is as follows.

   i. The received data sample (after frequency error elimination and resampling for Tc-spaced samples and code de-correlation) is based on Xi (where Xi is the chip-spaced starting at the interpolated peak position). Is given by

로 추정된다.ii. The signal is

Is estimated as

로 추정된다.iii. Noise is

Is estimated as

로 추정된다.iv. SNR is

Is estimated as

와 같은 노이즈 특이값을 선택한다.3) satisfying the following conditions

Select a noise singular value such as.

d) Another method involves determining the noise subspace and selecting the partition n _start by iteratively estimating the SNR for different partitions of the noise and signal subspaces using c) 1). .

31 is a flow chart for estimating a noise subspace in another alternative embodiment.

 e) FIG. 32 is a flow chart for estimating noise subspace in another alternative embodiment.

를 정의한다. 그리고 나서, 첫 번째 wLen 특이 값은 유효 신호-플러스-노이즈 서브공간 또는 노이즈 서브공간 특이값을 나타낸다(특이값의 나머지는 상관된 노이즈과 신호 및 양자화 효과를 나타낸다).One)

Define Then, the first wLen singular value represents the effective signal-plus-noise subspace or noise subspace singular value (the rest of the singular value represents the correlated noise and signal and quantization effects).

  2) The estimation of SNR is calculated as follows.

에 의해 나타난다고 가정하고, 노이즈 분산은

로 계산한다.i. Noise is

Is assumed to be

Is calculated as

로 계산한다.ii. Signal power

Is calculated as

iii. Estimation of SNR:

를 정의한다. 그리고 나서, winLen까지 n_start는 노이즈 특이값을 나타낸다.

의 일반적인 값은 10이다.3)

Define Then, n _start until winLen represents the noise singular value.

The typical value of is 10.

12. To create VN, select the corresponding noise right-singular vector, that is, select all the vectors of V that correspond to the noise singular values and make the noise subspatial matrix VN.

13. Estimation of arrival time of the first route:

 a) Definition

의 값의 범위를 위한

를 계산한다. 탐색의 분해능

은 요구되는 만큼 작게 선택될 수 있다. 예로서,

와

여서, τ는 [-5, 5]의 범위에서 0.05단계로 탐색된다.b)

For a range of values for

To calculate. Search resolution

Can be selected as small as required. As an example,

Wow

Therefore, τ is searched in 0.05 steps in the range of [-5, 5].

를 제어하는 것이 가능하다. 예를 들어, 지연-확산이 크다면,

은 크게 선택될 수 있고(가령, 10), 지연-확산이 작다면,

은 작게 선택될 수 있다(가령, 4).14. The peak of Ω (τ) provides the location of the channel impulse with respect to the brief peak (n _peak ). Theoretically, the first peak will correspond to the LOS pathway. Based on information about the radio wave environment that can be encrypted in transmission from the base station,

It is possible to control. For example, if the delay-diffusion is large,

Can be largely selected (eg 10), and if the delay-diffusion is small,

Can be chosen small (eg 4).

Combination of methods:

Apart from the standalone methods discussed above, other combination methods are possible. Combining schemes based on SNR on the chip is an effective method. The following describes a list of combination schemes that can be realized in practice.

1. For a chip SNR less than the chip SNRRef, pick 12 (d) and select the noise singular value. Otherwise, select 12 (a).

2. Chip SNRRefqhek For a large chip SNR, 12 (d) is selected to select a noise singular value, and a peak position is estimated. Alternatively, a direct peak estimation technique (eg, peak interpolation, peak shape) starting from the cross-correlation function z [n] is used.

3. For the chip SNR less than the chip SNRRef, select the noise singularity value by selecting 12 (e). Otherwise, select 12 (a).

The typical value of chip SNRRef is 10dB.

Calculation of location

로 주어진다.The position of the receiver unit is determined by a positioning engine available on the terminal unit or server. The receiver can use range measurements from the system, or it can combine system range measurements with certain measurements from other signals of opportunity. A sufficient set of range measurements results in a given position fix, which is a measurement derived from a known position. In 3D space, the range equation

Is given as

The location of the transmitter is given by (x _i , y _i , z _i ), and the unknown location of the mobile unit is given by (X, Y, Z) in some local coordinate frame. Three or more transmitters produce three or more range measurements, which are used to calculate the fix. The measurement also has an additional term for receiver time bias because the receiver time is not synchronized with the WAPS timing.

과 같은 솔루션을 위해 필요한 정보를 제공한다.This equation is later referred to as "pseudo range measurement equation". Note that visual bias is common because the transmitter is timing synchronized. The pseudorange must be corrected for transmitter timing correction, which is possible from the embedded data stream in the transmission from each transmitter. This delta visual bias creates a new unknown parameter, so at least 4 measurements are used in the solution. Barometric altimeter measurements

It provides the necessary information for such a solution.

One way to solve these nonlinear simultaneous equations is to linearize the problem at an arbitrary initial point, repeatedly find a correction for this initial position and lead it to the final solution.

로 사용된다.This method uses initial guesses for the X, Y, and Z solutions, so the center of the transmitter is

Is used as

를 형성하는 것으로 가정한다.The final location solution

It is assumed to form.

에 대한 테일러 시리즈로 확장될 수 있다.Geometric range

For the Taylor series.

로 계산되고, 편도함수는

으로 주어진다.Here, the estimated range

Is calculated as, and the one-way function is

Is given as

In this embodiment, four unknown and four linear equations are shown. The additional range estimate will produce more rows in the matrix. The results are shown in the set below.

. 바로미터 측정없이 추가 측정이 상기 매트릭의 행 1에서 3과 마차가지로 추가 행이 하나 추가되는 것을 주목하라. 이 추가 측정은 수신기의 고도의 측정을 활성화 시킨다. 알려지지 않은 수 보다 더 많은 측정이 가능할 때, 솔루션은

로 주어진 A의 의사역행렬(pseudoinverse)에 기초하고, 최소 자승 솔루션(least squre solution)은

으로 주어진다는 것을 주목하라. 측정의 품질이 동일하지 않을 경우, 최소 자승 센스(least square sense)에서 수학식 Ax=b를 푸는 적합한 방법은 각각의 수학식으로부터 오차에 대한 SNR에 가중치 비례(weight proportional)를 사용하는 것이다. 이는

와 함께 솔루션

를 야기한다. 대각선 가중화 행렬 W는 측정의 노이즈 분산에 대한 가중치 비례에 의해 형성된다. 이들 수학식의 솔루션은 X, Y, Z에 대한 델타 정정과 델타 시각 추정을 생산한다.The last row of the observation matrix represents the barometric altimeter measurement. 1 in the third column represents the same visual bias for all three ranges. These equations are in the form of Ax = b. solution

. Note that an additional measurement is added without the barometer measurement, as in the rows 1 to 3 of the metric above. This additional measurement activates the receiver's high altitude measurement. When more measurements than unknown are possible, the solution

Based on the pseudoinverse of A given by, the least squares solution is

Note that is given by If the quality of the measurements is not the same, a suitable way to solve equation Ax = b in least square sense is to use weight proportional to the SNR for error from each equation. this is

Solutions with

Causes The diagonal weighting matrix W is formed by the weight proportional to the noise variance of the measurement. The solution of these equations produces delta correction and delta time estimation for X, Y, Z.

This completes the first iteration of the method. The updated position and visual bias estimates change the initial guess, and the algorithm continues until the delta parameter becomes some threshold below. A typical stop point will be some threshold (eg 1 meter) below the delta value for reference.

In GPS, the system of linearized equations is solved using the least squares and the initial guess of the user's location in order for the algorithm to converge to the end user's location. Linearization is based on the basic assumption that the distance between the satellite position and the user position is greater than the distance between the user position and the estimated position on Earth. For the same set of equations in a terrestrial environment (with a small geometry), the initial guess can be based on the center (as described above), and the point is that the received signal is close to the strongest transmitter, or without repetition. Obtained by a direct method of giving a closed form solution by sequence. If the initial guess is the center or the point where the received signal is closest to the strongest transmitter, the initial guess is improved using the least squares method. If the initial guess is obtained by a direct method that gives a closed form solution by a sequence of formulas without repetition, the initial solution itself is the final solution, and individualized weighted by using the expected error in these measurements. The measurement of is improved using least squares only when there are more measurements (and thus equations) than are unknown (which are obtained from parameters such as signal strength and embossment). Moreover, if the sequence of measurements is processed in time, the solution obtained as above is passed to a Kalman filter to obtain the best solution "trajectory".

와 같이 정의된다.Another approach to overcoming the linearization problem in the terrestrial case involves formulating a set of equations such as the non-linear minimization problem (specifically, the weighted non-linear least squares problem). Specifically, the non-linearization objective function to be minimized is

Is defined as

으로 수정된다.The weight W _t is inversely proportional to the SNR of the measured range R _i . The best estimate of the receiver position is obtained with a set of (X, Y, Z, Δt) minimizing the objective function. Supporting barometers or other altitudes means the objective function

Is corrected to

Location solutions based on this method are more stable and robust, especially under small geometric terrestrial system configurations.

In this configuration, small changes in receiver coordinates significantly change the observation matrix and sometimes lead to a lack of convergence of linearized iterations. Convergence or divergence to a local minimum often occurs more due to residual bias in the measurement, which may affect the shape of the objective function, so that local minimization may exist. Residual bias is very common in indoor / urban canyon environments. The non-linear formulation makes the position algorithm robust against measurement bias, rather than overcoming small geometric linearization problems.

One approach to performing minimization of function f to obtain optical X, Y, Z is to find the global minimization of the function using a common algorithm (eg differential evolution). The use of this algorithm allows the solution to avoid local minimization that occurs in small geometric ground positioning when multi-path bias is present in the range measurement.

로 주어진다.
Regardless of whether a linearized least squares or non-linearized least squares method is used to solve the pseudorange measurement equation, it is important that a quality metric is provided along with the location estimate. The location quality metric should be a function of the quality of the measurement as well as the residual geometry of the pseudorange measurement equation, the tower geometry for the estimated location. The residual of the pseudorange measurement for the i tower measurement is

Is given as

로 주어진다.* Average weighted rms pseudorange remainder

Is given as

의 대각선 원소로부터

로 정의된다.HDOP, VDOP, PDOP

From the diagonal elements of

Is defined as

로 정의된다. 여기서, f는 일반적으로 그 인수의 비-선형 단조 감수 함수이다. 함수 f는 신호BW와 수신기 BW의 함수로서 특정 수신기 구성에서 분석적으로 파생될 수 있고, 테이블 맵핑 SNR로서의 시뮬레이션에서 레인지 오차까지 찾을 수 있다.The pseudorange RMS (root-mean-square) error at a specific SNR is

Is defined as Where f is generally the non-linear monotonic subtraction function of its argument. The function f is a function of the signal BW and the receiver BW and can be analytically derived from a specific receiver configuration, and range error can be found in simulation as a table mapping SNR.

로 정의된다. 마찬가지로, 고도와 3-D 위치에 대한 품질 메트릭은

으로 정의된다.The quality metric for 2-D position

Is defined as Similarly, the quality metrics for elevation and 3-D position

Is defined as

Quality αsms are selected based on the level of reliability desired. For example, a value of 3 is used to achieve 95% confidence, while a value of 1 is used to achieve 68% confidence.

Another method of positioning using a WAPS system involves the use of WAPS reference receivers in different schemes. Time-stamped reference receiver measurements and reference receivers with a specific time-stamp, as shown in the "differential wide-area positioning system" and discussed in the context of timing synchronization, with the WAPS tower's longitude, latitude, and altitude. Can be used to determine the timing delta between WAPS tower transmissions. Once the timing delta between transmitters is known, the range equation can be reduced back to one common visual bias. Then, the WAPS receiver can prevent demodulation of the WAPS data stream (eg, extract timing correction from the data stream). WAPS receiver measurements can be sent to the server, and then the location can be computed at the server, or alternatively, the reference receiver measurement can be passed back to the WAPS receiver, and the location can be computed there. It is assumed that the latitude, longitude and altitude of the WAPS tower are already known / available in the location calculation. If the WAPS data stream is secure, this differential system can eliminate the need to extract data from the secure data stream for timing correction.

Another alternative method for obtaining positioning from a WAPS system uses the RSSI finger-printing technique. A database of WAPS tower transmit power / location and RSSI level is established for a given target area based on training measurements in the area where positioning is required. Note that the RSSI database can also be increased with the Angle of Arrival (AOA) to retrofit the solution. WAPS receiver RSSI measurements (and possibly AOA measurements) are used to find this database to obtain a location estimate. An alternative method of using WAPS RSSI measurements is to convert the measurement to range estimation using a propagation model (or simple extrapolation / interpolation technique), and then position using tri-lateration. Decide. The RSSI measurement of these finger-printing techniques can be replaced by other measurements that can be converted into ranges.

An alternative method of calculating the location using the WAPS infrastructure does not use the prior knowledge of WAPS tower location, but uses a blind method to obtain location from the WAPS system. In this method, the approximate location of the WAPS towers is measured in situ (eg, measuring RSSIs from many angles around the WAPS towers at GNSS tagged locations, and then using the weighted averages based on the RSSIs of these locations to WAPS) (By estimating tower position). Then, one of the RSSI finger-printing methods is used to determine the location (eg, as described in the paragraph above).

