The invention claimed is:1. An operating method of a base station, the operating method comprising:transmitting first control resource set configuration information including first demodulation reference signal (DMRS) configuration information for a first control resource set;transmitting second control resource set configuration information including second DMRS configuration information for a second control resource set;identifying a third control resource set in which the first control resource set and the second control resource set overlap each other; andtransmitting a DMRS based on the first DMRS configuration information in the first control resource set including the third control resource set,wherein the first DMRS configuration information corresponds to a configuration of transmission of a wideband DMRS for the first control resource set, andwherein the second DMRS configuration information corresponds to a configuration in which, in the second control resource set, a narrowband DMRS is transmitted only on a region for transmission of control information.2. The operating method of claim 1, wherein a DMRS, which is based on the second DMRS configuration information, is not allocated to the second control resource set including the third control resource set.3. The operating method of claim 1, further comprising:transmitting control information, to which a precoding identical to a precoding applied to a DMRS depending on the first DMRS configuration information is applied, in the first control resource set including the third control resource set; andtransmitting control information, to which a precoding identical to a precoding applied to a DMRS depending on the second DMRS configuration information is applied, in the second control resource set except for the third control resource set.4. An operating method of a terminal, the operating method comprising:receiving, from a base station, first control resource set configuration information including first demodulation reference signal (DMRS) configuration information for a first control resource set;receiving, from the base station, second control resource set configuration information including second DMRS configuration information for a second control resource set;identifying a third control resource set, in which the first control resource set and the second control resource set overlap each other, based on the first control resource set configuration information and the second control resource set configuration information; andreceiving a DMRS based on the first DMRS configuration information in the first control resource set including the third control resource set,wherein the first DMRS configuration information corresponds to a configuration of transmission of a wideband DMRS for the first control resource set, andwherein the second DMRS configuration information corresponds to a configuration in which, in the second control resource set, a narrowband DMRS is transmitted only on a region for transmission of control information.5. The operating method of claim 4, further comprising, in case that the second control resource set is decoded, assuming that a DMRS, which is based on the second DMRS configuration information, is not allocated to the second control resource set including the third control resource set.6. The operating method of claim 4, further comprising:performing blind-decoding based on a DMRS depending on the first DMRS configuration information in the first control resource set including the third control resource set; andperforming blind-decoding based on a DMRS depending on the second DMRS configuration information in the second control resource set except for the third control resource set.7. A base station comprising:a transceiver configured to transmit and receive signals; anda controller configured to control to:transmit first control resource set configuration information including first demodulation reference signal (DMRS) configuration information for a first control resource set,transmit second control resource set configuration information including second DMRS configuration information for a second control resource set,identify a third control resource set in which the first control resource set and the second control resource set overlap each other, andtransmit a DMRS based on the first DMRS configuration information in the first control resource set including the third control resource set,wherein the first DMRS configuration information corresponds to a configuration of transmission of a wideband DMRS for the first control resource set, andwherein the second DMRS configuration information corresponds to a configuration in which, in the second control resource set, a narrowband DMRS is transmitted only on a region for transmission of control information.8. The base station of claim 7, wherein a DMRS, which is based on the second DMRS configuration information, is not allocated to the second control resource set including the third control resource set.9. The base station of claim 7, wherein the controller is further configured to control to:transmit control information, to which a precoding identical to a precoding applied to a DMRS depending on the first DMRS configuration information is applied, in the first control resource set including the third control resource set; andtransmit control information, to which a precoding identical to a precoding applied to a DMRS depending on the second DMRS configuration information is applied, in the second control resource set except for the third control resource set.10. A terminal comprising:a transceiver configured to transmit and receive signals; anda controller configured to control to:receive, from a base station, first control resource set configuration information including first demodulation reference signal (DMRS) configuration information for a first control resource set,receive, from the base station, second control resource set configuration information including second DMRS configuration information for a second control resource set,identify a third control resource set, in which the first control resource set and the second control resource set overlap each other, based on the first control resource set configuration information and the second control resource set configuration information, andreceive a DMRS based on the first DMRS configuration information in the first control resource set including the third control resource set,wherein the first DMRS configuration information corresponds to a configuration of transmission of a wideband DMRS for the first control resource set, andwherein the second DMRS configuration information corresponds to a configuration in which, in the second control resource set, a narrowband DMRS is transmitted only on a region for transmission of control information.11. The terminal of claim 10, wherein the controller is further configured to control to:perform blind-decoding based on a DMRS depending on the first DMRS configuration information in the first control resource set including the third control resource set, andperform blind-decoding based on a DMRS depending on the second DMRS configuration information in the second control resource set except for the third control resource set.12. The terminal of claim 10, wherein the controller is further configured to control to, in case that the second control resource set is decoded, assuming that a DMRS, which is based on the second DMRS configuration information, is not allocated to the second control resource set including the third control resource set.