KR102096043B1 - Method for reconstructing transmission and reception time of a high frequency signal and apparatus thereof - Google Patents

Abstract

The present invention relates to an apparatus for adjusting transmission / reception time of a high frequency signal, comprising: a signal divider for dividing a reference signal into two reference signals having the same phase; A phase controller that adjusts the phase of any one of the two reference signals; And a first phase locked loop that outputs a first signal based on the reference signal whose phase is not adjusted. And a second phase locked loop that outputs a second signal having a predetermined time difference from the first signal based on the reference signal in which the phase is adjusted.

Description

Method and apparatus for adjusting the transmission / reception time of a high-frequency signal {METHOD FOR RECONSTRUCTING TRANSMISSION AND RECEPTION TIME OF A HIGH FREQUENCY SIGNAL AND APPARATUS THEREOF}

The present invention relates to a method and apparatus for adjusting the transmission / reception time, and more particularly, to a method and apparatus for adjusting the transmission / reception time of a high frequency signal using a low frequency signal or a digital signal.

A time-delay (TTD) is a device used to intentionally delay a signal by a predetermined time. This time delay has been applied in various wireless communication technology fields.

As a method of creating a delay time through a time delayer, there is a method using a delay line. That is, a method of delaying the transmission / reception time of the corresponding signal by adding a delay line on the path through which the transmission / reception signal flows.

However, such a time delay method has a point in that it causes transmission loss of a transmission / reception signal or inadvertent amplitude modulation. In addition, there is a problem in that it is difficult to accurately implement a desired delay time or to require a large space for implementing the delay line.

Particularly, reconstructing the time of the transmission / reception signal in the high frequency band causes a high transmission loss of the corresponding signal, and causes a problem of increasing the volume of the corresponding system, which means that the more the transmission / reception signal is a broadband signal. It becomes a bigger problem. Therefore, there is a need for a method for effectively controlling the transmission / reception time of such high-frequency signals.

The present invention aims to solve the above and other problems. Another object is to provide a transmission / reception time control method and apparatus for adjusting a transmission / reception time of a high frequency signal using a low frequency signal or a digital signal.

Another object is to provide a transmission / reception time control method and apparatus for adjusting a transmission / reception time of a radar signal using a low frequency signal or a digital signal in an FMCW radar system.

Another object is to provide a transmission / reception time control method and apparatus for controlling transmission / reception time of a wireless power signal using a low frequency signal or a digital signal in a wireless power transmission system.

According to an aspect of the present invention to achieve the above or another object, a signal divider for distributing a reference signal to two reference signals having the same phase; A phase controller that adjusts the phase of any one of the two reference signals; And a first phase locked loop that outputs a first signal based on the reference signal whose phase is not adjusted. And a second phase locked loop for outputting a second signal having a predetermined time difference from the first signal based on the phase-adjusted reference signal.

More preferably, the reference signal in the transmission / reception time adjusting device is characterized in that it is a low-frequency signal or a digital signal.

More preferably, the transmission / reception time adjustment device is characterized in that it further comprises a signal generator for generating a reference signal.

More preferably, the first signal in the transmission / reception time adjusting device is a transmission chirp signal, and the second signal is a local chirp signal.

More preferably, the first signal in the transmission / reception time adjusting device is a local chirp signal, and the second signal is a transmission chirp signal.

According to another aspect of the invention, the transmit / receive antenna; A signal generator for generating a reference signal; A transmission / reception time adjusting unit configured to output a transmission chirp signal and a local chirp signal having a predetermined time difference based on a reference signal output from the signal generator; And it provides a FMCW radar system including a mixer unit for mixing the received chirp signal input to the receive antenna and the local chirp signal to output a bit frequency.

을 통해 계산되는 것을 특징으로 한다.More preferably, the bit frequency in the FMCW radar system is an equation

It is characterized by being calculated through.

More preferably, the FMCW radar system is characterized in that it further comprises a filter for filtering unwanted signals among signals output from the mixer unit.

More preferably, the filter unit in the FMCW radar system is characterized in that it is a bandpass filter of a medium frequency band.

More preferably, the transmission / reception time adjusting unit in the FMCW radar system includes a signal divider for distributing a reference signal to two reference signals, a phase controller for adjusting the phase of either of the two reference signals, and the two. And first and second phase locked loops for outputting the transmission chirp signal and the local chirp signal based on two reference signals.

