Wireless communication system, wireless communication method, and transmitter
A radio communication system that performs MIMO transmission. The radio communication system includes a precoding unit that precodes multi-streams of transmission signals in a time domain; a plurality of transmission power control units that controls transmission power of each multi-stream precoded by the precoding unit. Further, there is a plurality of amplification units that amplifies each multi-stream precoded by the precoding unit in accordance with control of the plurality of transmission power control units; and a number-of-taps control unit that performs control to change the number of taps of the precoding unit to improve communication quality of the multi-streams on the basis of quality information of a received signal fed back from a reception device that has received the multi-stream amplified by each of the plurality of amplification units.
1. A radio communication system that performs MIMO transmission, the radio communication system comprising:
precoding circuitry configured to precode multi-streams of transmission signals in a time domain;
a plurality of transmission power control circuitry configured to control transmission power of each multi-stream precoded by the precoding circuitry;
a plurality of amplification circuitry configured to amplify each multi-stream precoded by the precoding circuitry in accordance with control of the plurality of transmission power control circuitry; and
a number-of-taps control circuitry configured to perform control to change a number of taps of the precoding circuitry to improve communication quality of the multi-streams on a basis of quality information of a received signal fed back from a reception device that has received the multi-stream amplified by each of the plurality of amplification circuitry or quality information of a received signal calculated using at least characteristics of the plurality of amplification circuitry.
2. The radio communication system according to claim 1 , wherein:
the number-of-taps control circuitry performs control to change the number of taps of the precoding circuitry to reduce inter-stream interference while increasing an SNR of the multi-streams.
3. The radio communication system according to claim 1 , wherein:
the number-of-taps control circuitry performs control to change the number of taps of the precoding circuitry on the basis of at least one of a peak to average power ratio, a signal power to interference power ratio, and a bit error rate of the multi-streams.
4. A radio communication method for performing MIMO transmission, the radio communication method comprising:
precoding multi-streams of transmission signals in a time domain;
controlling transmission power of each precoded multi-stream; and
amplifying each precoded multi-stream by a plurality of amplification circuitry to achieve controlled transmission power,
wherein the radio communication method further comprises performing control to change a number of precoding taps to improve communication quality of the multi-streams on a basis of quality information of a received signal fed back from a reception device that has received the amplified multi-stream or quality information of a received signal calculated using at least characteristics of the plurality of amplification circuitry.
5. The radio communication method according to claim 4 , wherein:
the performing control to change the number of precoding taps to reduce inter-stream interference while increasing an SNR of the multi-streams.
6. A transmission device that performs MIMO transmission, the transmission device comprising:
precoding circuitry configured to precode multi-streams of transmission signals in a time domain;
a plurality of transmission power control circuitry configured to control transmission power of each multi-stream precoded by the precoding circuitry;
a plurality of amplification circuitry configured to amplify each multi-stream precoded by the precoding circuitry in accordance with control of the plurality of transmission power control circuitry; and
a number-of-taps control circuitry configured to perform control to change a number of taps of the precoding circuitry to improve communication quality of the multi-streams on a basis of quality information of a received signal fed back from a reception device that has received the multi-stream amplified by each of the plurality of amplification circuitry or quality information of a received signal calculated using at least characteristics of the plurality of amplification circuitry.
7. The transmission device according to claim 6 , wherein:
the number-of-taps control circuitry performs control to change the number of taps of the precoding circuitry to reduce inter-stream interference while increasing an SNR of the multi-streams.
8. The transmission device according to claim 6 , wherein:
the number-of-taps control circuitry performs control to change the number of taps of the precoding circuitry on the basis of at least one of a peak to average power ratio, a signal power to interference power ratio, and a bit error rate of the multi-streams.