POWER-LIMIT REPORTING IN A COMMUNICATION SYSTEM USING CARRIER AGGREGATION

• US 20120224552A1
• Filed: 10/20/2010
• Published: 09/06/2012
• Est. Priority Date: 11/02/2009
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Loehr, Joachim, Feuersanger, Martin, Wengerter, Christian
• Granted Patent: US 8,811,322 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04W 52/146 Uplink power control
• 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 52/365 Power headroom reporting
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The invention relates to methods for informing an eNodeB on the transmit power status of a user equipment in a mobile communication system using component carrier (CC) aggregation. Furthermore, the invention is also related to the implementation of these methods by hardware and their implementation in software. The invention proposes procedures that allow the eNodeB to recognize the power usage status of a UE in a communication system using carrier aggregation. The UE indicates to the eNodeB, when the UE is close to using its total maximum UE transmit power or when it has exceeded same. This is achieved by the UE including indicator(s) and/or new MAC CEs to one or more protocol data units transmitted on respective component carriers within a single sub-frame that is providing the eNodeB with power status information. The MAC CEs may report a per-UE power headroom. Alternatively, the MAC CEs may report per-CC power headrooms and/or power reductions applied to the respective uplink CCs.

Claims

1-49. -49. (canceled)

50. A method for informing an eNodeB of a transmit power status of a user equipment in a mobile communication system using component carrier aggregation, wherein the method comprises the following steps performed by the user equipment:

generating a power status report that includes a power headroom report and a component carrier specific maximum transmission power for each configured and activated uplink component carrier,

wherein the component carrier specific maximum transmission power takes into account an amount of power reduction on the respective configured and activated uplink component carrier and is generated when the user equipment has a resource assignment for the configured and activated uplink component carrier, and

transmitting the power status report to the eNodeB.

51. The method according to claim 50, wherein the transmission of the power status report is triggered at activation of a configured uplink component carrier.

52. The method according to claim 50, wherein the power status report takes into account a Physical Uplink Control Channel (PUCCH) power transmitted on the same sub-frame.

53. The method according to claim 50, wherein in case the power headroom report is to be transmitted for a configured and activated uplink component carrier for which there is no resource assignment available in the given sub-frame, the user equipment generates the power status report for the component carrier based on a predefined uplink grant or a predefined Physical Uplink Shared Channel (PUSCH) power.

54. The method according to claim 50, wherein the power headroom report and the component carrier specific maximum transmission power of each configured and activated component carrier are included into a single Media Access Control (MAC) control element that is used for multiple power headroom reporting with a bitmap,

wherein a bit set at a certain position of the bitmap indicates that there is a power headroom report field for the associated component carrier in the MAC control element.

55. The method according to claim 54, wherein the MAC control element for multiple power headroom reporting further includes indicators that indicate the presence of the associated component carrier specific maximum transmission power for the corresponding power headroom report, respectively.

56. The method according to claim 50, wherein the component carrier specific maximum transmission power is a Pcmax,c.

57. A user equipment for informing an eNodeB of a transmit power status of the user equipment in a mobile communication system using component carrier aggregation, wherein the user equipment comprises

a processor configured to generate a power status report that includes a power headroom report and a component carrier specific maximum transmission power for each configured and activated uplink component carrier,

wherein the component carrier specific maximum transmission power takes into account an amount of power reduction on the respective configured and activated uplink component carrier and is generated when the user equipment has a resource assignment for the configured and activated uplink component carrier, and

a transmitter configured to transmit the power status report to the eNodeB.

58. The user equipment according to claim 57, wherein the transmitting of the power status report is triggered at activation of a configured uplink component carrier.

59. The user equipment according to claim 57, wherein the power status report takes into account a Physical Uplink Control Channel (PUCCH) power transmitted on the same sub-frame.

60. The user equipment according to claim 57, wherein in case the power headroom report is to be transmitted for a configured and activated uplink component carrier for which there is no resource assignment available in the given sub-frame, the processor generates the power status report for the component carrier based on a predefined uplink grant or a predefined Physical Uplink Shared Channel (PUSCH) power.

61. The user equipment according to claim 57, wherein the power headroom report and the component carrier specific maximum transmission power of each configured and activated component carrier are included into a single Media Access Control (MAC) control element that is used for multiple headroom reporting with a bitmap,

wherein a bit set at a certain position of the bitmap indicates that there is a power headroom report field for the associated component carrier in the MAC control element.

62. The user equipment according to claim 61, wherein the MAC control element for multiple power headroom reporting further includes indicators that indicate the presence of the associated component carrier specific maximum transmission power for the corresponding power headroom report, respectively.

63. The user equipment according to claim 57, wherein the component carrier specific maximum transmission power is a Pcmax,c.