Wireless communication apparatus and wireless communication method

A wireless communication apparatus comprising:

• a designation unit which generates format designation information for designating a format of transmission and reception for another wireless communication apparatus;
• a transmission unit which wirelessly transmits the format designation information to the other wireless communication apparatus;
• an acquisition unit which acquires a packet;
• a propagation channel estimation unit which estimates uplink propagation channel information indicating a propagation channel from the other wireless communication apparatus to the wireless communication apparatus based on the packet;
• a calibration coefficient calculation unit which calculates a calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• and
• a transmission weight value calculation unit which calculates a transmission weight value based on the calibration coefficient and the uplink propagation channel information,
• wherein the transmission unit wirelessly transmits a predetermined signal to the other wireless communication apparatus based on the transmission weight value, and the designation unit performs designation so that a known signal for dealing with estimation of the uplink propagation channel information corresponding to a plurality of antennas is transmitted using the same antenna as that at a time of reception.

A wireless communication apparatus comprising:

• a designation unit which generates format designation information for designating a format of transmission and reception for another wireless communication apparatus;
• a transmission unit which wirelessly transmits the format designation information to the other wireless communication apparatus;
• an acquisition unit which acquires a packet;
• a propagation channel estimation unit which estimates uplink propagation channel information indicating a propagation channel from the other wireless communication apparatus to the wireless communication apparatus based on the packet;
• a calibration coefficient calculation unit which calculates a calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• and
• a transmission weight value calculation unit which calculates a transmission weight value based on the calibration coefficient and the uplink propagation channel information,
• wherein the transmission unit wirelessly transmits a predetermined signal to the other wireless communication apparatus based on the transmission weight value, and when the other wireless communication apparatus receives a signal via a plurality of antennas, the designation unit designates a format with which the uplink propagation channel information corresponding to the plurality of antennas is capable of being estimated as a format of a training preamble of a frame of the packet for providing a notification of the downlink propagation channel information.

A wireless communication apparatus comprising:

• a designation unit which generates format designation information for designating a format of transmission and reception for another wireless communication apparatus;
• a transmission unit which wirelessly transmits the format designation information to the other wireless communication apparatus;
• an acquisition unit which acquires a packet;
• a propagation channel estimation unit which estimates uplink propagation channel information indicating a propagation channel from the other wireless communication apparatus to the wireless communication apparatus based on the packet;
• a calibration coefficient calculation unit which calculates a calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• and
• a transmission weight value calculation unit which calculates a transmission weight value based on the calibration coefficient and the uplink propagation channel information,
• wherein the transmission unit wirelessly transmits a predetermined signal to the other wireless communication apparatus based on the transmission weight value, and the designation unit designates an antenna to be used in transmission and reception so that the antenna to be commonly used in the transmission and the reception is selected when the calibration coefficient is calculated.

A wireless communication method in a wireless communication apparatus, the method comprising:

• a step of generating format designation information for designating a format of transmission and reception for another wireless communication apparatus;
• a step of wirelessly transmitting the format designation information to the other wireless communication apparatus;
• a step of acquiring a packet;
• a step of estimating uplink propagation channel information indicating a propagation channel from the other wireless communication apparatus to the wireless communication apparatus based on the packet;
• a step of calculating a calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• a step of calculating a transmission weight value based on the calibration coefficient and the uplink propagation channel information;
• and
• a step of wirelessly transmitting a predetermined signal to the other wireless communication apparatus based on the transmission weight value,
• the step of generating the format designation information performs designation so that a known signal for dealing with estimation of the uplink propagation channel information corresponding to a necessary band is transmitted.

A wireless communication apparatus comprising:

• a propagation channel estimation unit which estimates first uplink propagation channel information indicating a propagation channel from another wireless communication apparatus to the wireless communication apparatus based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and a predetermined signal received from the other wireless communication apparatus;
• a correction value calculation unit which calculates a correction value by calculating temporary correction values based on the downlink propagation channel information and the first uplink propagation channel information and multiplying the temporary correction values by weights based on channel gains to combine the temporary correction values;
• a transmission weight value calculation unit which calculates a transmission weight value based on the correction value and the first uplink propagation channel information or second uplink propagation channel information;
• and
• a transmission unit which wirelessly transmits a predetermined signal to the other wireless communication apparatus through a beam formed based on the transmission weight value and the second uplink propagation channel information.

A wireless communication method in a wireless communication apparatus, the method comprising:

• a step of estimating first uplink propagation channel information indicating a propagation channel from another wireless communication apparatus to the wireless communication apparatus based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and a predetermined signal received from the other wireless communication apparatus;
• a step of calculating a correction value by calculating temporary correction values based on the downlink propagation channel information and the first uplink propagation channel information and multiplying the temporary correction values by weights based on channel gains to combine the temporary correction values;
• a step of calculating a transmission weight value based on the correction value and the first uplink propagation channel information or second uplink propagation channel information;
• and
• a step of wirelessly transmitting a predetermined signal to the other wireless communication apparatus through a beam formed based on the transmission weight value and the second uplink propagation channel information.

