KR20220129487A - Variable binary offset carrier modulation method with discrete time varying frequency and satellite navigation signal generator - Google Patents

Abstract

Disclosed are a method for modulation of a variable binary offset carrier (BOC) having a discrete time-variant frequency and a satellite navigation signal generator using the same. The method for modulation of a VBOC having a discrete time-variant frequency may comprise the steps of: generating navigation message data; generating a carrier; generating a VBOC subcarrier; generating a pseudo-random code; synthesizing the pseudocode and the VBOC subcarrier; and synthesizing a synthesized signal of the pseudocode and the VBOC subcarrier, the carrier, and the navigation message data.

Description

VARIABLE BINARY OFFSET CARRIER MODULATION METHOD WITH DISCRETE TIME VARYING FREQUENCY AND SATELLITE NAVIGATION SIGNAL GENERATOR

The present invention relates to a satellite navigation signal modulation technique, and more particularly, a method for generating a modulated signal by sweeping a Binary Offset Carrier (BOC) frequency having a frequency that varies discretely with time, and the method It relates to an apparatus for generating a satellite navigation signal used.

Currently, a global navigation satellite system (GNSS) including a global positioning system (GPS) is widely used. Existing GNSS transmits a navigation message using BPSK (BiPhase Shift Keying) and BOC (Binary Offset Carrier) based modulation techniques based on Code Division Multiple Access (CDMA).

Meanwhile, the frequency band allocated to the navigation satellite signal is saturated due to the existing GNSS currently in commercial use or various modulation techniques planned for GNSS modernization, and patent costs are expected to occur due to the use of the existing satellite navigation signal system. In other words, it is necessary to study the satellite navigation signal system of a new technique in order to avoid performance degradation and regulation due to the influence of mutual interference with the existing system and to increase the positioning performance in the urban area where the positioning performance is rapidly falling.

In addition, the development of GNSS satellite navigation systems in countries around the world is overheating. As GNSS signal entry into the satellite navigation signal band is oversaturated, it is becoming important to consider the effect of interference between signals.

In addition, it is very important to improve positioning accuracy in an urban area where location-based services are rapidly increasing in an urban environment due to the increase of modern people living in cities.

However, although many research and development results have appeared on technologies for minimizing the influence of interference on existing signals and improving positioning accuracy, there has been no attempt to change the satellite navigation signal itself.

As such, unless a satellite navigation system of a new direction is not developed, there is a limit to the development of a technology that improves positioning performance while avoiding interference effects because positioning technology must be developed focusing on the existing GNSS signal.

The present invention was derived to overcome the above-described limitations of the prior art, and an object of the present invention is to minimize interference effects and improve positioning accuracy by using discrete time-varying frequencies that have not been attempted in the existing GNSS satellite navigation signal modulation technique. An object of the present invention is to provide a method for variable binary offset carrier modulation.

A variable binary offset carrier modulation method according to an aspect of the present invention for solving the above technical problem is a variable binary offset carrier modulation method having a discrete time-varying frequency, the method comprising: generating navigation message data; generating a carrier wave; generating a Variable Binary Offset Carrier (VBOC) subcarrier; generating pseudo code; synthesizing the pseudo code and the VBOC subcarrier; and synthesizing the synthesized signal of the pseudo code and the VBOC subcarrier, and the carrier and navigation message data.

In an embodiment, the generating of the VBOC subcarrier may include multiplying the original signal by a square wave having a specific fixed frequency.

In an embodiment, the generating of the VBOC subcarrier may include discretely increasing or decreasing the frequency of a Binary Offset Carrier (BOC) signal according to time during a specific period.

In one embodiment, the start frequency, end frequency and frequency interval of the frequency of the BOC signal may be adjustment parameters set for VBOC modulation.

A satellite navigation signal generator according to another aspect of the present invention for solving the above technical problem is a satellite navigation signal generator for performing Variable Binary Offset Carrier (VBOC) modulation having a discrete time-varying frequency, processor; and a memory storing program instructions executed by the processor, wherein when executed by the processor, the program instructions cause the processor to: generate navigation message data; generating a carrier wave; generating a VBOC subcarrier; generating pseudo code; synthesizing the pseudo code and the VBOC subcarrier; and synthesizing the synthesized signal of the pseudo code and the VBOC subcarrier with the carrier and the navigation message data.

