Mobile communications system, base station apparatus, user apparatus, and method

• US 8,203,987 B2
• Filed: 03/21/2008
• Issued: 06/19/2012
• Est. Priority Date: 03/30/2007
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Ishii, Hiroyuki, Nakamura, Takehiro
• Primary Examiner(s): Wu, Jianye
• Assistant Examiner(s): Duong, Christine
• Application Number:
  US12/532,791
• Publication Number:
  US 20100118805A1
• Time in Patent Office: 1,551 Days
• Field of Search: None
• US Class Current: 370/311
• CPC Class Codes: H04W 52/146 Uplink power control
• 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 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

A user apparatus which wirelessly communicates with a base station apparatus within a mobile communications system is disclosed. The user apparatus includes a receive unit which receives control information in downlink; and a transmit unit which transmits a first channel in uplink, wherein the transmit unit, based on the control information, makes a value of a maximum transmit power of the first channel smaller than that of a nominal power specified for the mobile communications system.

Claims

1. A user apparatus which wirelessly communicates with a base station apparatus within a mobile communications system, comprising:

a receive unit which receives control information in downlink, the control information indicating a network signaling value, the network signaling value specified in multiple numbers, and a combination of requirements on adjacent-channel interference and a spurious emission, position of a frequency band, a channel bandwidth, the number of frequency resources, and a maximum power reduction amount being specified for each of the network signaling value;

a maximum transmit power control unit which specifies a maximum transmit power reduction amount based on the network signaling value indicated in the control information received at the receive unit and modifies a maximum value of a transmit power with the maximum transmit power reduction amount; and

a transmit unit which transmits a channel in uplink in accordance with the maximum value of the transmit power modified at the maximum transmit power control unit.

2. The user apparatus as claimed in claim 1, wherein the control information is transmitted using a broadcast channel, a radio resource control (RRC) message when starting communications, or a non access stratum (NAS) message when registering a position.

3. The user apparatus as claimed in claim 1, wherein the channel is at least one of an uplink shared channel, an uplink control channel and an uplink reference signal.

4. The user apparatus as claimed in claim 1, wherein the control information specifies whether the value of the maximum transmit power of the channel is made smaller.

5. The user apparatus as claimed in claim 4, wherein, when the control information specifies that the value of the maximum transmit power of the channel is made smaller,

the transmit unit makes the value of the maximum transmit power of the channel smaller based on at least one of an amount of a frequency resource on the channel, a number of resource blocks, a modulation scheme, a frequency, and a cubic metric.

6. The user apparatus as claimed in claim 4, wherein, when the control information specifies that the value of the maximum transmit power of the channel is made smaller,

the transmit unit makes the value of the maximum transmit power of the channel smaller such that an amount of interference to a predetermined frequency band becomes no larger than a predetermined threshold.

7. The user apparatus as claimed in claim 4, wherein, when the control information specifies that the value of the maximum transmit power of the channel is made smaller,

the transmit unit makes the value of the maximum transmit power of the channel smaller such that it meets at least one of a spurious emission requirement, an adjacent channel leakage power ratio (ACLR) requirement, and a spectrum emission mask (SEM) requirement that are predetermined.

8. The user apparatus as claimed in claim 1, wherein the control information specifies one of information on a geographical area in which the mobile communications system is provided, a country code, information identifying an operator providing the mobile communications system, and a public land mobile network (PLMN) identifier, wherein

the transmit unit makes the value of the maximum transmit power of the channel smaller based on at least one of the information on the geographical area in which the mobile communications system is provided, the country code, the information identifying the operator providing the mobile communications system, and the PLMN identifier.

9. The user apparatus as claimed in claim 8, wherein the transmit unit makes the value of the maximum transmit power of the channel smaller based on at least one of an amount of a frequency resource on the channel, a number of resource blocks, a modulation scheme, a frequency, and a cubic metric.

10. The user apparatus as claimed in claim 8, wherein the transmit unit reduces the maximum transmit power such that an amount of interference to a predetermined frequency band becomes no larger than a predetermined threshold.

11. The user apparatus as claimed in claim 5, wherein the transmit unit sets a transmit power of the channel to be no more than the value of the maximum transmit power of the channel.

12. The user apparatus as claimed in claim 1, wherein the value of the maximum transmit power of the channel is set differently for each of multiple bandwidths.

13. A base station apparatus which wirelessly communicates with a user apparatus within a mobile communications system, comprising:

a transmit unit which transmits control information in downlink, the control information indicating a network signaling value, the network signaling value specified in multiple numbers, and a combination of requirements on adjacent-channel interference and a spurious emission, position of a frequency band, a channel bandwidth, a number of frequency resources, and a maximum power reduction amount being specified for each of the network signaling value;

a broadcast information generator unit which generates the control information on a maximum transmit power of the user apparatus, wherein the maximum transmit power is set to be smaller than a nominal power based on the network signaling value indicated in the control information transmitted at the transmit unit; and

a receive unit which receives a channel in uplink in accordance with the maximum value of the transmit power modified at the user apparatus based on the information provided by the broadcast information generator unit.

14. The base station apparatus as claimed in claim 13, wherein the transmit unit transmits the control information using a broadcast channel, an RRC message when starting communications, or an NAS message when registering a location.

15. The base station apparatus as claimed in claim 13, wherein the first channel is at least one of an uplink shared channel and an uplink control channel.

16. The base station apparatus as claimed in claim 13, wherein the control information specifies a leakage power into a predetermined frequency band such that it becomes no greater than a predetermined threshold.

17. The base station apparatus as claimed in claim 13, wherein the control information specifies that it meets at least one of a spurious emission requirement, an ACLR requirement, and an SEM requirement that are predetermined.

18. The base station apparatus as claimed in claim 13, wherein the value of the maximum transmit power of the first channel is set differently for each of multiple bandwidths.

19. A method of controlling in a user apparatus which wirelessly communicates with a base station apparatus within a mobile communications system, comprising:

a first step of receiving control information in downlink, the control information indicating a network signaling value, the network signaling value specified in multiple numbers, and a combination of requirements on adjacent-channel interference and a spurious emission, position of a frequency band, a channel bandwidth, a number of frequency resources, and a maximum power reduction amount being specified for each of the network signaling value,

wherein a maximum transmit power control unit specifies the maximum transmit power reduction amount based on the network signaling value indicated in the control information received at the receive unit and modifies a maximum value of a transmit power with the maximum transmit power reduction amount;

a second step of making a maximum of a transmit power in uplink to be less than a nominal power specified for the mobile communications system based on the control information; and

a third step of transmitting a first channel in uplink in accordance with the maximum value of the transmit power modified at the maximum transmit power control unit.