Apparatus for wireless communication and method for synchronizing time thereof

• US 20100034190A1
• Filed: 04/10/2008
• Published: 02/11/2010
• Est. Priority Date: 05/17/2007
• Status: Abandoned Application

• Current Assignee: Hanyang Navicom Co., Ltd.
• Original Assignee: Hanyang Navicom Co., Ltd.
• Inventors: Lee, Hyun-myung, Yun, Sang-jun
• Application Number:
  US12/082,388
• Publication Number:
  US 20100034190A1
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04W 56/0035 detecting errors in frequency or phase

Abstract

Disclosed are a wireless communication apparatus and a time synchronization method performed thereby.

Claims

1. An apparatus for wireless communication, comprising:

a receiving unit for wirelessly receiving a synchronization signal and time information from a global navigation satellite system;

an input unit for input of a set value for setting daylight-saving time and a Greenwich Mean Time offset;

a memory for storing the time information and the set value;

a processor for correcting an internal reference pulse compared with the synchronization signal, creating a data packet including an internal time information created using the time information and the set value, and transforming the data packet into a data stream in accordance with timing of the internal reference pulse; and

a transmitting unit for wirelessly transmitting the data stream.

2. The apparatus as claimed in claim 1, wherein the receiving unit wirelessly receives the synchronization signal and the time information from the global navigation satellite system periodically, and the processor sets the time information as the internal time information if the time information and the internal time information, which is created by increasing the time information to a fixed size, are repeatedly same for a fixed number of times when compared with each other.

3. The apparatus as claimed in claim 2, wherein the data packet includes a main time packet, a date packet, a clock adjust pending packet and a time offset packet, and the processor transforms the data packet into the data stream allocating a slot to every time offset packet, in which the processor divides a message ID of the time offset packet by a predetermined figure so that gets quotient and remainder, allocates the slot which is to be filled with the time offset packet in order of a value of the quotient, and determines where the time offset packet is located after the clock adjust pending packet in order of a value of the remainder.

4. The apparatus as claimed in claim 1, wherein the processor creates the internal time information by applying a leap second if the set value further includes leap second information.

5. The apparatus as claimed in claim 1, further comprising:

a network connection unit for receiving the time information with a wired connection, wherein the processor controls the network connection unit to receive the time information with the wired connection if the receiving unit is not capable of wirelessly receiving the time information.

6. The apparatus as claimed in claim 1, wherein the processor includes a transmitting processor and a signal processor, in which the signal processor corrects the internal reference pulse, and the transmitting processor creates the data packet and transforms the data packet into the data stream.

7. The apparatus as claimed in claim 6, wherein the signal processor corrects the internal reference pulse by repeatedly calculating an error by comparing the internal reference pulse with the synchronization signal and correcting the internal reference pulse by an amount of the error.

8. A method for synchronizing time of an apparatus for wireless communication, comprising the steps of:

receiving a synchronization signal and time information from a global position system;

inputting of a set value for setting daylight-saving time and a Greenwich Mean Time offset;

correcting an internal reference pulse compared with the synchronization signal;

creating a data packet including an internal time information created by using the time information and the set value, and transforming the data packet into a data stream in accordance with timing of the internal reference pulse; and

wirelessly transmitting the data stream.

9. The method as claimed in claim 8, wherein, in the receiving step, the synchronization signal and time information is received from the global navigation satellite system periodically, and in the creating step, the time information is set to the internal time information if the time information and the internal time information, which is created by increasing the time information to a fixed size, are repeatedly same for a fixed number of times when compared with each other.

10. The method as claimed in claim 9, wherein the data packet includes a main time packet, a date packet, a clock adjust pending packet and a time offset packet, wherein, in the transforming step, the data packet is transformed into the data stream by allocating a slot every time offset packet, in which a message ID of the time offset packet is divided by a predetermined figure so that quotient and remainder are obtained, a slot to be filled with the time offset packet is allocated in accordance with a value of the quotient, and a position where the time offset packet is to be located after the clock adjust pending packet is determined in order of a value of the remainder.

