Provided are methods of operating a wireless communication system. The methods include determining first resource mapping patterns of a first physical channel used to generate virtual pilot signals so as to perform downlink channel estimation, based on state information of user equipment (UE) in every first period. The first physical channel is mapped onto resource elements adjacent to resource elements onto which pilot signals are mapped, in a time-frequency resource area (TFRA) of a downlink signal based on the determined first resource mapping patterns. A downlink signal of which resource mapping is completed is then transmitted to the UE.