Femtocell handset assisted clock correction

• US 8,306,527 B2
• Filed: 04/22/2010
• Issued: 11/06/2012
• Est. Priority Date: 04/23/2009
• Status: Expired due to Fees

• Current Assignee: Broadcom Semiconductors Israel Limited (Broadcom, Inc.)
• Original Assignee: Percello Ltd. (Broadcom, Inc.)
• Inventors: Volloch, Yoav, Appel, Amir, Levy, Sharon, Carmon, Rafy
• Primary Examiner(s): Agosta, Steve D
• Application Number:
  US12/765,197
• Publication Number:
  US 20100273474A1
• Time in Patent Office: 929 Days
• Field of Search: 455/422.1, 455/424, 455/13.2, 455/501, 455/502, 455/63.1, 455/67.13, 370/310, 370/310.2, 370/324, 370/338
• US Class Current: 455/424
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 56/0035 detecting errors in frequency or phase
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 92/10 between terminal device and access point, i.e. wireless air interface

Abstract

A method of improving frequency accuracy of a clock unit adapted to clock a femtocell local cellular communication home base station is provided. The method comprising: providing a local cellular communication home base station having an oscillator adapted to operate as a clock therein, wherein at least one cellular communication device is camped thereto, and wherein the at least one camped cellular communication device is further in communication with at least one neighboring cellular communication base station which is associated with an oscillator adapted to operate as a clock therein; periodically applying a derivative operator over periodically obtained local communication parameters and periodically obtained neighboring communication parameters thereby generating derivative communication parameters over time; and correcting the accuracy of the frequency of the clock in the femtocell local cellular communication home base station using the derivative communication parameters over time.

Claims

1. A system comprising:

a first wireless communication base station;

a second wireless communication base station; and

a wireless communication device camped on the first wireless communication base station and in communication with the second wireless communication base station,

wherein the first wireless communication base station is configured to;

conduct a frequency scan by altering a clock frequency of its clock source across a frequency range;

while performing the frequency scan, receive from the wireless communication device signal strength measurements of a signal between the wireless communication device and the second wireless communications base station as a function of a frequency being scanned; and

select a desirable clock frequency for the clock source of the first wireless communication base station, wherein selecting the desirable clock frequency includes generating a Gaussian representation of the signal strength measurements as a function of scanned frequencies and selecting as the desirable clock frequency, a clock frequency in which the signal strength measurement is at a Gaussian center;

receive frame number parameters associated with the second wireless communication base station at a rate that enables the determination of a clock drift rate; and

derive an adjustment to the clock source of the first wireless communications base station and apply the adjustment to the clock source of the first wireless communications base station to converge the accuracy of the clock source of the first wireless communications base station to an accuracy of a clock source of the second wireless communications base station.

2. The system according to claim 1, wherein the first wireless communication base station is a femtocell base station, and the second wireless base station is a macrocell base station.

3. The system according to claim 1, wherein the clock frequency of the first wireless communication base station has a substantially lower accuracy level than a clock frequency of the second wireless communication base station.

4. The system according to claim 1, wherein the received signal strength measurements include one or more of a received signal strength indication (RSSI), a received signal code power (RSCP) or a ratio of received pilot energy to a total received energy.

5. The system according to claim 1, wherein the first and second wireless communication base stations and the wireless communication device communicate utilizing one or more wireless standards comprising:

Code Division Multiple Access (CDMA) -2000;

Global System for Mobile Communications (GSM);

Universal Mobile Telecommunications System (UMTS);

Time Division Synchronous Code Division Multiple Access (TD-SCDMA);

High-Speed Packet Access (HSPA);

Long Term Evolution (LTE); and

Worldwide Interoperability for Microwave Access (WiMAX).

6. A computer program product, comprising a tangible, non-transitory computer-readable medium having computer program code recorded thereon that, when executed by a processor, causes the processor to perform operations, the operations comprising:

conducting a frequency scan by altering a clock frequency of a clock source of a first wireless communication base station across a frequency range;

while performing the frequency scan, receiving from a wireless communication device signal strength measurements of a signal between the wireless communication device and a second wireless communications base station as a function of a frequency being scanned; and

selecting a desirable clock frequency for the clock source of the first wireless communication base station, wherein selecting the desirable clock frequency includes generating a Gaussian representation of the signal strength measurements as a function of scanned frequencies and selecting a as the desirable clock frequency, a clock frequency in which the signal strength measurement is at a Gaussian center;

receiving frame number parameters associated with the second wireless communication base station at a rate that enables the determination of a clock drift rate; and

deriving an adjustment to the clock source of the first wireless communications base station to converge the accuracy of the clock source of the first wireless communications base station to an accuracy of a clock source of the second wireless communications base station.

7. The computer program product according to claim 6, wherein the first wireless communication base station is a femtocell base station and the second wireless communication base station is a macrocell base station.

8. The computer program product according to claim 6, wherein the clock frequency of the first wireless communication base station has a substantially lower accuracy level than a clock frequency of the second wireless communication base station.

9. The computer program product according to claim 6, wherein the received signal strength measurements include one or more of a received signal strength indication (RSSI), a received signal code power (RSCP) or a ratio of received pilot energy to a total received energy.

10. The computer program product according to claim 6, wherein the first and second wireless communication base stations and the wireless communication device communicate utilizing one or more wireless standards comprising:

Code Division Multiple Access (CDMA)-2000;

Global System for Mobile Communications (GSM);

Universal Mobile Telecommunications System (UMTS);

Time Division Synchronous Code Division Multiple Access (TD-SCDMA);

High-Speed Packet Access (HSPA);

Long Term Evolution (LTE); and

Worldwide Interoperability for Microwave Access (WiMAX).

11. A method comprising:

conducting a frequency scan by altering a clock frequency of a clock source of a first wireless communication base station across a frequency range;

while performing the frequency scan, receiving from a wireless communication device signal strength measurements of a signal between the wireless communication device and a second wireless communication base station, as a function of a frequency being scanned; and

selecting a desirable clock frequency for the clock source of the first wireless communication base station,

wherein selecting the desirable clock frequency includes generating a Gaussian representation of the signal strength measurements as a function of scanned frequencies and selecting as the desirable clock frequency, a clock frequency, in which the signal strength measurement is at a Gaussian center;

receiving frame number parameters associated with the second wireless communication base station at a rate that enables the determination of a clock drift rate;

deriving an adjustment to the clock source of the first wireless communications base station based on the clock drift rate and applying the adjustment to the clock source of the first wireless communications base station to converge the accuracy of the clock source of the first wireless communications base station to an accuracy of a clock source of the second wireless communications base station,

wherein at least one of the conducting, receiving and determining is executed by a processor.

12. The method according to claim 11, wherein the first wireless communication base station is a femtocell base station and the second wireless communication base station is a macrocell base station.

13. The method according to claim 11, wherein the clock frequency of the first wireless communication base station has a substantially lower accuracy level than a clock frequency of the second wireless communication base station.

14. The method according to claim 11, wherein the received signal strength measurements include one or more of a received signal strength indication (RSSI), a received signal code power (RSCP) or a ratio of received pilot energy to a total received energy.

15. The method according to claim 11, wherein the first and second wireless communication base stations and the wireless communication device communicate utilizing one or more wireless standards comprising:

Code Division Multiple Access (CDMA)-2000;

Global System for Mobile Communications (GSM);

Universal Mobile Telecommunications System (UMTS);

Time Division Synchronous Code Division Multiple Access (TD-SCDMA);

High-Speed Packet Access (HSPA);

Long Term Evolution (LTE); and

Worldwide Interoperability for Microwave Access (WiMAX).