In an embodiment, in the generating of the VBOC subcarrier, the processor may perform multiplying the original signal by a square wave having a specific fixed frequency.

In an embodiment, in the generating of the VBOC subcarrier, the processor may perform discretely increasing or decreasing the frequency of a Binary Offset Carrier (BOC) signal according to time for a specific period.

A satellite navigation signal generator according to another aspect of the present invention for solving the above technical problem is a satellite navigation signal generator for performing Variable Binary Offset Carrier (VBOC) modulation having a discrete time-varying frequency. , a navigation message processing unit for generating navigation message data; a carrier wave generator generating a carrier wave; a subcarrier generator generating a VBOC subcarrier; a pseudo code generator for generating pseudo code; a first synthesizer for synthesizing the pseudo code and the VBOC subcarrier; and a second synthesizer that synthesizes the synthesized signal of the pseudo code and the VBOC subcarrier, the carrier, and the navigation message data.

In one embodiment, the navigation message processing unit, carrier generation unit, subcarrier generation unit, pseudo code generation unit, first combining unit and second combining unit are implemented as means mounted on a processor or a component performing a function corresponding to these means. can be

In an embodiment, the navigation message processor, carrier generator, subcarrier generator, pseudo code generator, first combiner, and second combiner may be implemented as software modules or program instructions executed by a processor.

In an embodiment, the subcarrier generator may perform an operation or operation of multiplying an original signal by a square wave having a specific fixed frequency.

In an embodiment, the subcarrier generator may perform an operation or operation of discretely increasing or decreasing the frequency of a Binary Offset Carrier (BOC) signal according to time during a specific period.

According to the present invention, positioning performance can be significantly improved in most newly released GNSS receivers as well as existing Global Navigation Satellite System (GNSS) receivers.

In particular, it is easy to estimate the changing frequency pattern by one-time inference by increasing the existing BOC signal to the maximum frequency or decreasing it to the minimum frequency at a predetermined constant time interval using an algorithm that finds the frequency that varies discretely during a certain period. In this way, it is possible to provide a variable binary offset carrier (BOC) modulation method having similar or improved performance while having very low complexity of a transmitter and a receiver compared to the prior art.

1 is a block diagram of an apparatus for generating a satellite navigation signal according to a comparative example.
2 is a diagram illustrating a structure of a satellite navigation signal generating apparatus according to an embodiment of the present invention and a VBOC subcarrier generated by the apparatus.
FIG. 3 is an exemplary diagram illustrating a Variable BOC (VBOC) signal usable by the satellite navigation signal generating apparatus of FIG. 2 and a Binary Offset Carrier (BOC) of a comparative example.
4 is a graph illustrating a comparison between the normalized power spectrum density (PSD) of the VBOC signal generated by the satellite navigation signal generating apparatus of FIG. 2 and the PSD of the GNSS signal of the comparative example.
FIG. 5 is an exemplary diagram illustrating autocorrelation envelopes that can be employed for VBOC modulation of the apparatus for generating a satellite navigation signal of FIG. 2 .
FIG. 6 is an exemplary diagram illustrating multipath error envelopes that can be employed for VBOC modulation of the apparatus for generating a satellite navigation signal of FIG. 2 .
FIG. 7 is a block diagram of a configuration of a main device that can be employed in the satellite navigation signal generating device of FIG. 2 .

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

In embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B”. Also, in the embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B”.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that this does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

A communication system or a memory system to which embodiments according to the present invention are applied will be described. A communication system or memory system to which embodiments according to the present invention are applied is not limited to the contents described below, and embodiments according to the present invention may be applied to various communication systems. Here, a communication system may be used in the same meaning as a communication network (network).

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, in order to facilitate the overall understanding, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

1 is a block diagram of an apparatus for generating a satellite navigation signal according to a comparative example.

