There is provided a signal processor with a plurality of antennas connected for transmitting and receiving wireless signals, including a plurality of analog reception processing units, AD converters, DA converters, and analog transmission processing units, wherein each of the analog reception processing units converts the wireless signal received through the antenna into an analog baseband signal and outputs the signal to the AD converter, each of the DA converters converts the digital baseband signal into analog format and outputs the signal, and each of the analog transmission processing units shifts the frequency band of the analog baseband signal output from the DA converter to the high frequency side. The signal processor further includes a transmission switch which switches among the DA converters respectively connected to the analog transmission processing units and a reception switch which switches among the AD converters respectively connected to the analog reception processing units.