11. The method as claimed in claim 8, wherein, in the creating step, the internal time information is created by applying a leap second if the set value further includes leap second information.

12. The method as claimed in claim 8, further comprising:

receiving the time information with a wired connection, wherein, in the receiving step, the time information is received with the wired connection when the time information cannot be received wirelessly.

13. The method as claimed in claim 8, wherein, in the transforming step, the internal reference pulse is corrected by repeatedly performing a procedure of calculating an error by comparing the internal reference pulse with the synchronization signal and a procedure of correcting the internal reference pulse by an amount of the error.

14. An apparatus for wireless communication, comprising:

a receiving unit for receiving a radio signal, demodulating the radio signal into a data stream, and extracting a data packet from the data stream;

a processor for correcting a time synchronization pulse generated by a internal counter/timer with timing of receiving the data packet, and extracting time information, leap second information and daylight saving time information from the data packet; and

a clock for reflecting the leap second information and the daylight saving time in time gotten from the extracted time information, and displaying the time.

15. The apparatus as claimed in claim 14, wherein the data packet includes a message ID, and the receiving unit extracts the data packet from the data stream if a group ID of the apparatus and the message ID are same.

16. The apparatus as claimed in claim 14, further comprising:

a real time clock generator for generating a time synchronization pulse, wherein the processor corrects the time synchronization pulse generated by the real time clock generator by comparing the time synchronization pulse generated by the real time clock generator with the timing and correcting a counter/timer of the real time clock generator.

17. The apparatus as claimed in claim 16, wherein the processor corrects the time synchronization pulse generated by the real time clock generator by accumulating an error of frequency between the time synchronization pulse generated by the real time clock generator and the timing and correcting the counter/timer of the real time clock generator by an integer value of the accumulated error of the frequency if a value of the accumulated error of the frequency exceeds one.

18. The apparatus as claimed in claim 14, wherein the processor controls the clock to display time in accordance with the time information included in the data packet received consequently three times if the time, in accordance with the time information included in the data packet received consequently three times, and time, in accordance with a internal clock, are same.

19. The apparatus as claimed in claim 14, further comprising:

a buzzer for informing a user when a battery voltage is below a fixed voltage or a receiving channel is found.

25. The method as claimed in claim 14, further comprising:

informing a user when a battery voltage is below a fixed voltage or a receiving channel is found.

20. A method for synchronizing time of an apparatus for wireless communication, comprising the step of:

receiving a radio signal, demodulating the radio signal into a data stream, and extracting a data packet from the data stream;

generating a time synchronized pulse;

correcting a time synchronization pulse generated by a internal counter/timer with timing of receiving the data packet, and extracting time information, leap second information and daylight saving time information from the data packet; and

reflecting the leap second information and the daylight saving time in time gotten from the extracted time information, and displaying the time.

21. The method as claimed in claim 20, wherein the data packet includes a message ID, wherein, in the extracting step, the data packet is extracted from the data stream if a group ID of the apparatus and the message ID are same.

22. The method as claimed in claim 20, further comprising:

generating a time synchronization pulse with a real time clock generator, wherein, in the correcting step, the time synchronization pulse generated from the real time clock generator is corrected by comparing the time synchronization pulse generated from the real time clock generator with the timing and correcting a counter/timer of the real time clock generator.

23. The method as claimed in claim 22, wherein, in correcting step, the time synchronization pulse generated from the real time clock generator is corrected by accumulating an error of frequency between the time synchronization pulse generated by the real time clock generator and the timing, and by correcting the counter/timer of the real time clock generator by an integer value of the accumulated error of the frequency if a value of the accumulated error of the frequency exceeds one.

24. The method as claimed in claim 20, wherein, in the displaying step, time is displayed in accordance with the time information included in the data packet received consequently three times when the time in accordance with the time information included in the data packet received consequently three times is identical to time of an internal clock.