POWER CONTROL FOR ACK/NACK FORMATS WITH CARRIER AGGREGATION

• US 20120113907A1
• Filed: 04/01/2011
• Published: 05/10/2012
• Est. Priority Date: 11/09/2010
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Baldemair, Robert, Larsson, Daniel, Gerstenberger, Dirk, Cheng, Jung-Fu
• Granted Patent: US 8,582,518 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Abstract

A system and method for determining a Physical Uplink Control Channel (PUCCH) power control parameter h(n_CQI,n_HARQ) for two Carrier Aggregated (CA) PUCCH formats—PUCCH format 3 and channel selection. The value of h(n_CQI,n_HARQ) may be based on only a linear function of n_HARQ for both of the CA PUCCH formats. Based on the CA PUCCH format configured for the User Equipment (UE), the e-Node B (eNB) may instruct the UE to select or apply a specific linear function of n_HARQ as a value for the power control parameter h(n_CQI,n_HARQ), so as to enable the UE to more accurately establish transmit power of its PUCCH signal. Values for another PUCCH power control parameter—Δ_F—PUCCH(F)—are also provided for use with PUCCH format 3. A new offset parameter may be signaled for each PUCCH format that has transmit diversity configured

Claims

1. A method of controlling transmit power of a Physical Uplink Control Channel (PUCCH) signal to be transmitted by a User Equipment (UE) in wireless communication with a processor via a wireless network associated therewith, the PUCCH signal including a number of Channel Quality Indicator (CQI) bits and a number of Hybrid Automatic Repeat Request (HARQ) bits, the method comprising the steps of:

using the processor, configuring a PUCCH format for the PUCCH signal; and

using the processor, instructing the UE to apply only a linear function of n_HARQ as a value for h(n_CQI, n_HARQ), wherein h(n_CQI, n_HARQ) is a first power control parameter based on the PUCCH format and affecting the transmit power of the PUCCH signal, and wherein n_CQI indicates the number of CQI bits and n_HARQ indicates the number of HARQ bits in the PUCCH signal.

2. The method of claim 1, wherein the PUCCH format is one of the following:

PUCCH format 3;

PUCCH format 1a;

PUCCH format 1b; and

a PUCCH format with transmit diversity.

3. The method of claim 2, wherein a value of the n_HARQ is based on at least one of the following:

a first number of Acknowledge/Negative Acknowledge (ACK/NACK) bits in the PUCCH signal;

a second number of Scheduling Request (SR) bits in the PUCCH signal; and

a Semi-Persistent Scheduling (SPS) deactivation message in the PUCCH signal.

4. The method of claim 2, wherein the PUCCH format is the PUCCH format 3 used with Carrier Aggregation (CA), and wherein a value of the n_HARQ is based on at least one of the following:

a first number of Acknowledge/Negative Acknowledge (ACK/NACK) bits that corresponds to the number of configured component carriers and configured transmission modes on the configured component carriers;

a second number of ACK/NACK bits that corresponds to the number of activated component carriers and configured transmission modes on the activated component carriers; and

a third number of ACK/NACK bits that corresponds to the number of transport blocks received at the UE.

5. The method of claim 4, wherein at least one of the first, the second, and the third number of ACK/NACK bits is generated using spatial bundling.

6. The method of claim 2, wherein the PUCCH format is the PUCCH format 3 used without Carrier Aggregation (CA), and wherein a value of the n_HARQ is based on at least one of the following:

a first number of Acknowledge/Negative Acknowledge (ACK/NACK) bits that corresponds to the maximum number of scheduled Downlink (DL) transport blocks corresponding to utilized Uplink/Downlink (UL/DL) subframe configuration and configured transmission modes for the UE;

a second number of ACK/NACK bits that corresponds to the maximum number of possible scheduled DL transport blocks within a feedback window of a UL subframe where the PUCCH format 3 is transmitted; and

a third number of ACK/NACK bits that corresponds to the number of transport blocks received at the UE.

7. The method of claim 6, wherein at least one of the first, the second, and the third number of ACK/NACK bits is generated using spatial bundling.