According to another aspect of the present invention, in a method for adjusting transmission / reception time in a wireless power transmission system including a plurality of wireless power transmitters and one or more wireless power receivers, the first chirp signal from the first wireless power transmitter ( generating a chirp signal) and transmitting it to the second wireless power transmitter; The second chirp signal generated by the second wireless power transmitter is compared with the first chirp signal to adjust the time of the second chirp signal, and the time-controlled second chirp signal is used as the first wireless power transmitter. Transmitting; Detecting a distance between the first wireless power transmitter and the second wireless power transmitter based on the second chirp signal received from the second wireless power transmitter and the first chirp signal generated by the first wireless power transmitter; Provides a method for adjusting transmission / reception time in a wireless power transmission system.

When explaining the effect of the transmission / reception time control method and the apparatus according to the embodiments of the present invention are as follows.

According to at least one of the embodiments of the present invention, by reconfiguring the transmission / reception time of the FMCW radar signal using one phase controller and two phase locked loops, clutter is achieved through one fixed high-order filter. It has the advantage that it can be effectively removed.

In addition, according to at least one of the embodiments of the present invention, by adjusting the transmission time of each wireless power transmitter on the basis of the distance information between the wireless power transmitter in the wireless power transmission system, the wireless power receiver located at a long distance wireless power signal It has the advantage of being able to focus and investigate.

However, the effect of the transmission / reception time control method and the apparatus according to the embodiments of the present invention is not limited to those mentioned above, and other effects not mentioned belong to the present invention from the following description It will be clearly understood by those skilled in the art.

1 is a configuration diagram for explaining the FMCW radar system related to the present invention;
2A and 2B are diagrams referenced to describe the operation of the FMCW radar system;
3 is a configuration diagram for explaining the FMCW radar system to which the transmission / reception time adjustment method is applied;
4 is a view showing the output frequency of the mixer according to whether the transmission / reception time adjustment method is applied;
5 is a view showing the strength of a received signal with or without application of a transmission / reception time adjustment method;
6 is a block diagram schematically showing a transmission / reception time adjustment device according to an embodiment of the present invention;
7 is a configuration diagram for explaining an FMCW radar system implemented with a transmission / reception time adjustment device;
8 is a view referred to for describing an input signal and an output signal of a phase locked loop (PLL);
9 is a view showing a simulation result by applying the transmission / reception time control method according to the present invention to the FMCW radar system;
10 is a configuration diagram for explaining a wireless power transmission system to which the transmission / reception time adjustment method is applied;
11 is a signal flow chart referenced to describe the operation of a wireless power transmission system to which a transmission / reception time adjustment method is applied.

Hereinafter, exemplary embodiments disclosed herein will be described in detail with reference to the accompanying drawings, but the same or similar elements are assigned the same reference numbers regardless of the reference numerals, and overlapping descriptions thereof will be omitted. The suffixes "modules" and "parts" for the components used in the following description are given or mixed only considering the ease of writing the specification, and do not have meanings or roles distinguished from each other in themselves. That is, the term 'unit' used in the present invention refers to a hardware component such as software, FPGA or ASIC, and 'unit' performs certain roles. However, 'wealth' is not limited to software or hardware. The 'unit' may be configured to be in an addressable storage medium or may be configured to reproduce one or more processors. Thus, as an example, 'part' refers to components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, Includes subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, database, data structures, tables, arrays and variables. The functionality provided within components and 'parts' may be combined into a smaller number of components and 'parts' or further separated into additional components and 'parts'.

In addition, in describing the embodiments disclosed in the present specification, when it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed herein, detailed descriptions thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed in the specification is not limited by the accompanying drawings, and all modifications included in the spirit and technical scope of the present invention , It should be understood to include equivalents or substitutes.

The present invention proposes a method for effectively adjusting the transmission / reception time of a high frequency signal using a low frequency signal or a digital signal.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings.

1 is a configuration diagram for explaining the FMCW radar system related to the present invention.

