Reducing interference with a multiple format channel in a communication system

• US 20040203987A1
• Filed: 07/29/2002
• Published: 10/14/2004
• Est. Priority Date: 07/29/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Butala, Amit
• Granted Patent: US 7,751,843 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/223 predicting future states of the transmission
• CPC Class Codes: H04W 52/226 using past references to control power, e.g. look-up-table
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

Techniques for reducing interference with a multiple format channel in a communication system are disclosed. In one aspect, a minimum power level is determined for each format transmitted during a transmission interval. The minumum power level for formats that will experience the interference are increased to compensate. The power level selected for transmission during the transmission interval is the most stringent of the minimum power levels. Various other aspects are also presented. These aspects have the benefit of mitigating the effects of a known interfering signal, while avoiding unnecessarily increasing transmit power, thus reducing the interference to other users and increasing system capacity.

Claims

1. An apparatus, operable with a signal comprising a plurality of transport channels, each transport channel associated with one of a plurality of formats, the number and format of the channels variable from frame to frame, and further operable with an interfering signal, the time and duration of which is known, the apparatus comprising:

a variable power level transmitter, for transmitting the signal at various power levels in response to a power level signal;

a processor for;

determining a plurality of minimum power levels, each power level the minimum power level for a transport channel in the frame;

increasing one or more of the plurality of power levels in accordance with one or more interference power levels when the interfering signal interferes with the one or more transport channels associated with those power levels;

selecting the highest power level of the plurality of minimum power levels; and

generating the power level signal in accordance with the highest power level.

2. The apparatus of claim 1, further comprising a table for storing the interference power levels.

3. The apparatus of claim 2, wherein the table further stores the minimum power levels.

4. The apparatus of claim 1, wherein the interference power levels are pre-determined.

5. The apparatus of claim 1, further comprising a receiver for receiving power level information generated in response to the transmitted signal.

6. The apparatus of claim 5, wherein the power level information comprises one or more minimum power levels.

7. The apparatus of claim 5, wherein the power level information comprises one or more interference power levels.

8. The apparatus of claim 1, wherein the interference power levels are determined in response to varying geometry between two wireless communication devices.

9. The apparatus of claim 1, wherein the minimum power levels are increased by adding the interference power level to a base minimum power level.

10. The apparatus of claim 9, wherein the base minimum power is power controlled.

11. The apparatus of claim 9, wherein the base minimum power is comprised of a format dependent offset added to a normalized power level.

12. The apparatus of claim 11, wherein the normalized power level is determined in accordance with a closed-loop power control mechanism.

13. The apparatus of claim 1, wherein the minimum power levels are updated in accordance with a closed-loop power control mechanism.

14. The apparatus of claim 1, wherein the interference power levels are updated in accordance with a closed-loop power control mechanism.

15. The apparatus of claim 1, wherein the minimum power levels are increased by selecting an interference power level.

16. The apparatus of claim 1, wherein the interference power level is comprised of a format dependent offset added to a normalized power level.

17. A wireless communication device, operable with a signal comprising a plurality of transport channels, each transport channel associated with one of a plurality of formats, the number and format of the channels variable from frame to frame, and further operable with an interfering signal, the time and duration of which is known, the wireless communication device comprising:

a variable power level transmitter, for transmitting the signal at various power levels in response to a power level signal;

a processor for;

determining a plurality of minimum power levels, each power level the minimum power level for a transport channel in the frame;

increasing one or more of the plurality of power levels in accordance with one or more interference power levels when the interfering signal interferes with the one or more transport channels associated with those power levels;

selecting the highest power level of the plurality of minimum power levels; and

generating the power level signal in accordance with the highest power level.

18. A wireless communication system, including a wireless communication device, operable with a signal comprising a plurality of transport channels, each transport channel associated with one of a plurality of formats, the number and format of the channels variable from frame to frame, and further operable with an interfering signal, the time and duration of which is known, the wireless communication device comprising:

a variable power level transmitter, for transmitting the signal at various power levels in response to a power level signal;

a processor for;

determining a plurality of minimum power levels, each power level the minimum power level for a transport channel in the frame;

increasing one or more of the plurality of power levels in accordance with one or more interference power levels when the interfering signal interferes with the one or more transport channels associated with those power levels;

selecting the highest power level of the plurality of minimum power levels; and

generating the power level signal in accordance with the highest power level.

19. A method of reducing interference with a multiple format channel, the method comprising:

determining one or more transport channels that will experience interference;

determining the minimum power level required for each format in the channel, increasing the minimum power level for those channels that will experience interference;

selecting the largest of the minimum power levels as the transmit power level; and

transmitting the multiple format channel in accordance with the transmit power level.

20. The method of claim 19, wherein the minimum power levels are updated in accordance with a closed loop power control mechanism.

21. The method of claim 19, wherein the minimum power increase is computed based on a spreading factor associated with the channel.

22. The method of claim 19, wherein the minimum power levels are computed based on the geometry of a wireless communication device receiving the transmitted signal.

23. The method of claim 19, wherein the minimum power levels required for each format are determined by selecting a power level associated with that format from a power level table.

24. The method of claim 23, wherein the minimum power level for an interfered with channel is selected from one or more interference power levels stored in the table.

25. The method of claim 23, wherein the minimum power level for an interfered with channel is determined by selecting a non-interference power level stored in the table, selecting an interference offset stored in the table, and adding the offset to the non-interference power level to produce the minimum power level for the interfered with channel.

26. An apparatus, comprising:

means for determining one or more transport channels that will experience interference;

means for determining the minimum power level required for each format in the channel, increasing the minimum power level for those channels that will experience interference;

means for selecting the largest of the minimum power levels as the transmit power level; and

means for transmitting the multiple format channel in accordance with the transmit power level.

27. The apparatus of claim 26, further comprising means for selecting one or more interference power levels stored in a table.

28. A wireless communication device, comprising:

means for determining one or more transport channels that will experience interference;

means for determining the minimum power level required for each format in the channel, increasing the minimum power level for those channels that will experience interference;

means for selecting the largest of the minimum power levels as the transmit power level; and

means for transmitting the multiple format channel in accordance with the transmit power level.

29. A wireless communication system, including a wireless communication device, comprising:

means for determining one or more transport channels that will experience interference;

means for determining the minimum power level required for each format in the channel, increasing the minimum power level for those channels that will experience interference;

means for selecting the largest of the minimum power levels as the transmit power level; and

means for transmitting the multiple format channel in accordance with the transmit power level.

30. Processor readable media operable to perform the following steps:

determining one or more transport channels that will experience interference;

determining the minimum power level required for each format in the channel, increasing the minimum power level for those channels that will experience interference;

selecting the largest of the minimum power levels as the transmit power level; and

transmitting the multiple format channel in accordance with the transmit power level.

31. The processor readable media of claim 30, further operable to perform the step of selecting one or more inteference power levels stored in a table.