Communication device and SRS transmission control method
View Patent ↗Provided are a communication device and an SRS transmission method capable of reducing the possibility of a difference in recognition between the presence or absence of an SRS transmission between a base station and a terminal or of an SRS resource so as to prevent degradation of system throughput. At a terminal ( 200 ), a reception processing unit ( 203 ) detects control information indicating whether or not to request transmission of a sounding reference signal (SRS), whereupon a transmission signal forming unit ( 207 ) transmits an A-SRS by way of control by a transmission control unit ( 206 ) on the basis of control information. The transmission control unit ( 206 ) determines whether or not to execute SRS transmission on the basis of an “SRS Transmission Execution Rule” and the reception status of trigger information.
1. A communication apparatus comprising:
a transmitter, which, in operation, transmits, to a terminal, control information indicating whether or not to request transmission of a sounding reference signal (SRS) and indicating a transmission parameter of the SRS; and
a receiver, which, in operation, receives the SRS that is transmitted from the terminal based on the control information, wherein,
when the transmitter transmits to the terminal first control information that requests the transmission of the SRS and second control information that requests the transmission of the SRS for the same subframe and the same cell and that indicates a transmission parameter different from the transmission parameter indicated by the first control information, the receiver receives the SRS that is transmitted based on the first control information.
2. The communication apparatus according to claim 1 , wherein the first control information and the second control information are control information, which is detected within a predetermined period by the terminal.
3. The communication apparatus according to claim 2 , wherein the first control information is control information, which is detected first within the predetermined period by the terminal.
4. The communication apparatus according to claim 2 , wherein the first control information is control information, which is detected last within the predetermined period by the terminal.
5. The communication apparatus according to claim 2 , wherein
the receiver receives the SRS in first subframe n among subframes located at or after a k-th subframe from a subframe in which the control information requesting the transmission of the SRS is detected by the terminal, the subframes being configured based on periodicity Np and a subframe offset, and
the predetermined period is a period from subframe n−(Np−k+1) until subframe n−k.
6. The communication apparatus according to claim 1 , wherein the transmitter transmits, to the terminal, only one of the first and second control information within a predetermined period.
7. The communication apparatus according to claim 1 , wherein the receiver receives the SRS in a first subframe among subframes located at or after a k-th subframe from a subframe in which the control information requesting the transmission of the SRS is detected by the terminal, the subframes being configured based on a periodicity and a subframe offset.
8. The communication apparatus according to claim 1 , wherein the transmission parameter includes one or more of a bandwidth, an RB position where the bandwidth starts, Cyclic Shift, transmission Comb, the number of antenna ports, and frequency hopping.
9. The communication apparatus according to claim 1 , wherein the control information is transmitted in one of a plurality of formats, and the transmission parameter is identified based on the format.
10. The communication apparatus according to claim 1 , wherein the SRS is an aperiodic SRS triggered by downlink control information.
11. A communication apparatus comprising:
a transmitter, which, in operation, transmits, to a terminal, control information indicating whether or not to request transmission of a sounding reference signal (SRS) and indicating a transmission parameter of the SRS; and
a receiver, which, in operation, receives the SRS that is transmitted from the terminal based on the control information, wherein,
when the transmitter transmits to the terminal first control information that requests the transmission of the SRS and second control information that requests the transmission of the SRS for the same subframe and the same cell and that indicates a transmission parameter different from the transmission parameter indicated by the first control information, the receiver receives no SRS.
12. The communication apparatus according to claim 11 , wherein the first control information and the second control information are control information that is detected within a predetermined period by the terminal.
13. The communication apparatus according to claim 12 , wherein the first control information is control information that is detected first within the predetermined period by the terminal.
14. The communication apparatus according to claim 12 , wherein the first control information is control information that is detected last within the predetermined period by the terminal.
15. The communication apparatus according to claim 12 , wherein
the receiver receives the SRS in first subframe n among subframes located at or after a k-th subframe from a subframe in which the control information requesting the transmission of the SRS is detected by the terminal, the subframes being configured based on periodicity Np and a subframe offset, and
the predetermined period is a period from subframe n−(Np−k+1) until subframe n−k.
