Wireless communication apparatus and wireless communication method
To suppress concentration of channel quality information requests and reports in a case of discontinuously transmitting reference signals at specific resources in a time domain, and thereby preventing degradation in throughput. A transmission apparatus transmits an instruction of CSI request distributed for each reception apparatus in a subframe concurrently with or earlier than a reference signal CSI-RS to each of reception apparatuses. Each of the reception apparatuses detects the CSI request from the transmission apparatus and calculates CSI from a channel estimation value of CSI-RS received thereafter. Then, the reception apparatus identifies CSI report subframe of the own apparatus from CSI report interval information of a given time interval notified in advance, the subframe in which the CSI request is detected and transmission timing of CSI-RS, and transmits a feedback signal including CSI report value by using PUSCH at the timing of the CSI report subframe.
1. A communication apparatus comprising:
a transmission section configured to transmit, to a terminal apparatus, a request signal for requesting a transmission of a signal; and
a reception section configured to receive the signal, which is transmitted from the terminal apparatus in a subframe which is configured to be specific for a terminal among a plurality of terminals and which is one among a plurality of subframes that are configured using a value common to the plurality of terminals,
wherein said reception section receives the signal, which is transmitted with a period that is specific for the terminal among the plurality of terminals, the period being from a detection of the request signal to a transmission of the signal at the terminal apparatus.
2. The communication apparatus according to claim 1 , wherein said reception section receives the signal, which is transmitted at a time that is specific for the terminal among the plurality of terminals.
3. The communication apparatus according to claim 1 , wherein said reception section receives the signal transmitted in the subframe after a defined number of subframes or more from a detection of the request signal at the terminal apparatus.
4. The communication apparatus according to claim 3 , wherein the defined number of subframes is configured to be common for the plurality of terminals.
5. The communication apparatus according to claim 1 , wherein said transmission section transmits the request signal at a time that is specific for the terminal among the plurality of terminals.
6. The communication apparatus according to claim 1 , wherein said transmission section transmits the request signal on a control channel.
7. The communication apparatus according to claim 1 , wherein said transmission section transmits, to the terminal apparatus, a first information indicating the plurality of subframes configured using the value that is common to the plurality of terminals and a second information indicating the subframe configured to be specific for the terminal.
8. The communication apparatus according to claim 1 , wherein the subframes configured using the value that is common to the plurality of terminals and the subframe configured to be specific for the terminal are configured using a period represented by a number of subframes.
9. The communication apparatus according to claim 1 , wherein the subframes configured using the value that is common to the plurality of terminals are subframes configured to be specific for a cell.
10. The communication apparatus according to claim 1 , wherein the signal is a sounding reference signal.
11. The communication apparatus according to claim 1 , wherein the signal is a signal indicating channel quality.
12. The communication apparatus according to claim 11 , wherein said transmission section transmits, to the terminal apparatus, a reference signal with a period, which is represented by a number of subframes, and said reception section receives the signal indicating channel quality, which is computed based on the reference signal at the terminal apparatus.
13. The communication apparatus according to claim 12 , wherein the reference signal is used for a communication system compatible with 8 antennas.
14. The communication apparatus according to claim 12 , wherein the reference signal is a CSI reference signal.
15. A communication method comprising:
transmitting, to a terminal apparatus, a request signal for requesting a transmission of a signal; and
receiving the signal, which is transmitted from the terminal apparatus in a subframe which is configured to be specific for a terminal among a plurality of terminals and which is one among a plurality of subframes that are configured using a value common to the plurality of terminals,
wherein the signal, which is transmitted with a period that is specific for the terminal among the plurality of terminals, is received, the period being from a detection of the request signal to a transmission of the signal at the terminal apparatus.