Referring to Figure 1, FMCW (Frequency Modulation Continuous Wave) radar system 100 is a radar system in which the transmission frequency rises or falls in proportion to time, radiates a detection signal having a continuous frequency to the target, and targets the target By detecting the returned Doppler frequency, it is possible to measure the characteristics of the target, for example, the distance and speed to the target.

The FMCW radar system 100 includes a signal generating unit 110, a power amplifying unit 120, a transmitting antenna 130, a receiving antenna 140, a low noise amplifying unit 150, a mixer unit 160, a filter unit 170, and a signal processing unit (not shown).

The signal generator 110 may perform a function of generating a transmission signal applied in the direction of the transmitting antenna 130 and a local signal applied in the direction of the mixer unit 160. At this time, the transmission signal and the local signal may be a chirp signal of a triangular or sawtooth waveform.

The power amplification unit 120 may perform a function of amplifying a transmission signal received from the signal generation unit 110 and providing it to the transmission antenna 130.

The transmission antenna 130 may perform a function of radiating a transmission signal amplified through the power amplification unit 120 to the outside. The transmit signal emitted from the transmit antenna 130 hits a target and is doppled, and the doppled reflected signal is received by the receive antenna 140. At this time, the transmit / receive antennas 130 and 140 may be composed of a single antenna or may be composed of individual antennas.

The low noise amplifying unit 150 may perform a function of amplifying a received signal input through the receiving antenna 140 and reducing noise newly added.

The mixer 160 may perform a function of mixing and outputting a received signal output from the low noise amplifying unit 150 and a local signal output from the signal generating unit 110. When the two signals are mixed through the mixer unit 160, various signals are output, including a signal corresponding to a frequency difference between the two signals and a signal corresponding to a sum of frequencies of the two signals.

The filter unit 170, among the signals output from the mixer unit 160, unwanted signals (for example, when a signal corresponding to a frequency difference between two signals is desired, a signal corresponding to a frequency sum, a signal corresponding to a frequency multiple) , It can perform the function of filtering signals, etc.).

In addition, the filter unit 170, the signals coming from an undesired distance among the signals output from the mixer unit 160 (for example, if the radar wants to detect a target existing in 2m to 5m, a target in front of 1m or 10m) It may also perform a function of filtering the signals reflected by the ().

For example, the filter unit 170 may be a high-pass filter (HPF), a low-pass filter (low-pass filter, band-pass filter (BPF)) or a combination of two or more filters It can be configured, but is not limited thereto.

The signal processing unit (not shown) may convert an analog signal passing through the filter unit 170 into a digital signal, and extract characteristics of the detected target, for example, detection speed and distance from the target. To this end, the signal processing unit detects the frequency of a bit signal in a digital signal using an A / D converter that converts an analog signal into a digital signal, and a Fast Fourier Transform (FFT) technique, and the magnitude of the frequency of the bit signal It may include a digital signal processing (DSP) for comparing and analyzing.

2A and 2B are diagrams referenced to describe the operation of the FMCW radar system.

2A and 2B, the FMCW radar system 100 may radiate a transmission signal output from the transmitter 101 through the transmit antenna 102 to the outside. The FMCW radar system 100 receives an obstacle, i.e., the first received signal reflected by the wall 200 and the second received signal reflected by the target 250 through the receiving antenna 104 to receive the receiver. (103).

In this FMCW radar system 100, the difference T _TOF between the transmission time of the transmission signal and the reception time of the first reception signal is proportional to the distance from the wall 200, and the transmission time of the transmission signal and the second reception signal The difference between reception times of T _TOF is proportional to the distance from the target 300. Therefore, since the first and second received signals have a time delay with respect to the transmitted signal, they have a constant frequency difference from the transmitted signal.

For example, as shown in FIG. 2B, when comparing the reflected signal (ie, the first received signal 270) and the transmitted signal 260 by the wall 200, the frequency is analyzed because it has a bit frequency of f _W. By doing so, the distance from the wall 200 can be detected. In addition, since the reflected signal (ie, the second received signal 280) and the transmitted signal 260 by the target 250 have a bit frequency called f _T , the corresponding frequency is analyzed to distance the target 250 Can be detected.