A wireless communication apparatus comprising:

• an acquisition unit which acquires a packet;
• a propagation channel estimation unit which estimates uplink propagation channel information indicating a propagation channel from another wireless communication apparatus to the wireless communication apparatus based on the packet;
• a calibration coefficient calculation unit which calculates first calibration coefficients based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• a correlation processing unit which determines a second calibration coefficient based on a correlation between the first calibration coefficients in a frequency domain;
• a transmission weight value calculation unit which calculates a transmission weight value based on the second calibration coefficient and the uplink propagation channel information;
• and
• a transmission unit which wirelessly transmits a predetermined signal to the other wireless communication apparatus based on the transmission weight value.

A wireless communication method in a wireless communication apparatus, the method comprising:

• a step of acquiring a packet;
• a step of estimating uplink propagation channel information indicating a propagation channel from another wireless communication apparatus to the wireless communication apparatus based on the packet;
• a step of calculating first calibration coefficients based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• a step of determining a second calibration coefficient based on a correlation between the first calibration coefficients in a frequency domain;
• a step of calculating a transmission weight value based on the second calibration coefficient and the uplink propagation channel information;
• and
• a step of wirelessly transmitting a predetermined signal to the other wireless communication apparatus based on the transmission weight value.

A wireless communication apparatus comprising:

• a reception unit which receives a radio signal;
• a demodulation unit which demodulates the radio signal and generates a demodulated signal in accordance with a demodulated result;
• a propagation channel estimation unit which estimates uplink propagation channel information indicating a propagation channel from another wireless communication apparatus to the wireless communication apparatus based on the demodulated signal;
• a calibration coefficient calculation unit which calculates a new calibration coefficient as a last calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• a calibration coefficient storage unit which stores a history of the new calibration coefficient as an old calibration coefficient;
• a calibration coefficient update unit which calculates a calibration coefficient for value calculation based on the new calibration coefficient and the old calibration coefficient;
• a transmission weight value calculation unit which calculates a transmission weight value based on the calibration coefficient for value calculation and the uplink propagation channel information;
• a modulation unit which generates a modulated signal in accordance with a result of modulating data;
• and
• a transmission unit which wirelessly transmits a predetermined signal based on the modulated signal to the other wireless communication apparatus based on the transmission weight value.

A wireless communication method in a wireless communication apparatus, the method comprising:

• a step of receiving a radio signal;
• a step of demodulating the radio signal and generating a demodulated signal in accordance with a demodulated result;
• a step of estimating uplink propagation channel information indicating a propagation channel from another wireless communication apparatus to the wireless communication apparatus based on the demodulated signal;
• a step of calculating a new calibration coefficient as a last calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• a step of storing a history of the new calibration coefficient as an old calibration coefficient;
• a step of calculating a calibration coefficient for value calculation based on the new calibration coefficient and the old calibration coefficient;
• a step of calculating a transmission weight value based on the calibration coefficient for value calculation and the uplink propagation channel information;
• a step of generating a modulated signal in accordance with a result of modulating data;
• and
• a step of wirelessly transmitting a predetermined signal based on the modulated signal to the other wireless communication apparatus based on the transmission weight value.

A wireless communication apparatus for performing spatial multiplexing transmission using the same frequency band at the same time when data is transmitted to a plurality of other wireless communication apparatuses, the wireless communication apparatus comprising:

• a propagation channel estimation unit which estimates propagation channel information between the other wireless communication apparatuses and the wireless communication apparatus for each of subcarriers included in the same frequency band based on known signals included in signals received from the other wireless communication apparatuses;
• a propagation channel interpolation unit which interpolates propagation channel information of a subcarrier for which no propagation channel information has been obtained based on the propagation channel information estimated by the propagation channel estimation unit and outputs the propagation channel information estimated by the propagation channel estimation unit and the interpolated propagation channel information;
• a transmission weight value calculation unit which calculates a transmission weight value based on the propagation channel information output by the propagation channel interpolation unit;
• and
• a transmission unit which transmits data multiplexed based on the transmission weight value calculated by the transmission weight value calculation unit to the plurality of other wireless communication apparatuses.

A wireless communication apparatus for performing spatial multiplexing transmission using the same frequency band at the same time when data is transmitted to a plurality of other wireless communication apparatuses, the wireless communication apparatus comprising:

• a propagation channel estimation unit which estimates propagation channel information between the other wireless communication apparatuses and the wireless communication apparatus for each of subcarriers included in the same frequency band based on known signals included in signals received from the other wireless communication apparatuses;
• a transmission weight value calculation unit which calculates a transmission weight value based on the propagation channel information estimated by the propagation channel estimation unit;
• a transmission weight value interpolation unit which interpolates a transmission weight value of a subcarrier for which no transmission weight value has been obtained based on the transmission weight value calculated by the transmission weight value calculation unit and outputs the transmission weight value calculated by the transmission weight value calculation unit and the interpolated transmission weight value;
• and
• a transmission unit which transmits data multiplexed based on the transmission weight value output by the transmission weight value interpolation unit to the plurality of other wireless communication apparatuses.

