WIRELESS COMMUNICATION DEVICE

• US 20140198866A1
• Filed: 07/23/2012
• Published: 07/17/2014
• Est. Priority Date: 07/27/2011
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Miyata, Takeo
• Granted Patent: US 9,112,755 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

A wireless communication device communicates with, using a plurality of antennas, a communication partner device including a plurality of antennas. The wireless communication device includes a communication unit, an interference intensity judgment unit, and a determination unit. The communication unit communicates with the communication partner device using the plurality of antennas and is configured to use a MIMO (multiple input multiple output) scheme when transmitting a signal to the communication partner device. The interference intensity judgment unit judges, based on predetermined criteria, whether or not an intensity of an interference wave included in a received signal at the communication partner device is high. The determination unit prohibits, upon the interference intensity judgment unit judging that the intensity of the interference wave is high, the communication unit from using the MIMO scheme when transmitting a signal.

Claims

1. A wireless communication device that communications with, using a plurality of antennas, a communication partner device including a plurality of antennas, the device comprising:

a communication unit that communicates with the communication partner device using the plurality of antennas and is configured to use a MIMO (multiple input multiple output) scheme in transmitting a signal to the communication partner device;

an interference intensity judgment unit that judges, based on predetermined criteria, whether or not an intensity of an interference wave included in a received signal at the communication partner device is high; and

a determination unit that determines to prohibit, upon the interference intensity judgment unit judging that the intensity of the interference wave is high, the communication unit from using the MIMO scheme when transmitting a signal.

2. The wireless communication device according to claim 1, wherein the interference intensity judgment unit judges whether or not the intensity of the interference wave is high based on a reception quality obtained based on a received signal yet to be subjected to a demodulation process in the communication partner device and a reception quality obtained based on a received signal subjected to the demodulation process in the communication partner device.

3. The wireless communication device according to claim 1, further comprising a reception quality judgment unit that judges whether or not the reception quality at the communication partner device is good based on predetermined criteria, wherein

the determination unit does not prohibit the communication unit from using the MIMO scheme when transmitting a signal in a case where the interference intensity judgment unit judges that the intensity of the interference wave is high and in a case where the reception quality judgment unit judges that the reception quality is good, and

the determination unit prohibits the communication unit from using the MIMO scheme when transmitting a signal in a case where the interference intensity judgment unit judges that the intensity of the interference wave is high and in a case where the reception quality judgment unit judges that the reception quality is not good.

4. (canceled)

5. (canceled)

6. A wireless communication device that communicates with, using a plurality of antennas, a communication partner device including a plurality of antennas, the communication partner device being configured to use a MIMO (multiple input multiple output) scheme when transmitting a signal to the wireless communication device,

the wireless communication device comprising a communication unit that communicates with the communication partner device using the plurality of antennas and is configured to, when receiving a signal from the communication partner device, perform null steering using an algorithm that does not need information regarding an interference wave for the reception directivity at the plurality of antennas, wherein

in a case where the communication partner device transmits a signal without using the MIMO scheme, the communication unit performs the null steering based on a known reference signal from the communication partner device and then receives a data signal from the communication partner device, and

in a case where the communication partner device transmits a signal using the MIMO scheme, the communication unit does not perform the null steering based on a known reference signal from the communication partner device and then receives a data signal from the communication partner device.

12. The wireless communication device according to claim 6, wherein in a case where the communication partner device transmits a signal using the MIMO scheme, the communication unit estimates a channel matrix of a desired wave based on a known reference signal, which has been received through the null steering based on the known reference signal from the communication partner device, from the communication partner device and performs a reception process on the data signal from the communication partner device using the estimated channel matrix.

7. A wireless communication device that communicates with, using a plurality of antennas, a communication partner device including a plurality of antennas, the communication partner device being configured to use a MIMO (multiple input multiple output) scheme when transmitting a signal to the wireless communication device,

the wireless communication device comprising:

a communication unit that communicates with the communication partner device using the plurality of antennas;

an interference intensity judgment unit that judges, based on predetermined criteria, whether or not an intensity of an interference wave included in a received signal at the communication unit is high; and

a determination unit that determines to prohibit, upon the interference intensity judgment unit judging that the intensity of the interference wave is high, the use of the MIMO scheme when the communication partner device transmits a signal.

8. The wireless communication device according to claim 7, further comprising:

a reception processing unit that performs a demodulation process on a received signal received by the communication unit; and

a reception quality acquisition unit that obtains a reception quality based on a received signal yet to be subjected to the demodulation process and obtains a reception quality based on a received signal subjected to the demodulation process,

wherein the interference intensity judgment unit judges whether or not the intensity of the interference wave is high based on the reception quality obtained by the reception quality acquisition unit based on the received signal yet to be subjected to the demodulation process and the reception quality obtained by the reception quality acquisition unit based on the received signal subjected to the demodulation process.

9. The wireless communication device according to claim 7, further comprising a reception quality judgment unit that judges, based on predetermined criteria, whether or not the reception quality obtained by the reception quality acquisition unit is good, wherein

in a case where the interference intensity judgment unit judges that the intensity of the interference wave is high but in a case where the reception quality judgment unit judges that the reception quality is good, the determination unit does not prohibit the use of the MIMO scheme when the communication partner device transmits a signal, and

in a case where the interference intensity judgment unit judges that the intensity of the interference wave is high and in a case where the reception quality judgment unit judges that the reception quality is not good, the determination unit prohibits the use of the MIMO scheme when the communication partner device transmits a signal.

10. The wireless communication device according to claim 7, wherein the communication unit is configured to, when receiving a signal from the communication partner device, perform null steering using an algorithm that does not need information regarding an interference wave for the reception directivity at the plurality of antennas,

in a case where the communication partner device transmits a signal without using the MIMO scheme, the communication unit performs the null steering based on a known reference signal from the communication partner device and then receives a data signal from the communication partner device, and

in a case where the communication partner device transmits a signal using the MIMO scheme, the communication unit does not perform the null steering based on the known reference signal from the communication partner device and then receives a data signal from the communication partner device.

11. The wireless communication device according to claim 10, wherein in a case where the communication partner device transmits a signal using the MIMO scheme, the communication unit estimates a channel matrix of a desired wave based on a known reference signal, which has been received through the null steering based on the known reference signal from the communication partner device, from the communication partner device and performs a reception process on the data signal from the communication partner device using the estimated channel matrix.