8. The method of claim 2, further comprising:

using the processor, assigning either the PUCCH format 1a or the PUCCH format 1b to the UE to enable the UE to generate the PUCCH signal with Carrier Aggregation (CA) to implement a Channel Selection (CS) based HARQ feedback scheme for the assigned PUCCH format.

9. The method of claim 8, further comprising one of the following when said CS based HARQ feedback scheme uses 3 HARQ bits:

using the processor, instructing the UE to insert a Signal-to-Noise Ratio (SNR) offset value into said value for h(n_CQI, n_HARQ); and

using the processor, supplying said SNR offset value to the UE via a Transmit Power Control (TPC) command.

10. The method of claim 1, wherein the value for h(n_CQI, n_HARQ) is given by the following linear function of n_HARQ:

11. The method of claim 10, wherein α

=2 and β

=(−

½

), and wherein the PUCCH format is one of the following;

PUCCH format 3;

a PUCCH format associated with a channel selection based HARQ feedback scheme; and

PUCCH format 3 with transmit diversity.

12. The method of claim 10, further comprising:

using the processor, determining whether the PUCCH format uses transmit diversity; and

using the processor, instructing the UE to apply at least one of the following sets of values when it is determined that the PUCCH format uses transmit diversity;

α

=2, β

=(−

½

); and

α

=3 and β

=(−

⅓

).

13. The method of claim 10, wherein α

=2, β

=(−

½

), and the PUCCH format is PUCCH format 3, wherein the method further comprises;

using the processor, instructing the UE to apply a value for Δ

<sub>F—

PUCCH</sub>(F) from a set of values consisting essentially of 0 dB, 1 dB, and 2 dB, wherein Δ

<sub>F—

PUCCH</sub>(F) is a second power control parameter based on the PUCCH format and affecting the transmit power of the PUCCH signal.

14. The method of claim 1, further comprising:

using the processor, instructing the UE via a Transmit Power Control (TPC) command to apply only the linear function of n_HARQ as the value for h(n_CQI, n_HARQ).

15. A mobile communication node configured to provide a radio interface to a mobile handset in a wireless network associated with the mobile handset, wherein the mobile communication node comprises:

means for configuring a Physical Uplink Control Channel (PUCCH) format for a PUCCH signal to be transmitted by the mobile handset, the PUCCH signal including a number of Channel Quality Indicator (CQI) bits and a number of Hybrid Automatic Repeat Request (HARQ) bits; and

first means for instructing the mobile handset to apply the following linear function of n_HARQ as a value for h(n_CQI, n_HARQ);

16. The mobile communication node of claim 15, wherein the first means for instructing includes:

means for transmitting an indication of the linear function to the mobile handset via a Transmit Power Control (TPC) field in a Downlink Control Information (DCI) message from the mobile communication node.

17. The mobile communication node of claim 15, wherein the first means for instructing includes:

means for lowering the transmit power of the PUCCH signal from the mobile handset by using a Transmit Power Control (TPC) command when the mobile handset is configured to transmit 3 HARQ bits in the PUCCH signal and when the mobile communication node uses Freq(PUCCH DTX→

ACK bits)≦

10².

18. The mobile communication node of claim 15, wherein the PUCCH format is one of the following:

PUCCH format 3;

a PUCCH format associated with a Channel Selection (CS) based HARQ feedback scheme; and

a PUCCH format with transmit diversity.

19. The mobile communication node of claim 15, wherein a value of the n_HARQ is based on at least one of the following:

a first number of Acknowledge/Negative Acknowledge (ACK/NACK) bits in the PUCCH signal;

a second number of Scheduling Request (SR) bits in the PUCCH signal; and

a Semi-Persistent Scheduling (SPS) deactivation message in the PUCCH signal.

20. The mobile communication node of claim 15, wherein one of the following sets of values applies for “

α

” and

“

β

”

;

α

=2, β

=(−

½

); and

α

=3 and β

=(−

⅓

).