An alternative method of calculating location using WAPS infrastructure can be used to calculate location offline. Position calculations include storing sample segments of a WAPS signal from a WAPS receiver (eg, the stored data can be I data at low IF or IQ data at baseband), optionally with approximate location and WAPS time tags. Related Note that it is enough to store enough samples to capture the signal. Samples are then processed to calculate the range for the search, capture and WAPS towers in time. The method can use offline data to find timing correction information that can be stored in a tower location and a central database on the server. The method of offline location calculation provides the ability to support WAPS positioning at the cost of only memory on the device. Another advantage of this method is that the time required to store WAPS IQ data is very short, and the application required to tag the location is quick and easy, but the exact location is not immediately required. One possible application for this method could be geo-tagging of photos.

로 기재될 수 있다.Another approach to positioning uses carrier phase measurements as well as code phase measurements described above. Carrier phase measurement

It can be described as.

로 기재될 수 있다.Various techniques can be used to decompose the ambiguous constant N in carrier phase measurement. Carrier phase measurements, measurements in multiple frequencies and / or other methods can be used to resolve ambiguity. Then, the carrier phase measurement at time t _k can provide an accurate tracking of the position starting from the correct initial position. From a future perspective, carrier phase measurement

It can be described as.

Ni does not change unless the carrier phase measurement has a cycle slip (i.e., the signal should not be tracked with a continuous phase lock), and the new position is calculated using least squares. Alternatively, these measurements can be used in a Callan filter to update the new position status. If the phase lock is lost, a new value of the ambiguous integer needs to be calculated.

Another approach uses differential positioning relative to the reference receiver, as described above. Differential positioning can be done using code measurement or carrier measurement or a combination of both. One difference observable is calculated for the code phase and the carrier phase by subtracting the measurement of the same tower from the reference receiver r and receiver s.

Note that any timing error in the transmitter does not appear in these observations, thus enabling a location solution even when the system is asynchronous or incompletely synchronized. In addition, since the convective delay is likely to be correlated in the local area for a short reference value (ie, the distance between the reference receiver r and the receiver s), the convective delay error in measurement is almost eliminated. The communication channel is used to send from the reference receiver r to the receiver s for location calculation. Or, alternatively, the receiver s and the receiver r need to communicate with the server for location calculation of the range and carrier.

In any location solution method, the height of the receiver can be determined by placing it on a topographic map or barometric sensing. By placing it on a map, the user's location during triangulation can be limited to the terrain database and the terrain based on the determined user's height. Also, the user's height can be limited to any height above the terrain. For example, based on the tallest building in the area, the maximum altitude above the terrain can be limited. This type of limitation can improve the quality of the height solution (e.g., when using a biased range measurement, by eliminating the obscure solution sometimes produced).

In addition, if indoor building maps are possible, information (subject to possible user location restrictions) can be used to support location solutions. For example, physical constraints can be used to limit the user motion model, thereby improving the quality of tracking Kalman position filters. Another use of building maps is to determine / estimate the quality of a range measurement for a particular tower based on the physical environment from the tower to the indoor location. A better estimate of the range quality can be used to weight position calculations leading to a better position estimate.

When using a barometric sensor, the calibrated barometric sensor can be used to measure the air pressure difference as the receiver terminal moves up and down in altitude. This is compared to a calibration value for various altitudes or an average value to determine the height of the receiver.

In the calculation of the position solution, additional measurements larger than the minimum 3 measurements required for the 2-dimensional position are possible.

Receiver integrity monitoring based on confirming the consistency of the measurements is used to eliminate "outlier" measurements. “Outlier” measurements may be due to loss of timing synchronization at the transmitter or channel effects such as multipath.

Altimeter-based approach to determining altitude

The WAPS system of the embodiment includes an altimeter (pressure sensor) to assist in determining user altitude. The only information available from the pressure sensor is atmospheric pressure at the time and place of measurement. In order to convert this into an estimate of the altitude of the sensor, a large amount of additional information is required. There are standard formulas related to pressure to altitude, based on the weight of the air column, as follows.

Where z ₁ and z ₂ are the two altitudes, P ₁ and P ₂ are the pressures at that altitude, and the temperature of the air in T (K). R = 287.052m ² / Ks ² is the gas constant, g = 9.80665 m / s ² is the gravitational acceleration. Note that this formula provides relative information that determines the altitude difference for the pressure difference. In general, this formula is used together with z ₂ = 0, so P ₂ is the sea level pressure. Because sea level pressure varies significantly with weather and location, sea level pressure needs to add temperature and air pressure in areas where altitude is determined. When the standard atmospheric pressure conditions (T = 15 ° C and P = 101,325 Pa) were applied, it was found that the 12.01 Pa air pressure decreased as the 1 m altitude increased.

Accordingly, in order to determine the altitude according to the resolution of 1 m, the sea level pressure must be known more precisely and more accurately than 36 Pa. Also, it is preferable to note that since T is measured in Kelvin temperature, a 3 ° C (or K) error in temperature corresponds to a highly approximately 1% error. This can be important when determining the altitude above sea level, and when attempting to disassemble the upper floors in a tall building. Accordingly, in order to determine the altitude with a resolution of 1 m, a pressure sensor with high precision and high resolution is required. To fit into a mobile device, these sensors must be low cost, low power and small size. Note that commercial weather grade sensors do not provide this level of accuracy or resolution and cannot update at the speed required to determine altitude.

The key to determining altitude to 1 m accuracy is to have a system that provides sufficiently local and sufficiently accurate reference pressure information. In order to capture changing weather conditions, it should be possible to provide measurements close to unknown locations in temperature, distance and time, and finally be sufficiently accurate. Accordingly, altitude for determining the system of an embodiment includes, but is not limited to, the following factors. Mobile sensor to determine pressure and temperature at an unknown location with sufficient accuracy, an array of reference sensors to determine pressure and temperature at a known location with sufficient accuracy, and close enough to a known location, all reference sensor data, reference An interpolation-based estimation algorithm that inputs sensor location and other incremental information and produces an accurate reference pressure estimate at a location of interest in the WAPS network, a communication link between the reference sensor and the mobile sensor to provide reference information in a sufficiently timely manner. Each of these elements is described in detail below.

33 is a block diagram of a reference altitude pressure system in an embodiment. Generally, the reference altitude pressure system or reference system includes a reference sensor array that includes at least a set of reference sensor units. Each set of reference sensor units includes at least one reference sensor unit located at a known location. In addition, the system includes a standby sensor that collects standby data at the location of the remote receiver or includes a connected remote receiver. The positioning application running on the processor is connected to the remote receiver or is part of the remote receiver. The positioning application produces a reference pressure estimate at the location of a remote receiver that uses atmospheric data and reference data from the reference sensor unit of the reference sensor array. The positioning application calculates the altitude of the remote receiver using reference pressure estimation.

More specifically, the reference altitude pressure system includes a mobile sensor that determines pressure and temperature at a known location with sufficient accuracy, and the mobile sensor is part of or connected to the remote receiver. The system includes a reference sensor array, the reference sensor array comprising at least one reference sensor that accurately determines pressure and temperature at a known location, the reference sensor being suitable for the location of the remote receiver. The reference sensor unit communicates with a remote receiver and / or intermediate device (eg, repeaters, etc.) to provide reference information. The system includes, in an embodiment, a positioning application, wherein the positioning application inputs all reference sensor data, reference sensor location and other incremental information, and produces an interpolation-based estimation algorithm that produces a relatively accurate reference pressure estimate at the location of interest. to be. The positioning application can be a configuration of a remote receiver, a host of a remote server or other processing device, and can be distributed between the remote receiver and the remote processing device.

34 is a block diagram of a WAPS including a reference altitude pressure system, in an embodiment. As described herein, WAPS is a network of synchronized beacons, a beacon and / or a receiver unit (and optionally having a location calculation engine) that captures and tracks global positioning system (GPS) satellites and the index of the tower. , A server that includes a billing interface, a dedicated cryptographic algorithm (and, optionally, a location calculation engine). The system operates in licensed / unlicensed operating bands and transmits dedicated waveforms for location and navigation. The WAPS system can be used in conjunction with other positioning systems or sensor systems to provide a more accurate location solution. Note that the altitude of the remote receiver calculated using reference pressure estimation can be used in any position location system, either explicitly, such as altitude estimation, or implicitly to support position calculation.

One exemplary system incorporates a reference altitude pressure system into the WAPS. Generally, the integrated system includes a terrestrial transmitter network, the terrestrial transmitter network includes a transmitter that broadcasts a positioning signal, and the positioning signal includes at least one range signal and positioning system information. The range signal includes information used to measure the distance to the transmitter broadcasting the range signal. The system includes a reference sensor array that includes at least one reference sensor unit located at a known location. The remote receiver includes or is connected to a standby sensor that collects standby data at the location of the remote receiver. The positioning application running on the processor is connected to or configured with a remote receiver. The positioning application produces a reference pressure estimate at the location of the remote receiver using reference data and atmospheric data from a set of reference sensor units in the reference sensor array. The positioning application calculates the position of the remote receiver, which includes altitude, uses reference pressure estimates and information derived from at least one positioning signal and a satellite signal, the positioning signal and satellite signal being satellite-based This is a signal from the positioning system.

More specifically, this integrated system includes mobile sensors that determine pressure and temperature at a known location with sufficient accuracy. The mobile sensor is, but is not limited to, a remote receiver configuration or connection therewith. The system includes a reference sensor array, the reference sensor array includes at least one reference sensor unit, the reference sensor unit accurately determines pressure and temperature at a known location, and the known location is suitable for the position of the remote receiver. Do. The reference sensor unit communicates with a remote receiver and / or intermediate device (eg, server, repeater, etc., not shown) to provide reference information. The reference sensor unit can be juxtaposed with one or more WAPS transmitters, and / or can be located separately at other known locations. The system, in an embodiment, includes a positioning application, where the positioning application inputs all reference sensor data, reference sensor location and other incremental information, and interpolation-based estimation to produce a relatively accurate reference pressure estimate at the location of interest. Algorithm. The positioning application can be a configuration of a remote receiver, a host of a remote server or other processing device, and can be distributed between the remote receiver and the remote processing device.

As mentioned above, mobile sensors can determine pressure with resolution and accuracy, which should be much finer than 36 Pa. Many pressure sensors have a built-in temperature sensor to provide compensation for non-ideal sensor performance, but due to the self-heating effect, these sensors may not be able to provide sufficiently accurate measurements of external air temperature. have. Even if accurate sensors are not commercially available, these sensors can be used for estimating altitude at the bottom, provided that sensors with appropriate resolution are available. The mobile sensor of the embodiment determines reference pressure data with a resolution lower than approximately 36 Pascals and temperature data with a resolution of approximately 3 degrees Celsius or less.

These sensors have inherent short-term and long-term stability issues, which can be calibrated by modern filtering techniques and averaged over several samples. In addition, each sensor has an offset, for example, with temperature changes that need to be calibrated or compensated by reference tables.

With sufficient calibration, these sensors must provide the required accuracy. In addition, some sensors may be sensitive to high-speed motion. When high speed or acceleration is found, some empirical law can be used to limit the use of pressure information. However, high speeds are rare in indoor environments. When moving at high speed, GPS positioning and map data generally provide sufficient vertical position information.

It should also be noted that the sensor should be mounted in such a way that it is exposed to outside air, but not exposed to wind, ventilation or other air movement. Mounting or internal positioning on a typical consumer product should produce acceptable results. The battery compartment and connections provide an indirect path for external air reaching the sensor, while preventing direct air movement. However, the waterproof device will require special preparation to provide a sensor for access to the outside.

The reference sensor is deployed in a very small volume and a dedicated position, so that relatively good accuracy can be obtained in the reference system and it is possible to place the volume of the overall error allocation in the mobile sensor. Existing markets for absolute pressure sensors, such as weather altimeters and aircraft altimeters, do not have the same high accuracy requirements as the application of the embodiment. In a reference application, embodiments use multiple sensors for improved accuracy and for redundancy by averaging their measurements. Further, the sensor can be packaged to limit the temperature range, the sensor is exposed, and preferably the sensor is calibrated for this limited temperature range.

The reference system must average different individual filter measurements to improve accuracy on a visual scale of approximately a few seconds to a few minutes. The height of the reference sensor must be accurately measured at the 'centimeter' level. External air temperature should be measured and recorded continuously. The sensor should be exposed to outside air to measure air pressure, but not exposed to wind, ventilation or other effective air movement (a partition or other packaging is used to guide air along an indirect path to the sensor). The sensor should not be sealed in a waterproof closure, as it prevents the measurement of external air pressure. The reference sensor of the embodiment determines reference pressure data with a resolution lower than approximately 36 Pascals, and a temperature with a resolution of approximately 3 degrees Celsius or less.

The example activates interpolation-based reference pressure estimation. Considering pressure measurement and temperature measurement at each WAPS transmitter tower, as well as tower location and other incremental information, the embodiment predicts sea level pressure at the mobile user location as a reference value for user height estimation. Thus, an atmospheric pressure surface gradient model is created, and the pressure measurement at each tower location serves as sample data for local modification of the model. Thus, this estimation algorithm corrects the reference pressure accuracy compared at the user's location, such as a direct measurement captured at a beacon tower.

