Method for compensating for capacity overload in a spread spectrum communication system

• US 5,245,629 A
• Filed: 10/28/1991
• Issued: 09/14/1993
• Est. Priority Date: 10/28/1991
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hall, Scott M.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/783,751
• Time in Patent Office: 687 Days
• Field of Search: 375/1, 380/34
• US Class Current: 455/522
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level

Abstract

A method for compensating for capacity overload in a communication system by first determining the received signal power level at a base site is described. The power level is compared with a threshold power level. If the received power level is greater than the threshold, the signal-to-noise ratio for the system is reduced. With the acceptable signal-to-noise ratio reduced, the subscriber power will be reduced. The received signal power level at the base site will then return to the threshold level. Alternatively, a signal-to-noise ratio of a pilot signal can be determined at the base. The signal-to-noise ratio is compared to a threshold signal-to-noise ratio. If the signal-to-noise ratio of the pilot is less than the threshold, the threshold level is reduced. With the acceptable signal-to-noise ratio reduced, the subscribers are directed to reduce their power.

Claims

1. A method of compensating for capacity overload in a spread spectrum communication system comprising the steps of:

determining a receiver site power level at a first base site of said spread spectrum communication system;

comparing said receiver site power level to a threshold power level;

adjusting a signal-to-noise ratio for said spread spectrum communication system at said first base site if said receiver site power level is greater than said threshold power level;

transmitting a power control signal from said first base site to a subscriber of said spread spectrum communication system; and

adjusting a transmit power of said subscriber in response to said power control signal.

2. The method of claim 1 whereby adjusting said transmit power of said subscriber reduces said receiver site power level to a reduced receiver site power level.

3. The method of claim 2 wherein said spread spectrum communication system has a maximum threshold power level and a minimum threshold power level.

4. The method of claim 3 wherein said receiver site power level is compared to said maximum threshold power level.

5. The method of claim 4 wherein said reduced receiver site power level is said minimum threshold power level.

6. The method of claim 5 wherein a request to add a new user to said spread spectrum communication system is refused.

7. The method of claim 5 wherein a request to add a new user to said first base site of said spread spectrum communication system is handed off to a second base site of said spread spectrum communication system.

8. The method of claim 5 wherein a current user of said first base site is handed off to a second base site of said spread spectrum communication system.

9. A method of compensating for capacity overload in a spread spectrum communication system comprising the steps of:

determining a signal-to-noise ratio of a pilot signal of a pilot of said spread spectrum communication system;

comparing said signal-to-noise ratio to a threshold signal-to-noise ratio;

adjusting said threshold signal-to-noise ratio for said spread spectrum communication system at a first base site if said signal-to-noise ratio is less than said threshold signal-to-noise ratio;

transmitting a power control signal from said first base site to a subscriber of said spread spectrum communication system; and

adjusting a transmit power of said subscriber in response to said power control signal.

10. The method of claim 9 wherein said spread spectrum communication system has a maximum threshold signal-to-noise ratio and a minimum threshold signal-to-noise ratio.

11. The method of claim 10 wherein said pilot signal-to-noise ratio is compared to said maximum threshold signal-to-noise ratio.

12. The method of claim 11 wherein said pilot signal-to-noise ratio is said minimum threshold signal-to-noise ratio.

13. The method of claim 12 wherein a request to add a new user to said spread spectrum communication system is refused.

14. The method of claim 12 wherein a request to add a new user to said first base site of said spread spectrum communication system is handed off to a second base site of said spread spectrum communication system.

15. The method of claim 12 wherein a current user of said first base site is handed off to a second base site of said spread spectrum communication system.

16. A spread spectrum communication system comprising:

determining means for determining a receiver site power level at a base site of said spread spectrum communication system;

comparing means coupled to said determining means for comparing said receiver site power level to a threshold power level;

adjusting means coupled to said comparing means for adjusting a signal-to-noise ratio for said spread spectrum communication system at said base site if said receiver site power level is greater than said threshold power level;

transmitting means coupled to said adjusting means for transmitting a power control signal from said base site to a subscriber of said spread spectrum communication system; and

adjusting means at said subscriber for adjusting a transmit power of said subscriber in response to said power control signal.

17. A spread spectrum communication system comprising:

determining means for determining a signal-to-noise ratio of a pilot signal of a pilot of said spread spectrum communication system;

comparing means coupled to said determining means to compare said signal-to-noise ratio to a threshold signal-to-noise ratio;

adjusting means coupled to said comparing means for adjusting said threshold signal-to-noise ratio for said spread spectrum communication system at said base site if said signal-to-noise ratio is less than said threshold signal-to-noise ratio;

transmitting means coupled to said adjusting means for transmitting a power control signal from said base site to a subscriber of said spread spectrum communication system; and

adjusting means at said subscriber for adjusting a transmit power of said subscriber in response to said power control signal.