a wireless communication system comprises radio base station apparatuses each of which transmits an estimation pilot in advance for estimating the quality of a downlink communication after a spatial signal processing performed after a time unified among the radio base station apparatuses ; and radio terminal apparatuses each of which receives the estimation pilot to determine the quality of the downlink communication , thereby reporting the determined downlink communication quality to the radio base station apparatus via an uplink channel . the estimation pilot is transmitted at the same time and frequency established among the radio base station apparatuses by use of the same directivity beam as used for transmitting the data after the unified time .