Wireless communication device

1. A wireless communication device comprising:

a circuitry configured to

communicate wirelessly with a plurality of slave stations under control;

control data transmission with each of the slave stations;

control the wireless communication device serving as a master station to perform multicast transmission to the plurality of slave stations;

specify, in an acknowledgement request frame, two or more slave stations selected from the plurality of slave stations transmitting respective acknowledgement responses and a transmission scheme of the respective acknowledgement responses;

transmit the acknowledgement request frame that requests the respective acknowledgement responses for the multicast transmission from the two or more of the plurality of slave stations;

receive the respective acknowledgement responses simultaneously transmitted from the two or more of the plurality of slave stations;

acquire information on each of respective propagation paths between each of the two or more of the plurality of slave stations and the wireless communication device from each of training signals simultaneously transmitted from each of the two or more of the plurality of slave stations in accordance with an encoding scheme; and

separate the respective acknowledgement responses received simultaneously from the two or more of the plurality of slave stations on a basis of the information on the respective propagation paths between the two or more of the plurality of slave stations and the wireless communication device,

wherein the transmission scheme includes the encoding scheme of the training signals for the plurality of acknowledgement responses to be separated, the training signals being encoded orthogonal to each other in accordance with the encoding scheme and transmitted simultaneously, each of the training signals being included in each response frame together with each of the acknowledgement responses.

2. The wireless communication device according to claim 1 ,

wherein the transmission scheme includes information on a modulation method and/or an error correction coding for the plurality of acknowledgement responses.

3. The wireless communication device according to claim 1 ,

wherein the transmission scheme includes information on transmission power of the plurality of acknowledgement responses.

4. The wireless communication device according to claim 1 ,

wherein the two or more of the plurality of slave stations are classified into a subgroup, and

the circuitry is further configured to:

notify the two or more of the plurality of slave stations of the transmission scheme in a management frame or a beacon frame that contains subgroup identification information specifying that the two or more of the plurality of slave stations are members of the subgroup.

5. The wireless communication device according to claim 1 ,

wherein the wireless communication device is configured to operate as an access point supporting IEEE 802.11 standard or a group owner (GO) supporting Wi-Fi direct standard.

6. A wireless communication device comprising:

circuitry configured to

communicate wirelessly with a master station; and

control data transmission with the master station,

wherein the circuitry is further configured to:

receive a frame transmitted by multicast to a multicast group including the wireless communication device, and an acknowledgement request frame transmitted from the master station that requests respective acknowledgement responses for the multicast transmission from a subgroup of the multicast group, wherein the acknowledgement request frame specifies the subgroup and a transmission scheme of the respective acknowledgement responses, and

when the subgroup includes the wireless communication device, transmit an acknowledgement response after a lapse of a predetermined time from reception of the acknowledgement request frame in accordance with the transmission scheme of the respective acknowledgement responses,

wherein the transmission scheme includes an encoding scheme of a training signal to spatially multiplex the acknowledgement response, the spatially multiplexed acknowledgement response being spatially demultiplexed in the master station from among the respective acknowledgement responses transmitted simultaneously from a plurality of slave stations of the subgroup, and

the circuitry is further configured to:

encode the training signal in accordance with the encoding scheme, respective training signals of the plurality of slave stations of the subgroup being encoded orthogonal to each other in accordance with the encoding scheme, and

transmit the encoded training signal.

7. The wireless communication device according to claim 6 , wherein the transmission scheme of the acknowledgement response includes information on a modulation method and/or an error correction coding, and the circuitry is further configured to: determine the modulation method and/or the error correction coding to be used for the acknowledgement response in accordance with the transmission scheme specified from the master station.

8. The wireless communication device according to claim 6 , wherein the transmission scheme includes information on transmission power of the acknowledgement response, and the circuitry is further configured to: determine transmission power to be used for the acknowledgement response in accordance with the transmission scheme specified from the master station.

9. The wireless communication device according to claim 6 ,

wherein the circuitry is further configured to:

determine whether to cause the circuitry to transmit the acknowledgement response based on a relationship between a sequence number of a received multicast data frame and subgroup identification information notified previously from the master station.

10. The wireless communication device according to claim 6 ,

wherein the circuitry is further configured to:

set transmission power in such a way that received power in the master station is predetermined power based on an estimation of a path loss between the wireless communication device and the master station, and transmit the acknowledgement response.

11. The wireless communication device according to claim 6 ,

wherein the wireless communication device is configured to operate as a station supporting IEEE 802.11 standard or a client supporting Wi-Fi direct standard.