On the other hand, in the FMCW radar system 100, the reflected signal by the target 300 is significantly reduced in the wall transmission process, while the reflected signal by the wall 200 can be significantly larger than the reflected signal by the target 300. have. In this case, the reflected signal (wall-clutter) by the wall 200 exists as an interference signal, thereby limiting the dynamic range or reception sensitivity of the radar receiver. In order to effectively remove the clutter caused by the wall 200, the method for adjusting transmission / reception time according to the present invention can be applied to the FMCW radar system 100.

3 is a configuration diagram for explaining the FMCW radar system to which the transmission / reception time adjustment method is applied.

Referring to FIG. 3, the FMCW radar system 300 includes a signal generator 310, a power amplification unit 320, a transmission antenna 330, a reception antenna 340, a low noise amplification unit 350, and a mixer unit ( 360), a filter unit 370, and a time adjustment unit 380.

The signal generating unit 310, the power amplifying unit 320, the transmitting antenna 330, the receiving antenna 340, the low noise amplifying unit 350 and the mixer unit 360 illustrated in FIG. 3 generate the signals disclosed in FIG. Since the unit 110, the power amplifying unit 120, the transmitting antenna 130, the receiving antenna 140, the low noise amplifying unit 150 and the mixer unit 160 are the same or similar, detailed descriptions thereof will be omitted. .

The filter unit 370 may perform a function of filtering unwanted signals among signals output from the mixer unit 360. For example, the filter unit 370 may be formed of a band-pass filter (BPF) in an intermediate frequency (IF) band, but is not limited thereto.

When such a band pass filter is used, there is an advantage that the antenna coupling signal can be prevented from entering the pass band through a frequency folding effect. In addition, since filters having a high quality factor (Q) can be used, there is an advantage that a very high attenuation effect can be obtained. However, the band pass filter of the IF band has a narrow band pass width, difficulty in reconstruction, and high cost.

Therefore, the FMCW radar system proposed in the present invention uses a fixed BPF, but it does not change the radar detection distance by reconfiguring the filter characteristics, but changes the frequency by adjusting the time difference of the radar signal. The detection distance limitation can be solved, and since only one fixed filter needs to be used, there is no need to use multiple expensive filters.

The time adjusting unit 380 generates a time difference (T _offset ) between the transmission signal and the local signal, and adjusts the output frequency (that is, the bit frequency) of the mixer unit 260 in a manner to adjust the time difference. You can do The operation of the time adjusting unit 380 will be described with reference to FIGS. 4 and 5.

4 is a view showing the output frequency of the mixer according to whether the transmission / reception time adjustment method is applied.

Referring to FIG. 4, in the FMCW radar system, the first bit frequency 410 and f _W and the second bit frequency (in proportion to the time T _TOF ) when the transmission signal radiates to the outside and hits the wall and the target, respectively, return 420 and f _T ) are output through the mixer unit.

The first and second bit frequencies 410, 420, f _T , and f _W output from the mixer unit may be calculated through Equation 1 below.

Here, f is the bit frequency, C _R is the chirp rate, and T _TOF is the time difference between the point at which the transmitted signal is emitted and the point at which the signal is reflected and returned.

When the transmission / reception time adjustment method is not applied to the FMCW radar system, the first bit frequency (410, f _W ) among the bit frequencies (410, 420, f _T , f _W ) output from the mixer unit is fixed. Since it is not properly removed through the band pass filter 450, it is necessary to install a separate additional filter.

On the other hand, when the transmission / reception time adjustment method is applied to the FMCW radar system, the output frequency (ie, bit frequency) of the mixer unit can be changed through time adjustment (T _offset ) between the transmission signal and the local signal.

That is, the bit frequencies (430, 440, f ' _T , f' _W ) output from the mixer unit may be calculated through Equation 2 below.

Here, f 'is the bit frequency, C _R is the patch rate, T _TOF is the time difference between the point at which the transmitted signal is emitted and the point at which the signal is reflected back to the object, and T _offset is the time difference between the transmitted signal and the local signal. being.

In the above Equation 2, when the T _offset has a negative value, the bit frequencies 430, 440, f ' _T , and f' _W output from the mixer unit may be changed to a high frequency band. Among the converted bit frequencies 430, 440, f ' _T , and f' _W , the bit frequency 430, f ' _W by the wall may be removed through one fixed bandpass filter 450. That is, through adjustment of the T _offset value, only the second bit frequencies 440 and f ′ _T may be configured to pass through the bandpass filter 450.

