WIRELESS COMMUNICATION APPARATUS, WIRELESS COMMUNICATION SYSTEM AND WIRELESS COMMUNICATION METHOD

• US 20100290548A1
• Filed: 10/23/2008
• Published: 11/18/2010
• Est. Priority Date: 12/25/2007
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Hiramatsu, Katsuhiko, Miyoshi, Kenichi, Hoshino, Masayuki
• Granted Patent: US 8,588,321 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0426 Power distribution
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0036 arrangements specific to the receiver
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

When power scaling is applied to multi-user MIMO, a reduction in transmission rate is suppressed and transmission efficiency is improved. When signals are transmitted through spatial multiplexing from a wireless base station 11 to a plurality of pieces of user equipment 12 and 13, notification of a transmission parameter (MCS) of the distant user equipment (UE-B) 13 is provided as control information to the adjacent user equipment (UE-A) 12. The user equipment 12 calculates, based on the received control information, a reception quality (CQI) after cancellation of a signal serving as an interference signal and destined for the other user equipment 13, and feeds back the calculated result to the wireless base station 11. Based on this feedback, the wireless base station 11 sets a transmission parameter (MCS) of each piece of the user equipment 12 and 13 using the CQI after the cancellation, and transmits signals intended for respective users through spatial multiplexing after performing power distribution between the users by power scaling.

Claims

1. A wireless communication apparatus used in a wireless communication system for performing communication from a transmitting device to a plurality of receiving devices including the wireless communication apparatus using a plurality of antennas, the wireless communication apparatus comprising:

a reception quality calculator for receiving, from the transmitting device, control information destined for the other receiving device, and for calculating, based on a transmission parameter destined for the other receiving device included in the control information, a reception quality of a signal destined for the wireless communication apparatus when a signal destined for the other receiving device is cancelled; and

a feedback information transmission section for transmitting, to the transmitting device, feedback information including the reception quality when cancelled.

2. The wireless communication apparatus according to claim 1,

wherein the wireless communication apparatus comprises a cancellation capability notification section for notifying, in advance, the transmitting device that there is the capability of canceling the signal destined for the other receiving device.

3. The wireless communication apparatus according to claim 1,

wherein the wireless communication apparatus comprises a demodulator for demodulating the signal destined for the wireless communication apparatus while canceling the signal destined for the other receiving device with respect to a reception signal using the transmission parameter destined for the other receiving device.

4. The wireless communication apparatus according to claim 1,

wherein the reception quality calculator receives, as the control information destined for the other receiving device, control information of a cell-edge-oriented signal of a cellular system, and calculates, based on a transmission parameter of the cell-edge-oriented signal included in the control information, the reception quality of the signal destined for the wireless communication apparatus when the cell-edge-oriented signal is cancelled.

5. The wireless communication apparatus according to claim 1,

wherein the wireless communication apparatus comprises a cancellation-capable bit number judging section for judging a cancelable bit number of the signal destined for the other receiving device in a receiving situation in which the transmission parameter destined for the other receiving device is envisaged,

wherein the reception quality calculator calculates, in accordance with the cancellation-capable bit number resulting from the judgment, the reception quality of the signal destined for the wireless communication apparatus when the signal destined for the other receiving device is cancelled, and

wherein the feedback information transmission section transmits, to the transmitting device, feedback information including:

the reception quality after the cancellation; and

the cancellation-capable bit number.

6. The wireless communication apparatus according to claim 1,

wherein the wireless communication apparatus comprises a power correction value judging section for judging a power correction value capable of canceling the signal destined for the other receiving device in a receiving situation in which the transmission parameter destined for the other receiving device is envisaged,

wherein the reception quality calculator calculates, in accordance with the power correction value destined for the other receiving device resulting from the judgment, the reception quality of the signal destined for the wireless communication apparatus when the signal destined for the other receiving device is cancelled, and

wherein the feedback information transmission section transmits, to the transmitting device, feedback information including:

the reception quality after the cancellation; and

the power correction value destined for the other receiving device.

