Configuration of overhead channels in a mixed bandwidth system

• US 20040252724A1
• Filed: 06/28/2004
• Published: 12/16/2004
• Est. Priority Date: 04/23/1999
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Jou, Yu-Cheun
• Granted Patent: US 7,508,790 B2
• Time in Patent Office: Days
• US Class Current: 370/480
• CPC Class Codes: H04L 27/262 Reduction thereof by selection of pilot symbols
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 5/0021 in which codes are applied as a frequency-domain sequences, e.g. MC-CDMA
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority

Abstract

A method and apparatus for transmitting broadcast information in a multi-carrier communication system. The Sync Channel of the multi-carrier system is transmitted a 1.25 MHz channel bandwidth (i.e., over a single carrier), and to specify the preferred channels for the Sync Channel transmission instead of the preferred channels for the entire multi-carrier system. The Sync Channel Message will carry additional information indicating the center frequency of a multi-carrier system within a reserved set of frequency bands and indicating the frequency of a single carrier system in the reserved set of frequency bands. Considering the A block of the PCS band again, the preferred channels for Sync Channel transmission can be selected as channels 75, 150 and 225. This selection ensures that one of the preferred channels will always be used by any multi-carrier system regardless of the location of its center channel.

Claims

1. A multi-carrier base station, comprising:

a first transmission subsystem for transmitting some data components of forward link data comprising a sync channel message on at least one of a set of preferred frequency channels included within a predetermined set of frequencies in a personal communications system (PCS) block of frequencies ; and

at least one additional transmission subsystem for simultaneously transmitting remaining components of said forward link data.

2. The base station of claim 1, wherein said sync channel message indicates the frequency of a single carrier system in said set of frequencies.

3. The base station of claim 1, wherein said sync channel message indicates the center frequency of at least one multi-carrier system in said set of frequencies.

4. The base station of claim 3, wherein said set of a preferred frequency channels have channel numbers comprising 75, 150 and 225, and wherein the number of frequency channels in said set of preferred frequency channels is less number of frequencies in the predetermined set of frequencies.

5. A method of acquiring a sync channel message using a wireless device operable in at least one of a single carrier mode in a single carrier system and a multi-carrier mode in a multi-carrier system, the method comprising:

defining a predetermined set of frequencies that each have channel number associated with a band; and

tuning to preferred channel numbers until a sync channel message is received, wherein any combination of three adjacent channel numbers includes a preferred channel number upon which the wireless device can receive the sync channel message.

6. A method according to claim 5, wherein tuning to preferred channel numbers until a sync channel message is received, comprises:

attempting to receive the sync channel message by tuning to a first preferred channel number located on one of a group of bands including the first through third bands; and

if the sync channel message is not received on the group of bands including the first through third bands, attempting to receive the sync channel message by tuning to the first preferred channel number located on one of a group of bands including the second through fourth bands.

7. A method according to claim 6, further comprising:

if the sync channel message is not received on the group of bands including the second through fourth bands, attempting to receive the sync channel message by tuning to a second preferred channel number located on one of a group of bands including the third through fifth bands.

8. A method according to claim 7, further comprising:

if the sync channel message is not received on the group of bands including the third through fifth bands, attempting to receive the sync channel message by tuning to the second preferred channel number located on one of a group of bands including the fourth through sixth bands.

9. A method according to claim 8, wherein channel numbers of the predetermined set of frequencies comprise 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, and 275, and wherein the preferred channel numbers are 75, 150 and 225 such that such that a sync channel message provided anywhere in the predetermined set of frequencies will include one of the preferred channel numbers.

10. A method according to claim 9, wherein each band has a width of approximately 1.25 Mhz and carries CDMA transmission.

11. A method according to claim 5, wherein the sync channel message is received if:

a detector in the wireless device detects a pilot signal on a band that includes a preferred channel number; and

a receiver in the wireless device receives, demodulates, and decodes the sync channel message.

12. A method according to claim 5, further comprising:

deciding to operate, responsive to the sync channel message, in one of the multi-carrier system and the single carrier system.

13. A method according to claim 12, wherein the sync channel message is transmitted in a 1x band and indicates the frequency of a 1x band in the current set of frequency bands, and if the wireless device decides to operate in the single carrier system, then the wireless device uses the information received in the sync channel message to tune to the appropriate frequency of the single carrier system, and receives a general paging channel message on a primary paging channel that provides a number of paging channels used by the single carrier system.