Referring to FIG. 1 , the satellite navigation signal generating apparatus 100 of the comparative example is used for a satellite transmitter, etc., and adds 1 to the N spreading code generated by the spreading code generating unit 141 through the voice data selective synthesizer 130 ( true) After adding 0 (false), it is input as sub-chirp 1 (142-1) or sub-chirp 2 (142-2), and down from sub-chirp 1 (142-1) and sub-chirp 2 (142-2) A signature code is generated by passing the chirp and up-chirp signals through a root raised cosine (RRC) window 143 . The signature code generated by the signature code generator 140 is used to spread the navigation message 110 through the synthesizer 150 . Here, the two sub-chips of the sub-chirp 1 142-1 and the sub-chirp 2 142-2 are composed of a down chirp sweeping from a high band to a low band and an up chirp swiping from a low band to a high band.

In the case of a chirp signal, since the frequency used varies according to time, the interference effect is significantly smaller than that of general satellite navigation signals. However, since the chirp signal continuously sweeps the frequency, an expensive receiver supporting a high sampling frequency is required when receiving the corresponding signal, and the low-cost receiver has a large error or cannot be used.

In addition, when two types of sub-chirps are used according to the spreading code, the receiver must have a structure in which Doppler frequency detection for the two sub-chirps must be processed respectively, so an additional frequency phase detection algorithm for continuous frequency sweep is required. do.

For example, the BOC subcarrier generated by the BOC modulation technique is multiplied with a BPSK (Binary Phase Shift Keying) signal to give an effect of shifting the intermediate frequency of the existing BPSK signal. The BOC subcarrier is a square wave f _S (f _S =m/T _C0 [Hz]) of the chip duration T _C (T _C =T _C0 /n, where T _C0 is 10 ^-3 /1023[s]) generated differently according to At this time, the generated BOC subcarrier is divided into SinBOC(BOC _S (m,n)) or CosBOC(BOC _C (m,n)) according to the phase of the square wave. The BOC signal contains several square waves for the duration of the BPSK chip, so the ACF has 2 (2m/n-1) peaks, unlike the BPSK auto-correlation function (ACF) envelope. Show the envelope. Secondary peaks other than the main peak generate an error of a multipath error envelope, thereby reducing the stability of the receiver for multipath. Therefore, in order to reduce an error occurring in a multipath channel, a signal modulation technique for lowering the signal level or reducing the number of secondary peaks is required.

Also, most GNSS receivers do not include an associated algorithm. In addition, since an expensive receiver with a very high sampling frequency is required to detect a continuous frequency change, the use area is considerably limited.

Therefore, the advantages of the chirp spreading technique of the comparative example, which maximizes the autocorrelation characteristic of a signal by continuously sweeping the frequency according to time, and the frequency hopping technique, which varies the frequency discretely according to time by discretely changing the frequency pseudorandomly. The present invention was implemented based on the fact that the BOC modulation technique of dividing the intermediate frequency by multiplying the original signal by multiplying the spherical subcarrier has the effect of shifting the frequency similarly to the sine wave.

In the present invention, it is based on the BOC subcarrier applied to avoid the effect of interference between signals in the existing GNSS satellite navigation system. The BOC subcarrier is a modulation technique that multiplies the original signal by a square wave with a specific fixed frequency. The variable BOC modulation technique of the present invention can increase or decrease the frequency of the BOC signal discretely according to time for a specific period, thereby increasing the autocorrelation characteristic of the signal and reducing the interference effect relatively less than that of existing signals. In addition, the present invention can be robust against noise and multipath because it exhibits inherently correlated properties of signals with time.

2 is a diagram illustrating a structure of a satellite navigation signal generating apparatus according to an embodiment of the present invention and a VBOC subcarrier generated by the apparatus. FIG. 3 is an exemplary diagram illustrating a Variable BOC (VBOC) signal usable by the satellite navigation signal generating apparatus of FIG. 2 and a Binary Offset Carrier (BOC) of a comparative example.