7. The wireless communication apparatus according to claim 1,

wherein the wireless communication apparatus comprises a cancellation-capable frequency band judging section for judging a frequency band capable of canceling the signal destined for the other receiving device in a receiving situation in which the transmission parameter destined for the other receiving device is envisaged,

wherein the reception quality calculator calculates, in accordance with cancellation-capable frequency band information resulting from the judgment, the reception quality of the signal destined for the wireless communication apparatus when the signal destined for the other receiving device is cancelled for each frequency band, and

wherein the feedback information transmission section transmits, to the transmitting device, feedback information including:

the reception quality after the cancellation; and

the cancellation-capable frequency band information.

14. A wireless communication base station apparatus comprising the wireless communication apparatus according to claim 1.

8. A wireless communication apparatus used in a wireless communication system for performing communication from the wireless communication apparatus to a plurality of receiving devices including a first receiving device and a second receiving device using a plurality of antennas, the wireless communication apparatus comprising:

a control information retaining section for retaining control information including a transmission parameter destined for the second receiving device other than the first receiving device;

a control information notification section for notifying the first receiving device of the control information destined for the second receiving device; and

a signal transmission section for receiving feedback information from the first receiving device to which the notification is provided, for setting a transmission parameter of a signal destined for the first receiving device based on a reception quality of a signal destined for the first receiving device when a second-receiving-device-destined signal included in the feedback information is cancelled, and for performing spatially-multiplexed transmission after performing transmission power distribution for signals destined for the plurality of receiving devices.

9. The wireless communication apparatus according to claim 8,

wherein the control information retaining section retains, as the control information destined for the second receiving device, control information including a transmission parameter of a cell-edge-oriented signal of a cellular system, and

wherein the control information notification section announces the control information of the cell-edge-oriented signal to the plurality of receiving devices within a cell of the cellular system.

10. The wireless communication apparatus according to claim 9,

wherein the signal transmission section sets a transmission parameter of a signal destined for the first receiving device based on a reception quality of a signal destined for the first receiving device when a cell-edge-oriented signal, included in feedback information from the first receiving device to which the announcement is provided, is cancelled, and performs spatially-multiplexed transmission after performing transmission power distribution for the signal destined for the first receiving device and the cell-edge-oriented signal.

11. The wireless communication apparatus according to claim 8,

wherein the signal transmission section sets a transmission parameter of a signal destined for the first receiving device based on:

a reception quality of a signal destined for the first receiving device when the second-receiving-device-destined signal included in the feedback information is cancelled; and

a cancellation-capable bit number indicative of the number of cancelable bits of the second-receiving-device-destined signal.

12. The wireless communication apparatus according to claim 8,

wherein the signal transmission section sets a transmission parameter of a signal destined for the first receiving device based on a reception quality of a signal destined for the first receiving device when the second-receiving-device-destined signal included in the feedback information is cancelled, and performs transmission power distribution for a plurality of receiving-device-destined signals based on a second-receiving-device-destined signal power correction value indicative of a power correction value capable of canceling the second-receiving-device-destined signal included in the feedback information.

13. The wireless communication apparatus according to claim 8,

wherein the wireless communication apparatus comprises a scheduler for setting:

frequency bands of signals destined for the plurality of receiving devices; and

transmission parameters destined for the plurality of receiving devices, and

wherein the scheduler sets the transmission parameters of signals destined for the plurality of receiving devices based on;

a reception quality of a signal destined for the first receiving device when the second-receiving-device-destined signal included in the feedback information is cancelled; and

cancellation-capable frequency band information indicative of a frequency band capable of canceling the second-receiving-device-destined signal.

15. A wireless communication mobile station apparatus comprising the wireless communication apparatus according to claim 8.

16. A wireless communication system for performing communication from a transmitting device to a plurality of receiving devices including a first receiving device and a second receiving device using a plurality of antennas,

wherein the first receiving device includes:

a reception quality calculator for receiving, from the transmitting device, control information destined for the second receiving device, and for calculating, based on a transmission parameter destined for the second receiving device included in the control information, a reception quality of a signal destined for the first receiving device when a signal destined for the second receiving device is cancelled; and

a feedback information transmission section for transmitting, to the transmitting device, feedback information including the reception quality after the cancellation, and

wherein the transmitting device includes;

a control information retaining section for retaining control information including a transmission parameter destined for the second receiving device;

a control information notification section for notifying the first receiving device of the control information destined for the second receiving device; and

a signal transmission section for receiving feedback information from the first receiving device, for setting a transmission parameter of a signal destined for the first receiving device based on a reception quality of a signal destined for the first receiving device when a second-receiving-device-destined signal included in the feedback information is cancelled, and for performing spatially-multiplexed transmission after performing transmission power distribution for signals destined for the plurality of receiving devices.

