CHANNEL ASSIGNMENT BASED ON SPATIAL STRATEGIES IN A WIRELESS NETWORK USING ADAPTIVE ANTENNA ARRAYS

• US 20100118729A1
• Filed: 01/21/2010
• Published: 05/13/2010
• Est. Priority Date: 03/28/2002
• Status: Active Grant

• Current Assignee: Athanasios A. Kasapi, Elvino S. Sousa, Mitchell D. Trott
• Original Assignee: Athanasios A. Kasapi, Elvino S. Sousa, Mitchell D. Trott
• Inventors: Sousa, Elvino S., Trott, Mitchell D., Kasapi, Athanasios A.
• Granted Patent: US 7,805,144 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• 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
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

Channels are assigned based on co-spatial constraints in wireless network using spatial division multiple access. In one example, the invention includes assigning a co-spatial constraint to each of a plurality of conventional traffic communications channels of a base station, and receiving a request from a user terminal to communicate using a traffic communication channel of the base station. The invention further includes measuring a quality parameter of the request deriving a co-spatial constraint for the user terminal, assigning the user terminal co-spatial constraint to the user terminal, and assigning the user terminal to a traffic communication channels having a channel co-spatial constraint that is no less than the user terminal co-spatial constraint and that has no more assigned radios than permitted by the channel co-spatial constraint.

Claims

1. A method comprising:

determining a radio channel signal quality parameter for a plurality of user terminals of a radio communications system;

assigning a co-spatial constraint to each of the user terminals based on the parameter, the user terminal co-spatial constraints comprising a limitation on the quantity of other user terminals with which the respective user terminal can share a traffic communications channel of the radio communications system using spatial division multiple access; and

assigning the user terminals each to one of a plurality of traffic communication channels based on the assigned user terminal co-spatial constraint.

2. The method of claim 1, wherein determining a parameter comprises receiving a signal quality measurement from each of the plurality of user terminals.

3. The method of claim 1, wherein determining a parameter comprises measuring a quality parameter of a signal received from each of the plurality of user terminals through a respective radio channel.

4. The method of claim 1, wherein determining a parameter comprises measuring one or more of a distance, a signal strength, a signal to noise ratio, a quality of service designation, a mobility designation, a mobility, a Doppler shift, a Doppler spread, a velocity, and an angle spread.

5. The method of claim 1, wherein assigning the user terminals comprises assigning the user terminals such that each user terminal shares a channel with no more additional user terminals than allowed by its respective co-spatial constraint.

6. The method of claim 5, wherein the co-spatial constraint of the additional user terminals are less than or equal to that of the user terminal.

7. The method of claim 1, further comprising assigning a co-spatial constraint to traffic communications channels, the channel co-spatial constraints comprising a limitation on the quantity of radios that can share the respective channel using spatial division multiple access;

and

assigning the user terminals each to one of a plurality of traffic communication channels having a channel co-spatial constraint that is no less than the user terminal co-spatial constraint and that has no more assigned radios than permitted by the channel co-spatial constraint.

8. The method of claim 1, further comprising receiving a request from a user terminal to communicate using a traffic communication channel of the base station and wherein assigning the user terminals is in response to receiving the request.

9. The method of claim 1, wherein assigning comprises first assigning user terminal each to a different traffic communications channel and then assigning subsequent user terminals to a traffic communications channel having an assigned user terminal with a co-spatial constraint less than or equal to the user terminal to be assigned.

10. A machine-readable medium having stored thereon data representing instructions, which if executed by the machine, cause the machine to perform operations comprising:

determining a radio channel signal quality parameter for a plurality of user terminals of a radio communications system;

assigning a co-spatial constraint to each of the user terminals based on the parameter, the user terminal co-spatial constraints comprising a limitation on the quantity of other user terminals with which the respective user terminal can share a traffic communications channel of the radio communications system using spatial division multiple access; and

assigning the user terminals each to one of a plurality of traffic communication channels based on the assigned user terminal co-spatial constraint.

11. The medium of claim 10, wherein a traffic communication channel has at least two assigned user terminals and wherein the instructions further cause the machine to transmit nulls to one user terminal of the traffic communications channel when transmitting traffic to the other user terminal of the traffic communications channel.

12. The medium of claim 10, wherein the instructions further cause the machine to perform:

assigning a co-spatial constraint to traffic communications channels, the channel co-spatial constraints comprising a limitation on the quantity of radios that can share the respective channel using spatial division multiple access;

searching for a channel having a channel co-spatial constraint equal to the user terminal co-spatial constraint and having a number of assigned radios no more than the channel co-spatial constraint;

if a such a channel is not found, then searching for a channel having a channel co-spatial constraint that is less than the user terminal co-spatial constraint and having a number of assigned radios no more than the channel co-spatial constraint;

if such a channel is not found, then denying service to the user terminal; and

wherein assigning the user terminal comprises assigning the user terminal to the channel found by searching.

13. A communications device comprising:

a receiver to receive radio signals from a plurality of user terminals; and

a processor communicatively coupled to the receiver to measure a quality parameter of the received radio signals received from the user terminals, to assign a co-spatial constraint to each of the user terminals based on the quality parameter, the user terminal co-spatial constraint comprising a limitation on the quantity of additional radios with which the user terminal can share a traffic communications channel using spatial division multiple access and to assign the user terminals each to one of the plurality of traffic communication channels based on the assigned co-spatial restraint.

14. The device of claim 13, wherein the device is a base station, wherein the received radio signals comprise a request from a user terminal to communicate using a traffic communication channel of a base station, and wherein assigning a user terminal is in response to the request.

15. The device of claim 13, wherein processor is further to assign a co-spatial constraint to each of the traffic communications channels, the channel co-spatial constraints comprising a limitation on the quantity of radios that can share the respective channel using spatial division multiple access and wherein assigning a user terminal comprises assigning the user terminal to a traffic communications channel having a channel co-spatial constraint that is no less than the user terminal co-spatial constraint and that has no more assigned radios than permitted by the channel co-spatial constraint.

16. The device of claim 13, further comprising a transmitter to transmit a communications signal to the user terminal over the communications channel.

17. The device of claim 16, wherein the transmitter further transmits nulls to the user terminal corresponding to the other radios assigned to the same channel.

18. The device of claim 13, wherein the signal quality parameter comprises a distance between the device and the user terminals and wherein assigning the user terminals comprises assigning user terminal having a similar distance to share a traffic communications channel.

19. The device of claim 13, wherein the signal quality parameter comprises a noise parameter and wherein a higher co-spatial constraint is assigned to a user terminal with less signal noise.

20. The device of claim 13, wherein the processor is further to reassign the user terminals to traffic communications channels at time intervals.