Duplex power control system in a communication network

• US 5,345,598 A
• Filed: 04/10/1992
• Issued: 09/06/1994
• Est. Priority Date: 04/10/1992
• Status: Expired due to Term

• Current Assignee: Ericsson GE Mobile Communications Holding, Inc. A Corp. Of New Jersey (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson GE Mobile Communications Holding, Inc. A Corp. Of New Jersey (Telefonaktiebolaget LM Ericsson)
• Inventors: Dent, Paul W.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): PHAM, CHI H
• Application Number:
  US07/866,554
• Time in Patent Office: 879 Days
• Field of Search: 455/13.4, 455/52.1, 455/52.3, 455/53.1, 455/54.1, 455/67.1, 455/69, 455/70, 455/103, 455/127, 455/63, 455/56.1, 375/1
• US Class Current: 455/522
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission

Abstract

Measurements of mobile signal strength received at the base station are used to determine the portion of power that should be transmitted by the base station to a particular mobile. Each of a plurality of mobiles measure the relative strength of the base station signal specifically intended for that mobile. The relative strength is compared to either the total base station signal power or to a cumulative ranking of the power of signals intended for other mobiles. That comparison is used to determine whether the mobile should increase or decrease its power.

Claims

1. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power regulation system, comprising:

each mobile including;

mobile receiving means for receiving a composite signal formed from signals transmitted from said base station to all of said plurality of mobiles, each transmitted signal intended for one of said mobiles, and for determining corresponding signal strength values for each received signal in said composite signal and,

means, connected to said mobile receiving means, for computing from said signal strength values a desired mobile transmitter power level, and

said base station including;

base station receiving means for receiving signals transmitted from said plurality of mobiles and for measuring their corresponding signal strength values, and

means for modifying power levels of signal transmissions to said mobiles based on said measured signal strength values so that each of said mobile receiving means receives its intended signal with substantially equal signal quality and said base station receiving means receives said mobile transmitted signals with substantially equal signal quality.

2. A system as described in claim 1, wherein said computing means computes said desired power level for each mobile transmitter form a relative ranking of said determined signal strength values from greatest to weakest signal strength.

3. The system according to claim 2, wherein said computing means includes:

means for detecting changes in a power level of transmissions intended for said mobile based on changes in said relative ranking;

means for increasing said mobile'"'"'s transmitter power level when said relative ranking increases; and

means for decreasing said mobile'"'"'s transmitter power level when said mobile'"'"'s relative ranking decreases.

4. A system as described in claim 1, wherein said computing means computes said desired power level for its respective mobile as a function of a ratio of said determined signal strength value associated with said respective mobile to a mean of said determined signal strength values associated with other mobiles.

5. A system according to claim 4, wherein said computing means includes:

means for detecting changes in power levels of transmitted signal intended for said mobile based on changes in said ration;

means for increasing said mobile'"'"'s transmitter power level when said ratio increases; and

means for decreasing said mobile'"'"'s transmitter power level when said ratio decreases.

6. A system according to claim 1, wherein said computing means includes:

means for storing in table form a non-linear power distribution function, and

means for determining said desired power level based on said non-linear power distribution function.

7. A system according to claim 6, wherein said base station includes means for generating and transmitting a modification command;

and

wherein each mobile further includes mean, responsive to said modification command, for altering said storing means to adapt to said non-linear function.

8. A system according to claim 1, each mobile further comprising:

transmission means for transmitting a mobile signal from said mobile, and

means, connected to said computing means, for gradually altering power of said transmission means based on said computed desired mobile transmitter power level.

9. A system according to claim 1, wherein said modifying means increases power levels of signal transmissions to mobiles having relatively lesser measured signal strength values and decreases power levels to mobiles having relatively greater measured signal strength values.

10. A system as in claim 1, wherein said computing means includes:

means for sorting said determined signal strength values in an order from greatest to lowest signal strength value, and

means for selecting said desired mobile transmitter power level from a predetermined look-up table stored in a memory based on the position of said mobile'"'"'s determined signal strength value in said sorted order.

