To provide a wireless entrance system wherein a receiver side wireless communication apparatus absorbs an offset of a transmission signal caused when an active system transmitter side wireless communication apparatus is switched into a standby system transmitter side wireless communication apparatus.

When detecting a switching prediction signal from a first wireless frame before the switching, a switching prediction signal detection means 184 holds an AGC circuit 170 and a carrier recovery circuit 174 and informs an estimate signal reception circuit 178 about a timing when the circuit 178 acquires an estimate signal. The estimate signal reception circuit 178 acquires the estimate signal from a second wireless frame after the switching on the basis of the timing to provide an output of the estimate signal to a phase difference estimate circuit 180 and a gain difference estimate circuit 182. The phase difference estimate circuit 180 estimates a phase offset of the wireless frames before and after the switching, and the gain difference estimate circuit 182 estimates a gain offset of the wireless frames before and after the switching.

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