17. A wireless communication system used in a cellular system for performing communication from a transmitting device to a plurality of receiving devices including a first receiving device and a second receiving device using a plurality of antennas:

wherein the first receiving device includes;

a reception quality calculator for receiving, from the transmitting device, control information of a cell-edge-oriented signal of the cellular system, and for calculating, based on a transmission parameter of the cell-edge-oriented signal included in the control information, a reception quality of a signal destined for the first receiving device when the cell-edge-oriented signal is cancelled; and

a feedback information transmission section for transmitting, to the transmitting device, feedback information including the reception quality after the cancellation; and

wherein the transmitting device includes;

a control information retaining section for retaining the control information including the transmission parameter of the cell-edge-oriented signal;

a control information notification section for announcing the control information of the cell-edge-oriented signal to the plurality of receiving devices within a cell of the cellular system; and

a signal transmission section for receiving the feedback information from the first receiving device, for setting a transmission parameter of a signal destined for the first receiving device based on a reception quality of a signal destined for the first receiving device when the cell-edge-oriented signal included in the feedback information is cancelled, and for performing spatially-multiplexed transmission after performing transmission power distribution for the signal destined for the first receiving device and the cell-edge-oriented signal.

18. A wireless communication method for performing communication from a transmitting device to a plurality of receiving devices including a first receiving device and a second receiving device using a plurality of antennas,

wherein the wireless communication method comprises a reception quality calculation step and a feedback information transmission step performed in the first receiving device,

the reception quality calculation step comprising:

receiving, from the transmitting device, control information destined for the second receiving device; and

calculating, based on a transmission parameter destined for the second receiving device included in the control information, a reception quality of a signal destined for the first receiving device when a signal destined for the second receiving device is cancelled,

the feedback information transmission step comprising transmitting, to the transmitting device, feedback information including the reception quality after the cancellation, and

wherein the wireless communication method comprises a control information notification step and a signal transmission step performed in the transmitting device,

the control information notification step comprising notifying the first receiving device of control information including a transmission parameter destined for the second receiving device,

the signal transmission step comprising;

receiving feedback information from the first receiving device;

setting a transmission parameter of a signal destined for the first receiving device based on a reception quality of a signal destined for the first receiving device when a second-receiving-device-destined signal included in the feedback information is cancelled; and

performing spatially-multiplexed transmission after performing transmission power distribution for signals destined for the plurality of receiving devices.

19. A wireless communication method used in a cellular system for performing communication from a transmitting device to a plurality of receiving devices including a first receiving device and a second receiving device using a plurality of antennas,

wherein the wireless communication method comprises a reception quality calculation step and a feedback information transmission step performed in the first receiving device,

the reception quality calculation step comprising:

receiving, from the transmitting device, control information of a cell-edge-oriented signal of the cellular system; and

calculating, based on a transmission parameter of the cell-edge-oriented signal included in this control information, a reception quality of a signal destined for the first receiving device when the cell-edge-oriented signal is cancelled,

the feedback information transmission step comprising transmitting, to the transmitting device, feedback information including the reception quality after the cancellation, and

wherein the wireless communication method comprises a control information notification step and a signal transmission step performed in the transmitting device,

the control information notification step comprising announcing the control information including a transmission parameter of the cell-edge-oriented signal to the plurality of receiving devices within a cell of the cellular system,

the signal transmission step comprising;

receiving the feedback information from the first receiving device;

setting a transmission parameter of a signal destined for the first receiving device based on a reception quality of a signal destined for the first receiving device when the cell-edge-oriented signal included in this feedback information is cancelled; and

performing spatially-multiplexed transmission after performing transmission power distribution for the signal destined for the first receiving device and the cell-edge-oriented signal.