Communication apparatus and communication method
View Patent ↗A communication apparatus and a communication method capable of suppressing an increase of bits used for a request to send a reference signal and flexibly setting a resource used for sending a reference signal. In a base station, a transmission processing unit transmits, in one of a plurality of formats, control information containing a request to send a sounding reference signal (A-SRS), and a reception processing unit receives the transmitted A-SRS using the resource specified by the format of the transmitted control information. Then, the plurality of formats is associated with each different SRS resource by a setting unit.
1. A communication apparatus comprising:
a transmitter, which, in operation, transmits downlink control information including a transmission request of a sounding reference signal (SRS) using one downlink control information format (DCI format) among a plurality of DCI formats,
wherein each DCI format corresponds to at least one set of SRS parameters, the at least one set of SRS parameters for one DCI format is different from the at least one set of SRS parameters for another DCI format, and each set of SRS parameters specifies one of a plurality of SRS resources for use in transmitting the SRS, and
wherein the plurality of DCI formats include a first DCI format corresponding to one set of SRS parameters and a second DCI format corresponding to three sets of SRS parameters; and
a receiver, which, in operation, receives the SRS transmitted using an SRS resource specified by a set of SRS parameters corresponding to said one DCI format.
2. The communication apparatus according to claim 1 , wherein
the set of SRS parameters includes an initial resource block position of the SRS resource, a bandwidth, a cyclic shift and a transmission comb.
3. The communication apparatus according to claim 1 , wherein
a number of bits used for the SRS transmission request is one for the first DCI format and a number of bits used for the SRS transmission request is two for the second DCI format.
4. The communication apparatus according to claim 1 , wherein
a correspondence between each of the plurality of DCI formats and the set of SRS parameters is shared with a terminal apparatus.
5. A communication method comprising:
transmitting downlink control information including a transmission request of a sounding reference signal (SRS) using one downlink control information format (DCI format) among a plurality of DCI formats,
wherein each DCI format corresponds to at least one set of SRS parameters, the at least one set of SRS parameters for one DCI format is different from the at least one set of SRS parameters for another DCI format, and each set of SRS parameters specifies one of a plurality of SRS resources for use in transmitting the SRS, and
wherein the plurality of DCI formats include a first DCI format corresponding to one set of SRS parameters and a second DCI format corresponding to three sets of SRS parameters; and
receiving the SRS transmitted using an SRS resource specified by a set of SRS parameters corresponding to said one DCI format.
6. The communication method according to claim 5 , wherein
the set of SRS parameters includes an initial resource block position of the SRS resource, a bandwidth, a cyclic shift and a transmission comb.
7. The communication method according to claim 5 , wherein
a number of bits used for the SRS transmission request is one for the first DCI format and a number of bits used for the SRS transmission request is two for the second DCI format.
8. The communication method according to claim 5 , wherein
a correspondence between each of the plurality of DCI formats and the set of SRS parameters is shared by a terminal apparatus and a base station apparatus.