Method and mobile station for synchronizing to a common synchronization channel and obtaining a channel estimate

• US 7,751,838 B2
• Filed: 04/27/2006
• Issued: 07/06/2010
• Est. Priority Date: 01/17/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Balachandran, Kumar, Zangi, Kambiz, Ramesh, Rajaram
• Primary Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US11/380,476
• Publication Number:
  US 20070167181A1
• Time in Patent Office: 1,531 Days
• Field of Search: None
• US Class Current: 455/502
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 48/10 using broadcasted information
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 56/00 Synchronisation arrangements

Abstract

A mobile station for operating in a broadcast-centric cellular communication system. The system improves broadcast channel performance by exploiting the benefits of macro-diversity in a cellular communication system having a plurality of base stations that transmit signals within a plurality of associated cells. System-specific control information common to all cells is synchronously and simultaneously broadcast from multiple base stations using a broadcast channel that is identical across the entire system. Cell-specific control information is transmitted individually from each base station. The mobile station uses the broadcast information for initial synchronization to the system, and to obtain most relevant system information. After system synchronization, the mobile station identifies the connected cell through a physical layer characteristic, and performs initial access to the system.

Claims

1. A mobile station comprising:

means for receiving from a plurality of base stations, a signal on a Single System Synchronization Channel (SSCH) that is uniform and synchronized across an entire wireless multi-cellular telecommunication system, said signal including initial frequency and time synchronization information transmitted from all base stations in the telecommunication system;

means for synchronizing to the SSCH utilizing macro-diversity combining of the signals received from the plurality of the base stations;

means for receiving from the plurality of base stations, a pilot pattern and control messages on a System Broadcast Control Channel (SBCCH) that is uniform across the entire wireless multi-cellular telecommunication system, wherein the pilot pattern is common to all cells in the system, and the control messages include modulated SBCCH control information common to all cells in the system; and

means for utilizing the entire received signal strength of the pilot pattern to obtain a channel estimate and to demodulate the SBCCH control information.

2. The mobile station according to claim 1, wherein the control messages also include information on pointers to cell-specific control information that is specific to different cells, and cell identifiers for different cells, and the mobile station further comprises means for determining a suitable cell to which the mobile station can connect utilizing synchronization patterns, pilot patterns, and the cell identifiers.

3. The mobile station according to claim 2, wherein the means for determining a suitable cell includes means for performing focused searches at different locations in time and frequency for the cell identifiers for particular cells.

4. The mobile station according to claim 3, further comprising means for utilizing the pointers to cell-specific control information to obtain the cell-specific control information required to access the system and perform registration and attach procedures.

5. A method in a mobile station comprising the steps of:

receiving from a plurality of base stations, a signal on a Single System Synchronization Channel (SSCH) that is uniform and synchronized across an entire wireless multi-cellular telecommunication system, said signal including initial frequency and time synchronization information transmitted from all base stations in the telecommunication system;

synchronizing to the SSCH utilizing macro-diversity combining of the signals received from the plurality of the base stations;

receiving from the plurality of base stations, a pilot pattern and control messages on a System Broadcast Control Channel (SBCCH) that is uniform across the entire wireless multi-cellular telecommunication system, wherein the pilot pattern is common to all cells in the system, and the control messages include modulated SBCCH control information common to all cells in the system; and

utilizing the entire received signal strength of the pilot pattern to obtain a channel estimate and to demodulate the SBCCH control information.

6. The method according to claim 5, wherein the control messages also include information on pointers to cell-specific control information that is specific to different cells, and cell identifiers for different cells, and the method further comprises determining a suitable cell to which the mobile station can connect utilizing synchronization patterns, pilot patterns, and the cell identifiers.

7. The method according to claim 6, wherein the step of determining a suitable cell includes performing focused searches at different locations in time and frequency for the cell identifiers for particular cells.

8. The method according to claim 7, further comprising utilizing the pointers to cell-specific control information to obtain the cell-specific control information required to access the system and perform registration and attach procedures.