Method and system for operating a CDMA cellular system having beamforming antennas

• US 6,108,323 A
• Filed: 11/26/1997
• Issued: 08/22/2000
• Est. Priority Date: 11/26/1997
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Gray, Steven D
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): KWOH, JASPER C
• Application Number:
  US08/979,744
• Time in Patent Office: 1,000 Days
• Field of Search: 370/335, 370/342, 375/200, 455/13.1, 455/33.1, 455/561, 455/562, 455/277.1, 455/277.2
• US Class Current: 370/335
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams

Abstract

A method and system for operating a CDMA cellular telecommunications system having beamforming antennas in combination with other antenna access techniques. System capacity and demand on system resources are dynamically adjusted using beamforming antennas for some mobile stations, and other antenna access techniques for other mobile stations. Forward link channels on the beamforming and non-beamforming antennas are dynamically allocated among mobile stations depending upon resources available and the type of channel required by each mobile station. Forward link channels requiring a higher data rate, above a predetermined threshold, may be assigned to channels transmitted on beamformed antennas. In an embodiment of the invention, the cellular system includes beamformed and non-beamforming antennas.

Claims

1. A method for operating a cellular system having a base station transmitting over beamformed channels from beamforming antennas and non-beamformed channels from non-beamforming antennas, said method comprising the steps of:

receiving a request for access from a mobile station on a non-beamformed access channel;

determining, in response to receiving said request for access, whether said mobile station is to be assigned to a beamformed traffic channel or to a non-beamformed traffic channel based on at least one system parameter, the at least one system parameter including an indication of availability of system resources for use for said beamformed channels;

and if it is determined that said mobile station is to be assigned to said beamformed channel;

determining information at said mobile station from a beamformed pilot channel; and

transmitting from said base station to said mobile station on said beamformed traffic channel according to said information.

2. The method of claim 1, wherein said step of determining whether said mobile station is to be assigned to a beamformed traffic channel or to a non-beamformed traffic channel comprises determining whether a data rate of a transmission from said base station to said mobile station on said non-beamformed traffic channel would exceed a predetermined level.

3. The method of claim 2, wherein said non-beamformed traffic channel comprises a first non-beamformed traffic channel and wherein said method further comprises the steps of:

determining that said mobile station is to be transferred from said beamformed traffic channel to a second non-beamformed traffic channel based on said at least one system parameter; and

assigning said mobile station to said second non-beamformed traffic channel.

4. The method of claim 3, wherein said step of determining that said mobile station is to be transferred from said beamformed traffic channel comprises determining that said data rate of a transmission from said base station to mobile station on said beamformed traffic channel has fallen below said predetermined level.

5. The method of claim 1, wherein said information determined from said beamformed pilot channel in said step of determining information comprises timing information.

6. The method of claim 1, wherein said beamformed pilot channel comprises a CDMA pilot channel and said beamformed traffic channel comprises a CDMA traffic channel transmitted on the same antenna.

7. A method of operating a cellular system having a base station transmitting on beamforming and non-beamforming antennas, said method comprising the steps of:

transmitting a first control message on a first control channel from said base station to a mobile station, said first control channel transmitted from a non-beamforming antenna of said base station;

demodulating, in response to receiving said first control message, a first traffic channel at said mobile station, said first traffic channel transmitted from said non-beamforming antennas of said base station;

determining that said mobile station is to be transferred from said first traffic channel to a second traffic channel based on at least one system parameter, the at least one system parameter including an indication of availability of system resources for use of said beamforming antennas, said second traffic channel transmitted from a first beamforming antenna of said beamforming antennas of said base station;

transmitting, in response to said determination made in said step of determining, a second control message on said first traffic channel, said second control message identifying a second control channel associated with said second traffic channel;

demodulating, in response to receiving said second control message at said mobile station, said second control channel;

transmitting channel data from said mobile station to said base station, said channel data determined from said second control channel;

transmitting a transmission on said second traffic channel from said base station to said mobile station according to said channel data; and

demodulating said transmission on said second traffic channel at said mobile station.

8. The method of claim 7, wherein said step of determining that said mobile station is to be transferred from said first traffic channel comprises determining that a data rate of a transmission from said base station to said mobile station on said first traffic channel has exceeded a predetermined level.

9. The method of claim 8, further comprising the steps of:

determining that said mobile station should be transferred from said second traffic channel to a third traffic channel, said third traffic channel transmitted from a non-beamforming antenna of said base station;

transmitting a third control message to said mobile station on said second traffic channel; and

demodulating said third traffic channel at said mobile station.

10. The method of claim 9, wherein said step of determining that said mobile station should be transferred from said second traffic channel comprises determining that a data rate of a transmission from said base station to said mobile station on said second traffic channel has fallen below said predetermined level.