Referring to FIG. 2 , the apparatus 200 for generating a satellite navigation signal may be used for a satellite receiver or the like. The satellite navigation signal generating apparatus 200 includes a navigation message processing unit 10 , a carrier generating unit 20 , a subcarrier generating unit 30 , a pseudo code generating unit 40 , a first combining unit 50 , and a second combining unit. (60).

The navigation message processing unit 10 generates navigation message data. The carrier wave generator 20 generates a carrier wave. The subcarrier generator 30 generates a VBOC subcarrier. The VBOC subcarrier may be generated by multiplying an original signal by a square wave having a specific fixed frequency. This VBOC subcarrier modulation method increases or decreases the frequency of the BOC signal with time for a specific period to increase the autocorrelation characteristic of the signal.

The pseudo code generator 40 generates a pseudo code. The first synthesizer 50 synthesizes the pseudo code and the VBOC subcarrier. In addition, the second synthesizer 60 generates a VBOC-modulated spread spectrum navigation message signal by synthesizing a synthesized signal of a pseudo code and a VBOC subcarrier, a carrier wave, and a navigation message.

Unlike frequency hopping, the discrete time-varying frequency of the present embodiment has a pattern of increasing or decreasing at regular frequency intervals. In this case, the start and end frequencies and the frequency interval may be control parameters that can be set in the modulation method of the present embodiment.

As described above, the apparatus for generating a navigation satellite signal according to the present embodiment may generate a VBOC-modulated spread signal using a square wave having a discrete time-varying frequency, that is, a VBOC signal, rather than a square wave having a fixed frequency in BOC modulation of the GNSS signal. The BOC signal may refer to the left or upper signal of FIG. 3 , and the VBOC signal may refer to the right or lower signal of FIG. 3 , respectively. Here, VBOC may be VBOC(1:1:6,1) (ie, M _list = {1:1:6}, chip rate 1.023 MHz), which considers the GNSS signal currently being serviced in the L1 band. will be.

A common method to analyze code-lock performance in a multipath channel environment with a single reflection path is to generate a multipath error envelope. The multipath error envelope can be expressed by providing, for each reflected path delay (excess delay) value, the maximum code phase error obtained with a given code discriminator, such as an early-late (EL) discriminator. .

4 is a graph showing a comparison between the normalized power spectrum density (PSD) of the VBOC (1:1:6,1) signal generated by the satellite navigation signal generating apparatus of FIG. 2 and the PSD of the GNSS signal of a comparative example. to be.

4 shows the VBOC(1:1:6,1) signal of the present embodiment proposed as a GNSS signal for comparison with signals of other GNSS systems operating in the L1 band, assuming that it is disposed in the L1 band. :1:6,1) The signal is normalized so that the power becomes 1 over the entire 20 MHz bandwidth, and this is shown in the L1 band. That is, in FIG. 4, the VBOC (1:1:6,1) signal of the present embodiment having a bandwidth (B) of 20 MHz and a chip spacing (Δ) of 0.1 × T _C0 and the BPSK (1), CBOC ( 6,1,1/11), PBPSK(10), MBOC(10,5) and BOC signals multipath error envelopes are shown.

Looking at the normalized power spectral density (PSD) of the VBOC (1:1:6,1) signal, it can be seen that it affects almost all areas except the intermediate frequency of the L1 band. On the other hand, the VBOC (1:1:6,1) signal, unlike the signals of other satellite navigation systems of the comparative example, has different frequency bands over time and is evenly distributed throughout the band, so the influence of interference on a specific GNSS system is reduced. It is not expected to be strong. When expressed numerically using a Spectrum Separate Coefficient (SSC) indicating how much frequency overlap between signals in a frequency band is, the SSC may be expressed as in Equation (1).

는 해당 신호,

는 상대할 신호의 PSD이며,

는 해당 신호와 상대신호 간의 SSC를 나타낸다.In Equation 1,

is the corresponding signal,

is the PSD of the signal to be dealt with,

represents the SSC between the corresponding signal and the counterpart signal.