On the other hand, when the T _offset in Equation 2 has a positive value, the bit frequencies f ' _T and f' _W output from the mixer unit may be changed to a low frequency band. Likewise, the conversion of the bit frequency _{(f 'T, f' W} ) from the beat frequency (f _'W) due to the wall may be removed through either the band-pass filter fixed. That is, through adjustment of the T _offset value, only the second bit frequency f ′ _T may be configured to pass through the bandpass filter.

5 is a view showing the strength of a received signal depending on whether or not the transmission / reception time adjustment method is applied.

Referring to FIG. 5, the first received signal 510 represents a received signal in an FMCW radar system to which the transmission / reception time adjustment method according to the present invention is not applied, and the second received signal 520 according to the present invention Represents the received signal in the FMCW radar system to which the transmission / reception time adjustment method is applied.

As shown in the figure, depending on whether or not the transmission / reception time adjustment method is applied, the intensity of the second received signal 520 reflected by the target depends on the intensity of the first received signal 510 reflected by the target. On the other hand, an attenuation effect of about 0.8 dB appears, whereas the intensity of the second received signal 520 reflected by the wall is attenuated by about 46 dB compared to the intensity of the first received signal 510 reflected by the wall. You can see that appears. As described above, by applying the transmission / reception time adjustment method to the FMCW radar system, the clutter phenomenon caused by the wall can be effectively reduced.

6 is a block diagram schematically showing an apparatus for adjusting transmission / reception time according to an embodiment of the present invention.

Referring to FIG. 6, the transmission / reception time adjustment device 600 may generate a short time difference (T _offset ) by adjusting the phase of the reference signal. The transmitting / receiving time adjusting device 600 may generate a long time difference by repeatedly performing a method of generating a short time difference using the periodicity of the circuit.

The transmission / reception time adjustment device 600 includes a signal divider 610, a phase controller 620, a first phase lock loop (PLL, 630), and a second phase lock loop (PLL). , 640).

The signal divider 610 may perform a function of distributing one reference signal to two reference signals 1 and 2 having the same phase. Here, the reference signal may be a low frequency signal or a digital signal.

The phase controller 620 may perform a function of adjusting any one of two reference signals output from the signal divider 610. At this time, the phase controller 620 may increase or decrease the phase depending on the type of the system in which the transmission / reception time adjustment device 600 is implemented.

Meanwhile, in the present exemplary embodiment, the signal divider 610 and the phase controller 620 are illustrated to be independently configured, but the present invention is not limited thereto, and it will be apparent to those skilled in the art that they may be formed as one module.

The first phase locked loop 630 may perform a function of outputting the TX chirp signal based on the first reference signal output from the phase controller 620. The second phase locked loop 640 may perform a function of outputting a local oscillator (LO) chirp signal based on the second reference signal output from the signal divider 610.

Meanwhile, in the present exemplary embodiment, the phase controller 620 is illustrated as being installed at the front end of the first phase locked loop 630, but is not limited thereto, and is installed at the front end of the second phase locked loop 640. It might be.

The first and second phase locked loops 630 and 640 are devices that control an output signal by using a phase difference between a signal fed back from an input signal and an output signal. A phase comparator, a loop filter, and a voltage control oscillator (Voltage Control) Oscillator, VCO), and the like. That is, the purpose of the phase locked loop is to adjust the frequency of the output signal in accordance with the input signal. It detects the phase difference between the frequency divider result of the current output signal, which is a feedback loop, and the input signal, determines the detected phase difference as an error, and adjusts the output frequency by changing the input voltage of the VCO to reduce the error. When the feedback phase difference between the input and output is synchronized, the phase is locked, and the frequency of the output to the input is adjusted to maintain the locked state.

As described above, the transmission / reception time adjusting device according to the present invention reconstructs the transmission / reception time of the FMCW radar signal by using one phase controller and two phase locked loops, thereby allowing one fixed high-order filter. Through this, clutter can be effectively removed. In addition, the transmission / reception time adjusting device according to the present invention can not only transmit the maximum energy to the wireless power receiver, but also transmit the maximum energy to the wireless power receiver by intensively irradiating the beam by adjusting the transmission time of wireless power transmitters in wireless power transmission It can reduce the radio interference that acts as an interference.