16. The communication apparatus according to claim 11 , wherein the transmitter transmits, to the terminal, only one of the first and second control information within a predetermined period.
17. The communication apparatus according to claim 11 , wherein the receiver receives the SRS in a first subframe among subframes located at or after a k-th subframe from a subframe in which the control information requesting the transmission of the SRS is detected by the terminal, the subframes being configured based on a periodicity and a subframe offset.
18. The communication apparatus according to claim 11 , wherein the transmission parameter includes one or more of a bandwidth, an RB position where the bandwidth starts, Cyclic Shift, transmission Comb, the number of antenna ports, and frequency hopping.
19. The communication apparatus according to claim 11 , wherein the control information is transmitted in one of a plurality of formats, and the transmission parameter is identified based on the format.
20. The communication apparatus according to claim 11 , wherein the SRS is an aperiodic SRS triggered by downlink control information.
21. A communication apparatus comprising:
a transmitter, which, in operation, transmits, to a terminal, control information indicating whether or not to request transmission of a sounding reference signal (SRS) and indicating a transmission parameter of the SRS; and
a receiver, which, in operation, receives the SRS that is transmitted from the terminal based on the control information, wherein,
when the transmitter transmits the control information twice or more within a predetermined period, the transmitter transmits the control information, which indicates a same transmission parameter, within the predetermined period.
22. The communication apparatus according to claim 21 , wherein
the receiver receives the SRS in first subframe n among subframes located at or after a k-th subframe from a subframe in which the control information requesting the transmission of the SRS is detected by the terminal, the subframes being configured based on periodicity Np and a subframe offset, and
the predetermined period is a period from subframe n−(Np−k+1) until subframe n−k.
23. The communication apparatus according to claim 21 , wherein the receiver receives the SRS in a first subframe among subframes located at or after a k-th subframe from a subframe in which the control information requesting the transmission of the SRS is detected by the terminal, the subframes being configured based on a periodicity and a subframe offset.
24. The communication apparatus according to claim 21 , wherein the transmission parameter includes one or more of a bandwidth, an RB position where the bandwidth starts, Cyclic Shift, transmission Comb, the number of antenna ports, and frequency hopping.
25. The communication apparatus according to claim 21 , wherein the control information is transmitted in one of a plurality of formats, and the transmission parameter is identified based on the format.
26. The communication apparatus according to claim 21 , wherein the SRS is an aperiodic SRS triggered by downlink control information.
27. A communication method comprising:
transmitting, to a terminal, control information indicating whether or not to request transmission of a sounding reference signal (SRS) and indicating a transmission parameter of the SRS; and
receiving the SRS that is transmitted from the terminal based on the control information, wherein,
when the transmitting includes transmitting, to the terminal, first control information that requests the transmission of the SRS and second control information that requests the transmission of the SRS for the same subframe and the same cell and that indicates a transmission parameter different from the transmission parameter indicated by the first control information, the receiving includes receiving the SRS that is transmitted based on the first control information.
28. A communication method comprising:
transmitting, to a terminal, control information indicating whether or not to request transmission of a sounding reference signal (SRS) and indicating a transmission parameter of the SRS; and
receiving the SRS that is transmitted from the terminal based on the control information, wherein,
when the transmitting includes transmitting, to the terminal, first control information that requests the transmission of the SRS and second control information that requests the transmission of the SRS for the same subframe and the same cell and that indicates a transmission parameter different from the transmission parameter indicated by the first control information, the receiving includes receiving no SRS.
29. A communication method comprising:
transmitting, to a terminal, control information indicating whether or not to request transmission of a sounding reference signal (SRS) and indicating a transmission parameter of the SRS; and
receiving the SRS that is transmitted from the terminal based on the control information, wherein,
when the control information is transmitted twice or more within a predetermined period, the transmitting includes transmitting the control information, which indicates a same transmission parameter, within the predetermined period.