Method and system for synchronization of at least two terminal communication systems and at least one counterpart communication station within a multi-standard wireless communication system

• US 8,457,103 B2
• Filed: 11/09/2009
• Issued: 06/04/2013
• Est. Priority Date: 05/09/2007
• Status: Active Grant

• Current Assignee: ST-Ericcson SA (Telefonaktiebolaget LM Ericsson)
• Original Assignee: ST-Ericcson SA (Telefonaktiebolaget LM Ericsson)
• Inventors: Neumann, Markus, Wuensch, Christian
• Primary Examiner(s): TORRES, MARCOS L
• Application Number:
  US12/615,151
• Publication Number:
  US 20100113014A1
• Time in Patent Office: 1,303 Days
• Field of Search: 370/350, 370342-347, 370321-324, 370/395.62, 370/503, 370507-514, 370/520, 455/502, 455/208, 455/265
• US Class Current: 370/350
• CPC Class Codes: H04B 7/2675 Frequency synchronisation
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 56/0035 detecting errors in frequency or phase
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 92/10 between terminal device and access point, i.e. wireless air interface

Abstract

A method synchronizes plural terminal communication systems and a counterpart communication station connected via a radio link within a multi-standard wireless communication system, wherein a counterpart transmission signal is transmitted from said counterpart communication station to the corresponding terminal communication system. A common reference clock signal is generated and supplied to a signal generation unit within said terminal communication system, wherein each terminal communication system comprises a conversion ratio unit having a conversion ratio. An accurate frequency datum is derived from each counterpart transmission signal in the terminal communication systems and a frequency control signal is determined from said accurate frequency datum. A synchronization between said terminal communication stations and counterpart communication station is obtained by adjusting the frequency of the common reference clock signal and/or the conversion ratio of said conversion ratio units according to the frequency control signal.

Claims

1. A method, comprising:

synchronizing a plurality of terminal communication systems and a counterpart communication station coupled via a radio link within a multi-standard wireless communication system, the synchronizing including;

transmitting a counterpart transmission signal from the counterpart communication station to a corresponding terminal communication system of the plurality of terminal communication systems;

generating a common reference clock signal;

supplying the common reference clock signal to a signal generation unit within the terminal communication systems, wherein each terminal communication system comprises a conversion ratio unit having a respective conversion ratio;

deriving a plurality of accurate frequency data from a plurality of respective counterpart transmission signals via a plurality of respective signal conversion units;

deriving a plurality of frequency control signals from the respective accurate frequency data in the respective terminal communication systems;

deriving a common frequency control signal from the frequency control signals by prioritizing the frequency control signal provided by the terminal communication system that is most accurate and selecting the prioritized frequency control signal as the common reference clock signal;

controlling the frequency of the common reference clock signal via the common frequency control signal; and

obtaining synchronization between the corresponding terminal communication system and the counterpart communication station, the obtaining including at least one of;

adapting a frequency of the common reference clock signal according to the frequency control datum; and

adapting the conversion ratio of the conversion ratio unit of the corresponding terminal communication system according to the frequency control datum.

2. A method according to claim 1, comprising:

sharing among the terminal communication systems at least one of the accurate frequency datum and the frequency control signal determined from the accurate frequency datum.

3. A method according to claim 1, wherein each terminal communication system includes a respective one of a plurality of signal generating units, the method comprising, for each terminal communication system, supplying the frequency control signal that was derived in the terminal communication system to the signal generation unit of the terminal communication system.

4. A method according to claim 1, comprising:

detecting a discontinuous operation of one of the terminal communication systems; and

applying a buffered frequency control signal while the at least one of the terminal communication systems is inactive.

5. A method according to claim 1, wherein deriving the common frequency control signal is performed by a clock control evaluation unit, the method comprising:

selecting as the common frequency control signal whichever one of the terminal communication systems is currently active, wherein the activeness of the terminal communication systems is determined by an operation mode detector arranged within the clock control evaluation unit.

6. A method according to claim 1, comprising:

detecting a frequency offset datum in one of the terminal communication systems by comparing said common reference clock signal with the accurate frequency datum and

deriving the frequency control signal from the detected frequency offset datum.

7. A method, comprising:

synchronizing a plurality of terminal communication systems and a counterpart communication station coupled via a radio link within a multi-standard wireless communication system, the synchronizing including;

transmitting a counterpart transmission signal from the counterpart communication station to a corresponding terminal communication system of the plurality of terminal communication systems;

generating a common reference clock signal;

supplying the common reference clock signal to a signal generation unit within the terminal communication systems, wherein each terminal communication system comprises a conversion ratio unit having a respective conversion ratio;

deriving a plurality of accurate frequency data from a plurality of respective counterpart transmission signals via a plurality of respective signal conversion units;

deriving a plurality of frequency control signals from the respective accurate frequency data in the respective terminal communication systems;

deriving the frequency control signal from the accurate frequency data provided by the signal conversion units using a common control unit—

by prioritizing the accurate frequency data provided by the signal conversion units and selecting one prioritized accurate frequency datum for deriving the frequency control signal;

controlling the conversion ratio of the conversion ratio units via the frequency control signals; and

obtaining synchronization between the corresponding terminal communication system and the counterpart communication station, the obtaining including at least one of;

adapting a frequency of the common reference clock signal according to the frequency control datum; and

adapting the conversion ratio of the conversion ratio unit of the corresponding terminal communication system according to the frequency control datum.

8. A method according to claim 7, comprising:

detecting a discontinuous operation of at least one of the terminal communication systems; and

using a buffered frequency control signal as the frequency control signal while the at least one of the terminal communication systems is inactive.

9. A method according to claim 7, comprising:

selecting one of the accurate frequency data provided by currently active terminal communication systems of the terminal communication systems as the frequency control signal, wherein the activeness of the terminal communication systems is determined by the common clock control unit.