21. The mobile communication node of claim 15, further comprising:

second means for instructing the mobile handset to apply a value for Δ

<sub>F—

PUCCH</sub>(F) from a set of values consisting essentially of 0 dB, 1 dB, and 2 dB, wherein Δ

<sub>F—

PUCCH</sub>(F) is a second power control parameter based on the PUCCH format and affecting the transmit power of the PUCCH signal.

22. A system comprising:

a mobile handset operable in a wireless network associated therewith; and

a mobile communication node configured to provide a radio interface to the mobile handset in the wireless network, wherein the mobile communication node is further configured to perform the following;

determine a Physical Uplink Control Channel (PUCCH) format for a PUCCH signal to be transmitted by the mobile handset, the PUCCH signal including a number of Channel Quality Indicator (CQI) bits and a number of Hybrid Automatic Repeat Request (HARQ) bits; and

instruct the mobile handset to apply only a linear function of n_HARQ as a value for h(n_CQI, n_HARQ), wherein h(n_CQI, n_HARQ) is a power control parameter based on the PUCCH format and affecting the transmit power of the PUCCH signal, and wherein n_CQI indicates the number of CQI bits and n_HARQ indicates the number of HARQ bits in the PUCCH signal.

23. The system of claim 22, wherein the mobile handset is configured to store therein the linear function of n_HARQ as:

24. The system of claim 22, wherein the PUCCH format is one of the following:

a CA (Carrier Aggregation) PUCCH format with transmit diversity; and

a CA PUCCH format without transmit diversity.

25. A method comprising the steps of:

using a processor, receiving a power control signal from a mobile communication node to control transmit power of a Physical Uplink Control Channel (PUCCH) signal, the PUCCH signal including a number of Channel Quality Indicator (CQI) bits and a number of Hybrid Automatic Repeat Request (HARQ) bits;

in response to the power control signal, selecting a linear function of n_HARQ as a value for h(n_CQI, n_HARQ) using the processor, wherein h(n_CQI, n_HARQ) is a power control parameter affecting the transmit power of the PUCCH signal, and wherein n_CQI, indicates the number of CQI bits and n_HARQ indicates the number of HARQ bits in the PUCCH signal; and

using the processor, transmitting the PUCCH signal with the linear function applied thereto so as to partially control the transmit power of the PUCCH signal.

26. The method of claim 25, wherein the step of receiving the power control signal includes:

receiving an indication of the linear function via a downlink control signal from the mobile communication node

27. The method of claim 25, wherein the step of selecting the linear function includes:

selecting a stored version of the linear function from a memory.

28. A User Equipment (UE) operable in a wireless network associated therewith, the UE comprising:

means for receiving a power control signal from a mobile communication node to control transmit power of a Physical Uplink Control Channel (PUCCH) signal to be transmitted by the UE, the PUCCH signal including a number of Channel Quality Indicator (CQI) bits and a number of Hybrid Automatic Repeat Request (HARQ) bits, wherein the mobile communication node is configured to provide a radio interface to the UE in the wireless network; and

means for applying only a linear function of n_HARQ as a value for h(n_CQI, n_HARQ) in response to the power control signal, wherein h(n_CQI, n_HARQ) is a power control parameter affecting the transmit power of the PUCCH signal, and wherein n_CQI indicates the number of CQI bits and n_HARQ indicates the number of HARQ bits in the PUCCH signal.

29. The UE of claim 28, further comprising:

means for storing the linear function; and

means for selecting the stored linear function in response to the power control signal and supplying the selected linear function to the means for applying.

30. The UE of claim 28, wherein the linear function of n_HARQ is:

31. A method of controlling transmit power of a Physical Uplink Control Channel (PUCCH) signal to be transmitted by a User Equipment (UE) in wireless communication with a processor via a wireless network associated therewith, the PUCCH signal including a number of Channel Quality Indicator (CQI) bits and a number of Hybrid Automatic Repeat Request (HARQ) bits, the method comprising the steps of:

using the processor, determining whether a PUCCH format for the PUCCH signal uses transmit diversity; and

when the PUCCH format is determined to use transmit diversity, selecting an offset parameter for the PUCCH format using the processor, wherein the offset parameter may or may not affect the value of h(n_CQI, n_HARQ), wherein h(n_CQI, n_HARQ) is a power control parameter based on the PUCCH format and wherein the offset parameter affects the transmit power of the PUCCH signal, and wherein n_CQI indicates the number of CQI bits and n_HARQ indicates the number of HARQ bits in the PUCCH signal.

