KR101480331B1 - Time synchronization method and electronic device - Google Patents

Abstract

The present invention relates to a method to synchronize time between devices by using an audio signal, and to an electronic device for performing the time synchronization. The time synchronization method by an embodiment of the present invention includes the following steps of: generating first sound recording information by recording the sound of a reference audio signal (the first recording information includes first time information); receiving second sound recording information from an auxiliary device (the second sound recording information includes second time information as information generated by recording the reference audio signal in the auxiliary device); producing time difference information of the auxiliary device by using the first sound recording information and the second sound recording information; and transmitting the produced time difference information to the auxiliary device.

Description

[0001] TIME SYNCHRONIZATION METHOD AND ELECTRONIC DEVICE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time synchronization method and an electronic apparatus, and more particularly, to a method of synchronizing time between devices using an audio signal and an electronic apparatus performing time synchronization.

Recently, as the number of mobile devices capable of multimedia playback and recording and internet access has increased, synchronized time has been increasingly required between different devices. For example, when a text message is sent or received, if there is an error in the time of the sender and the time of the receiver, it may occur that the character is mistakenly received earlier than the actual send time. Conversely, even if you have sent a text message a long time ago, it may happen that the recipient is mistaken for being late. Also, in the same place, two people taking the same event photographed the camera device, respectively, but the period of the photographed image may be recorded due to the error of the system.

One way to synchronize system time is to get time from the base station or use GPS information. A related prior art document is disclosed in Japanese Patent Laid-Open No. 10-2013-0116392.

However, in the case of using the conventional technology, the time error ranges from several tens of milliseconds to several seconds due to the error of the network due to the time delay and the error of the GPS information.

Therefore, it is necessary to study the technology for precise time synchronization.

SUMMARY OF THE INVENTION An object of the present invention is to provide a time synchronization method capable of performing time synchronization precisely using an audio signal and an electronic apparatus performing time synchronization.

According to an embodiment of the present invention, there is provided a method for recording a reference audio signal, the method comprising: generating a first recording information by recording a reference audio signal, the first recording information including first time information; Receiving second recording information from the secondary device, the second recording information including second time information as information generated by the secondary device recording the reference audio signal; Calculating time difference information with the sub-device using the first recorded information and the second recorded information; And transmitting the calculated time difference information to the sub-device.

According to an embodiment of the present invention, there is provided a method for recording a reference audio signal, the method comprising: generating recording information by recording a reference audio signal, the recording information including time information; Transmitting the generated recording information to a main device; Receiving time difference information from the main device with the main device; And correcting the time based on the received time difference information.

In order to achieve the above object, according to an embodiment of the present invention, there is provided a recording unit for recording a reference audio signal to generate first recording information, the first recording information including first time information; A receiving unit for receiving second recorded information from a secondary device, the second recorded information including second time information as information generated by the secondary device recording the reference audio signal; A time difference information calculation unit for calculating time difference information with the sub-device using the first recorded information and the second recorded information; A transmission unit for transmitting the calculated time difference information to the sub-device; And a control unit for controlling the recording unit, the receiving unit, the time difference information calculating unit, and the transmitting unit.

According to an embodiment of the present invention, there is provided a recording unit for recording a reference audio signal to generate recording information, the recording information including time information; A transmitting unit for transmitting the generated recording information to a main device; A receiving unit for receiving time difference information from the main device with the main device; A time corrector for correcting time based on the received time difference information; And a control unit for controlling the recording unit, the transmission unit, the reception unit, and the time correction unit.

The time synchronization method and the electronic device according to the embodiment of the present invention perform time synchronization using an audio signal, and the accuracy level of time synchronization is greatly improved.

In addition, according to an embodiment of the present invention, period time synchronization can be performed even when an external time information server is not available.

FIG. 1 shows a state in which a plurality of devices record reference audio signals before time synchronization related to an embodiment of the present invention.
2 is a block diagram of an electronic apparatus according to an embodiment of the present invention.
3 is a flow chart illustrating a time synchronization method associated with an embodiment of the present invention.
FIG. 4 illustrates a process in which an electronic apparatus according to an embodiment of the present invention records reference audio signals.
FIG. 5 illustrates a process in which an auxiliary device related to an embodiment of the present invention transmits recording information to a main device.
FIG. 6 illustrates a process in which a main device related to an embodiment of the present invention calculates time difference information.
FIG. 7 illustrates a process in which an auxiliary device related to an embodiment of the present invention receives time difference information.
FIG. 8 shows a process in which an auxiliary device related to an embodiment of the present invention corrects time using time difference information.

