A terminal is disclosed including a receiver that receives downlink control information including a field that indicates a frequency domain resource assigned to a downlink shared channel; and a processor that, when the terminal is in a connected state and information regarding an initial downlink bandwidth part (BWP) for a cell is provided via a higher layer, determines a bandwidth to use in a determination of a number of bits in the field based on a specified information included in the information regarding the initial downlink bandwidth part (BWP). In other aspects, a radio communication method, a base station, and a system are also disclosed.