There are other signals operating in the L1 band, but in the case of CosBOC (15, 2.5), since the PSD is placed outside the previously set 20 MHz bandwidth, the SSC is expected to be significantly lower, so it was not considered. Therefore, the SSC is analyzed for signals existing within the 20 MHz bandwidth where the VBOC (1:1:6,1) signal is expected to be affected by interference, and the results of the analysis are shown in Table 1.

As described above, the satellite navigation signal generating apparatus of the present embodiment may change the frequency interval and the minimum maximum frequency when increasing and decreasing the frequency of the VBOC subcarrier. This can be expressed as a power spectral density as shown in FIG. 4 . FIG. 4 corresponds to the power spectrum density obtained by adding the VBOC (1:1:6,1) signal of the present embodiment to the L1 band where the current GNSS signal enters the most. In the case of VBOC(1:1:6,1) signal expressed in power spectral density, considering CBOC(6,1,1/11) signal having the widest main bandwidth in L1 band, 1 MHz to 6 MHz It can vary discretely by MHz.

The present embodiment provides a Variable Binary Offset Carrier (VBOC) modulation method for a next-generation Global Navigation Satellite System (GNSS). The modulation method of the present embodiment is based on a BOC signal giving an effect of shifting the intermediate frequency of a signal using a square wave and a chirp signal increasing or decreasing the frequency according to time.

In addition, in the modulation method of this embodiment, the auto-correlation function (ACF) envelope of the VBOC signal modulated with an appropriate internal parameter setting is significantly higher than the ACF envelope of signals generated by the conventional signal modulation technique. It has a characteristic of being sharp and the level of the secondary peak is very low. With these characteristics, the GNSS receiver can significantly reduce code delay errors in the acquisition and tracking phases in a multi-channel environment occurring in urban areas.

In addition, when a next-generation GNSS signal enters an existing band, it is highly likely to be affected by interference from existing signals. Existing signals sharing the same band avoid the interference effect by using the BOC signal to offset the intermediate frequency in order to reduce the interference effect between the signals. However, since the signal generated by the modulation method of the present embodiment changes the frequency of the BOC signal for a certain short time unlike the existing signals, the time for sharing the same frequency during the signal collection time is very short, so the influence of interference is very small.

In order to confirm this, the performance is checked in the multipath channel by generating a multipath error envelope of the existing signals and the VBOC signal of the present embodiment, and the signals of the L1 band are combined with the VBOC signal and the SSC (Spectral Separation Coefficient) ) can be calculated to analyze the interference effect.

A process of generating the VBOC-modulated spread signal by the apparatus for generating a satellite navigation signal according to the present embodiment described above will be described in more detail as follows.

Considering the Chip section, the square wave of the BOC modulation technique can be defined as in Equation 2.

The _VBOC signal of this example increases or decreases m for an integer multiple of TCO. The VBOC signal may be defined as BOC(M _list ,n), and M _list may be defined as in Equation (3).

And the VBOC signal y _VBOC or y _V-BOC (t) expressed based on the BOC signal may be expressed as Equation (4).

개씩 각

동안 동일한 생성 파라미터 (M_list(x),n)을 갖고 l번 중간 주파수의 증가 및 감소를 반복하는 BOC 신호들의 조합으로 생성될 수 있다. 예를 들어, 소정의 샘플링 주파수가 20㎒의 전체 1㎳ 동안 시간에 따라 다양한 조합의 M_list 배열, 예컨대 {1:1:6}, {1:2:5}와 같은 VBOC 생성 파라미터(m)의 변화 값을 이용할 수 있다.The VBOC signal is (fs)/q M _list array elements during T _CO

each by

It can be generated as a combination of BOC signals that have the same generation parameter (M _list (x), n) while repeating the increase and decrease of the l-th intermediate frequency. For example, an M _list array of various combinations according to time for a total of 1 ms of 20 MHz with a predetermined sampling frequency, for example, VBOC generation parameters (m) such as {1:1:6}, {1:2:5} You can use the change value of .

