A terminal apparatus (1A, 1B) for communicating with a base station apparatus in new radio, NR, systems, the terminal apparatus (1A, 1B) comprising: a receiver configured to receive, from the base station apparatus, a physical downlink control channel, PDCCH, including downlink control information, DCI, in a search space specific to the terminal apparatus (1A, 1B); a controller configured to determine, based on whether a Radio Resource Control, RRC, parameter pdsch-TimeDomainAllocationList is received, a number of bits of a time domain resource allocation field in the DCI as ceiling(log2), in which the time domain resource allocation field indicates a time domain resource allocation configuration for a physical downlink shared channel, PDSCH, scheduled by the DCI; wherein the receiver is configured to receive, from the base station apparatus, the PDSCH based on the time domain resource allocation configuration indicated by the time domain resource allocation field, when the RRC parameter pdsch-TimeDomainAllocationList is received, I is given by a number of entries in the RRC parameter pdsch-TimeDomainAllocationList and the time domain resource allocation configuration indicated by the time domain resource allocation field corresponds to one of the entries in the RRC parameter pdsch-TimeDomainAllocationList, when the RRC parameter pdsch-TimeDomainAllocationList is not received, I is given by a fixed number of entries in a default table and the time domain resource allocation configuration indicated by the time domain resource allocation field corresponds to one of the entries in the default table, the entries in the RRC parameter pdsch-TimeDomainAllocationList indicate time domain resource allocation information for the PDSCH, and the default table is predefined and indicates default time domain resource allocation information for the PDSCH. a receiver configured to receive, from the base station apparatus, a physical downlink control channel, PDCCH, including downlink control information, DCI, in a search space specific to the terminal apparatus (1A, 1B); a controller configured to determine, based on whether a Radio Resource Control, RRC, parameter pdsch-TimeDomainAllocationList is received, a number of bits of a time domain resource allocation field in the DCI as ceiling(log2), in which the time domain resource allocation field indicates a time domain resource allocation configuration for a physical downlink shared channel, PDSCH, scheduled by the DCI; wherein the receiver is configured to receive, from the base station apparatus, the PDSCH based on the time domain resource allocation configuration indicated by the time domain resource allocation field, when the RRC parameter pdsch-TimeDomainAllocationList is received, I is given by a number of entries in the RRC parameter pdsch-TimeDomainAllocationList and the time domain resource allocation configuration indicated by the time domain resource allocation field corresponds to one of the entries in the RRC parameter pdsch-TimeDomainAllocationList, when the RRC parameter pdsch-TimeDomainAllocationList is not received, I is given by a fixed number of entries in a default table and the time domain resource allocation configuration indicated by the time domain resource allocation field corresponds to one of the entries in the default table, the entries in the RRC parameter pdsch-TimeDomainAllocationList indicate time domain resource allocation information for the PDSCH, and the default table is predefined and indicates default time domain resource allocation information for the PDSCH.