7 is a configuration diagram for describing an FMCW radar system in which a transmission / reception time adjustment device is implemented.

Referring to FIG. 7, the FMCW radar system 700 includes a signal generation unit 701, a transmission / reception time adjustment unit 750, a power amplification unit 706, a transmission antenna 707, a reception antenna 708, a low It may include a noise amplification unit 709, a mixer unit 710, a filter unit 711 and a signal processing unit (not shown). Here, the transmission / reception time adjustment unit (or transmission / reception time adjustment device 750) may include a signal divider 702, a phase controller 703, and first and second phase locked loops 704 and 705. .

The signal generator 701 may perform a function of generating a reference signal. For example, the reference signal may be a square wave signal, but is not limited thereto.

The signal divider 702 may perform a function of distributing the reference signal output from the signal generator 701 into two reference signals having the same phase.

The phase controller 703 may perform a function of adjusting the phase of any one of the two reference signals output from the signal divider 702. Through this phase adjustment, a time difference between a transmission signal and a reception signal can be generated.

Of the two reference signals output from the signal divider 702, the first reference signal that has passed through the phase controller 703 is input to the first phase locked loop 704, and the second reference signal that has not passed through the phase controller 703 is The second phase locked loop 705 is input. For example, as shown in FIG. 8, a reference clock (810) is input to the second phase locked loop (705), and an adjusted clock (820) is input to the first phase locked loop (704). do.

The first phase locked loop 704 generates a TX chirp signal based on a first reference signal (ie, a phase change signal) output from the phase controller 703, and transmits the TX chirp signal to the power amplifier 706. You can perform the output function. More specifically, as shown in FIG. 8, the signal 820 input to the first phase locked loop 704 changes phase by the adjusted clock phase. As a result, the output signal (TX chirp signal, 830) also changes in time as much as its phase.

When the phase is slowed by adjusting the phase controller 703, the time of the output signal of the corresponding PLL 704 is relatively slow compared to the time of the output signal of the other PLL 705. Conversely, when the phase is increased by adjusting the phase controller 703, the time of the corresponding output signal of the PLL 704 is relatively faster than the time of the output signal of the other PLL 705.

The second phase locked loop 705 generates an LO chi signal based on the second reference signal (ie, the original reference signal) output from the phase controller 703 and sends the LO chi signal to the mixer 710. You can perform the output function.

The power amplifying unit 706 may perform a function of amplifying the TX chirp signal output from the first phase locked loop 704 and providing it to the transmission antenna 707. The transmit antenna 707 may perform a function of radiating the TX chirp signal amplified through the power amplifier 706 to the outside.

The TX chirp signal emitted from the transmit antenna 707 hits the target and is doppled, and the doppled reflected signal is received by the receive antenna 708. The low noise amplifying unit 709 may perform a function of amplifying a received signal (ie, an RF signal) input through the receiving antenna 708 and reducing noise newly added.

The mixer 710 may perform a function of mixing and outputting a received signal output from the low noise amplifying unit 709 and a local signal output from the second phase locked loop 705. When the two signals are mixed through the mixer unit 710, various signals are output, including a signal corresponding to the frequency difference between the two signals and a signal corresponding to the sum of the frequencies of the two signals.

In addition, the bit frequencies (f ' _T , f' _W ) output from the mixer unit 710 are the time difference (T _offset ) between the transmission signal and the local signal, the time at which the transmission signal is emitted, and the corresponding signal to the object. It may be determined based on a time difference (T _TOF ) between the time points reflected and returned. That is, the bit frequencies f ' _T and f' _W may be calculated through Equation 2 described above. At this time, the T _offset value may be determined through phase adjustment by the phase controller 703.

The filter unit 711 may perform a function of filtering unwanted signals (for example, a signal reflected by a wall or a signal passed due to limited isolation) among signals output from the mixer unit 710. At this time, the filter unit 711 may include a fixed one filter. As the filter unit 711, a middle band band pass filter, a high frequency band pass filter, or a low frequency band pass filter may be used and is not limited thereto.

The signal processing unit (not shown) may convert an analog signal that has passed through the filter unit 711 into a digital signal, and extract characteristics of the detected target, for example, detection speed and distance from the target.