11. A system as in claim 1, wherein said mobile and base station receiving means each include a Code Division Multiple Access receiver.

12. A system as described in claim 1, wherein said mobile receiving means is a code division multiple access demodulator (CDMA) including:

subtractive CDMA demodulation means for demodulating said composite signal into a plurality of demodulated signals corresponding to said transmitted signals to each of said plurality of mobiles;

13. The system according to claim 12, wherein said ranking means includes a memory for storing said demodulated signal strengths in table format.

14. The system according to claim 12, each mobile further comprising:

CDMA signal generating means, connected to said computing means, for generating coded blocks of CDMA data signals and for staggering in time transmission of said coded blocks.

15. The power control system according to claim 1, wherein each mobile includes:

means for detecting periods of silence in communications from said base station to any mobile, and

means for deactivating demodulation of a signal detected to be silent.

16. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system, comprising:

each mobile having a transmitter; and

said base station having means for altering base transmitter power transmitted to each mobile to produce, for each mobile, a corresponding base station transmitter power that is a desired proportion of total base transmitter power and thereby to instruct each mobile to regulate its mobile transmitter power,

wherein an increase in said corresponding base station transmitter power in proportion to total base transmitter power indicates to a corresponding mobile that said corresponding mobile is to increase its mobile transmitter power.

17. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system, comprising:

each mobile having a transmitter; and

said base station having means for altering base transmitter power transmitted to each mobile to produce, for each mobile, a corresponding base station transmitter power that is a desired proportion of total base transmitter power and thereby to instruct each mobile to regulate its mobile transmitter power,

wherein said altering means includes means for determining, for each mobile, said desired proportion that will equalize signal power levels received at said base station from each of said mobile.

18. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system, comprising:

each mobile having a transmitter; and

said base station having means for altering base transmitter power transmitted to each mobile to produce, for each mobile, a corresponding base station transmitter power that is a desired proportion of total base transmitter power and thereby to instruct each mobile to regulate its mobile transmitter power,

wherein each mobile further comprises;

means for detecting alterations in received signal strength of a corresponding signal transmitted to said mobile in proportion to total signal strength of all signals received from said base station, and

means for changing said mobile transmitter power based on said detected alternations.

19. The power control system as in claim 18, wherein said changing means changes said mobile transmitter power as a function of a ratio of a strength value of a signal intended for said mobile to a mean of strength values of signals intended for other of said mobiles.

20. The power control system as in claim 18, wherein said detecting means includes means for ranking from greatest to least signal strength values to all signals transmitted to said mobiles and wherein said changing means increases said mobile transmitter power if its relative ranking increases and decreases said mobile transmitter power if its relative ranking decreases.

21. A system according to claim 18, said changing means including:

means for storing in table form a non-linear power distribution function, and

means for determining said changed mobile transmitter power based on said non-linear function.

22. A system according to claim 21, wherein said base station includes means for generating and transmitting a modification command,

and wherein each mobile further includes means for modifying said storing means in each mobile to adapt said non-linear function.

23. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system, comprising:

each mobile having a transmitter; and

said base station having means for altering base transmitter power transmitted to each mobile to produce, for each mobile, a corresponding base station transmitter power that is a desired proportion of total base transmitter power and thereby to instruct each mobile to regulate its mobile transmitter power,

wherein each mobile includes;

a receiver;

means, coupled to said receiver, for detecting periods of silence in communications from said base station to any mobile; and

means, coupled to said detecting means and to aid receiver, for deactivating processing by said receiver of any signal detected to be silent.

24. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system, comprising:

each mobile having a transmitter; and

said base station having means for altering base transmitter power transmitted to each mobile to produce, for each mobile, a corresponding base station transmitter power that is a desired proportion of total base transmitter power and thereby to instruct each mobile to regulate its mobile transmitter power,

wherein the system further comprises;

means for achieving approximately the same signal-to-interference ratios at said base station for all of said mobiles, and

means for regulating the power of signal transmissions from said base station to achieve approximately the same signal-to-interference ratio at each mobile from said base station.