14. A method according to claim 12, wherein the sync channel message indicates the center frequency of a multi-carrier system in the current set of frequency bands, and if the wireless device decides to operate in the multi-carrier system, then the wireless device uses the center frequency of the multi-carrier system indicated in the sync channel message to tune to the multi-carrier system and receive a broadcast channel message that indicates a number of common control channels that are employed by the multi-carrier system.

15. A method of acquiring a sync channel message using a wireless device operable in at least one of a single carrier mode in a single carrier system and a multi-carrier mode in a multi-carrier system, the method comprising:

defining a predetermined set of frequencies that each have channel number associated with a band; and

tuning to preferred channel numbers until a sync channel message is received, wherein any combination of three adjacent channel numbers includes a preferred channel number upon which the wireless device can receive the sync channel, wherein tuning to preferred channel number until a sync channel message is received, comprises;

tuning to a first preferred frequency in the predetermined set of frequencies, wherein the first preferred frequency falls within the first though third bands; and

determining whether a sync channel message is available in the first though third bands, wherein the sync channel message is divided into three component parts that are each transmitted separately and simultaneously on a different bands;

if the sync channel message is not available at the first preferred frequency, tuning to a second preferred frequency in the predetermined set of frequencies, wherein the second preferred frequency falls within the second through fourth bands; and

determining whether the sync channel message is available in the second through fourth bands.

16. A method according to claim 15, wherein channel numbers of the predetermined set of frequencies comprise 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, and 275, and wherein the preferred channel numbers are 75, 150 and 225 such that such that a sync channel message provided anywhere in the predetermined set of frequencies will include one of the preferred channel numbers.

17. A method according to claim 16, wherein each band has a width of approximately 1.25 Mhz and carries CDMA transmission.

18. A wireless device operable in at least one of a single carrier mode in a single carrier system and a multi-carrier mode in a multi-carrier system, comprising:

means for storing a predetermined set of frequencies that each have channel number associated with a band; and

means for tuning to preferred channel numbers until a sync channel message is received, wherein any combination of three adjacent channel numbers includes a preferred channel number upon which the wireless device can receive the sync channel message.

19. A wireless device according to claim 18, wherein the means for tuning to preferred channel numbers until a sync channel message is received, comprises:

means for attempting to receive the sync channel message by tuning to a first preferred channel number located on one of a group of bands including the first through third bands, and, if the sync channel message is not received on the group of bands including the first through third bands, tuning to the first preferred channel number located on one of a group of bands including the second through fourth bands.

20. A wireless device according to claim 19, if the sync channel message is not received on the group of bands including the second through fourth bands, wherein the means for attempting to receive the sync channel message tunes to a second preferred channel number located on one of a group of bands including the third through fifth bands.

21. A wireless device according to claim 20, if the sync channel message is not received on the group of bands including the third through fifth bands, wherein the means for attempting to receive the sync channel message tunes to the second preferred channel number located on one of a group of bands including the fourth through sixth bands.

22. A wireless device according to claim 21, wherein channel numbers of the predetermined set of frequencies comprise 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, and 275, and wherein the preferred channel numbers are 75, 150 and 225 such that such that a sync channel message provided anywhere in the predetermined set of frequencies will include one of the preferred channel numbers.

23. A wireless device according to claim 22, wherein each band has a width of approximately 1.25 Mhz and carries CDMA transmission.

24. A wireless device according to claim 18, wherein the sync channel message is received if:

a detector in the wireless device detects a pilot signal on a band that includes a preferred channel number; and

a receiver in the wireless device receives, demodulates, and decodes the sync channel message.

25. A wireless device according to claim 18, further comprising:

means for deciding to operate, responsive to the sync channel message, in one of the multi-carrier system and the single carrier system.

26. A wireless device according to claim 25, wherein the sync channel message is transmitted in a 1x band and indicates the frequency of a 1x band in the current set of frequency bands, and if the means for deciding decides to operate in the single carrier system, then the wireless device uses the information received in the sync channel message to tune to the appropriate frequency of the single carrier system, and receives a general paging channel message on a primary paging channel that provides a number of paging channels used by the single carrier system.

27. A wireless device according to claim 25, wherein the sync channel message indicates the center frequency of a multi-carrier system in the current set of frequency bands, and if the means for deciding decides to operate in the multi-carrier system, then the wireless device uses the center frequency of the multi-carrier system indicated in the sync channel message to tune to the multi-carrier system and receive a broadcast channel message that indicates a number of common control channels that are employed by the multi-carrier system.