Broadcast-centric cellular communication system

• US 7,672,667 B2
• Filed: 04/27/2006
• Issued: 03/02/2010
• 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): PHAN, HUY Q
• Application Number:
  US11/380,474
• Publication Number:
  US 20070167180A1
• Time in Patent Office: 1,405 Days
• Field of Search: 455/3.01, 455/515, 455/403, 455/517, 455/426.1, 455/458, 455/561, 455/422.1, 455/423, 455/3.03, 379/170, 379/56.1
• US Class Current: 455/422.1
• 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 broadcast-centric cellular communication 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. Mobile stations use the broadcast information for initial synchronization to the system, and to obtain most relevant system information. After system synchronization, the mobile stations identify the connected cell through a physical layer characteristic, and perform initial access to the system.

Claims

1. A wireless multi-cellular telecommunication system having a plurality of base stations that transmit signals within a plurality of associated cells, said system comprising:

means for synchronously and simultaneously broadcasting from a predefined group of base stations, system-specific control information common to all cells;

means for transmitting individually from each base station in the group, cell-specific control information; and

a mechanism for cell identification, wherein a mobile station operating within one of the cells identifies the cell to which the mobile station is connected by detecting a unique physical-layer cell characteristic of the cell, wherein the unique physical-layer cell characteristic is a unique synchronization pattern.

2. The system according to claim 1, wherein the means for synchronously and simultaneously broadcasting system-specific control information includes means for simultaneously broadcasting an identical message from each base station.

3. The system according to claim 1, wherein the means for transmitting, cell-specific control information from each base station includes means for transmitting a message from each base station that can vary from cell-to-cell.

4. The system according to claim 3, wherein the means for transmitting cell-specific control information transmits the different messages at different times in each cell.

5. The system according to claim 3, wherein the means for transmitting cell-specific control information transmits the different messages at the same time in at least two cells.

6. A wireless multi-cellular telecommunication system having a plurality of base stations that transmit signals within a plurality of associated cells, said system comprising:

means for synchronously and simultaneously broadcasting from a predefined group of base stations, system-specific control information common to all cells;

means for transmitting individually from each base station in the group, cell-specific control information; and

a mechanism for cell identification, wherein a mobile station operating within one of the cells identifies the cell to which the mobile station is connected by detecting a unique physical-layer cell characteristic of the cell, wherein the unique physical-layer cell characteristic is a unique pilot pattern.

7. The system according to claim 6, wherein the means for broadcasting system-specific control information also broadcasts a cell identifier as part of the system-specific control information.

8. The system according to claim 6, wherein the system utilizes Orthogonal Frequency Division Multiplexing (OFDM).

9. The system according to claim 8, wherein the means for synchronously and simultaneously broadcasting system-specific control information also utilizes a pilot pattern that is well suited to estimate the channel response in order to perform demodulation.

10. The system according to claim 8, wherein the means for synchronously and simultaneously broadcasting system-specific control information also utilizes a cyclic prefix that is larger than is normally sufficient for single-cell operation.

11. A wireless multi-cellular telecommunication system having a plurality of base stations that transmit signals within a plurality of associated cells, said system comprising:

means for synchronously and simultaneously broadcasting from a predefined group of base stations, system-specific control information common to all cells;

means for transmitting individually from each base station in the group, cell-specific control information; and

means for simultaneously transmitting an identical synchronization signal from multiple base stations, wherein the synchronization signal has good time and frequency localization properties even in the presence of significant Inter-Symbol Interference (ISI).

12. A method of delivering broadcast information to mobile stations operating in a cellular communication system having a plurality of base stations that transmit signals within a plurality of associated cells, said method comprising:

synchronously and simultaneously broadcasting from a predefined group of base stations, system-specific control information common to all cells;

transmitting individually from each base station in the group, cell-specific control information; and

identifying by a mobile station operating within one of the cells, the cell to which the mobile station is connected by detecting a unique physical-layer cell characteristic of the cell, said unique physical-layer cell characteristic being selected from a group consisting of a unique synchronization pattern and a unique pilot pattern.

13. The method according to claim 12, wherein the step of synchronously and simultaneously broadcasting system-specific control information includes simultaneously broadcasting an identical message from each base station.

14. The method according to claim 12, wherein the step of transmitting, cell-specific control information from each base station includes transmitting a message from each base station that can vary from cell-to-cell.

15. The method according to claim 14, wherein the step of transmitting cell-specific control information includes transmitting the different messages at different times in each cell.

16. The method according to claim 14, wherein the step of transmitting cell-specific control information includes transmitting the different messages at the same time in each cell.

17. The method according to claim 12, wherein the step of broadcasting system-specific control information includes broadcasting a cell identifier as part of the system-specific control information.

18. The method according to claim 12, wherein the step of transmitting cell-specific control information includes:

collating the cell-specific information for all of the base stations in the group; and

transmitting the collated cell-specific information from each base station.

19. The method according to claim 12, wherein the step of transmitting cell-specific control information includes:

transmitting individually from each base station in the group, a first portion of the cell-specific control information;

wherein a second portion of the cell-specific control information is broadcast from the predefined group of base stations.

20. A method of delivering broadcast information to mobile stations operating in a cellular communication system having a plurality of base stations that transmit signals within a plurality of associated cells, said method comprising:

synchronously and simultaneously broadcasting from a predefined group of base stations, system-specific control information common to all cells and a list of cell identifiers;

broadcasting cell-specific information needed by a mobile station to make an initial system access, wherein a mobile station operating within one of the cells identifies the cell to which the mobile station is connected by detecting a unique physical-layer cell characteristic of the cell, wherein the unique physical-layer cell characteristic is a unique synchronization pattern; and

after the mobile station has made the initial system access, transmitting more detailed system information to the mobile station using a point-to-point link.

21. A wireless multi-cellular telecommunication system having a plurality of base stations that transmit signals within a plurality of associated cells, said system comprising:

means for synchronously and simultaneously broadcasting from a predefined group of base stations, system-specific control information common to all cells and a list of cell identifiers;

means for broadcasting cell-specific information needed by a mobile station to make an initial system access, wherein a mobile station operating within one of the cells identifies the cell to which the mobile station is connected by detecting a unique physical-layer cell characteristic of the cell, wherein the unique physical-layer cell characteristic is a unique pilot pattern; and

means responsive to the initial system access by the mobile station, for transmitting more detailed system information to the mobile station using a point-to-point link.