25. In a communications system including at least one base station an a plurality of mobiles for communicating with said at least one base station, a power control system comprising:

means for regulating the power levels of signal transmissions from said base station to achieve approximately the same signal-to-interference ratios at each mobile from said base station, and

means responsive to the power levels of signal transmissions from said base station for adjusting the power level of signals transmitted from said mobiles to said base station to achieve approximately the same signal-to-interference ratios at said base station for all of said mobiles, wherein said adjusting means increases the power level of signals transmitted from said mobiles to said base station in response to an increase in power level of signal transmissions from said base station.

26. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system comprising:

means for regulating the power levels of signal transmissions from said base station to achieve approximately the same signal-to-interference ratios at each mobile from said base station, and

means responsive to the power levels of signal transmissions from said base station for adjusting the power level of signals transmitted from said mobiles to said base station to achieve approximately the same signal-to-interference ratios at said base station for all of said mobiles,

wherein each mobile includes;

a receiver;

means for detecting periods of silence in communications from said base station to any mobile; and

means for deactivating processing by said mobile receiver of any signal detected to be silent.

27. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system comprising:

means for regulating the power levels of signal transmissions from said base station to achieve approximately the same signal-to-interference ratios at each mobile from said base station, and

means responsive to the power levels of signal transmissions from said base station for adjusting the power level of signals transmitted from said mobiles to said base station to achieve approximately the same signal-to-interference ratios at said base station for all of said mobiles,

wherein each mobile further comprises;

means for detecting signal strengths of signals transmitted from said base station intended for each mobile; and

means, coupled to said signal strength detecting means, for ranking said detected signal strengths in order to relative signal strength from greatest to weakest signal strength, wherein said adjusting means adjusts the power level of signal transmissions from each mobile based on said relative signal strength ranking.

28. A system according to claim 27, each mobile further comprising:

transmission means for transmitting a mobile signal from said mobile, wherein said adjusting means, connected to said ranking means, gradually adjusts power of each mobile'"'"'s transmitter based on said relative ranking.

29. A system according to claim 27, wherein said adjusting means increases the power level of signal transmissions from mobiles that determine its respective signal strength received from the base station to have increased, and decreases the power level of signal transmissions from mobiles that determine its respective signal strength received from said base station to have decreased.

30. A system as in claim 27, wherein said ranking means includes:

mean for sorting values of said detected signal strengths in an order from greatest to lowest, and

means for selecting mobile transmission power levels from a predetermined look-up table stored in a memory based on a position of a mobile'"'"'s signal strength value in said sorted order.

31. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system comprising:

means for regulating the power levels of signal transmissions from said base station to achieve approximately the same signal-to-interference ratios at each mobile from said base station, and

means responsive to the power levels of signal transmissions from said base station for adjusting the power level of signals transmitted from said mobiles to said base station to achieve approximately the same signal-to-interference ratios at said base station for all of said mobiles

wherein said regulating means includes means for computing a power level for each mobile as a function of a ratio of each mobile'"'"'s signal strength value to a mean of other mobile'"'"'s signal strength values.

32. In a communications system including at least one base station and a plurality of mobiles for communicating with said at least one base station, a power control system comprising:

means for regulating the power levels of signal transmissions from said base station to achieve approximately the same signal-to-interference ratios at each mobile from said base station, and

means responsive to the power levels of signal transmissions from said base station for adjusting the power level of signals transmitted from said mobiles to said base station to achieve approximately the same signal-to-interference ratios at said base station for all of said mobiles,

wherein each mobile includes;

means for storing in table form a non-linear power distribution function, and

means for determining a mobile transmitter power based on said non-linear function.

33. A system as described in claim 32, wherein said base station includes means for generating and transmitting a modification command;

and

wherein each mobile includes means, responsive to said modification command, for modifying said storing means in each mobile to adapt said non-linear function.