Communication apparatus, communication method, and recording medium
[Object] To provide a mechanism that enables flexible design in relation to communication timing. [Solution] A communication apparatus including: a communication control unit that controls communication with another communication apparatus, which is a communication counterpart, through frequency division duplexing (FDD). The communication control unit transmits a second sub frame that is transmitted from the communication apparatus to the other communication apparatus and corresponds to a first sub frame after the first sub frame that is transmitted from the other communication apparatus to the communication apparatus.
1 . A first radio communication device comprising:
a radio transceiver; and
circuitry coupled with the radio transceiver and configured to:
receive, from a second radio communication device, setting information related to uplink transmission from the first radio communication device, the setting information including information indicating which of a first mode and a second mode is to be set to the first radio communication device; and
switch, based on the setting information, a transmission timing mode between the first mode and the second mode, wherein a time required before setting of the transmission timing mode becomes valid after the transmission timing mode is set is set for the first radio communication device separately from the setting information,
wherein the first mode is a first transmission timing mode in which the first communication apparatus performs uplink transmission on an i-th wireless frame later than the corresponding i-th wireless frame for downlink transmission, and
wherein the second mode is a second transmission timing mode in which the first communication apparatus performs uplink transmission on an i-th wireless frame earlier than the corresponding i-th wireless frame for downlink transmission.
2 . The first radio communication device according to the claim 1 , wherein the circuitry is further configured to, for both the first mode and the second mode:
receive a Timing Advance command from the second radio communication device, and
control, based on a timing advance time (N TA ) and an offset (N TAoffset ), uplink transmission timing of the uplink transmission from the first radio communication device, wherein the N TA is set based on the received Timing Advance command.
3 . The first radio communication device according to the claim 2 , wherein N TAoffset is defined in advance based on a communication scheme and communication parameters.
4 . The first radio communication device according to the claim 2 , wherein N TAoffset is a predetermined value corresponding to a time for switching between uplink transmission and downlink transmission.
5 . The first radio communication device according to the claim 2 , wherein, in the first mode, N TA is set to zero.
6 . The first radio communication device according to the claim 2 , wherein N TA is set based on a number of symbols of a control channel in a downlink subframe.
7 . The first radio communication device according to the claim 2 , wherein N TA is set based on a number of symbols of a control channel in an uplink subframe.
8 . The first radio communication device according to the claim 2 , wherein N TAoffset is set based on a symbol length of a PUCCH subframe.
9 . A second radio communication device comprising:
a radio transceiver; and
circuitry coupled with the radio transceiver and configured to:
send, to a first radio communication device, setting information related to uplink transmission from the first radio communication device, the setting information including information indicating which of a first mode and a second mode is to be set to the first radio communication device; and
set, for the first radio communication device separately from the setting information, a time required before setting of a transmission timing mode of the first radio communication device becomes valid after the transmission timing mode is set,
wherein the first mode is a first transmission timing mode in which the first communication apparatus performs uplink transmission on an i-th wireless frame later than the corresponding i-th wireless frame for downlink, and
wherein the second mode is a second transmission timing mode in which the first communication apparatus performs uplink transmission on an i-th wireless frame earlier than the corresponding i-th wireless frame for downlink, and
wherein the transmission timing mode of the first radio communication is set based on the setting information to either the first mode or the second mode.
10 . The second radio communication device according to the claim 9 , wherein the circuitry is further configured to, for both the first mode and the second mode:
send a Timing Advance command to the first radio communication device,
wherein uplink transmission timing of the uplink transmission from the first radio communication device is controlled based on a timing advance time (N TA ) and an offset (N TAoffset ),
wherein the N TA is set based on the sent Timing Advance command.
11 . The second radio communication device according to the claim 10 , wherein N TAoffset is defined in advance based on a communication scheme and communication parameters.
12 . The second radio communication device according to the claim 10 , wherein N TAoffset is a predetermined value corresponding to a time for switching between uplink transmission and downlink transmission.
13 . The second radio communication device according to the claim 10 , wherein, in the first mode, N TA is set to zero.
14 . The second radio communication device according to the claim 10 , wherein N TA is set based on a number of symbols of a control channel in a downlink subframe.
15 . The second radio communication device according to the claim 10 , wherein N TA is set based on a number of symbols of a control channel in an uplink subframe.
16 . The second radio communication device according to the claim 10 , wherein N TAoffset is set based on a symbol length of a PUCCH subframe.
17 . The first radio communication device according to claim 1 , wherein the first mode is set in a case that the first radio communication device is in a radio resource control (RRC) connected state.
18 . The first radio communication device according to claim 1 , wherein the circuitry switches between the first mode and the second mode based on whether a non-orthogonal access scheme is used for the uplink transmission.
19 . The first radio communication device according to claim 1 , wherein the circuitry switches the transmission timing mode to the second mode in a case that the first radio communication devices performs random access processing.
20 . The second radio communication device according to claim 9 , wherein the circuitry is configured to set the transmission timing mode to the first mode in a case that a subcarrier interval for the uplink transmission exceeds a predetermined threshold.