Hereinafter, a time synchronization method and an electronic apparatus according to an embodiment of the present invention will be described with reference to the drawings.

As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. In this specification, the terms "comprising ", or" comprising ", etc. should not be construed as necessarily including the various elements or steps described in the specification, Or may be further comprised of additional components or steps.

In this specification, an electronic device is an apparatus that can confirm or display its own system time, and a mobile terminal may be an example thereof. The mobile terminal includes a smart phone, a notebook computer, a digital broadcast terminal, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), a navigation device, a tablet PC, a wearable device can do.

FIG. 1 shows a state in which a plurality of devices record reference audio signals before time synchronization related to an embodiment of the present invention. Hereinafter, the time synchronization of three electronic devices will be described in the embodiment, but the present invention is not limited thereto.

As shown, a plurality of electronic devices A, B, and C may be gathered in a certain space to record the same sound. In this specification, an electronic device that is a reference for time synchronization is referred to as a "main device", and an electronic device that performs time synchronization (ie, time correction) in accordance with the main device is referred to as a "secondary device". Also, the same sound to be recorded by the plurality of devices is referred to as a "reference audio signal ".

First, each device (A, B, C) for time synchronization can check their system time instantly, and can record ambient sound using a microphone. In order to record a reference audio signal, each of the devices A, B, and C may be located near the reference audio signal source and may perform a communication function to transmit specific information to each other.

2 is a block diagram of an electronic apparatus according to an embodiment of the present invention.

The electronic apparatus shown in Fig. 2 can be applied not only to the main apparatus but also to the sub apparatus. The electronic device 100 may perform a role as a main device or a sub-device as the case may be.

The electronic device 100 may include a recording unit 110, a receiving unit 120, a time difference information calculating unit 130, a transmitting unit 140, a time information unit 150, and a control unit 160.

The recording unit 110 can record the output reference audio signal through a microphone (not shown). The reference audio signal may be output from the electronic device 100 or may be output from an external device. In this embodiment, a case where a reference audio signal is outputted from an external device will be described.

The receiving unit 120 may receive various information or data. For example, the receiving unit 120 may receive recorded information recorded from another device or may receive time difference information calculated by another device.

The time difference information calculating unit 130 may calculate the time difference information with other apparatuses by comparing the recorded information received from other apparatuses with the recorded information recorded by the apparatus itself. A detailed description of calculating the time difference information will be described later.

The transmission unit 140 can transmit various information. For example, the transmission unit 140 may transmit its recording information to another device or may transmit the calculated time difference information to another device.

The time correction unit 150 may perform time synchronization by correcting its own system time using the time difference information received from other devices.

The control unit 160 may control the recording unit 110, the receiving unit 120, the time difference information calculating unit 130, the transmitting unit 140, and the time adjusting unit 150 as a whole.

3 is a flow chart illustrating a time synchronization method associated with an embodiment of the present invention.

The main apparatus and the sub apparatus can record the same sound (i.e., the reference audio signal) (S310).

FIG. 4 illustrates a process in which an electronic apparatus according to an embodiment of the present invention records reference audio signals.

As shown, the main unit C and the sub-units A and B can respectively record reference audio signals (e.g., ambient sounds) through a microphone. At this time, in order to increase the accuracy of the processing, a specific sound having high discrimination power can be used as a reference audio signal instead of surrounding sound. The reproduction of the reference audio signal may be reproduced by an external device other than the device (main device and sub device) participating in synchronization or the device participating in synchronization. Each device can measure and store its own system time at the same time as recording starts.

Each device can record the same reference audio signal to generate recording information. The recording information generated by each of the devices includes PCM data generated by a PCM (Pulse Code Modulation) method and may include corresponding time information. In addition, the PCM data generated at each device has the same sampling rate. The sampling rate is the number of sampling times per unit time (e.g., 1 second), and the higher the sampling rate, the higher the accuracy of data and the more accurate the time synchronization. The sampling rates mainly used in digital audio are 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz and 192 kHz. In this embodiment, a sampling rate of 44.1 kHz or higher can be used to increase the accuracy.

