Device, system and method of clock synchronization

• US 20070064740A1
• Filed: 09/19/2005
• Published: 03/22/2007
• Est. Priority Date: 09/19/2005
• Status: Abandoned Application

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Waxman, Shai
• Application Number:
  US11/228,253
• Publication Number:
  US 20070064740A1
• Time in Patent Office: Days
• US Class Current: 370/498
• CPC Class Codes: H04J 3/0658 Clock or time synchronisation among packet nodes
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Some embodiments of the invention provide devices, systems and methods of clock synchronization. For example, a system in accordance with an embodiment of the invention includes a wireless access point to transmit a signal instructing a plurality of wireless communication stations to substantially simultaneously transmit wireless signals at a pre-defined time; and a wireless communication station including a synchronizer to synchronize, at a non allocated time slot, a clock of the wireless communication station to a clock of the wireless access point based on an estimated frequency offset of a data packet received from the wireless access point.

Claims

1. A wireless communication system comprising:

a wireless access point to transmit a signal instructing a plurality of wireless communication stations to substantially simultaneously transmit wireless signals at a pre-defined time; and

a wireless communication station including a synchronizer to synchronize, at a non allocated time slot, a clock of the wireless communication station to a clock of the wireless access point based on an estimated frequency offset of a data packet received from the wireless access point.

2. The wireless communication system of claim 1, wherein the wireless communication station comprises:

an estimator to estimate the frequency offset and to provide the frequency offset to the synchronizer.

3. The wireless communication system of claim 1, wherein said synchronizer is to tune a Voltage Controlled Oscillator of the wireless communication station based on said estimated frequency offset.

4. The wireless communication system of claim 1, wherein said synchronizer is to bias a counter associated with the clock of said wireless communication station based on said first estimated frequency offset.

5. The wireless communication system of claim 1, wherein said wireless communication station comprises:

a transmitter to transmit data to said wireless access point at a transmission frequency substantially equal to a frequency of said wireless access point based on said estimated frequency offset.

6. The wireless communication system of claim 1, wherein said wireless communication station comprises:

a compensator to compensate said estimated frequency offset by modifying data intended for transmission based on said estimated frequency offset; and

a transmitter to transmit the modified data to said wireless access point.

7. The wireless communication system of claim 6, wherein said compensator comprises:

a first scaler to multiply a symbol in a frequency domain by a frequency domain compensation phasor; and

a second scaler to multiply a symbol in a time domain by a time domain compensation phasor.

8. The wireless communication system of claim 1, wherein said wireless access point comprises:

a wireless Multiple Input Multiple Output transceiver able to substantially simultaneously communicate with said plurality of wireless communication stations.

9. The wireless communication system of claim 1, wherein said plurality of wireless communication devices are to synchronize a plurality of internal clocks, respectively, and to substantially simultaneously transmit a plurality of wireless signals at said pre-defined time.

10. A wireless communication station comprising:

a synchronizer to synchronize, at a non allocated time slot, a clock of the wireless communication station to a clock of a wireless access point based on an estimated frequency offset of a data packet received from the wireless access point, in response to a signal received from said wireless access point instructing said wireless communication station and another wireless communication station to substantially simultaneously transmit wireless signals at a pre-defined time.

11. The wireless communication station of claim 10, further comprising:

an estimator to estimate the frequency offset and to provide the frequency offset to the synchronizer.

12. The wireless communication station of claim 10, wherein said synchronizer is to tune a Voltage Controlled Oscillator of said wireless communication station based on said estimated frequency offset.

13. The wireless communication station of claim 10, wherein said synchronizer is to bias a counter associated with said clock of said wireless communication station based on said estimated frequency offset.

14. The wireless communication station of claim 10, further comprising:

a transmitter to transmit data to said wireless access point at a transmission frequency substantially equal to a frequency of said wireless access point based on said estimated frequency offset.

15. The wireless communication station of claim 10, further comprising:

a compensator to compensate said estimated frequency offset by modifying data intended for transmission based on said estimated frequency offset; and

a transmitter to transmit the modified data to said wireless access point.

16. The wireless communication station of claim 10, further comprising:

a compensator to compensate said estimated frequency offset by modifying data intended for transmission based on said estimated frequency offset; and

a transmitter to transmit the modified data to said wireless access point.

17. The wireless communication station of claim 16, wherein said compensator comprises:

a first scaler to multiply a symbol in a frequency domain by a frequency domain compensation phasor; and

a second scaler to multiply a symbol in a time domain by a time domain compensation phasor.

18. A method comprising:

receiving a signal instructing a plurality of wireless communication stations to substantially simultaneously transmit wireless signals at a pre-defined time; and

synchronizing, at a non allocated time slot, a clock of a wireless communication station to a clock of a wireless access point based on an estimated frequency offset of a data packet received from the wireless access point.

19. The method of claim 18, further comprising:

estimating the frequency offset; and

providing the frequency offset to the synchronizer.

20. The method of claim 18, comprising:

tuning a Voltage Controlled Oscillator of said wireless communication station based on said estimated frequency offset.

21. The method of claim 18, wherein synchronizing comprises:

biasing a counter associated with the clock of said wireless communication station based on said estimated frequency offset.

22. The method of claim 18, further comprising:

transmitting data to said wireless access point at a transmission frequency substantially equal to a frequency of said wireless access point based on said estimated frequency offset.

23. The method of claim 18, further comprising:

compensating said estimated frequency offset by modifying data intended for transmission based on said estimated frequency offset; and

transmitting the modified data to said wireless access point.

24. The method of claim 23, wherein compensating comprises:

multiplying a symbol in a frequency domain by a frequency domain compensation phasor; and

multiplying a symbol in a time domain by a time domain compensation phasor.

25. A wireless communication station comprising:

a dipole antenna to receive wireless communication signals; and

a synchronizer to synchronize, at a non allocated time slot, a clock of the wireless communication station to a clock of a wireless access point based on an estimated frequency offset of a data packet received from the wireless access point, in response to a signal received from said wireless access point instructing said wireless communication station and another wireless communication station to substantially simultaneously transmit wireless signals at a pre-defined time.

26. The wireless communication station of claim 25, further comprising:

an estimator to estimate the frequency offset and to provide the frequency offset to the synchronizer.

27. The wireless communication station of claim 25, wherein said synchronizer is to tune a Voltage Controlled Oscillator of said wireless communication station based on said estimated frequency offset.