The description of the formula of this interpolation method is described below. In one of the WAPS networks, considering a given reference barometric pressure sensor at n transmitter towers, equivalent sea level pressure is estimated based on the reference sensor output. This is done in two steps, but is not limited to this.

을 사용하여 계산되고, 여기서, g는 중력 가속도 상수이고, R은 공기에 대한 특정 기체 상수이다. 두 번째 단계로서, WAPS 네트워크의 모든 n 개의 송신 위치에서의 등가적인 해면기압을 계산하고, WAPS로 사용자의 경도 정보 x₀와 경도 정보 y₀를 얻은 후에, 등가적인 해면 압력은 사용자 위치 P0에서 공식

으로 추정되고, 여기서, W_i = W_i(x₀,y₀,x_i,y_i)는 사용자 위치과 기준 위치 i 위치에 의존하는 가중치 함수이다.As a first step, considering the elevation sensor height h _i (in meters), pressure p _i (in Pascals) and temperature T _i (in Kelvins) in transmitter tower i, the equivalent sea level pressure P _i (in Pascals) is the formula for longitude x _i latitude y _i (in degrees) at position

Calculated using, where g is the gravitational acceleration constant and R is the specific gas constant for air. As a second step, after calculating the equivalent sea level pressure at all n transmission locations in the WAPS network and obtaining the user's hardness information x ₀ and the hardness information y ₀ with WAPS, the equivalent sea level pressure is calculated at the user location P0.

It is estimated that W _i = W _i (x ₀ , y ₀ , x _i , y _i ) is a weight function depending on the user position and the reference position i position.

The communication link of the embodiment provides information used by the mobile sensor. The embodiment broadcasts a pressure that is updated once every few seconds to several minutes, but is not limited thereto.

If the reference system rarely broadcasts reference information, the mobile unit performs at least one of the following. By continuously monitoring the broadcast to receive and store the last information, prepare for the case where the last information is needed before the next broadcast, wait for the next broadcast before calculating a new altitude, or criterion for the last information if necessary "Pull" or query the system. The pool approach of the embodiment minimizes system bandwidth rather than having a reference system that broadcasts information. However, the pool is two-way between the reference system and mobile. Since communication is used and multiple reference locations are used for mobile calculations, imitation days are required to determine which reference location is queried A good compromise to minimize monitoring by mobiles while lowering latency is making measurements It has a reference system that broadcasts its data more often than it takes to update.

Embodiments include two possible approaches to information content. The first approach has a mobile that does all the calculations, in which case the information sent by the criteria includes, but is not limited to: This is the height of the reference sensor with 0.1-0.2 m accuracy and the measured temperature at the reference position (after any filtering), the pressure of the air measured at the reference position with 1 Pa accuracy (filtering, sensor temperature compensation, and other And after local calibration).

Alternatively, the reference location can be used to measure its temperature and pressure to calculate equivalent sea level pressure. If this approach is used, the list of broadcast purlin information includes, but is not limited to: This is a measure of the reference position (with longitude and latitude) with 1 meter accuracy, the height of the reference sensor with an accuracy of 0.1-0.2m, the equivalent sea level pressure calculated with reference (with 1 Pa accuracy), and reliability.

In addition, embodiments reduce bits of transmitted data, but broadcast each piece of data for some known constant. For example, the reference location is relatively close to the mobile location, leaving an integer portion of longitude and latitude to play a role, and only a fractional degree can be transmitted. Likewise, it is generally approximately 10 ⁵ Pascals, but the air pressure varies from standard atmospheric pressure to several thousand Pa. Accordingly, the embodiment broadcasts an offset from standard atmospheric pressure to reduce bandwidth compared to broadcasting absolute pressure.

Longitude and latitude obtained from GPS or similar systems are not particularly useful in urban applications. Instead, the database is required to map longitude and latitude to street addresses. Altitude has a similar limitation in vertical dimensions. A useful parameter is who is on which floor. This can be accurately determined from the altitude information if you access the ground elevation database and the height of each floor of the building. For buildings as low as approximately 3 stories, the ground elevation can be fully known from mapping or similar databases and floor height estimation. For larger buildings, more detailed information about the floor height is required.

This presents an opportunity to implement a smart learning algorithm. For example, one person assumes that the cell phone will be carried from 1 m to 2 m from the floor. Accordingly, the system of the embodiment can accumulate the altitude of many cell phones in the building, where the data is expected to be 1.5 m from each floor. With enough data, you can grow confidence in the height of each floor in the building. Accordingly, the database can be learned and refined over time. These algorithms become more complex in buildings with sloped or mezzanine levels between floors, but can still produce useful data for most buildings.

Parameters that are partially different from the sensor offset can be corrected at the time of manufacture. This is a known good sensor that provides reference information, which is possible by cycling the sensor through a range of temperatures and pressures. These calibration parameters slowly propagate with life. Thus, embodiments use algorithms to progressively update the calibration over time (eg, the algorithm recognizes when the sensor is stopped at a known height and updates the calibration table under these conditions).

In addition to the general application for determining a person's location, the Shilling example may include a special application that uses more accurate relative altitude information that does not require absolute altitude information. For example, finding a firefighter who falls over in a building is not as important as its absolute location, but the location of the felled man relative to a known rescue group is required. Additional accuracy in relative positioning can be made possible by having additional manual steps early in the application. For example, all firefighters can launch a tracker at a known location, such as a building entrance, before entering. Their position relative to the point, and thus relative to each other, can be determined quite accurately over a period of time, even if the absolute altitude is not accurate and the pressure associated with the weather is not fully compensated. Likewise, shopping-related applications that require more accuracy than commercially available from absolute measurements can be launched by the user pressing a button at a known point in the mall. Then, their location relative to that point is determined quite accurately over a period of time.

Alternatively, mobile beacons can be used as a local reference to provide more accuracy at certain locations. For example, shopping malls can have their own reference sensors, providing more accuracy within the mall. Likewise, fire trucks can be equipped with a reference sensor to provide local reference information in a fire situation.

Low cost pressure sensors have a problem in that they have an offset from the calibration record. Experiments show that this offset is quite stable on a time scale of weeks to months. However, this offset is likely to slowly propagate over a period of many months to years. It is simple to measure this offset and compensate in manufacturing, but the compensation is unlikely to be accurate over the life of the product. Therefore, a means of re-calibration is needed in this area.

The sensor of the embodiment can be recalibrated if it is at a known altitude and atmospheric pressure is known. The embodiment identifies the actual situation where the sensor will be at a known altitude. For example, if the sensor is on a device with GPS capability, the GPS satellites are received with high signal strength, and the GPS derived altitude must be very accurate. In good signal situations, deposits derived from GPS altitude over time provide an estimate of the calibration required for sensor calibration.

Likewise, the sensor system can learn the user's habits and use this information to correct future calibrations. For example, if the user keeps her phone in one place at night, the sensor can start tracking altitude at this location at a specific time, such as late at night. Initially, these values will be accumulated and stored as true altitude at that location. Months later, if the sensor determines that it is at the same location at the same time of the night, it can start tracking the deviation from the true altitude previously determined. Then, these deviations can be slowly accumulated to create a correction for calibration. Since these approaches also use current atmospheric pressure information, they use the reference pressure measurement provided by the WAPS network.

이다. 높이는 종래적으로, 지구 표면으로부터 떨어진 플러스 방향의 움직으로 측정되기 때문에, 마이너스 사인이 부가된 것을 주목하라. 또한, 알고리즘은 이것이 자연로그이기 때문에, 'ln'에 대해 보정되었다. 이 공식(해면상 높이 z)은 그 포인트에서의 대기 온도(T)와 압력(P)와 그 포인트 아래의 해면기압(P₀)에 관한 것이다.The standard procedure for determining altitude from a pressure record involves using a measurement to switch measurements at a reference position for equivalent sea level pressure, and then determine the altitude of an unknown pressure sensor. The standard formula

to be. Note that a negative sign was added, since the height is conventionally measured in a positive direction away from the Earth's surface. Also, the algorithm was corrected for 'ln', since this is a natural logarithm. This formula (at sea level z) relates to the atmospheric temperature (T) and pressure (P) at that point and the sea level pressure (P ₀ ) below that point.

One additional problem with applying this formula is that the height is directly proportional to the temperature (measured quality, not exactly known). This means that a 1% error in temperature can cause a 1% error in height. If used near sea level, this should not be a big deal. However, when this formula is applied in high buildings and especially in high altitude areas such as Denver, the 1% error in height can be large when trying to decompose the floor elevation. For example, Denver's altitude is about 1608 m. Thus, a 1% error in temperature can cause an error of 16 m above sea level. It is almost 5 stories high.

로 일반화될 수 있다. 여기서, z₁과 z₂는 임의의 두 고도이고, P₁과 P₂는 그들 고도에서의 압력이다. z₂가 0으로 설정되는 종래의 상황에서, P₂는 해면기압으로 된다.One way to avoid this sensitivity to temperature accuracy is to recognize that the formula is actually a relative formula. This formula

Can be generalized to Where z ₁ and z ₂ are any two altitudes, and P ₁ and P ₂ are pressures at their altitudes. In the conventional situation where z ₂ is set to 0, P ₂ becomes the sea level pressure.

Instead of using the sea level as a reference point, any comfortable altitude is used. For example, the average altitude of a city is suitable, or the average altitude of a reference sensor used to collect pressure data can be utilized. As long as the reference altitude is used to keep the height difference small, the effect of temperature error will be negligible. The only requirement is that all devices involved in the system must know that the reference altitude is used.

이다. 이 공식은 해면과 관심 포인트 간의 일정한 온도에서, 공기 기둥이 있다고 가정한다. 따라서, 사용된 해면기압은 가상 구조물이고, 관심 포인트가 실제 해면과 가까이 있지 아니할 수 있기 때문에, 해면에서의 실제 압력일 필요는 없다.Standard formulas related to the altitude (z) of a point on Earth, the atmospheric temperature (T) and pressure (P) at that point, and the sea level pressure (P ₀ ) below that point

to be. This formula assumes that there is an air column at a constant temperature between the sea level and the point of interest. Therefore, the used sea level pressure is a virtual structure, and since the point of interest may not be close to the actual sea level, it does not need to be the actual pressure at sea level.

The standard procedure for determining object altitude is a two-step procedure. Uther, the sea level pressure is determined by measuring the temperature and pressure at a known altitude point, then inversely transforms this formula to solve for P ₀ . Next, the temperature and pressure at the point of unknown altitude are measured, and this formula is applied to determine the unknown altitude.

What is implied at this stage is to assume that only the parameters of interest are the height of other objects above the same horizontal position, using measurements in the aerospace sector for reference, such as a typical aircraft approaching the aerospace sector. In general, those interested in determining the height for other purposes have extended this concept to determine the height around the general of the reference location, but not directly above it. This extension assumes that the sea level pressure does not change between the surrounding position of interest and the reference position.

Accordingly, there are three assumptions in this procedure. The first assumption is that the temperature is constant from the reference location to the virtual sea level point below it. The second assumption is that the temperature is constant from the point of interest to the virtual sea level point below it. The third assumption is that the sea level pressure is the same at the reference point and point of interest. However, since the sea level pressure is temperature dependent, assuming that the sea level pressure is the same in both positions means that the temperature is the same in these positions. Accordingly, if different temperatures are measured at the reference location and point of interest, one of these assumptions is violated. Measurements show that even at distances greater than a few kilometers, differences in temperature and pressure can be important in determining altitude.

The assumption of constant temperature over altitude changes at a given location is part of the equilibrium model for the atmosphere and is probably necessary. The only alternative would be the full dynamic model of the atmosphere, including the effects of wind, surface heating, convection and turbulence. Atmospheric data suggests that at least a large distance scale, i.e., a constant temperature model is a very good approximation at altitudes below 1 km. At higher altitudes, a linear lapse rate is sometimes applied.

The embodiment relaxes assuming a constant sea level pressure between the reference position and the point of interest. The first approach of the example considers sea level air pressure as the reference position determined as described above, but further applies the ideal gas law for converting it from standard temperature to sea level air pressure. Then, assume that the sea level pressure at this standard temperature will be the same at the point of interest. The temperature at the new location will be used to convert it to sea level pressure for the location, and then the formula is applied to determine altitude.

The second approach of the embodiment uses a network of reference positions to determine the equivalent change in sea level pressure with a horizontal position in real time. Then, these multiple measurements are combined to determine the best estimate of sea level pressure at the point of interest. There are at least two ways to determine the best estimate. This is a weighted average approach, where weighting is a function of the horizontal distance from a particular reference point to the point of interest. The other is the least square fit to create a secondary surface, which is the best fit for calculating sea level pressure at a reference location, and can be used to interpolate the estimation of sea level air pressure at points of interest.

The two approaches described above can also be combined. That is, at each reference position, sea level air pressure at a standard temperature is determined, and these data are combined using one of the techniques above to generate an optimal estimate of the sea level air pressure at a standard temperature at the point of interest.

Additionally, when using an altimeter, the embodiment recognizes a change in the condition of the air conditioner (e.g., turn-on, etc.) or sudden movement in pressure, such as opening a window in the car, into the filter's hardware or software by application level data, and continuously Position data and altimeter data are activated.