In addition, the corresponding time information may include time information in which the PCM data is generated. The time at which the recording is started can be confirmed through the time information in which the PCM data is generated.

When a predetermined time has elapsed after the recording of each device is completed, the sub-devices A and B transmit their recorded information to the main device (S320).

FIG. 5 illustrates a process in which an auxiliary device related to an embodiment of the present invention transmits recording information to a main device.

Each device can stop recording sound and store it in the form of PCM (pulse code modulation) digital information (ie, PCM data). In this case, the recording duration of the reference audio signal in each device is preferably long enough for easy comparison between the information recorded on the main device and the information recorded on the sub-device, but a proper recording time can be used depending on the application .

The auxiliary devices A and B to be synchronized with the system time of the main device C transmit the recording information (including the PCM data and the own system time) recorded by the auxiliary devices A and B to the main device C. At this time, the network delay time to transmit to the main device does not affect the synchronization level.

The main apparatus C can calculate the time difference information with the sub-apparatus through comparison of the recorded information received from the sub-apparatus and its own recorded information (S330).

FIG. 6 illustrates a process in which a main device related to an embodiment of the present invention calculates time difference information.

The main apparatus C compares the PCM data received from the auxiliary apparatuses A and B with the PCM data thereof so that the same sound can be reproduced in the same time zone as the PCM data generated by the main apparatus C, The PCM data of the secondary devices (A and B) are arranged in units of one PCM sample. That is, the main device (C) compares the generation time of its own PCM data pattern and PCM data with the generation time of the PCM data pattern and the PCM data of each of the auxiliary devices (A, B) Time difference information with respect to time.

(Delta_Number_of_Aligned_Samples) between the PCM data of each sub-device (A, B) and the PCM data of the main device (C) in the alignment process into the sample difference time value (Delta_Time_of_Aligned_Samples) in units of time.

For example, if the PCM Sampling Rate (Sampling_Rate_per_Second) is 48KHz (48000 samples per second), then 48000 PCM samples per second are recorded, so the time for one PCM sample is 1/48000 seconds, or 1/48 milliseconds. That is, Delta_Time_of_Aligned_Samples = Delta_Number_of_Aligned_Sample / Sampling_Rate_per_Second.

The main device C adds the aligned PCM sample difference times (? TA_aligned_ samples,? TB_aligned_ samples) at the system time (tA_recorded, tB_recorded) recorded at the recording start timing received from each of the sub apparatuses (A, B) The system time (tA_aligned, tB_aligned, tC_aligned) of each device corresponding to the sample can be calculated. That is, tA_aligned = tA_recorded + tA_aligned_samples can be calculated.

The main device C computes the difference (ΔtA, ΔtB) between tC_aligned of its own tC_aligned and tA_aligned and tB_aligned of the secondary device as ΔtA = tC_aligned - tA_aligned, ΔtB = tC_aligned - tB_aligned, A, B) (that is, time difference information).

Each of the auxiliary devices A and B can receive the time difference information calculated from the main device C from the main device C at step S340.

FIG. 7 illustrates a process in which an auxiliary device related to an embodiment of the present invention receives time difference information.

As shown in the figure, the main device C transmits the calculated correction values (i.e., time difference information)? TA and? TB to each of the sub-devices A and B for each of the sub-devices A and B. At this time, the network delay time to transmit to the secondary devices (A and B) does not affect the synchronization level

Each of the sub-devices A and B can synchronize their system with the main device using the received correction values (i.e., time difference information) DELTA tA and DELTA tB (S350). For example, the auxiliary device A can acquire a corrected time tA 'by adding a correction value? TA to its system time tA, which is synchronized with the time tC of the main device Lt; / RTI >

FIG. 8 shows a process in which an auxiliary device related to an embodiment of the present invention corrects time using time difference information.

As shown in the figure, each of the sub-devices A and B corrects its own system time by adding the correction value received from the main device C to the current system time. Through the above correction, the system time of the sub-devices A and B is synchronized with the current system time t C of the main device C.

As described above, the time synchronization method according to an embodiment of the present invention and the electronic apparatus performing the time synchronization perform a time synchronization using an audio signal, which greatly improves the accuracy level of time synchronization.

In addition, according to an embodiment of the present invention, period time synchronization can be performed even when an external time information server is not available.