That is, the VBOC modulation method of the present embodiment can generate the VBOC signal of the M _list combination that provides optimal performance according to the hardware specification or frequency allocation condition of the GNSS receiver. For example, the simplest combination of the VBOC signal of this embodiment of M _list = {1:1:6} (eg, VBOC(1:1:6,1)) and the BPSK, BOC(1,1) of the comparative examples The normalized ACF envelope of , BOC(6,1), and CBOC(6,1,1/11) is expressed as shown in FIG. 5 . FIG. 5 is an exemplary diagram illustrating autocorrelation envelopes that can be employed for VBOC modulation of the apparatus for generating a satellite navigation signal of FIG. 2 .

개지만, 그에 반해 본 실시예의 VBOC(1:1:6,1)의 경우에는 0.1을 초과하는 세컨더리 피크가 없다. ACF 출력에서 세컨더리 피크의 크기가 작을 수록 탐색(acquisition)과 추적(tracking) 단계에서 부호 위상(code phase) 오차가 작아지기 때문에 본 실시예의 VBOC(1:1:6,1) 신호의 부호락(code-lock) 성능이 비교예들 대비 더 우수함을 알 수 있다.Referring to FIG. 5 , the main peak of ACF is the sharpest in BOC(6,1), but does not show a significant difference from VBOC(1:1:6,1). However, in the case of BOC(6,1), the secondary peak where the level of the ACF output exceeds 0.1 is 22.

On the other hand, in the case of VBOC (1:1:6,1) of this embodiment, there is no secondary peak exceeding 0.1. The smaller the size of the secondary peak in the ACF output, the smaller the code phase error in the acquisition and tracking steps. It can be seen that the code-lock) performance is better than that of the comparative examples.

FIG. 6 is an exemplary diagram illustrating multipath error envelopes that can be employed for VBOC (1:1:6,1) modulation of the apparatus for generating a satellite navigation signal of FIG. 2 .

6, the VBOC(1:1:6,1) signal of this embodiment is BPSK(1), BOC(1,1), BOC(6,1), CBOC(6,1,1/) of the comparative example. 11) It shows a much better modulation technique than the signals of the comparative example by having a very small error, that is, about 1 m at a shorter multipath delay (Multipath delay > 40 m) than the signals.

As such, it can be confirmed that the modulation method of the present embodiment is robust in a multipath channel as a next-generation GNSS and has very little interference effect when a proposed signal enters an existing band. In addition, the modulation method of this embodiment can be used by analyzing the performance of the VBOC signal according to various internal parameters to select and use the optimal parameters, and it is expected that it will also contribute to the improvement of the performance of the L6 and S bands where the next-generation GNSS will enter. do.

FIG. 7 is a block diagram of a configuration of a main device that can be employed in the satellite navigation signal generating device of FIG. 2 .

Referring to FIG. 7 , the satellite navigation signal generating apparatus 300 may be connected to or mounted on a satellite transmitter, a satellite receiver, or a satellite transmitter/receiver. The satellite navigation signal generating apparatus 300 may include at least one processor 310 , a memory 320 , and a transceiver 330 connected to a network to perform communication. In addition, the satellite navigation signal generating apparatus 300 may further include an input interface device 340 , an output interface device 350 , a storage device 360 , and the like. Each component included in the frequency sharing device 300 may be connected by a bus 370 to communicate with each other.

The processor 310 may execute a program command stored in at least one of the memory 320 and the storage device 360 . The processor 310 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed.

Each of the memory 320 and the storage device 360 may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 320 may be configured as at least one of a read only memory (ROM) and a random access memory (RAM).

The transceiver 330 is a sub-communication system supporting a communication connection with a satellite, a sub-communication system supporting wired or wireless communication with a general-purpose base station, or an ideal backhaul link with a mobile edge core network or a core network. (ideal backhaul link) or non- (non) may include a sub-communication system for the connection of the ideal backhaul link. Here, the processor 310 generates a VBOC-modulated spread signal, transmits the generated VBOC-modulated spread signal to the satellite through the transceiver 330, and receives the VBOC-modulated spread signal received from the satellite through the transceiver 330. It can be processed to obtain a navigation message.

