The present application discloses a reconfigurable transmitter and receiver, and methods for reconfiguring the same. A system adaptive control circuit generates a control signal according to frequency band information of an input signal; a system clock circuit generates a system clock; a preprocessing circuit preprocesses a received baseband signal according to the system clock and the control signal, to generate a frequency band signal; a digital intermediate frequency processing circuit processes the frequency band signal according to the system clock and the control signal, to generate a digital intermediate frequency signal; a digital-to-analog conversion circuit processes the digital intermediate frequency signal according to the system clock and the control signal, to generate an analog signal; and an analog transmitting circuit transmits the analog signal.