The above-described time synchronization method may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable recording medium. At this time, the computer-readable recording medium may include program commands, data files, data structures, and the like, alone or in combination. On the other hand, the program instructions recorded on the recording medium may be those specially designed and configured for the present invention or may be available to those skilled in the art of computer software.

The computer-readable recording medium includes a magnetic recording medium such as a magnetic medium such as a hard disk, a floppy disk and a magnetic tape, an optical medium such as a CD-ROM and a DVD, a magnetic disk such as a floppy disk, A magneto-optical media, and a hardware device specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like.

The recording medium may be a transmission medium, such as a light or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, and the like.

The program instructions also include machine language code, such as those generated by the compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

The above-described time synchronization method and electronic device are not limited to the configuration and method of the embodiments described above, but the embodiments may be modified so that all or some of the embodiments are selectively And may be configured in combination.

100: Electronic device
110:
120: Receiver
130: Time difference information calculation unit
140:
150: time correction unit
160:

Claims (18)

Recording a reference audio signal to generate first recorded information, the first recorded information including first time information;
Receiving second recording information from the secondary device, the second recording information including second time information as information generated by the secondary device recording the reference audio signal;
Calculating time difference information with the sub-device using the first recorded information and the second recorded information; And
And transmitting the calculated time difference information to the sub-device. The method according to claim 1,
Wherein the first recording information includes first pulse code modulation (PCM) data, the PCM data representing data generated by a PCM method,
And the second recorded information includes second PCM data. 3. The method of claim 2,
Wherein the first PCM data and the second PCM data have the same sample rate and the sampling rate is 44.1 kHz or more. 3. The method of claim 2,
Wherein the first time information includes time information in which the first PCM data is generated,
And the second time information includes time information in which the second PCM data is generated. 5. The method of claim 4, wherein the time difference information calculating step
Comparing a pattern of the first PCM data with a pattern of the second PCM data; And
And comparing the time information in which the first PCM data was generated with the time information in which the second PCM data was generated. Recording a reference audio signal to generate recording information, the recording information including time information;
Transmitting the generated recording information to a main device;
Receiving time difference information from the main device with the main device; And
And correcting the time based on the received time difference information. The method according to claim 6,
Wherein the recorded information includes PCM data generated by a PCM (Pulse Code Modulation) method. 8. The method of claim 7,
Wherein the sampling rate of the PCM data is 44.1 kHz or more. 8. The method of claim 7,
Wherein the time information includes time information in which the PCM data is generated. A recording unit for recording a reference audio signal to generate first recording information, the first recording information including first time information;
A receiving unit for receiving second recorded information from a secondary device, the second recorded information including second time information as information generated by the secondary device recording the reference audio signal;
A time difference information calculation unit for calculating time difference information with the sub-device using the first recorded information and the second recorded information;
A transmission unit for transmitting the calculated time difference information to the sub-device; And
And a control unit for controlling the recording unit, the receiving unit, the time difference information calculating unit, and the transmitting unit. 11. The method of claim 10,
Wherein the first recording information includes first pulse code modulation (PCM) data, the PCM data representing data generated by a PCM method,
And the second recording information includes second PCM data. 12. The method of claim 11,
Wherein the first PCM data and the second PCM data have the same sampling rate and the sampling rate is 44.1 kHz or more. 12. The method of claim 11,
Wherein the first time information includes time information in which the first PCM data is generated,
And the second time information includes time information in which the second PCM data is generated. 14. The apparatus of claim 13, wherein the time difference information calculation unit
And compares the pattern of the first PCM data with the pattern of the second PCM data and compares the time information in which the first PCM data was generated with the time information in which the second PCM data was generated. A recording unit for recording a reference audio signal to generate recording information, the recording information including time information;
A transmitting unit for transmitting the generated recording information to a main device;
A receiving unit for receiving time difference information from the main device with the main device;
A time corrector for correcting time based on the received time difference information; And
And a control unit for controlling the recording unit, the transmission unit, the reception unit, and the time correction unit. 16. The method of claim 15,
Wherein the recording information includes PCM data generated by a PCM (Pulse Code Modulation) method. 17. The method of claim 16,
Wherein the sampling rate of the PCM data is 44.1 kHz or more. 17. The method of claim 16,
Wherein the time information includes time information in which the PCM data is generated.

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