Base station, user equipment and wireless communication method
View Patent ↗Provided are base stations, user equipments and wireless communication methods related to DCI design for latency reduction. A base station comprises: circuitry operative to form either a first type of DCI or a second type of DCI depending on whether to schedule a normal TTI or a shortened TTI in a subframe; and a transmitter operative to transmit the first type of DCI or the second type of DCI in the subframe, wherein the first type of DCI and the second type of DCI are differentiable; and if the second type of DCI is transmitted and another shortened TTI is to be scheduled, the circuitry is further operative to form a third type of DCI and the transmitter is further operative to transmit the third type of DCI in a shortened TTI after said shortened TTI that is scheduled by the second type of DCI in the subframe.
1. A user equipment comprising:
a detector operative to detect a fourth type of downlink control information (DCI) or a second type of DCI in a Physical Downlink Control Channel (PDCCH) region or a starting shortened transmission time interval (TTI) of a subframe; and
circuitry operative to determine whether DCI detected by the detector is the fourth type of DCI or the second type of DCI, wherein:
if the DCI detected by the detector is the fourth type of DCI, the detector is further operative to detect the fourth type of DCI in one or more shortened TTIs after where the fourth type of DCI is detected for a first time in the subframe;
if the DCI detected by the detector is the second type of DCI, the detector is further operative to detect a third type of DCI in one or more shortened TTIs after the second type of DCI in the subframe;
each shortened TTI has 7 or less orthogonal frequency division multiplexing (OFDM) symbols,
the second type of DCI carries common information for one slot or one subframe, and the third type of DCI carries information specific to a target shortened TTI,
the circuitry is further operative to form a first type of DCI for the subframe if a normal TTI with 14 OFDM symbols is to be scheduled, and
the first type of DCI, the second type of DCI and the fourth type of DCI having the same size are differentiable from one another by a two-bit field.
2. The user equipment according to claim 1 , wherein
the detector is further operative to detect the first type of DCI in the PDCCH region of the subframe.
3. The user equipment according to claim 1 , wherein
the detector is further operative to detect the first type of DCI for scheduling a normal TTI with 14 OFDM symbols in the PDCCH region of the subframe; and
if the first type of DCI is detected, the detector is operative to not detect DCI any more in the subframe.