32. The method of claim 31, further comprising:

using the processor, determining whether a PUCCH format 1a with/without transmit diversity only influences the value of the offset parameter; and

upon making the determination in the affirmative, using the processor to instruct the UE to use the same value of h(n_CQI, n_HARQ) for the PUCCH format for the PUCCH signal regardless of whether the PUCCH format is with transmit diversity or without transmit diversity.

33. A User Equipment (UE) operable in a wireless network associated therewith, the UE comprising:

means for receiving a Physical Uplink Control Channel (PUCCH) format for a PUCCH signal to be transmitted by the UE, wherein the PUCCH format uses transmit diversity and wherein the PUCCH signal includes a number of Channel Quality Indicator (CQI) bits and a number of Hybrid Automatic Repeat Request (HARQ) bits; and

means for selecting an offset parameter for the PUCCH format, wherein the offset parameter may or may not affect the value of h(n_CQI, n_HARQ), wherein h(n_CQI, n_HARQ) is a power control parameter based on the PUCCH format and wherein the offset parameter affects the transmit power of the PUCCH signal, and wherein n_CQI indicates the number of CQI bits and n_HARQ indicates the number of HARQ bits in the PUCCH signal.

34. A mobile communication node configured to provide a radio interface to a mobile handset in a wireless network associated with the mobile handset, wherein the mobile communication node comprises:

means for determining whether a Physical Uplink Control Channel (PUCCH) format for a PUCCH signal to be transmitted by the mobile handset uses transmit diversity, the PUCCH signal including a number of Channel Quality Indicator (CQI) bits and a number of Hybrid Automatic Repeat Request (HARQ) bits; and

when the PUCCH format is determined to use transmit diversity, means for selecting an offset parameter for the PUCCH format, wherein the offset parameter may or may not affect the value of h(n_CQI, n_HARQ), wherein h(n_CQI, n_HARQ) is a power control parameter based on the PUCCH format and wherein the offset parameter affects the transmit power of the PUCCH signal, and wherein n_CQI, indicates the number of CQI bits and n_HARQ indicates the number of HARQ bits in the PUCCH signal.

35. A method comprising the steps of:

using a processor, receiving a power control signal from a mobile communication node to control transmit power of a Physical Uplink Control Channel (PUCCH) signal, wherein the PUCCH signal includes a number of Hybrid Automatic Repeat Request (HARQ) bits, wherein the power control signal provides an offset value in a power control function affecting the transmit power of the PUCCH signal, and wherein the offset value is provided when the number of HARQ bits is equal to 3;

in response to the power control signal, lowering the transmit power of the PUCCH signal by the offset value by applying the offset value-containing power control function to the PUCCH signal using the processor; and

using the processor, transmitting the PUCCH signal with lower transmit power.

36. A method of controlling transmit power of a Physical Uplink Control Channel (PUCCH) signal to be transmitted by a User Equipment (UE) in wireless communication with a processor via a wireless network associated therewith, the PUCCH signal including a number of Hybrid Automatic Repeat Request (HARQ) bits, the method comprising the steps of:

using the processor, sending a power control signal to the UE to control transmit power of a Physical Uplink Control Channel (PUCCH) signal, wherein the PUCCH signal includes a number of Hybrid Automatic Repeat Request (HARQ) bits, wherein the power control signal provides an offset value in a power control function affecting the transmit power of the PUCCH signal, and wherein the offset value is provided when the number of HARQ bits is equal to 3; and

using the processor, instructing the UE to lower the transmit power of the PUCCH signal by the offset value by applying the offset value-containing power control function to the PUCCH signal to be transmitted by the UE.