In this way, the FMCW radar system in which the transmission / reception time adjustment device is implemented does not need to additionally install a separate high-order filter, and adjusts the time difference (T _offset ) between the transmission signal and the local signal, thereby controlling one fixed filter. Through this, the clutter by the wall can be effectively removed. For example, as shown in FIG. 9, as a result of simulation by applying the transmission / reception time adjustment method according to the present invention to an FMCW radar system, the target signal is not attenuated much, while the wall signal obtains an attenuation effect of about 20 dB or more. You can see what you can do.

10 is a configuration diagram for explaining a wireless power transmission system to which a transmission / reception time adjustment method is applied.

Referring to FIG. 10, the wireless power transmission system 1000 may include a plurality of wireless power transmitters 1010 and one or more wireless power receivers 1020.

Each wireless power transmitter 1010 needs to maintain an appropriate time difference (a proper phase difference depending on the operation method) between each transmitter in order to focus power on the wireless power receiver 1020 located at an arbitrary location. Do. To this end, the transmission / reception time adjustment method according to the present invention can be applied to the wireless power transmission system 1000.

In such a wireless power transmission system, each transmitter 1010 may use an FMCW signal, which is a kind of high frequency signal, as a wireless power signal. Since the FMCW method has a lower signal density for each band than the CW method, it can satisfy the requirements required by the wireless power communication regulations (particularly, indoor regulations for the human body).

When the receiver 1020 to receive wireless power is present at an arbitrary location, the time difference between each transmitter 1010 may be determined using the characteristics of the FMCW signal, and if necessary, the location of the receiver 1020 may be determined.

In addition, by distributing the wireless power transmitters 1010 in an indoor space, it is possible to prevent electromagnetic waves from being concentrated too much in a specific space, and when one or two transmitters do not work or an obstacle is located and the radio waves do not reach the target well, It can be calibrated and operated. In addition, wireless power can be efficiently transmitted even when the distance between the transmitter 1010 and the receiver 1020 is long.

11 is a signal flow chart referenced to describe the operation of a wireless power transmission system to which a transmission / reception time adjustment method is applied.

Referring to FIG. 11, the first wireless power transmitter 1010_1 may generate a first chirp signal through a signal generator or the like (S1110). The second wireless power transmitter 1010_2 may also generate a second chirp signal through a signal generator or the like (S1120). In this case, the first and second chirp signals may be FMCW signals having the same phase, but are not limited thereto.

The first wireless power transmitter 1010_1 may transmit the first chirp signal to the second wireless power transmitter 1010_2 (S1130).

The second wireless power transmitter 1010_2 detects the bit frequency by mixing the first chirp signal received from the first wireless power transmitter 1010_1 and the self-generated second chirp signal, and detects the bit frequency. The time of the second chirp signal may be adjusted to be a DC frequency (or zero frequency) (ie, the time / phase of the first chirp signal and the second chirp signal coincide) (S1140).

The second wireless power transmitter 1010_2 may transmit a second time-controlled chirp signal to the first wireless power transmitter 1010_1 (S1150). The first wireless power transmitter 1010_1 may mix the time-controlled second chirp signal and the first chirp signal through a mixer unit, and detect a distance between devices based on the mixed signal (ie, bit frequency signal). Yes (S1160, S1170).

More specifically, the chirp signal received from the second wireless power transmitter 1010_2 is delayed by the propagation time proportional to the distance between the two devices of the chirp signal generated by the first wireless power transmitter 1010_1 (delay time = Since the distance / light speed = R / c) is a signal received, the time difference between the chirp signal received from the second wireless power transmitter 1010_2 and the chirp signal transmitted from the second wireless power transmitter 1010_2 is the same. The chirp signal transmitted by the second wireless power transmitter 1010_2 and the chirp signal generated by the first wireless power transmitter 1010_1 are different by the propagation time (R / c). When the second wireless power transmitter 1010_2 transmits the chirp signal to the first wireless power transmitter 1010_1, the chirp signal generated by the first wireless power transmitter 1010_1 is transmitted because the corresponding chirp signal is delayed by the same propagation time. It has a time delay of twice the propagation time (2R / c).