In addition, an anemometer can be used in the beacon to determine the direction of wind flow, which is considered an indication of the atmospheric pressure gradient. Anemometers with a compass can be used to accurately determine the direction and level of wind flow, which can be used to correct and / or filter our deformations at the user's sensor.

The height per floor of a given building can be determined by a variety of methods, including, but not limited to, a user walking through a staircase and collecting information about each floor (such as a slope). Also, electron conductivity can be used to determine the relative height of each layer.

If the height is estimated based on WAPS or altimeter, information such as terrain, height of the building, height of surrounding buildings, etc. is used to limit the height solution.

If the average pressure is known at a given location along with historical reference pressure data collected from the reference sensor over a long period of time (day, month, year), based on the pressure at that location (without calibration or user input) It can be used to determine the height as expected.

In one embodiment, the user's height can be calculated on a remote server by using data from the user's sensor and combining that data with data from the reference sensor. In this way, other information such as building information, crowd sourced information, etc. can also be used to determine the user's exact altitude.

If a user approaches another user whose height is known, information can be used to determine the height of the unknown user.

In one embodiment of the network, the reference sensor need not be located with the WAPS beacon. A fine or coarse grid of independent sensors with data connected to the server can be used for reference pressure measurements. The central server can send reference pressure information to the mobile or direct the transmitter with data that needs to be sent to the mobile as part of the WAPS data stream.

In another embodiment, the WAPS system uses simple beacons (supplementary beacons) that provide additional sensor information such as pressure and temperature in smaller areas such as buildings. This transmission can be synchronous or asynchronous to the main WAPS timing beacon. Additionally, the supplemental beacon may upload sensor data to a central server, which may be spread from the central server to a mobile unit, or transmit data via a predetermined set of PR codes (which can be demodulated by a WAPS mobile receiver).

The reference pressure network can be optimized based on accuracy requirements and historical pressure change data for a given local area. For example, for highly accurate measurements, the reference sensor can be deployed in a building or mall.

Along with the reference pressure data, the WAPS beacon network forms a closed network of accurate pressure and temperature measurements at short-term intervals, and can be used by other applications, such as axonology.

The rate of change of pressure combined with data from other sensors can be used to determine the vertical velocity, which can be used to determine if the user has gone through the elevator. This is very useful in emergency situations and / or application tracking.

For sensors with a lower resolution than necessary to estimate the floor height, under static conditions, averaging pressure measurements over time can be used to obtain user height based on reference data.

Hybrid positioning and information exchange with other systems

The system of the embodiments can be combined with any 'signal of opportunity' to provide positioning. Examples of signs of opportunity include, but are not limited to, one or more of the following. These include GPS receivers, Galileo, Glonass, analog or digital TV signals, media flows, signals from systems such as Wi-Fi, FM signals, WiMax, cellular (UMTS, LTE, CDMA, GSM, etc.), Bluetooth and LORAN and e -LORAN receiver.

Regardless of the signal type, the signal of opportunity provides a proxy for range measurement, such as range measurement or signal strength. This proxy for the range is weighted and combined appropriately to get an estimate for the location. Weighting uses the signal-to-noise ratio (SNR) of the received signal, or alternatively, the receiver's environment (knowledge of the urban, semi-urban, rural environment from the supplementary data, the receiver is based on input from the application, or indoors or Use 5 metric (5 metric) to define whether it is outdoor. This is generally done in such an environment where the system of the embodiment is not available or signal convergence is limited. When using SNR for weighting for a specific measurement, weighting is simply an inverse function of the SNR (or other function that provides low weighting for signals with low SNR), so that the optimal combination of WAPS measurements as well as other system measurements It may be possible to obtain a location. The final positioning solution is to combine range measurements with WAPS range measurements by taking range measurements from additional signal sources, and deriving position solutions for longitude, latitude and altitude, or position measurements from additional sources / devices and positions from the WAPS system. It can be calculated by taking measurements and providing an optimized location solution that uses a combination of these location measurements based on location quality metrics from different systems. Various configurations for obtaining a hybrid solution using WAPS measurement / WAPS location estimation are shown in FIGS. 35, 36 and 37. All of the architectures described below can be selected for use depending on the hardware and software partitioning of the system.

35 is a block diagram of hybrid position estimation using range measurements from various systems, in an embodiment. Range measurements (with associated range quality metrics) are used from GNSS and other location systems and combined into a single optimal location solution by a hybrid location engine. This architecture is optimal in terms of using available data, thus obtaining the best position estimate of the data.

36 is a block diagram of hybrid position estimation using position estimation from various systems, in an embodiment. In addition to position quality, independent position estimation from various systems is used to select the one with the highest quality. Since the different positioning systems are very far apart, this architecture is the easiest and most integrated to implement.

37 is a block diagram of hybrid position estimation using a combination of range estimation and position estimation from various systems in an embodiment. For example, location estimation from a WLAN positioning system can be compared with location estimation in range measurements from a GNSS system and WAPS system to reach the best solution.

Accelerometers and inertial navigation sensors (gyros) such as inertial navigation sensors (INS), magnetic sensors such as electronic compasses, and pressure sensors such as altimeters are information about the WAPS system for tracking mode use (loose coupling). Or raw sensor measurement.

The accelerometer can be used in the receiver of the embodiment to determine the frequency for updating the location reporting to the server. A combination of a positioning solution and a sequence of accelerometer measurements is used to detect a stationary position, constant velocity and / or other movement. This movement data or information determines the frequency of the update, for example, if there is a non-uniform motion, the frequency of update is a relatively high frequency, and if the receiver is constant or fixed for a predetermined period of time, the frequency of the update is It can be reduced to save power.

Sensors or position measurements can be combined into position solutions in position filters (such as Kalman filters). Two types of tight coupling are shown in FIGS. 38 and 39, where sensor measurements are combined with GNSS and WAPS measurements in a WAPS hybrid position engine. 38 is a flow chart for determining a hybrid position solution, in an embodiment, position / velocity estimation from a WAPS / GNSS system corrects the drifting bias of the sensor when the quality and / or speed estimation of the GNSS / WAPS position is good. It is fed back to help. This architecture simplifies algorithm formulation by dividing it into the sensor calibration part and the position calibration part of the algorithm. However, the drawback of this method is that it is complex to determine when it is a good time to recalibrate the sensor using WAPS / GNSS estimation.

39 is a flow chart for determining a hybrid position solution, in an embodiment, sensor parameters (such as bias, scale, and drift) are estimated as part of position / velocity calculation in a GNSS and / or WAPS unit without explicit feedback. . For example, sensor parameters can be included as part of the state vector of the Kalman filter used to track the position / velocity of the receiver. This architecture provides an optimal solution in that the information is used in one combined filter for updating the positional and sensor parameters.

The subcombination is shown in Figures 40 and 41, where the selection unit selects a position estimate from the GNSS engine or from the WAPS engine. Note that the selection unit can be part of a WAPS or GNSS location unit. 40 is, in an embodiment, a flow chart for determining a hybrid position solution, and sensor calibration is separate from the individual position calculation unit. 41 is a flow chart for a hybrid position solution, in an embodiment, and sensor parameter estimates are made as part of the state of the individual position calculation unit.

In general, the selection method uses information from one system, so the subcombination method is worse than the consolidation method. Among the small-combination method and the tight-combination method, it is better to use the range with the low sensor measurement to determine the position parameter and the sensor parameter in one optimal filter than when the sensor parameter and the position are calculated separately. Consequently, the preferred method from a performance standpoint is a tightly coupled system with nested sensor parameter estimation. However, depending on the hardware / software platform distinction, one or more of these methods can be easily implemented and selected for that reason.

In addition, information can be exchanged between WAPS systems on different platforms (such as cell-phones, laptops, PNDs) and other transceiver systems. For example, transceiver systems include Bluetooth transceivers, WLAN transceivers, FM receivers / transmitters, digital or analog TV systems, MediaFlow, satellite communication systems such as XM Radio Iridium, cellular modems such as GSM / UMTS / cdma2000 lx / EVDO or WiMax It can be a transceiver. 42 shows, in an embodiment, the exchange of information between WAPS and other systems. Exchange of information between systems can improve the performance of the system. Since the WAPS system time is aligned with GPS time, the WAPS system can provide good quality time estimation and frequency estimation to other systems. Time estimation and frequency estimation on WAPS can reduce WAPS capture search space in code and frequency. In addition, the WAPS system can provide location information to other transceiver systems. Likewise, if another system has possible location information (partial location, eg altitude or 2-D location, or full location, such as 3-D location or low range / pseudorange / pseudo-difference), WAPS is given for location information. Location quality metrics for the system may or may not be provided. Range / pseudo-range data is provided along with the location of the transmitter (or other means for calculating the range from the transmitter location to any receiver location) to enable the use of range information in a hybrid solution. The range difference between the two transmitters is provided with the location of the two transmitters. The WAPS system will use the information to support its location solution. Alternatively, the location information can be provided in the form of a range (or pseudorange) from a known transmitter location to a receiver device. These ranges (or pseudoranges) will be combined with WAPS ranges by a positioning algorithm to calculate the hybrid position.

Examples of specific systems and information that can be exchanged between them are shown in FIGS. 43, 44 and 45.

43 is a block diagram illustrating the exchange of position, frequency estimation and time estimation between an FM receiver and a WAPS receiver in an embodiment. Position estimation from the WAPS system can be provided to the FM receiver. This location estimation can be used, for example, to automatically determine the active FM radio station in the local area. The FM signal may also include RDS (Radio Data Service) transmission. If the location of the FM station is included in the RDS / RBDS data-stream (e.g., location and navigation (LN) features that provide data for the transmission location, city and state names, and DGPS navigation data) Can be used to provide location assistance to the WAPS receiver. Frequency estimation from the WAPS system can easily be used to reduce the FM receiver tuning time for a particular station. In another way, the frequency quality of the estimation at the FM receiver is based on the FM radio station transmission quality. The time estimate in the WAPS system is based on GPS time, and time can be sent to the FM receiver to support timing alignment. The clock time (CT) feature on the RDS / RBDS transmission can be used to determine the timing for the RDS data stream and can be transmitted to the WAPS receiver.

FIG. 44 is a block diagram illustrating exchanging a location, market price estimate and frequency estimate between a WLAN / BT transceiver and a WAPS receiver, in an embodiment. In general, these WLAN / BT transceivers do not have accurate frequency estimation, and as a result, the frequency estimation is very coarse, so the transmission of this estimation from the WLAN / BT transceiver to the WAPS receiver may have limited values. . In the opposite direction, WAPS frequency estimation can reduce the time for frequency acquisition on the WLAN system. For example, timing information extracted from a timestamp on a wireless LAN AP (access point) beacon can be transmitted to a WAPS system to support WAPS capture. Note that some criteria for WLAN timing over GPS time are needed to make it useful for WAPS systems. Similarly, if the WLAN / BT system has a possible position estimate (partial position, eg altitude or 2-D position, or full position, eg 3-D position or low range / pseudorange / pseudo-difference), then location information The location quality metric for the WAPS system may or may not be provided. WLAN location estimation can be simplified to the geo-location of nearby serving APs or other “hearing” APs. Also, the WLAN location estimate may be a partial, for example, elevation estimate based on the bottom of the AP. Also, the WLAN location information may be a range estimate for a known transmitter AP location (eg, a WLAN system may use round-trip time measurements to determine the range estimate) or an estimate of the range difference between two transmitting APs.

45 is a block diagram illustrating the exchange of position estimation, time estimation, and frequency estimation between a cellular transceiver and a WAPS receiver, in an embodiment. Position estimation (partial or complete or low range / range-difference) from a cellular system (TDOA, AFLT or other small cellular signal FL or RL based positioning method) can be provided to the WAPS system, which results in better position estimation. We will use these measurements to obtain. Frequency estimation from the cellular modem's frequency tracking loop can be provided to the WAPS system to reduce the frequency search space, thereby improving the WAPS acquisition time (ie, TTFF). Also, time estimation from the cellular system can be provided to the WAPS system to reduce code search space or support bit ordering and frame alignment. For example, a system synchronized to GPS time, such as cdma2000 / lx EVDO, provides precise time estimation for WAPS systems, while an asynchronous (transmission that is not precisely synchronized to a time scale such as GPS) cellular system simplifies time estimation. Can provide

Because the WAPS system time is aligned with GPS time, the WAPS system can provide good quality timing estimation and frequency estimation to other systems, even if they are not on the same platform. For example, a WAPS system provides timing information for a pico / femto-cell BTS, either through a periodic hardware signal such as pps (pulses per second) aligned with the GPS super-boundary or a single pulse signal with the associated GPS time. Can be used.

