Radio transmission apparatus and radio communication method
View Patent ↗There is provided a radio transmitting apparatus capable of improving spectrum efficiency and a transmission rate while maintaining communication quality. The present apparatus adaptively selects space multiplex where different information (transmission signal A≠transmission signal B) is transmitted from a plurality of antennas with the same frequency, frequency multiplex where different information (transmission signal A≠transmission signal B) is transmitted from the plurality of antennas with different frequencies, space diversity where the same information is transmitted from the plurality of antennas with the same frequency, and frequency diversity where the same information (transmission signal A=transmission signal B) is transmitted from the plurality of antennas with different frequencies according to circumstances of a propagation path.
1. A radio transmitting apparatus comprising:
a transmitter that transmits the same or different information using a plurality of antennas;
an acquirer that acquires a circumstance of a propagation path; and
a controller that determines whether the acquired circumstance is a good circumstance, a poor circumstance, or an extremely poor circumstance, and
in a case that the determined circumstance is the good circumstance, sets the same transmission frequency for said plurality of antennas and allows said transmitter to perform space multiplexing transmission in which different information is simultaneously transmitted from said plurality of antennas with the same transmission frequency,
in a case that the determined circumstance is the poor circumstance but not the extremely poor circumstance, sets different transmission frequencies for said plurality of antennas and allows said transmitter to perform frecquency multiplexing transmission in which different information is simultaneously transmitted from said plurality of antennas with the different frequencies, and
in a case that the determined circumstance is the extremely poor circumstance, sets the same transmission frequency or different transmission frequencies for said plurality of antennas and allows said transmitter to perform space diversity transmission of frequency diversity transmission in which the same information is simultaneously transmitted from said plurality of antennas with the same transmission frequency or the different transmission frequencies.
2. A radio transmitting method using a plurality of antennas, comprising:
acquiring a circumstance of a propagation path;
determining whether the acquired circumstance is a good circumstance, a poor circumstance, or an extremely poor circumstance;
performing a control including (i) in a case the determined circumstance is the good circumstance, setting the same transmission frequency for said plurality of antennas and allowing space multiplexing transmission to be performed in which different information is simultaneously transmitted from said plurality of antennas with the same transmission frequency, (ii) in a case the determined circumstance is the poor circumstance but not the extremely poor circumstance, setting different transmission frequencies for said plurality of antennas and allowing frequency multiplexing transmission to be performed in which different information is simultaneously transmitted from said plurality of antennas with the different transmission frequencies, and (iii) in a case the determined circumstance is the extremely poor circumstance, setting the same transmission frequency or different transmission frequencies for said plurality of antennas and allowing space diversity transmission or frequency diversity transmission to be performed in which the same information is simultaneously transmitted from said plurality of antennas with the same transmission frequency or the different transmission frequencies; and
transmitting the same or different information using said plurality of antennas according to the control.