The input interface device 340 includes at least one selected from input means such as a keyboard, a microphone, a touch pad, and a touch screen and an input signal processing unit that maps or processes a signal input through at least one input means with a pre-stored command. may include

The output interface device 350 includes an output signal processing unit that maps or processes the signal output under the control of the processor 310 to a pre-stored signal type or level, and a signal in the form of vibration, light, etc. according to the signal of the output signal processing unit. I may include at least one output means for outputting the information. The at least one output means may include at least one selected from output means such as a speaker, a display device, a printer, an optical output device, and a vibration output device.

In addition, the program instructions executed by the processor 310 include instructions for generating navigation message data, instructions for generating carriers, instructions for generating VBOC subcarriers, instructions for generating pseudo code, instructions for synthesizing pseudo code and VBOC subcarriers, It may include a command for synthesizing a synthesized signal of a pseudo code and a VBOC subcarrier, a carrier wave, and a navigation message.

The methods according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer readable medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software.

Examples of computer-readable media include hardware devices specially configured to store and carry out program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as at least one software module to perform the operations of the present invention, and vice versa.

Although it has been described with reference to the above embodiments, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. will be able

Claims (12)

A method for modulating a variable binary offset carrier wave having discrete time-varying frequencies, the method comprising:
generating navigation message data;
generating a carrier wave;
generating a Variable Binary Offset Carrier (VBOC) subcarrier;
generating pseudo code;
synthesizing the pseudo code and the VBOC subcarrier; and
and synthesizing the synthesized signal of the pseudo code and the VBOC subcarrier, and the carrier and navigation message data. The method according to claim 1,
The generating the VBOC subcarrier comprises multiplying the original signal by a square wave having a specific fixed frequency. The method according to claim 1,
The generating the VBOC subcarrier comprises discretely increasing or decreasing a frequency of a Binary Offset Carrier (BOC) signal according to time during a specific period. 4. The method of claim 3,
and the start frequency, end frequency and frequency interval of the frequency of the BOC signal become adjustment parameters set for modulation. A satellite navigation signal generator for performing Variable Binary Offset Carrier (VBOC) modulation having a discrete time-varying frequency, comprising:
processor; and a memory for storing program instructions executed by the processor;
When executed by the processor, the program instructions cause the processor to:
generating navigation message data;
generating a carrier wave;
generating a VBOC subcarrier;
generating pseudo code;
synthesizing the pseudo code and the VBOC subcarrier; and
and synthesizing the synthesized signal of the pseudo code and the VBOC subcarrier with the carrier and the navigation message data. 6. The method of claim 5,
In the step of generating, by the processor, the VBOC subcarrier, the original signal is multiplied by a square wave having a specific fixed frequency. 6. The method of claim 5,
The processor, in generating the VBOC subcarrier, discretely increases or decreases the frequency of the BOC (Binary Offset Carrier) signal according to time for a specific period. 8. The method of claim 7,
A start frequency, an end frequency, and a frequency interval of the frequency of the BOC signal become adjustment parameters set for modulation. A satellite navigation signal generator for performing Variable Binary Offset Carrier (VBOC) modulation having a discrete time-varying frequency, comprising:
a navigation message processing unit generating navigation message data;
a carrier wave generator generating a carrier wave;
a subcarrier generator generating a VBOC subcarrier;
a pseudo code generator for generating pseudo code;
a first synthesizing unit for synthesizing the pseudo code and the VBOC subcarrier; and
a second synthesizing unit synthesizing the synthesized signal of the pseudo code and the VBOC subcarrier, the carrier, and the navigation message data;
A satellite navigation signal generator comprising a. 10. The method of claim 9,
The subcarrier generating unit multiplies the original signal by a square wave having a specific fixed frequency. 10. The method of claim 9,
The subcarrier generating unit discretely increases or decreases the frequency of a BOC (Binary Offset Carrier) signal according to time during a specific period. 12. The method of claim 11,
A start frequency, an end frequency, and a frequency interval of the frequency of the BOC signal become adjustment parameters set for modulation.

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