As described below, the spectrum used by the WAPS system of an embodiment may include licensed or unlicensed bands or frequencies. Alternatively, the WAPS system can use the “White Space” spectrum. The white space spectrum is defined as any spectrum in which the WAPS system senses or determines freely in the local area (not limited to the TV white space) and transmits a location beacon in that spectrum. The transmitter of the embodiment may use spectrum-sensing technology to detect unused spectrum and / or communicate with a geo-location (which can be easily obtained from a GPS timing receiver) and a central database that adjusts the spectrum. The receiver can listen to these beacons, including spectrum-sensing technology, or in other embodiments, it may be known by tuning the frequency using a communication medium. The WAPS system can be adapted to dynamic white space availability or quotas. The WAPS system can broadcast continuously in this spectrum, or can be shared with other systems, controlled by a central throttling server for the spectrum. The chip rate and data rate of the WAPS system configuration can be dynamically modified to match the accuracy requirements and / or signal power and bandwidth availability at any given time. System parameters can be sensed by the receiver or communicated to the receiver via a communication medium. The transmitter can form a local network (for spectrum availability in a larger geographic area) or a continuous network.

Further, the transmitter of the embodiment can coexist with other networks on the same transmission system in a time-sharing manner. For example, the same spectrum can be used in a time-sharing manner between location and smart grid applications. The transmitter is a broadcast transmitter that uses the maximum available power level, and can dynamically adjust the power level based on what is required by a spectrum sensing or central conditioning server. The receiver can use spectral sensing, or it is communicated by a system parameter communication medium (which can also be a white space spectrum) and a wake-up time at that time.

Based on spectrum availability, the WAPS system of the embodiment may use one channel of TV white space (6MHz bandwidth) or, if multiple channels are available, multiple frequency bands for better multipath resolution. If adjacent channels are available, channel bonding (eg, a combination of adjacent channels) can be used. The increased bandwidth can be used for better multipath resolution, higher chip rates for higher accuracy, and the like. Alternatively, the available bandwidth can be used under FDMA to help solve near-wave problems and / or multipath resolution.

In more than one white space band, white space transmission / reception of WAPS waveforms can activate better and faster ambiguity integer resolution for WAPS carrier phase measurement. This increases the relative accuracy (less than about 1 wavelength) for single point positioning using WAPS.

In addition, the white space bandwidth can also be used as a communication channel in the WAPS (if a reference receiver is used) between the reference receiver at the investigated position and the receiver at the found position.

A licensed band WAPS system is available in a wide area network, and a white space based on the tower's local network can be used to increase the positioning accuracy of the WAPS receiver. The receiver can be designed to listen to both frequencies simultaneously, or it can be designed to switch between frequencies or licensed bands and white space bands to tune to the appropriate frequency.

In addition, the white space band can be used to send assistance information to a WAPS, GPS or AGPS system for other assistance information such as location assistance and clock bias, satellite location estimation (ephemeris), and the like.

When a plurality of widely separated frequencies are available, the WAPS system is designed to take advantage of diversity in frequency, thereby providing better multipath performance.

Correlator implementation

을 사용하여 계산되고, 여기서 x[n]은 복소 입력(complex input), gcref[k]는 PRN 기준 파형이며, corrsum[n]은 상관기로부터의 복소 출력(complex output)이다. 도 37은 홀수와 짝수의 샘플이 동일한 승산기(multiplier)와 가산기 트리(adder tree)를 공유하는 한 최적화를 도시한다.In any CDMA receiver (or receiver using a pseudo-random code as part of a transmission bit stream), the correlation of the received signal with its PRN code is important. The more parallel the correlations are made, the faster the time to capture the channel. The brute force implementation of a parallel complex correlator architecture for a signal using a maximum length sequence of length 1023 and an input signal oversampled to 2x is shown in FIG. 46. Odd and even samples correspond to 2x oversampled data. The shift register is shifted at the speed of 'clk'. The PRN generator generates a reference PRN and shifts at a rate of clk / 2. The sum of correlations in each cycle is expressed by the equation

Calculated using, where x [n] is the complex input, gcref [k] is the PRN reference waveform, and corrsum [n] is the complex output from the correlator. 37 shows the optimization as long as the odd and even samples share the same multiplier and adder tree.

As shown above, the execution requires a 2046 * 2 * n-input bit flip-flop for the shift register, a 1xn-input multiplier of 1023 and an adder that adds 1023 output. As an example, if the input bit width is a 2-bit sample, a 1023 multiplier of 1 x 2 is needed, and three 1023 multiplications will be added in one clock cycle. This can be a burdensome performance in terms of area, timing and power in hardware. In particular, in FPGA implementation, the brute force implementation of multiplier and adder structures may not be possible to implement a given limited measure.

Embodiments include a new approach to this implementation, which has the advantage of possible structures in the field of FPGAs. Modern FPGAs include several configurable logic blocks (CLBs) that execute logic and store elements. Also, the lookup table that forms an important part of the CLB has a built-in serial shift, but can be reprogrammed into a shift register with parallel random access to the storage element. In addition, this implementation can be used as an effective approach for calculating correlation in an ASIC implementation, and as an easy path of movement from an FPGA (used in prototyping) to an ASIC (for mass production).

Looking at the shift register implementation, a particular FPGA has a shift register primitive that is mapped onto the CLB. Some FPGAs have 16-bit shift registers, but some have 32-bit shift register mappings. Figure 47 shows a 32-bit shift register implementation derived from a 16-bit shift register primitive with parallel random access write capability. In this example implementation, a 16-bit shift register group primitive is used to construct a 32-bit shift register. 32 of these 32-bit shift registers are connected in series to form a 1024-bit shift register. As shown in Fig. 48, the shift operation occurs at the 'clk' speed, and the read operation occurs 32 times at the clock speed.

Also, the adder tree can be complex to run a 1023 x n-bit adder. In the case of certain FPGAs, a 48-bit DSP slice is available, which can be used as a 1023 x n-bit continuous adder. The hardware structure for this implementation is shown in FIG. 49. The 32 values from the 32 groups of shift registers are divided into 4 groups of 8 additions. In this example, a 2-bit input is used. Each 8-number adder produces a 10-bit output, which is aligned in a 12-bit group of 48-bit adders. The room allows growth of addition. After 32 cycles, a 1024-bit sum is obtained by adding 4 groups of 12-bit adders to one 14-bit sum.

Encryption and security

Overhead information in the system of the embodiment can be encrypted using a cryptographic algorithm. This allows the user to use the system and to charge for the use of the system, and to provide a means to control information security. The key can be applied to decrypt the signal. The key can be obtained using a PC, wireless network, hardware dongle, or burnt into the device's non-volatile memory in a way that is not accessible by unintended sources.

The encryption of the embodiments provides data security and authentication. Key configurations guaranteed using cryptography are transmitter, receiver, and server communications. Transmitter authentication clearly identifies the transmitter, so a malicious transmitter can be rejected. Receiver authentication is such that only the authenticated receiver can use the transmitted information. Receiver permission is that only authorized receivers (certified receivers) should be allowed to operate. The server communication is encrypted so that communication between the receiver and the server and the transmitter and the server is stabilized. In addition, user data protection is encrypted because the location that tracks the user database must prevent unauthorized access.

The encryption method of the embodiment can be roughly classified into two types, namely, symmetric key cryptography and asymmetric key cryptography. Symmetric key cryptography provides authentication and cryptography, while asymmetric key cryptography provides authentication of the user's private key because the public key can be used by anyone. The symmetric key cryptography of the data is ten times faster than the given similar means. 3DES and AES are examples of symmetric key cryptography. The combination of the two methods is used as part of the cryptographic architecture of the embodiment.

The over-the-air (OTA) broadcast message may include a general broadcast message or a system message. A typical broadcast message includes specific data for each transmitter, such as location information, transmitter timing coefficients, and other relevant information to assist the receiver in determining its location. System messages are used to construct the intended one-way information exchange with cryptographic keys, active / inactive receivers or a specific set of receivers.

The general format of the message of an embodiment includes message type (parity ECC protected), encrypted message, and encrypted message ECC. The ECC for the encrypted message is calculated after the message is encrypted.

OTA broadcasts include frames that are transmitted periodically (every second possible). Depending on the channel data rate, messages can be split (partially) into multiple frames. Each frame contains the frame type and frame data. The frame type (parity protected) indicates whether this is the first frame or a continuous frame of the message. In addition, it can display low-level format frames that can be used for other purposes. Frame data is essentially a segmented message or a low level data frame.

The OTA system message can be encrypted by the session key or the sender's private key, depending on the type of system message. The OTA general broadcast message is encrypted by the sender and receiver using a symmetric key algorithm with a session key as described below. This provides mutual authentication (the transmitter is authenticated by the receiver) so that the authenticated receiver can decode the OTA broadcast. The session key is known to all transmitters and receivers and changes periodically. The key change message is encrypted using the last several session keys, allowing a receiver that has not been activated at any time period to be synchronized with the current session key.

In addition, the OTA broadcast is encrypted by the sender's private key. The receiver clearly identifies the authenticity of the transmitter using the relevant public key. If the session key is compromised, this mechanism ensures that unauthorized transmitters cannot be executed.

50 is a block diagram of a session key setup in an embodiment. Each receiver is provided with a unique device ID and device specific key. 45 is a flow chart for encryption in an embodiment. The WAPS system data server maintains a database of device ID / device specific key pairs. The initial setting of the receiver between the receiver and the WAPS data server is possible using a special data connection (GPRS / USB / modem, etc.) for the receiver type. This connection is encrypted using the device specific key after the device identifies the device by device ID. During this initial setting, the current session key, the transmitter public key, and the authorization period (i.e., the period during which the receiver was authorized) are exchanged. The receiver initial setting may be performed when the receiver loses the current session key (initial power up) or when the session key is not synchronized (extended power off). The session key is updated periodically, and the new key used for the update is encrypted using the old N key.

The OTA data rate may be inadequate for the only mechanism to authorize the receiver. However, the system message protocol of the embodiment supports device ID specification and device ID range-based receiver authorization.

The corrupted session key requires all receivers to be re-initialized. Therefore, the session key storage should not be tampered with in the device. Session keys stored outside the device secret boundary (i.e., all types of attached storage) will be encrypted using the device's security key.

The corrupted session key cannot be used to impersonate the transmitter, since the transmitter periodically sends authentication information using the private key. Therefore, the transmitter's private key must never be compromised.

In an alternative embodiment, the key shown in FIG. 52 can be delivered directly from the WAPS server to the receiver via a communication link or can be bypassed through a third application or service provider. The key can have any validity period. The key can be made available on a per application basis or per device basis based on a contractual agreement with the customer. Whenever a location request is made by an application on the receiver or by an application on the network, the key is checked for validity before retrieving the location or parameters to calculate the location from the WAPS engine. The exchange of keys and information to the WAPS server can occur using a dedicated protocol or through a standard protocol such as OMA SUPL.

The security architecture of the system can be implemented as a combination of the architectures shown in FIGS. 50 and 52.

The parametric sensor can be integrated into the receiver of the WAPS system to time tag and / or position tags on measurements from the sensor. The parameter sensor may include, but is not limited to, a temperature sensor, a humidity sensor, a weight sensor, and a sensor for a scanner type. For example, an X-ray detector can be used to determine whether a tracked receiver or a device containing a tracked receiver passes through an X-ray machine. The time of the X-ray event and the location of the X-ray machine are tagged by the detector. In addition, other parametric sensors can be integrated into the WAPS system for time tag and location tag measurements from the sensor.

The user may be billed for the system on a per-user, per-application, per-hour, per-day, weekly, monthly, or yearly basis for individual or asset.

The position and height of the receiver unit can be sent to a network server using any application or communication protocol on the terminal. Alternatively, low range measurements can be sent to the network via a communication protocol. The communication protocol can be a standard serial or other digital interface to an application on a terminal or a standard or dedicated wireless protocol to a server. Possible ways to combine or connect a server via standard protocols include sending an SMS message to another phone connected to the server, or alternatively, through a wireless data service to a web server. The information sent includes one or more latitude / longitude, height (if available), and timestamp. An application or terminal unit on the server can initiate a location fix. The user's location can be communicated directly from the server or by an application on the server.

A WAPS standalone system independent of the GPS receiver can be used to determine the location of the device. WAPS system A single or integrated WAPS and GPS and / or other positioning system can be used to co-exist with a media storage card (such as an SD card) on a media card. WAPS System A single or integrated WAPS and GPS and / or other positioning system can co-exist on a cellular phone Subscriber Identity Module (SIM) card so that the SIM card can be tracked.

Accurate positioning with carrier phase

One way to increase the WAPS system performance to further improve accuracy (up to 1 m) is to implement a carrier phase positioning system, as described below. Beacons are prepared as regular WAPS transmitters. In this method, it would be desirable (but not required) not to use TDMA slotting to enable easy continuous phase tracking. When TDMA is not used, the near-wave problem can be overcome through interference cancellation and increased dynamic range at the receiver. WAPS receivers to support this method can measure all visible satellites in a continuous manner and time-stamp code and carrier phase. There is also a reference receiver capable of making similar measurements of code and carrier phase in a known irradiated position sequential manner. Measurements from the WAPS receiver and the reference receiver can be combined to calculate a location on the device or server. The configuration of this system will be the same as the differential WAPS system.

Carrier phase measurement is more accurate than code phase measurement, but includes an unknown integer of the carrier phase cycle called the ambiguous integer. However, there is a method of finding an ambiguous integer called ambiguous resolution. In this specification, one method will be considered to use an extension of the local minimum search algorithm to iteratively solve for user receiver locations and use measurements in multiple epochs for improved accuracy.

Consider carrier phase measurement at the user receiver at the first of a single epoch as follows.