11. The method of claim 7, wherein said second control channel comprises a CDMA pilot channel and said second traffic channel comprises a CDMA traffic channel transmitted on the same antenna.

12. The method of claim 7, wherein said first control channel and first traffic channel are CDMA channels transmitted from omnidirectional antennas.

13. The method of claim 7, wherein said channel data determined from said second control channel comprises timing information.

14. An apparatus for operating a cellular system having a base station transmitting over beamformed channels from beamforming antennas and over non-beamformed channels from non-beamforming antennas, said apparatus comprising:

means for receiving a request for access from a mobile station on a non-beamformed access channel;

means for determining, in response to receiving said request for access, whether said mobile station is to be assigned to a beamformed traffic channel or to a non-beamformed traffic channel based on at least one system parameter, the at least one system parameter including an indication of availability of system resources for use for of beamformed channels;

means for determining, in response to a determination that said mobile station is to be assigned to a beamformed traffic channel in said means for determining whether said mobile station is to be assigned to a beamformed traffic channel, information at said mobile station from a beamformed pilot channel; and

means for transmitting from said base station to said mobile station on said beamformed traffic channel based on said information determined in said means for determining information.

15. The apparatus of claim 14, wherein said means for determining whether said mobile station is to be assigned to a beamformed traffic channel or to a non-beamformed traffic channel comprises means for determining whether a data rate of a transmission from said base station to said mobile station on said non-beamformed channel would exceed a predetermined level.

16. The apparatus of claim 15, wherein said non-beamformed traffic channel comprises a first non-beamformed traffic channel and wherein said apparatus further comprises:

means for determining that said mobile station is to be transferred from said beamformed traffic channel to a second non-beamformed traffic channel based on said at least one system parameter; and

means for assigning said mobile station to said second non-beamformed traffic channel.

17. The apparatus of claim 16, wherein said means for determining that said mobile station is to be transferred from said beamformed traffic channel comprises means for determining that a data rate of a transmission from said base station to mobile station on said beamformed traffic channel has fallen below said predetermined level.

18. The apparatus of claim 14, wherein said information determined from said beamformed pilot channel by said means for determining information comprises timing information.

19. The apparatus of claim 14, wherein said beamformed pilot channel comprises a CDMA pilot channel and said beamformed traffic channel comprises a CDMA traffic channel transmitted on the same antenna.

20. An apparatus for operating a cellular system having a base station transmitting on beamforming and non-beamforming antennas, said apparatus comprising:

means for transmitting a first control message on a first control channel from said base station to a mobile station, said first control channel transmitted from a non-beamforming antenna of said base station;

means for demodulating, in response to receiving said first control message, a first traffic channel at said mobile station, said first traffic channel transmitted from said non-beamforming antenna of said base station;

means for determining that said mobile station is to be transferred from said first traffic channel to a second traffic channel based on at least one system parameter, said second traffic channel transmitted from a first beamforming antenna of said base station, said at least one system parameter including an indication of system resources for use of said beamforming antennas;

means for transmitting, in response to said determination made in said means for determining, a second control message on said first traffic channel, said second control message identifying a second control channel associated with said second traffic channel;

means for demodulating, in response to receiving said second control message at said mobile station, said second control channel;

means for transmitting channel data from said mobile station to said base station, said channel data determined from said second control channel;

means for transmitting a transmission on said second traffic channel from said base station to said mobile station according to said channel data; and

means for demodulating said transmission on said second traffic channel at said mobile station.

21. The apparatus of claim 20, wherein said means for determining that said mobile station is to be transferred from said first traffic channel comprises means for determining that a data rate of a transmission from said base station to said mobile station on said first traffic channel has exceeded a predetermined level.

22. The apparatus of claim 21, further comprising:

means for determining that said mobile station should be transferred from said second traffic channel to a third traffic channel, said traffic channel transmitted from a non-beamforming antenna of said base station;

means for transmitting a third control message to said mobile station on said second traffic channel; and

means for demodulating said first traffic channel at said mobile station.

23. The apparatus of claim 22, wherein said means for determining that said mobile station should be transferred from said second traffic channel comprises means for determining that a data rate of a transmission from said base station to said mobile station on said second traffic channel has fallen below said predetermined level.

24. The apparatus of claim 20, wherein said second control channel comprises a CDMA pilot channel and said second traffic channel comprises a CDMA traffic channel transmitted on the same antenna.

25. The apparatus of claim 20, wherein said first control channel and first traffic channel are CDMA channels transmitted from omnidirectional antennas.

26. The apparatus of claim 20, wherein said channel data determined from said second control channel by said means for determining comprises timing information.