APPARATUS, METHOD, AND SYSTEM FOR UPLINK CONTROL CHANNEL RECEPTION IN A HETEROGENEOUS WIRELESS COMMUNICATION NETWORK

• US 20120213092A1
• Filed: 02/16/2012
• Published: 08/23/2012
• Est. Priority Date: 02/18/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sun, Haitong, Vitthaladevuni, Pavan Kumar, Sambhwani, Sharad Deepak, Hou, Jilei, Mohanty, Bibhu Prasad
• Granted Patent: US 9,554,338 B2
• Time in Patent Office: Days
• US Class Current: 370/248
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/286 during data packet transmission, e.g. high speed packet access [HSPA]
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment

Abstract

A method and system for improving the reception of uplink transmissions in a heterogeneous wireless communication system includes a high-power node such as a macro-cell and a low-power node such as a femto-cell or pico-cell. To address an uplink imbalance where a nearby low-power node power controls a UE such that uplink transmissions of an HSDPA control channel are poorly received at the serving cell, an RNC can instruct the UE to boost its uplink transmit power, remove the UE from soft handover, or disable power control of the UE by the low-power node. To address inter-cell interference, the RNC can limit the UE transmit power and/or enable the victim cell to suppress the interference. Further, a common control channel can be used to power control UEs outside of the convention set of UEs available for power control.

Claims

1. A method of wireless communication operable at a user equipment, the method comprising:

monitoring a common control channel in response to a determination that a difference between a first path loss corresponding to a transmission received from a first cell and a second path loss corresponding to a transmission received from a second cell is less than a threshold; and

adjusting an uplink transmit power in accordance with information on the common control channel.

2. The method of claim 1, further comprising:

determining the first path loss corresponding to the transmission received from the first cell;

determining the second path loss corresponding to the transmission received from the second cell; and

determining that the difference between the first path loss and the second path loss is less than the threshold.

3. The method of claim 2, wherein the transmission from the first cell comprises a first pilot signal and the transmission from the second cell comprises a second pilot signal.

4. The method of claim 2, wherein the first cell is a serving cell for the user equipment, the method further comprising:

receiving a system information block comprising a scrambling code corresponding to the second cell, wherein the determining of the second path loss corresponding to the transmission from the second cell comprises utilizing the scrambling code corresponding to the second cell to decode the second pilot signal.

5. The method of claim 1, further comprising:

receiving a system information block comprising a channelization code corresponding to the common control channel, wherein the monitoring of the common control channel comprises utilizing the channelization code to decode the common control channel.

6. The method of claim 1, wherein the common control channel comprises a common E-RGCH comprising an instruction to alter a gain utilized for uplink transmissions.

7. A method of wireless communication operable at a user equipment, the method comprising:

transmitting information relating to a first path loss corresponding to a transmission received from a first cell and a second path loss corresponding to a transmission received from a second cell;

receiving, in response to the transmitted information, an instruction relating to an uplink transmit power; and

transmitting an uplink transmission in accordance with the instruction relating to the uplink transmit power.

8. The method of claim 7, further comprising:

determining the first path loss corresponding to the transmission received from the first cell;

determining the second path loss corresponding to the transmission received from the second cell; and

determining the difference between the first path loss and the second path loss,

wherein the information relating to the first path loss and the second path loss comprises the difference between the first path loss and the second path loss.

9. The method of claim 7, wherein the instruction relating to the uplink transmit power comprises a maximum uplink transmit power for the user equipment;

and

wherein the transmitting of the uplink transmission in accordance with the instruction relating to the uplink transmit power comprises reducing the uplink transmit power to fall within the received maximum uplink transmit power.

10. A method of wireless communication operable at a user equipment, the method comprising:

detecting a rate of decoding errors corresponding to an uplink control channel;

increasing an uplink power in response to an unsuccessful decoding of the uplink control channel; and

decreasing the uplink power in response to a successful decoding of the uplink control channel.

11. The method of claim 10, wherein the rate of decoding errors corresponds to an ACK to NACK/DTX error rate corresponding to an uplink HS-DPCCH.

12. The method of claim 11, further comprising setting a target ACK to NACK/DTX error rate,

wherein the increasing of the uplink power comprises increasing the uplink power by an amount C2P_up, and wherein the decreasing of the uplink power comprises decreasing the uplink power by an amount C2P_down, and

wherein C2P_up/C2P_down=(1−

TER)/TER, where TER is the target ACK to NACK/DTX error rate.

13. The method of claim 12, wherein the setting of the target ACK to NACK/DTX error rate comprises at least one of determining the ACK to NACK/DTX error rate at the user equipment or receiving a downlink transmission comprising the ACK to NACK/DTX error rate.

14. A wireless user equipment, comprising:

at least one processor; and

a memory coupled to the at least one processor,

wherein the at least one processor is configured to;

monitor a common control channel in response to a determination that a difference between a first path loss corresponding to a transmission received from a first cell and a second path loss corresponding to a transmission received from a second cell is less than a threshold; and

adjust an uplink transmit power in accordance with information on the common control channel.

15. The wireless user equipment of claim 14, wherein the at least one processor is further configured to:

determine the first path loss corresponding to the transmission received from the first cell;

determine the second path loss corresponding to the transmission received from the second cell; and

determine that the difference between the first path loss and the second path loss is less than the threshold.