Where φ, λ, f and N are carrier phase, wavelength, frequency and integer cycles, respectively, dt is clock bias, r is range, ε is measurement error and subscript u is user receiver, k is transmitter number Indicates.

The range is given in terms of user position p ^u and transmitter position p ^(k) as follows.

To eliminate errors in the information of the transmitter clock bias, consider another receiver (called a reference receiver) at a known location using the corresponding carrier phase equation.

Here, the subscript r denotes a reference receiver, and subtracting (2) from (1)

를 얻는다. 이는

로 기재되고, 여기서,

이다.

Get this is

It is described as, where

to be.

Since dt _u r is not a part of interest, it is eliminated by differentiating (5) for different values of the index k, so that a so-called second-order differential observation equation can be obtained.

, 여기서,

이다.

, here,

to be.

을 통하여 알려지지 않은 사용자 위치 p_u에서의 수학식이고,

여기서,

이다.Then, Equation (6)

Is an equation at the unknown user location p _u ,

here,

to be.

In general, the transmitter l used in the second derivative is one of the transmitters, and for convenience, it is referred to as 1 for inducing a matrix equation. The matrix is as follows.

or

으로 놓고, 여기서,Equation (10) is a non-obvious equation at the user location pu. The local minimum search algorithm operates on a linear equation, and (10) is linearized and solved iteratively as follows. Repeated m, approximated to p _u

And put it here,

와

Wow

여기서,

here,

, 여기서 l(k)는 가시선 행 백터

이다.

Where l (k) is the line of sight vector

to be.

와 같이 기재되고, 여기서,

및

이다.Then the equation (10)

It is described as, where:

And

to be.

로서 사용된다. 반복은 Δp_u이 수렴을 결정하기에 충분히 작아질 때까지 연속적이다. 반복의 초기에는,

이 솔루션에 기초한 코드 위상으로부터 취할 수 있다.Equation (13) is linear at x = Δp _u and is solved for Δp _u using the local minimum search algorithm given below. Using the obtained solution of Δp _u , equation (11) is used to obtain p _u at repetition m, so p _u obtained at the next repetition (m + 1)

Is used as The iteration is continuous until Δp _u is small enough to determine convergence. At the beginning of the iteration,

It can be taken from the code topology based on this solution.

를 2차 미분 캐리어 위상 오차 벡터의 공분산으로 놓는다. 아래와 같이 얻어진다. 단일 미분 관측량에서 오차의 분산

은

이고, 여기서

과

는 각각 캐리어 위상 오차 분산이고, 이는 송신기 k에 독립적인 것으로 가정된다.

의 분산은

이고,

와

의 교차-분산은

이며, 이는 공통 항

의 분산이다. 따라서,Now, consider solving equation (13).

Let be the covariance of the second-order differential carrier phase error vector. It is obtained as follows. Variance of error in a single differential observation

silver

And here

and

Is a carrier phase error variance, which is assumed to be independent of transmitter k.

The dispersion of

ego,

Wow

Is the cross-dispersion of

And this is the common term

It is the dispersion of. therefore,

이고, 여기서 G^L은 G의 좌역원이고,

The weighted least squares solution of (13)

, Where G ^L is the left inverse of G,

이며 이는 N의 함수이고, 로컬 최소 탐색은 N에 대하여 가중화된 정규 자스을 최소화하도록 시도한다. 여기서 N은

이고, 여기서,

및

이다. Then, the rest of the vector

And this is a function of N, and the local minimum search attempts to minimize the weighted regular jass for N. Where N is

And here,

And

to be.

를 푸는 것을 생각한다. 그리고 나서,

와

인데, 이는 W가 멱등원(idempotent)

이기 때문이다. 따라서, N에To solve (17), under the restriction that N is an integer,

Think to solve. Then the,

Wow

Which is W is idempotent

Because it is. Therefore, to N

The search for is limited to this N, which satisfies (18).

If N is solved, the estimation of x = Δp _u is obtained from equation (15). The matrices G and G ^L with dimensions (n-1) x 3 and 3 x (n-1), respectively, have rank 3, which is (n-1)> 3, and (n-1) x (n-1). ) The matrices S and W will be lacking from the whole line of (n-1) by 3.

, 여기서,

는 직교-법선 행렬(ortho-normal matrix)

이고, R은 상삼각(upper triangular)이어서,

이고,

이다.Using the QR decomposition of W for equation (18) (LU decomposition can also be used),

, here,

Is ortho-normal matrix

And R is the upper triangular,

ego,

to be.

의 솔루션은 정수값으로 3차원박스 내의 N₂에 대하여 탐색함으로서, (21)로부터의 N₁을 얻음으로서 및 (17)에서 c(N)을 최소화하는 N을 선택함에 의하여 얻어진다. N₂에 대한 탐색은 이전 반복으로부터 N₂의 값의 중심이 된다. N의 나중 파트인 0번째 반복에서의 N2는

의 부분 파트로서 얻는다.

는 솔루션에 기초한 코드 페이즈이다. 3차원 탐색 박스의 크기는 솔루션에 기초한 코드 페이즈의 불확실성에 의존한다. 이 박스는 더 작은 서브-박스로 나뉘어질 수 있고, 각각의 더 작은 크기의 서브-박스는 초기의

로서 시도될 수 있다.therefore,

The solution of is obtained by searching for N ₂ in a three-dimensional box with an integer value, by obtaining N ₁ from (21) and by selecting N that minimizes c (N) in (17). Searching for the N ₂ is the center of the value of N ₂ from the previous iteration. N2 in the 0th iteration, the later part of N,

It gets as part part of.

Is a code phase based solution. The size of the three-dimensional search box depends on the uncertainty of the code phase based on the solution. This box can be divided into smaller sub-boxes, and each smaller sized sub-box is initially

Can be tried as

이다.The method used a single epoch of measurement (immediate) to determine the location. The description below describes the extension to the single epoch method. Multiple epoch measurements are close enough in time, ignoring user receiver movement. In addition, the ambiguity constant of the initial epoch remains the same for subsequent epochs, so new and unknown ambiguity constants are not introduced to the epoch that continues. Since the transmitter position is fixed (unlike the GNSS case, the motion of the satellite transmitter changes on the line of sight to give an independent equation), so multiple epoch measurements do not give an independent equation. Thus, multiple epoch measurements do not help to solve for ambiguity constants such as floating ambiguity (unlike the GNSS case, the number of independent equations is greater than the number of unknown ambiguities plus 3 position coordinates). However, multiple epoch measurements allow for more carrier phase measurement errors, and still allow successful ambiguity resolution. In the case of multiple epochs, equation (13)

to be.

After development for a single epoch case, such as the above equation, the problem is reduced to the problem of finding N,

, 여기서,

이다.

, here,

to be.

, 여기서,

을

(LU 분해도 사용될 수 있음)의 QR 분해와 상기와 같이 (19) 내지 (21)의 다음 수학식을 사용한다. 다시 말하면, N이 풀린 후에, x = Δp_u 의 추정은 수학식 (15)로부터 얻는다. x = Δp_u의 이 추정이 작다면, 수학식 (11)의 반복이 정지되어 사용자 위치 p_u를 얻는다. 일반적으로, x의 각 구성은 크기 le-6보다 작다면, 그리고 나서, 수렴이 고표되고, 반복은 정지된다.To solve (23) against N,

, here,

of

QR decomposition of (LU decomposition can also be used) and the following equations of (19) to (21) are used as above. In other words, after N is solved, the estimation of x = Δp _u is obtained from equation (15). If this estimation of x = Δp _u is small, the repetition of equation (11) is stopped to obtain the user position p _u . In general, if each construct of x is smaller than size le-6, then convergence is declared and repetition is stopped.

로서 (10)으로부터 얻어진 나머지에 기초하여 행해진다. 각 에포크에 대한 나머지의 절대값의 최대치가

보다 작고, 수렴된 솔루션은 솔루션으로 받아들여지고, 아니면 탐색은 새로운 서브-박스를 선택함에 의하여 계속된다. 일반적으로, 확인 테스트의 척도 요소 κ는 5로 선택될 수 있다. 솔루션이 확인되면, 상기 기술된 차동 WAPS 시스템은 1 m 보다 우수하거나 근접한 정확성을 달성할 수 있다.The next step is to check if the converged user position p _u is correct. this is

This is done based on the remainder obtained from (10). The maximum value of the absolute value of the remainder for each epoch

Smaller, converged solutions are accepted as solutions, or the search continues by selecting a new sub-box. Generally, the scale factor κ of the confirmation test can be selected as 5. Once the solution is identified, the differential WAPS system described above can achieve better or closer accuracy than 1 m.

This differential WAPS carrier phase system can be overlaid or standalone on top of a conventional WAPS system through the addition of a reference receiver. Differential WAPS carrier topology systems can be used to achieve high accuracy positioning in any local target area (eg, mall, warehouse, etc.).

In a W-CDMA system, two receive chains are used to improve receive diversity. When WAPS is present with W-DCMA, one of the receive chains can be used temporarily to receive and process WAPS signals. In some cases of W-CDMA and CDMA architectures, while the processing of the W-CDMA / CDMA signal is temporarily suspended, the entire receive chain is re-used to receive the WAPS signal by turning the receiver into the WAPS band and processing the WAPS signal. Can be. In some other embodiments where the GSM receive chain is multiplexed with the W-CDMA receive chain, the receiver can be more time-shared and used for WAPS reception.

After determining which signals are used from WAPS or other towers for location determination in other TDMA systems, in order to save power, most of the receivers of the embodiments do not detect signals and / or signals from towers emitting from that slot Is turned off while not being used for positioning. Upon detecting a change in motion or position or a change in signal state, the receiver of the embodiment is turned on for all slots to determine which slot can be used for the next set of position calculations.

Embodiments described herein include a method for transmitting a positioning signal from a plurality of transmitters. The method includes selecting a set of digital pseudorandom sequences. The magnitude of the cross-correlation function between any two sequences in the set of digital pseudorandom sequences is below a specified threshold. The method includes selecting a subset of the digital pseudorandom sequence from the set of digital pseudorandom sequences. The size of the autocorrelation function of each member of the subset of the digital pseudorandom sequence is equal to, less than or equal to a specified value, within a specified region adjacent to the peak of the autocorrelation function, or less than or equal to the specified value. . The method includes transmitting a positioning signal from each transmitter of a plurality of transmitters. At least a first portion of each positioning signal is modulated according to at least one member of a subset of the digital pseudorandom sequence. At least two of the plurality of transmitters modulate the first portion of each positioning signal according to different members of a subset of the digital pseudorandom sequence.

Embodiments described herein include a method for transmitting a position signal from a plurality of transmitters, the method comprising: selecting a set of digital pseudorandom sequences, a cross-correlation function between two sequences of a set of digital pseudorandom sequences The size of is less than a certain threshold-selecting a subset of the digital pseudorandom sequence from the set of digital pseudorandom sequences-the magnitude of the autocorrelation function of each member of the subset of the digital pseudorandom sequence is the self Within the specified region adjacent to the peak of the correlation function, equal to or less than the specified value, or less than or equal to the specified value-and transmitting positioning signals from each transmitter of the plurality of transmitters- At least a first portion of each positioning signal is modulated according to at least one member of the subset of the digital pseudorandom sequence, and at least two of the plurality of transmitters are assigned to different members of the subset of the digital pseudorandom sequence. And modulating the first part of each positioning signal.

The set of digital pseudorandom sequences includes a set of binary pseudorandom sequences.

The set of binary pseudorandom sequences is selected from the set of Gold codes.

The specified value is a value obtained by dividing the peak value of the autocorrelation function by the non-repeating length of the digital pseudorandom sequence.

The set of binary pseudorandom sequences is one of Kasami code, Bent code, and Gold-like code.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has a truncated sequence length, which is shorter than the standard sequence length.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has an extended sequence length, and the extended sequence length is longer than a standard sequence length.

The method includes transmitting a positioning signal from at least one of a plurality of transmitters during a first time period in which a first portion of the positioning signal is modulated by a first member of a subset of the digital pseudorandom sequence-the digital The first member of the subset of the pseudorandom sequence has a first length-, and the positioning signal during a second time period in which the second part of the positioning signal is modulated by the first member of the subset of the digital pseudorandom sequence And transmitting the second member of the subset of the digital pseudorandom sequence has a second length.

The first length and the second length are different.

The second portion of the positioning signal is further modulated according to the data sequence.

The set of digital pseudorandom sequences has an alphabet size greater than 2.

The set of digital pseudorandom sequences is a set of quaternary sequences.

The alphabet size is a power of two.

The specified region adjacent to the peak of the autocorrelation function includes at least 10 consecutive symbols immediately adjacent to the peak of the autocorrelation function.

Embodiments described herein include a transmitter in a positioning system that includes a plurality of transmitters. The transmitter includes a processor coupled to memory, the processor running at least one application. The at least one application selects a set of digital pseudorandom sequences. The magnitude of the cross-correlation function between any two sequences in a set of digital pseudorandom sequences is below a specified threshold. The at least one application selects a subset of the digital pseudorandom sequence from the set of digital pseudorandom sequences. The size of the autocorrelation function of each member of the subset of the digital pseudorandom sequence is equal to, less than or equal to a specified value within a specified region adjacent to a peak of the autocorrelation function, or less than or equal to the specified value. . The at least one application transmits a positioning signal. At least a first portion of the positioning signal is modulated according to at least one member of the subset of the digital pseudorandom sequence, and the transmitter is at least one other transmitter of the plurality of transmitters of a subset of the digital pseudorandom sequence. It modulates each positioning signal according to a member different from that used by.