A wireless communication method performed by a wireless communication apparatus which performs spatial multiplexing transmission using the same frequency band at the same time when data is transmitted to a plurality of other wireless communication apparatuses, the method comprising:

• a propagation channel estimation step of estimating propagation channel information between the other wireless communication apparatuses and the wireless communication apparatus for each of subcarriers included in the same frequency band based on known signals included in signals received from the other wireless communication apparatuses;
• a propagation channel interpolation step of interpolating propagation channel information of a subcarrier for which no propagation channel information has been obtained based on the propagation channel information estimated in the propagation channel estimation step and outputting the propagation channel information estimated in the propagation channel estimation step and the interpolated propagation channel information;
• a transmission weight value calculation step of calculating a transmission weight value based on the propagation channel information output in the propagation channel interpolation step;
• and
• a transmission step of transmitting data multiplexed based on the transmission weight value calculated in the transmission weight value calculation step to the plurality of other wireless communication apparatuses.

A wireless communication method performed by a wireless communication apparatus which performs spatial multiplexing transmission using the same frequency band at the same time when data is transmitted to a plurality of other wireless communication apparatuses, the method comprising:

• a propagation channel estimation step of estimating propagation channel information between the other wireless communication apparatuses and the wireless communication apparatus for each of subcarriers included in the same frequency band based on known signals included in signals received from the other wireless communication apparatuses;
• a transmission weight value calculation step of calculating a transmission weight value based on the propagation channel information estimated in the propagation channel estimation step;
• a transmission weight value interpolation step of interpolating a transmission weight value of a subcarrier for which no transmission weight value has been obtained based on the transmission weight value calculated in the transmission weight value calculation step and outputting the transmission weight value calculated in the transmission weight value calculation step and the interpolated transmission weight value;
• and
• a transmission step of transmitting data multiplexed based on the transmission weight value output in the transmission weight value interpolation step to the plurality of other wireless communication apparatuses.

A wireless communication method in a wireless communication apparatus, the method comprising:

• a step of generating format designation information for designating a format of transmission and reception for another wireless communication apparatus;
• a step of wirelessly transmitting the format designation information to the other wireless communication apparatus;
• a step of acquiring a packet;
• a step of estimating uplink propagation channel information indicating a propagation channel from the other wireless communication apparatus to the wireless communication apparatus based on the packet;
• a step of calculating a calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• a step of calculating a transmission weight value based on the calibration coefficient and the uplink propagation channel information;
• and
• a step of wirelessly transmitting a predetermined signal to the other wireless communication apparatus based on the transmission weight value,
• wherein the step of generating the format designation information performs designation so that a known signal for dealing with estimation of the uplink propagation channel information corresponding to a plurality of antennas is transmitted using the same antenna as that at a time of reception.

A wireless communication method in a wireless communication apparatus, the method comprising:

• a step of generating format designation information for designating a format of transmission and reception for another wireless communication apparatus;
• a step of wirelessly transmitting the format designation information to the other wireless communication apparatus;
• a step of acquiring a packet;
• a step of estimating uplink propagation channel information indicating a propagation channel from the other wireless communication apparatus to the wireless communication apparatus based on the packet;
• a step of calculating a calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• a step of calculating a transmission weight value based on the calibration coefficient and the uplink propagation channel information;
• and
• a step of wirelessly transmitting a predetermined signal to the other wireless communication apparatus based on the transmission weight value,
• wherein, when the other wireless communication apparatus receives a signal via a plurality of antennas, the step of generating the format designation information designates a format with which the uplink propagation channel information corresponding to the plurality of antennas is capable of being estimated as a format of a training preamble of a frame of the packet for providing a notification of the downlink propagation channel information.

A wireless communication method in a wireless communication apparatus, the method comprising:

• a step of generating format designation information for designating a format of transmission and reception for another wireless communication apparatus;
• a step of wirelessly transmitting the format designation information to the other wireless communication apparatus;
• a step of acquiring a packet;
• a step of estimating uplink propagation channel information indicating a propagation channel from the other wireless communication apparatus to the wireless communication apparatus based on the packet;
• a step of calculating a calibration coefficient based on downlink propagation channel information indicating a propagation channel from the wireless communication apparatus to the other wireless communication apparatus and the uplink propagation channel information;
• a step of calculating a transmission weight value based on the calibration coefficient and the uplink propagation channel information;
• and
• a step of wirelessly transmitting a predetermined signal to the other wireless communication apparatus based on the transmission weight value,
• wherein the step of generating the format designation information designates an antenna to be used in transmission and reception so that the antenna to be commonly used in the transmission and the reception is selected when the calibration coefficient is calculated.