In conclusion, the chirp signal received from the first wireless power transmitter 1010_1 (that is, the chirp signal transmitted from the second wireless power transmitter 1010_2 is a signal delayed by the propagation time) and the first wireless power transmitter 1010_1 are generated. By mixing one chirp signal, the time difference between chirp signals of two devices can be detected, and the detected time difference is proportional to the distance between the two devices, so the distance between the two devices 1010_1 and 1010_2 is detected through the bit frequency. can do.

When the distance between the wireless power transmitters and the wireless power transmitters and the wireless power receivers is known, it is possible to detect a time difference required between the chirp signals generated by each wireless power transmitter in order to focus radio waves on the wireless power receiver.

For other wireless power transmitters, a distance and a required time difference between each transmitter can be obtained using the same method as described above, and the wireless power is concentrated in the wireless power receiver 1020 by allocating an appropriate time difference to each transmitter. Can be transmitted.

On the other hand, in the above embodiments, the transmission / reception time adjustment method is exemplarily described as being applied to the FMCW radar system and the wireless power transmission system, but is not limited thereto, and the same technical idea as the present invention can be applied to various communication systems. It will be apparent to those skilled in the art.

The above-described present invention can be embodied as computer readable codes on a medium on which a program is recorded. The computer-readable medium includes any kind of recording device in which data readable by a computer system is stored. Examples of computer-readable media include a hard disk drive (HDD), solid state disk (SSD), silicon disk drive (SDD), ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage device. This includes, and is also implemented in the form of a carrier wave (eg, transmission over the Internet). In addition, the computer may include a control unit of the terminal. Accordingly, the above detailed description should not be construed as limiting in all respects, but should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

600: transmission / reception time control device 610: signal distributor
620: phase controller 630: first phase fixed loop
640: second phase locked loop

Claims (14)

delete delete delete delete delete Transmit / receive antenna;
A signal generator for generating a reference signal;
A transmission / reception time adjusting unit configured to output a transmission chirp signal and a local chirp signal having a predetermined time difference based on a reference signal output from the signal generator; And
And a mixer unit for mixing the received chirp signal inputted to the receive antenna and the local chirp signal and outputting a bit frequency.
FMCW radar system, characterized in that the bit frequency output from the mixer unit is varied by adjusting the time difference (T _offset ) between the transmission chirp signal and the local chirp signal. The method of claim 6,
FMCW radar system, characterized in that the bit frequency is calculated through the following equation.
[Mathematics]

Here, f 'is the bit frequency, C _R is the patch rate, T _TOF is the time difference between the point at which the transmitted signal is emitted and the point at which the signal is reflected back to the object, and T _offset is the time difference between the transmitted signal and the local signal. being. The method of claim 6,
FMCW radar system further comprises a filter for filtering unwanted signals from the signals output from the mixer. The method of claim 8,
The filter unit FMCW radar system, characterized in that the band pass filter (Band-pass filter) of the intermediate frequency band. According to claim 6, The transmission / reception time control unit,
A signal divider that divides the reference signal into two reference signals, a phase controller that adjusts the phase of any one of the two reference signals, and outputs the transmission chirp signal and the local chirp signal based on the two reference signals. FMCW radar system further comprises a first and second phase locked loop. A method for adjusting transmission / reception time in a wireless power transmission system including a plurality of wireless power transmitters and one or more wireless power receivers,
Generating a first chirp signal from the first wireless power transmitter and transmitting it to the second wireless power transmitter;
The second chirp signal generated by the second wireless power transmitter is compared with the first chirp signal to adjust the time of the second chirp signal, and the time-controlled second chirp signal is used as the first wireless power transmitter. Transmitting; And
Detecting a distance between the first wireless power transmitter and the second wireless power transmitter based on the second chirp signal received from the second wireless power transmitter and the first chirp signal generated by the first wireless power transmitter; Method for adjusting transmission / reception time in a wireless power transmission system. The method of claim 11,
And obtaining necessary time difference information between wireless power signals transmitted by the first and second wireless power transmitters based on distance information between the first wireless power transmitter and the second wireless power transmitter. How to adjust the transmission / reception time in the system. The method of claim 12,
And transmitting a wireless power signal from the first and second wireless power transmitters to the wireless power receiver based on the obtained time difference information. The method of claim 6,
The reference signal is an FMCW radar system, characterized in that a low-frequency signal or a digital signal.

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