One embodiment described herein includes a transmitter in a positioning system comprising a plurality of transmitters, the transmitter comprising a processor coupled to memory, the processor running at least one application, and the at least one application, Select a set of digital pseudorandom sequences-the size of the cross-correlation function between any two sequences in the set of digital pseudorandom sequences is below a specified threshold-a subset of the digital pseudorandom sequences from the set of digital pseudorandom sequences And-the magnitude of the autocorrelation function of each member of the subset of the digital pseudorandom sequence is equal to or less than a specified value within a specified region adjacent to a peak of the autocorrelation function, or Below a specified value-, transmit a positioning signal-at least a first portion of the positioning signal is modulated according to at least one member of the subset of the digital pseudorandom sequence, and the transmitter is a subset of the digital pseudorandom sequence Of modulating respective positioning signals according to members different from those used by at least one other transmitter of the plurality of transmitters.

The set of digital pseudorandom sequences includes a set of binary pseudorandom sequences.

The set of binary pseudorandom sequences is selected from a set of gold codes.

The specified value is the peak value of the autocorrelation function divided by the non-repeating length of the digital pseudorandom sequence.

The set of binary pseudorandom sequences is one of Kasami code, Bent code, and Gold-like code.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has a truncated sequence length, and the truncated sequence length is shorter than a standard sequence length.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has an extended sequence length, the extended sequence length being longer than a standard sequence length.

The transmitter transmits the positioning signal during a first time period in which a first portion of the positioning signal is modulated according to a first member of a subset of the digital pseudorandom sequence-the first of the subset of the digital pseudorandom sequence The member has a first length, and transmitting a positioning signal during a second time period in which the second part of the positioning signal is modulated by a second member of a subset of the digital pseudorandom sequence-the digital pseudo And the second member of the subset of the random sequence has a second length.

The first length and the second length are different.

The set of digital pseudorandom sequences has an alphabet size greater than 2.

The set of digital pseudorandom sequences is a set of quaternary sequences.

The alphabet size is a power of two.

The specified region adjacent to the peak of the autocorrelation function includes at least 10 contiguous symbols immediately adjacent to the peak of the autocorrelation function.

The first portion of the positioning signal comprises a positioning signal modulated according to a member of the subset of the digital pseudorandom sequence and the second portion of the positioning signal is further modulated according to a data sequence.

Multiple transmitters are synchronized.

The plurality of transmitters transmit auxiliary data.

The plurality of transmitters form a CDMA network.

Multiple transmitters form a TDMA network.

The carrier signals of at least one transmitter are frequency offset from the carrier signals of at least one other transmitter of the plurality of transmitters.

The auxiliary data includes a system time at a rising edge of a pulse of a waveform, a system time at a falling edge of a pulse of a waveform, geocode data of a plurality of transmitters, and a plurality of transmitters, respectively. Geocode data of adjacent transmitters, indexes of sequences used by at least one transmitter proximate to a plurality of transmitters, clock timing correction for at least one transmitter, local atmospheric correction, and local It contains at least one of the indicators for the environment.

Embodiments described herein include a receiver in a positioning system. The receiver includes a processor connected to memory. The processor executes at least one application that acquires positioning signals from a plurality of transmitters and calculates location information of the receiver using the positioning signals. At least a first portion of the first positioning signal is modulated according to a member of a subset of the digital pseudorandom sequence, and at least a first portion of the second positioning signal is modulated according to different members of the digital pseudorandom sequence subset. Selecting a subset of the digital pseudorandom sequence includes selecting a set of digital pseudorandom sequences such that the size of the cross-correlation function between any two sequences in the set of digital pseudorandom sequences is lower than a specified threshold. The selection further comprises selecting a subset of the digital pseudorandom sequence from the set of digital pseudorandom sequences. The magnitude of the autocorrelation function of each member of a subset of the digital pseudorandom sequence is equal to, less than or equal to a specified value, within a specified region adjacent to a peak of the autocorrelation function.

Embodiments described herein include a receiver in a positioning system, the receiver comprising a processor coupled to a memory, the processor obtaining a positioning signal from a plurality of transmitters and using the positioning signal to position the receiver Running at least one application to compute, wherein at least a first portion of the first positioning signal is modulated according to a member of a subset of the digital pseudorandom sequence, and at least a first portion of the second positioning signal is digital pseudorandom Modulated according to different members of the sequence subset, and the selection of a subset of the digital pseudorandom sequence is such that the digital pseudorandom is such that the magnitude of the cross-correlation function between any two sequences of the set of digital pseudorandom sequences is lower than a specified threshold. Selecting a set of sequences, and selecting a subset of the digital pseudorandom sequences from the set of digital pseudorandom sequences, and the magnitude of the autocorrelation function of each member of the subset of the digital pseudorandom sequences is: Within a specified area adjacent to the peak of the function, it is equal to, less than, or less than the specified value.

The set of digital pseudorandom sequences includes a set of binary pseudorandom sequences.

The set of binary pseudorandom sequences is selected from a set of gold codes.

The specified value is the peak value of the autocorrelation function divided by the non-repeating length of the digital pseudorandom sequence.

The set of binary pseudorandom sequences is one of Kasami code, Bent code, and Gold-like code.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has a truncated sequence length, and the truncated sequence length is shorter than a standard sequence length.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has an extended sequence length, the extended sequence length being longer than a standard sequence length.

The second portion of the first positioning signal is modulated according to a member of a subset of the digital pseudorandom sequence.

A member of the subset of the digital pseudorandom sequence used to modulate the first portion has a first sequence length, and a subset of the digital pseudorandom sequence used to modulate the second portion has a second sequence length. And the first sequence length is different from the second sequence length.

The members of the subset of digital pseudorandom sequences used to modulate the first part are different from the members of the subset of digital pseudorandom sequences used to modulate the second part.

The set of digital pseudorandom sequences has an alphabet size greater than 2.

The set of digital pseudorandom sequences is a set of quaternary sequences.

The alphabet size is a power of two.

The specified region adjacent to the peak of the autocorrelation function includes at least 10 contiguous symbols immediately adjacent to the peak of the autocorrelation function.

The first portion of the positioning signal is modulated by a member of a subset of the digital pseudorandom sequence and the second portion of the positioning signal comprises a positioning signal that is further modulated according to the data sequence.

The positioning signal includes data describing timing differences between transmissions from different transmitters of a plurality of transmitters.

Each of the positioning signals is initially synchronized to a time reference, and timing correction corresponding to the synchronization is provided to the receiver.

The receiver identifies the multipath component of the high resolution positioning signal using a high resolution earliest time of arrival estimation including an estimated reference correlation function.

The receiver identifies the multipath component of the positioning signal using high resolution earliest arrival time estimation, including partitioning of the signal and noise subspaces.

The receiver correlates the received samples with the sequence transmitted from the transmitter, and a peak vector including a left sample of the first number of peaks of the peak of the cross correlation function and a right sample of the second number of peaks of the peak from the cross correlation function. By generating the cross-correlation function by extracting, multipath components of the positioning signal are identified.

The receiver generates a reference peak vector from a correction function measured in a channel environment having at least one of low noise and easily separable multipath components and non-multipath components, and averages interference over at least a plurality of pseudorandom code periods By improving the signal-to-noise ratio in the peak vector by coherently averaging, the multipath component of the positioning signal is identified.

The receiver calculates the Fourier transform of the peak vector and generates the frequency domain estimate of the channel corresponding to the transmitted sequence using the Fourier transform of the measured peak vector and the Fourier transform of the reference peak vector, thereby generating the multipath component of the positioning signal. Discern.

The receiver generates a reduced channel estimation vector from the frequency domain estimation of the channel, defines an estimated covariance matrix of the reduced channel estimation vector, and performs singular value decomposition on the estimated covariance matrix, thereby multipathing the positioning signal. Identify the ingredients.

The receiver generates a vector of sorted singular values, separates a signal and a noise subspace using the vector of sorted singular values, generates a noise subspace matrix, and generates the noise subspace matrix. Multipath components of the positioning signal are identified by estimating the arrival time of the first path using.

The receiver receives the auxiliary data, the auxiliary data is the system time at the rising edge (rising edge) of the pulse of the waveform, the system time at the falling edge (falling edge) of the pulse of the waveform, the geocode of a plurality of transmitters ( geocode) data, geocode data of transmitters adjacent to multiple transmitters, indexes of sequences used by at least one transmitter proximate to multiple transmitters, clock timing correction for at least one transmitter, local standby correction (local atmospheric correction), relationship of WAPS timing to GNSS time, indicator for local environment to assist receiver at pseudorange resolution, and offset from base index of set of pseudorandom sequences, set of transmitters At least one of a list of pseudorandom number sequences from and a list of transmitters using a particular pseudorandom number sequence.

Embodiments described herein include methods for determining location information using positioning signals transmitted from a plurality of transmitters. The method includes selecting a set of digital pseudorandom sequences. The magnitude of the cross-correlation function between any two sequences in the set of digital pseudorandom sequences is below a specified threshold. The method includes selecting a subset of digital pseudorandom sequences from the set of digital pseudorandom sequences. The size of the autocorrelation function of each member of the subset of the digital pseudorandom sequence is equal to, less than or equal to the specified value, within a specified region adjacent to the peak of the autocorrelation function. The method includes transmitting a positioning signal from each of the transmitters of the plurality of transmitters. At least a first portion of the positioning signal is modulated according to at least one member of a subset of the digital pseudorandom sequence, and at least two transmitters of the plurality of transmitters are according to different members of the subset of the digital pseudorandom sequence. Modulate the first part of each positioning signal. The method includes receiving at least one of a positioning signal and a satellite signal at a remote receiver. The satellite signal is a signal from a satellite-based positioning system, and the first mode of operation of the remote receiver includes terminal-based positioning where the remote receiver calculates the position of the remote receiver from at least one of a positioning signal and a satellite signal. do.

Embodiments described herein include a method for determining location information using a positioning signal transmitted from a plurality of transmitters, the method comprising selecting a set of digital pseudorandom sequences-any of a set of digital pseudorandom sequences The magnitude of the cross-correlation function between two sequences of-is less than a specified threshold.

Selecting a subset of the digital pseudorandom sequence from the set of digital pseudorandom sequences, the size of each autocorrelation function of a member of a subset of the digital pseudorandom sequence is within a specified region adjacent to a peak of the autocorrelation function. , Equal to or less than the specified value, or less than or equal to the specified value,-transmitting a positioning signal from each of the transmitters of a plurality of transmitters-at least a first portion of the positioning signal comprises a digital pseudorandom sequence Modulated according to at least one member of the subset, and at least two transmitters of the plurality of transmitters modulate the first part of their positioning signal according to different members of the subset of the digital pseudorandom sequence, and Receiving at least one of a positioning signal and a satellite signal at a remote receiver, wherein the satellite signal is a signal of a satellite-based positioning system, and a first operation mode of the remote receiver is that the remote receiver is one of a positioning signal and a satellite signal. And terminal-based positioning that calculates the location of the remote receiver from at least one.

The set of digital pseudorandom sequences includes a set of binary pseudorandom sequences.

The set of binary pseudorandom sequences is selected from a set of gold codes.

The specified value is the peak value of the autocorrelation function divided by the non-repeating length of the digital pseudorandom sequence.

The set of binary pseudorandom sequences is one of Kasami code, Bent code, and Gold-like code.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has a truncated sequence length, and the truncated sequence length is shorter than a standard sequence length.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has an extended sequence length, the extended sequence length being longer than a standard sequence length.

The method comprises transmitting a positioning signal from at least one of a plurality of transmitters during a first time period in which a first portion of the positioning signal is modulated by a first member of a subset of the digital pseudorandom sequence-digital pseudo The first member of the subset of the random sequence has a first length-, and the positioning signal during the second time period in which the second part of the positioning signal is modulated by the second member of the subset of the digital pseudorandom sequence. Transmitting; the second configuration of the subset of the digital pseudorandom sequence has a second length.

The first length and the second length are different.

The set of digital pseudorandom sequences has an alphabet size greater than 2.

The set of digital pseudorandom sequences is a set of quaternary sequences.

The alphabet size is a power of two.

The specified region adjacent to the peak of the autocorrelation function includes at least 10 contiguous symbols immediately adjacent to the peak of the autocorrelation function.

The second portion of the positioning signal is further modulated according to the data sequence.

The second mode of operation of the remote receiver includes network-based positioning where the server calculates the position of the remote receiver from information obtained from at least one of a positioning signal and a satellite signal, wherein the remote receiver includes the positioning signal and satellite The information obtained from at least one of the signals is received and transmitted to the server.

