In reference to FIG. 3, it is illustratively described that a resource grid is configured with NRBμNscRB subcarriers in a frequency domain and one subframe is configured with 14·2μ OFDM symbols, but it is not limited thereto. In an NR system, a transmitted signal is described by OFDM symbols of 2μNsymb(μ) and one or more resource grids configured with NRBμNscRB subcarriers. Here, NRBμ≤NRBmax,μ. The NRBmax,μ represents a maximum transmission bandwidth, which may be different between an uplink and a downlink as well as between numerologies. In this case, one resource grid may be configured per p and antenna port p. Each element of a resource grid for p and an antenna port p is referred to as a resource element and is uniquely identified by an index pair (k,l′). Here, k=0, . . . , NRBμNscRB?1 is an index in a frequency domain and l′=0, . . . , 2μNsymb(μ)?1 refers to a position of a symbol in a subframe. When referring to a resource element in a slot, an index pair (k,l) is used. Here, l=0, . . . , Nsymbμ?1. A resource element (k,l′) for p and an antenna port p corresponds to a complex value, ak,l′(p,μ). When there is no risk of confusion or when a specific antenna port or numerology is not specified, indexes p and μ may be dropped, whereupon a complex value may be ak,l′(p) or ak,l′. In addition, a resource block (RB) is defined as NscRB=12 consecutive subcarriers in a frequency domain.
Point A plays a role as a common reference point of a resource block grid and is obtained as follows.