Wireless communication device and method for determining transmission rate based on interference amount information

1. A wireless communication device comprising:

a receiver configured to receive a first frame from a first terminal and a second frame from a second terminal; and

controlling circuitry configured to

obtain quality information of a first channel with the first terminal based on the first frame and quality information of a second channel with the second terminal based on the second frame, and

determine a transmission rate applied to the first terminal and a transmission rate applied to the second terminal in spatially multiplexed transmission, based on the quality information of the first channel, the quality information of the second channel and interference amount information being indicative of an amount of interference depending on an execution condition of the spatially multiplexed transmission,

wherein the execution condition of the spatially multiplexed transmission includes a channel aging time after acquisition of the quality information of the first or the second channel, and

the interference amount indicated by the interference amount information takes a larger value as the channel aging time becomes longer.

2. The wireless communication device according to claim 1 , wherein the receiver is configured to receive a third frame to an nth frame from a third terminal to an nth terminal, and

the controlling circuitry is configured to

obtain quality information of a third channel with the third terminal to quality information of an nth channel with the nth terminal,

calculate first to nth transmission rates applicable to the first terminal to the nth terminal based on the quality information of the first to the nth channels and the interference amount information,

calculate transmission time lengths necessary for transmitting frames to the first to nth terminals based on the first to the nth transmission rates and sizes of the frames transmitted to the first to the nth terminals, and

select a plurality of terminals targeted for the spatially multiplexed transmission from among the first to the nth terminals based on proximity of the transmission time lengths of the frames transmitted to the first to the nth terminals.

3. The wireless communication device according to claim 2 , wherein the controlling circuitry is configured to

identify a terminal to which the frame needs to be most preferentially transmitted among the first to the nth terminals, and

select at least one another terminal other than the identified terminal from among the first to the nth terminals based on proximity of the transmission time length with respect to that of the identified terminal,

wherein the identified terminal and the selected at least one another terminal corresponds to a plurality of terminals targeted for the spatially multiplexed transmission.

4. The wireless communication device according to claim 1 , wherein the controlling circuitry is configured to

calculate a communication quality value based on a difference between the quality information of the first or the second channel and the interference amount information, and

calculate the transmission rate of the first or the second terminal higher as the communication quality value becomes larger.

5. The wireless communication device according to claim 1 , wherein the interference amount information indicates an average value of either simulation values or actual measurement values for inter-terminal interference amounts of respective terminals in a plurality of terminal combinations.

6. The wireless communication device according to claim 1 , comprising at least one antenna.

7. A wireless communication method comprising:

receiving a first frame from a first terminal and a second frame from a second terminal;

obtaining quality information of a first channel with the first terminal based on the first frame and quality information of a second channel with the second terminal based on the second frame; and

determining a transmission rate applied to the first terminal and a transmission rate applied to the second terminal in spatially multiplexed transmission, based on the quality information of the first channel, the quality information of the second channel and interference amount information being indicative of an amount of interference depending on an execution condition of the spatially multiplexed transmission,

wherein the execution condition of the spatially multiplexed transmission is a channel aging time after acquisition of the Quality information of the first or the second channel, and

the interference amount indicated by the interference amount information takes a larger value as the channel aging time becomes longer.

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

receiving a third frame to an nth frame from a third terminal to an nth terminal,

obtaining quality information of a third channel with the third terminal to quality information of an nth channel with the nth terminal,

calculating first to nth transmission rates applicable to the first terminal to the nth terminal based on the quality information of the first to the nth channels and the interference amount information,

calculating transmission time lengths necessary for transmitting frames to the first to nth terminals based on the first to the nth transmission rates and sizes of the frames transmitted to the first to the nth terminals, and

selecting a plurality of terminals targeted for the spatially multiplexed transmission from among the first to the nth terminals based on proximity of the transmission time lengths of the frames transmitted to the first to the nth terminals.

9. The wireless communication method according to claim 8 , comprising:

identifying a terminal to which the frame needs to be most preferentially transmitted among the first to the nth terminals, and

selecting at least one another terminal other than the identified terminal from among the first to the nth terminals based on proximity of the transmission time length with respect to that of the identified terminal,

wherein the identified terminal and the selected at least one another terminal correspond to a plurality of terminals targeted for the spatially multiplexed transmission.

10. The wireless communication method according to claim 7 , comprising:

calculating a communication quality value based on a difference between the quality information of the first or the second channel and the interference amount information, and

calculating the transmission rate of the first or the second terminal higher as the communication quality value becomes larger.

11. The wireless communication method according to claim 7 , wherein the interference amount information indicates an average value of either simulation values or actual measurement values for inter-terminal interference amounts of respective terminals in a plurality of terminal combinations.

12. A wireless communication device comprising:

a receiver configured to receive a first frame from a first terminal and a second frame from a second terminal; and

controlling circuitry configured to

obtain quality information of a first channel with the first terminal based on the first frame and quality information of a second channel with the second terminal based on the second frame, and

determine a transmission rate applied to the first terminal and a transmission rate applied to the second terminal in spatially multiplexed transmission, based on the quality information of the first channel, the quality information of the second channel and interference amount information being indicative of an amount of interference depending on an execution condition of the spatially multiplexed transmission,

wherein the receiver is configured to receive a third frame to an nth frame from a third terminal to an nth terminal, and

the controlling circuitry is configured to

obtain quality information of a third channel with the third terminal to quality information of an nth channel with the nth terminal,

calculate first to nth transmission rates applicable to the first terminal to the nth terminal based on the quality information of the first to the nth channels and the interference amount information,

calculate transmission time lengths necessary for transmitting frames to the first to nth terminals based on the first to the nth transmission rates and sizes of the frames transmitted to the first to the nth terminals, and

select a plurality of terminals targeted for the spatially multiplexed transmission from among the first to the nth terminals based on proximity of the transmission time lengths of the frames transmitted to the first to the nth terminals.