Embodiments described herein include a positioning system. The system includes a terrestrial transmitter network including a plurality of transmitters that broadcast positioning signals and positioning data. The positioning data includes a positioning signal and data bits used to calculate a distance to a transmitter that broadcasts positioning data. Multiple transmitters select a set of digital pseudorandom sequences, and the magnitude of the cross-correlation function between any two sequences of the set of digital pseudorandom sequences is below a specified threshold. The plurality of transmitters selects a subset of the digital pseudorandom sequence from the set of digital pseudorandom sequences, and the size of the autocorrelation function of each member of the subset of the digital pseudorandom sequence is a specified region adjacent to the peak of the autocorrelation function. Within, it is equal to or less than the specified value, or less than or equal to the specified value. For each transmitter, at least a first portion of the positioning signal is modulated by at least one member of a subset of the digital pseudorandom sequence, and at least two transmitters of the plurality of transmitters transmit the positioning signal to a sub of the digital pseudorandom sequence. It is modulated by different members of the set.

Embodiments described herein include a positioning system, the system comprising a terrestrial transmitter network comprising a plurality of transmitters that broadcast positioning signals and positioning data, the positioning data being located A data bit used to calculate a distance to a transmitter that broadcasts the decision signal and positioning data, wherein multiple transmitters select a set of digital pseudorandom sequences, and any 2 of the set of digital pseudorandom sequences The size of the cross-correlation function between the four sequences is less than a specified threshold, and multiple transmitters select a subset of the digital pseudorandom sequence from the set of digital pseudorandom sequences, and autocorrelate each member of the subset of the digital pseudorandom sequence. The magnitude of the function, within a specified region adjacent to the peak of the autocorrelation function, is equal to, less than, or less than the specified value, and for each transmitter, at least a first portion of the positioning signal It is modulated by at least one member of a subset of the digital pseudorandom sequence, and at least two transmitters of the plurality of transmitters modulate the positioning signal by different members of the subset of the digital pseudorandom sequence.

A remote receiver for acquiring at least one of a positioning signal and a satellite signal, wherein the satellite signal is a signal of a satellite-based positioning system, and the first mode of operation of the remote receiver is that the remote receiver has a positioning signal and a satellite signal. And terminal-based positioning to calculate the position of the remote receiver from at least one of the following.

And a server connected to a remote receiver, wherein the second mode of operation of the remote receiver includes network-based positioning where the server calculates the position of the remote receiver from information obtained from at least one of a positioning signal and a satellite signal, wherein The remote receiver receives information obtained from at least one of the positioning signal and the satellite signal and transmits the information to the server.

The set of digital pseudorandom sequences includes a set of binary pseudorandom sequences.

The set of binary pseudorandom sequences is selected from a set of gold codes.

The specified value is the peak value of the autocorrelation function divided by the non-repeating length of the digital pseudorandom sequence.

The set of binary pseudorandom sequences is one of Kasami code, Bent code, and Gold-like code.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has a truncated sequence length, and the truncated sequence length is shorter than a standard sequence length.

At least one digital pseudorandom sequence in the set of digital pseudorandom sequences has an extended sequence length, the extended sequence length being longer than a standard sequence length.

Transmit a positioning signal from at least one of a plurality of transmitters during an hour period in which a first portion of the positioning signal is modulated by a first member of a subset of the digital pseudorandom sequence, and the subset of the digital pseudorandom sequence The first member of has a first length and transmits the positioning signal during a second period in which a second portion of the positioning signal is modulated by a second member of a subset of the digital pseudorandom sequence, and the digital pseudorandom The second member of the subset of the sequence has a second length.

The first length and the second length are different.

The set of digital pseudorandom sequences has an alphabet size greater than 2.

The set of digital pseudorandom sequences is a set of quaternary sequences.

The alphabet size is a power of two.

The specified region adjacent to the peak of the autocorrelation function includes at least 10 contiguous symbols immediately adjacent to the peak of the autocorrelation function.

The first part of the positioning signal is modulated by a member of a subset of the digital pseudorandom sequence, and the second part of the positioning signal is further modulated according to a data sequence containing positioning data.

The system includes a communication system connected to at least one of a remote receiver and a plurality of transmitters, and the communication system is a cellular communication system.

Multiple transmitters are synchronized.

Each transmitter of a plurality of transmitters transmits positioning data including auxiliary data, the auxiliary data being a system time at an epoch of a waveform, geocode data of a plurality of transmitters, and a plurality of transmitters Geocode data of adjacent adjacent transmitters, indexes of sequences used by at least one transmitter proximate to multiple transmitters, clock timing correction for at least one transmitter, local atmospheric correction ), An indicator for the local environment to assist the remote receiver at pseudorange resolution, an offset from the base index of the set of digital pseudorandom sequences, a list of digital pseudorandom sequences from the transmitter set, and a specific digital pseudo. And a list of transmitters using a random number sequence.

The signal transmitted by the plurality of transmitters includes a preamble for at least one of frequency acquisition and timing alignment.

The plurality of transmitters form a CDMA network.

The plurality of transmitters form a TDMA network.

The carrier signal of each transmitter is offset from at least one other carrier signal of the other transmitter among the plurality of transmitters.

The plurality of transmitters are positioned such that a remote receiver receives signals from at least three transmitters, and the geometric dilution of precision at each location is lower than a threshold, and the location of each transmitter of the plurality of transmitters is covered. It is determined by minimizing a function that is the volume integral of the power-of-squares of the rate of degradation of geometric precision over the volume of the volume, the volume integral being relative to the coordinates of the position of the remote receiver, the minimization of the function being multiple transmitters within a specified coverage area Of transmitters for the transmitter's location coordinates, the function is weighted according to the performance quality of the coverage area.

Each transmitter of the plurality of transmitters is synchronized to a time reference, and the time correction of each transmitter is provided to the remote receiver.

The remote receiver receives ancillary data, the ancillary data being the system time at the epoch of the waveform, the system time at the falling edge of the pulse of the waveform, and the geocode data of the plurality of transmitters , Geocode data of transmitters adjacent to a plurality of transmitters, indexes of sequences used by at least one transmitter close to the plurality of transmitters, clock timing correction for at least one transmitter, local atmospheric correction correction), an indicator for the local environment to assist the remote receiver at pseudorange resolution, offset from the base index of the set of digital pseudorandom sequences, a list of digital pseudorandom sequences from the set of transmitters, and the number of specific digital pseudorandoms. And a list of transmitters using the sequence.

An atmospheric data sensor is included as a component of a remote receiver, and at least one of the remote receiver and the server calculates the position of the remote receiver using the data of the standby data sensor, and the data of the standby data sensor Pressure data, temperature data, and humidity data.

At least one of the remote receiver and the server calculates the final position of the remote receiver using a combination of range measurements determined using a positioning signal and range measurements from at least one additional signal source, the final positions being latitude, longitude, and And at least one of height.

The components described herein may be located together or in separate locations. The communication path includes any medium for connecting components and communicating or transferring files between components. Communication paths include wireless connections, wired connections, and hybrid wired / wireless connections. Communication paths also include connections or connections to networks, such as local area networks (LANs), urban area networks (MANs), wide area networks (WANs), private networks, interoffice or backend networks, and the Internet. In addition, communication paths include removable fixed media, such as floppy disks, hard disk drives, and CD-ROM disks, as well as flash RAM, global serial bus (USB) connections, RS-232 connections, telephone lines, buses, and e-mail. Message.

Aspects of the systems and methods described herein include, for example, programmable logic devices (PLDs), such as field programmable gate arrays (FPGA), programmable array logic (PAL) devices, electrical programmable logic and memory devices, and standard cells. -Can be implemented as a functional unit programmed in any of a variety of circuits, such as based devices, application specific integrated circuits (ASICs). Some other possibilities for implementing aspects of the systems and methods include: microcontrollers that include memory (eg, electronically erasable programmable read-only memory (EEPROM)), embedded microprocessors, firmware, software, etc. Additionally, aspects of the systems and methods have software-based circuit emulation, discrete logic (sequential and combination), custom devices, fuzzy (neural) logic, quantum devices, and hybrids of any of the above device types. It can be embedded in a microprocessor. The underlying device technology includes various component types, such as metal-oxide semiconductor field-effect transistor (MOSFET) techniques, such as complementary metal-oxide semiconductor (CMOS), bipolar techniques, such as emitter-coupled logic (ECL), polymer technologies. (Eg, silicon-conjugated polymer and metal-conjugated polymer-metal structure), analog and digital mixed type, and the like.

Throughout the description and claims, unless expressly required otherwise by context, "include", "comprising", and similar words are to be interpreted inclusively, not exclusively or exclusively, ie, "non-limiting." It is interpreted as "including." Words using the singular or plural form include the plural or singular form, respectively. In addition, the words "here", "below", "above", "below" and similar meanings, when used herein, are used herein to refer to the application as a whole, not to any specific portion. When used with reference to a list of two or more items, the word “or” includes the meaning of any item in the list, all items in the list, and any combination of items in the list.

The above description of embodiments of systems and methods is not intended to limit the systems and methods to the precise disclosed forms. Although specific embodiments and examples of systems and methods have been described for illustrative purposes, various equivalent modifications are possible within the scope of the systems and methods that would be known to those skilled in the art. Descriptions of the systems and methods provided herein can be applied to the systems and methods described above, as well as other systems and methods. The elements and steps of the various embodiments described above can be combined to provide additional embodiments. These and other changes can be made to the system and method in connection with the detailed description above.

In general, in the following claims, the terms used should not be construed as limiting the systems and methods to the specific embodiments disclosed in the description and claims, but as including all systems and methods possible within the scope of the claims. Should be interpreted. Accordingly, the system and method should not be limited by the disclosure so far, but should be determined only by the claims. Although specific aspects of the systems and methods are provided in the specific claims form below, the inventors contemplate various aspects of the systems and methods in any number of claims. Accordingly, the inventors have the right to add these additional claims to other aspects of the system and method after filing.

Claims (102)

A method for transmitting one or more positioning signals from one or more transmitters, the method comprising:
Identifying a set of pseudorandom sequences, each pseudorandom sequence of the set of pseudorandom sequences comprising a set of phase angles used to phase modulate the positioning signal, and any two of the sets of pseudorandom sequences The maximum size of the cross-correlation function between two pseudorandom sequences is below a specified threshold.
Identifying a subset of at least three pseudorandom sequences from the set of pseudorandom sequences
And all sizes of an autocorrelation function corresponding to the pseudorandom sequence of the subset are equal to or less than a specified value within a designated area adjacent to a peak of the autocorrelation function,
The size of two or more of the autocorrelation functions, outside the designated area, exceeds the specified value,
The cross-correlation function and the auto-correlation function are cyclic cross-correlation functions and cyclic auto-correlation functions. The method of claim 1, wherein the specified value is less than a maximum size of a cross-correlation function between any two pseudorandom sequences of a subset of pseudorandom sequences. 3. The method according to claim 2, wherein the specified value is a value of +/- 1 times the peak value of the autocorrelation function divided by the non-repeating length of the pseudorandom sequence. delete The method of claim 1, wherein a designated area adjacent to a peak of the autocorrelation function comprises at least 10 pseudorandom sequence symbols. The signal of claim 2, wherein the set of pseudorandom sequences comprises a set of binary pseudorandom sequences selected from one of Kasami code, Bent code, or Gold code. Method for sending. The method of claim 1, wherein at least one pseudorandom sequence in the set of pseudorandom sequences has a truncated sequence length, wherein the truncated sequence length is shorter than a standard sequence length. The method of claim 1, wherein at least one pseudorandom sequence in the set of pseudorandom sequences has an extended sequence length, wherein the extended sequence length is longer than a standard sequence length. The method of claim 1, wherein the method
Transmitting a positioning signal from a first one of the one or more transmitters for a first period of time, wherein a first portion of the positioning signal is modulated by a first pseudorandom sequence of a subset of the pseudorandom sequence, and the first The pseudorandom sequence has a first length-, and
Transmitting a positioning signal from the first transmitter for a second period of time-a second portion of the positioning signal is modulated by a second pseudorandom sequence of a subset of the pseudorandom sequence, and the second pseudorandom sequence Has a second length-
A method for transmitting a signal, further comprising. 10. The method of claim 9, wherein the first length and the second length are different. The method of claim 1, wherein the set of pseudorandom sequences has an alphabet size greater than 2. 12. The method of claim 11, wherein the set of pseudorandom sequences is a set of quaternary sequences. 12. The method of claim 11, wherein the alphabetic size is at least a power of two. The method of claim 1, wherein the method
Modulating at least a first portion of the first positioning signal according to the first pseudorandom sequence of the subset of the pseudorandom sequence,
Transmitting a first positioning signal from a first one of the one or more transmitters,
Modulating at least a second portion of the second positioning signal according to the second pseudorandom sequence of the subset of the pseudorandom sequence,
And transmitting a second positioning signal from a second one of the one or more transmitters. The method of claim 1, wherein the set of pseudorandom sequences comprises at least 176 pseudorandom sequences, and the subset of pseudorandom sequences comprises 10 or fewer pseudorandom sequences. delete delete delete One or more computer readable storage storing program instructions that, when executed by one or more processors, cause the one or more processors to perform a method according to any one of claims 1 to 3 and 5 to 15. media. A network of transmitters for transmitting one or more signals from one or more transmitters, wherein the one or more transmitters are configured to perform a method according to any one of claims 1 to 3 and 5 to 15, Network of transmitters. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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