A user equipment, UE, configured to operate in a wireless communication system, the UE comprising: a receiver; and a processor configured to control the receiver, characterized in that, the processor is further configured to: receive, via higher layer signaling, bundle size information regarding a bundle size value of resource element groups, REGs over which same precoding is applied, each REG occupying 1 resource block, RB, in a frequency domain during 1 orthogonal frequency divisional multiplexing, OFDM, symbol in a time domain; and receive, based on REG bundling according to the bundle size value, downlink control information, DCI, through a physical downlink control channel, PDCCH, comprising at least one control channel element, CCE, in a control resource set, CORESET, the CORESET is configured with a plurality of REGs in a CORESET duration that spans a plurality of OFDM symbols in the time domain, the CORESET comprises a plurality of REG bundles, each REG bundle comprising a same number of REGs as the bundle size value, the plurality of REGs in the CORESET is mapped to CCEs each comprising at least one REG bundle, the bundle size information informs the UE of the bundle size value as a first number or a second number, where the first number is equal to a number of the plurality of the OFDM symbols in the CORESET duration, and the second number is different from the first number, in a case of the first number of the bundle size value, only the first number of REGs that occupy a same RB in the frequency domain and the first number of the OFDM symbols in the time domain, in the CORESET, are bundled as 1 REG bundle, and in a case of the second number of the bundle size value, REGs that occupy other RB in the CORESET are bundled as 1 REG bundle along with the first number of REGs that occupy the same RB in the frequency domain and the first number of the OFDM symbols in the time domain. a receiver; and a processor configured to control the receiver, characterized in that, the processor is further configured to: receive, via higher layer signaling, bundle size information regarding a bundle size value of resource element groups, REGs over which same precoding is applied, each REG occupying 1 resource block, RB, in a frequency domain during 1 orthogonal frequency divisional multiplexing, OFDM, symbol in a time domain; and receive, based on REG bundling according to the bundle size value, downlink control information, DCI, through a physical downlink control channel, PDCCH, comprising at least one control channel element, CCE, in a control resource set, CORESET, receive, via higher layer signaling, bundle size information regarding a bundle size value of resource element groups, REGs over which same precoding is applied, each REG occupying 1 resource block, RB, in a frequency domain during 1 orthogonal frequency divisional multiplexing, OFDM, symbol in a time domain; and receive, based on REG bundling according to the bundle size value, downlink control information, DCI, through a physical downlink control channel, PDCCH, comprising at least one control channel element, CCE, in a control resource set, CORESET, the CORESET is configured with a plurality of REGs in a CORESET duration that spans a plurality of OFDM symbols in the time domain, the CORESET comprises a plurality of REG bundles, each REG bundle comprising a same number of REGs as the bundle size value, the plurality of REGs in the CORESET is mapped to CCEs each comprising at least one REG bundle, the bundle size information informs the UE of the bundle size value as a first number or a second number, where the first number is equal to a number of the plurality of the OFDM symbols in the CORESET duration, and the second number is different from the first number, in a case of the first number of the bundle size value, only the first number of REGs that occupy a same RB in the frequency domain and the first number of the OFDM symbols in the time domain, in the CORESET, are bundled as 1 REG bundle, and in a case of the second number of the bundle size value, REGs that occupy other RB in the CORESET are bundled as 1 REG bundle along with the first number of REGs that occupy the same RB in the frequency domain and the first number of the OFDM symbols in the time domain.