16. The wireless user equipment of claim 15, wherein the transmission from the first cell comprises a first pilot signal and the transmission from the second cell comprises a second pilot signal.

17. The wireless user equipment of claim 15, wherein the first cell is a serving cell for the wireless user equipment, wherein the at least one processor is further configured to:

receive a system information block comprising a scrambling code corresponding to the second cell, wherein the determining of the second path loss corresponding to the transmission from the second cell comprises utilizing the scrambling code corresponding to the second cell to decode the second pilot signal.

18. The wireless user equipment of claim 14, wherein the at least one processor is further configured to:

receive a system information block comprising a channelization code corresponding to the common control channel, wherein the monitoring of the common control channel comprises utilizing the channelization code to decode the common control channel.

19. The wireless user equipment of claim 14, wherein the common control channel comprises a common E-RGCH comprising an instruction to alter a gain utilized for uplink transmissions.

20. A wireless user equipment, comprising:

at least one processor; and

a memory coupled to the at least one processor,

wherein the at least one processor is configured to;

transmit information relating to a first path loss corresponding to a transmission received from a first cell and a second path loss corresponding to a transmission received from a second cell;

receive, in response to the transmitted information, an instruction relating to an uplink transmit power; and

transmit an uplink transmission in accordance with the instruction relating to the uplink transmit power.

21. The wireless user equipment of claim 20, wherein the at least one processor is further configured to:

determine the first path loss corresponding to the transmission received from the first cell;

determine the second path loss corresponding to the transmission received from the second cell; and

determine the difference between the first path loss and the second path loss,

wherein the information relating to the first path loss and the second path loss comprises the difference between the first path loss and the second path loss.

22. The wireless user equipment of claim 20, wherein the instruction relating to the uplink transmit power comprises a maximum uplink transmit power for the user equipment;

and

wherein the transmitting of the uplink transmission in accordance with the instruction relating to the uplink transmit power comprises reducing the uplink transmit power to fall within the received maximum uplink transmit power.

23. A wireless user equipment, comprising:

at least one processor; and

a memory coupled to the at least one processor,

wherein the at least one processor is configured to;

detect a rate of decoding errors corresponding to an uplink control channel;

increase an uplink power in response to an unsuccessful decoding of the uplink control channel; and

decrease the uplink power in response to a successful decoding of the uplink control channel.

24. The wireless user equipment of claim 23, wherein the rate of decoding errors corresponds to an ACK to NACK/DTX error rate corresponding to an uplink HS-DPCCH.

25. The wireless user equipment of claim 24, wherein the at least one processor is further configured to set a target ACK to NACK/DTX error rate,

wherein the increasing of the uplink power comprises increasing the uplink power by an amount C2P_up, and wherein the decreasing of the uplink power comprises decreasing the uplink power by an amount C2P_down, and

wherein C2P_up/C2P_down=(1−

TER)/TER, where TER is the target ACK to NACK/DTX error rate.

26. The wireless user equipment of claim 25, wherein the setting of the target ACK to NACK/DTX error rate comprises at least one of determining the ACK to NACK/DTX error rate at the user equipment or receiving a downlink transmission comprising the ACK to NACK/DTX error rate.

27. A wireless user equipment, comprising:

means for monitoring a common control channel in response to a determination that a difference between a first path loss corresponding to a transmission received from a first cell and a second path loss corresponding to a transmission received from a second cell is less than a threshold; and

means for adjusting an uplink transmit power in accordance with information on the common control channel.

28. A wireless user equipment, comprising:

means for transmitting information relating to a first path loss corresponding to a transmission received from a first cell and a second path loss corresponding to a transmission received from a second cell;

means for receiving, in response to the transmitted information, an instruction relating to an uplink transmit power; and

means for transmitting an uplink transmission in accordance with the instruction relating to the uplink transmit power.

29. A wireless user equipment, comprising:

means for detecting a rate of decoding errors corresponding to an uplink control channel;

means for increasing an uplink power in response to an unsuccessful decoding of the uplink control channel; and

means for decreasing the uplink power in response to a successful decoding of the uplink control channel.

30. A computer program product operable at a wireless user equipment, comprising:

a computer-readable medium comprising;

instructions for causing a computer to monitor a common control channel in response to a determination that a difference between a first path loss corresponding to a transmission received from a first cell and a second path loss corresponding to a transmission received from a second cell is less than a threshold; and

instructions for causing a computer to adjust an uplink transmit power in accordance with information on the common control channel.

31. A computer program product operable at a wireless user equipment, comprising:

a computer-readable medium comprising;

instructions for causing a computer to transmit information relating to a first path loss corresponding to a transmission received from a first cell and a second path loss corresponding to a transmission received from a second cell;

instructions for causing a computer to receive, in response to the transmitted information, an instruction relating to an uplink transmit power; and

instructions for causing a computer to transmit an uplink transmission in accordance with the instruction relating to the uplink transmit power.

32. A computer program product operable at a wireless user equipment, comprising:

a computer-readable medium comprising;

instructions for causing a computer to detect a rate of decoding errors corresponding to an uplink control channel;

instructions for causing a computer to increase an uplink power in response to an unsuccessful decoding of the uplink control channel; and

instructions for causing a computer to decrease the uplink power in response to a successful decoding of the uplink control channel.