A transceiver for a communication node adapted to transmit a first signal to an other communication node and to receive a second signal from the other communication node, the transceiver comprising: at least one antenna (110, 110a, 210, 211, 310, 311, 410, 411) adapted to simultaneously transmit the first signal and receive the second signal, wherein the first and second signals have equal carrier frequencies and different polarizations, wherein the second signal is for determining a channel characterization of a communication channel over which the second signal is received, and wherein the channel characterization is for determination of transmission parameters for the first signal; at least one transmitter module (120, 220, 221, 320, 321, 325, 326, 420, 421) adapted to process the first signal before transmission by the at least one antenna; at least one receiver module (130, 230, 231, 330, 331, 335, 336, 430, 431) adapted to process the second signal after reception by the at least one antenna; and a mode alternator (160, 260, 261, 360, 361, 460, 461) adapted to alternate a mode of operation of the transceiver between at least a first and a second mode of operation, wherein: - the first mode of operation comprises the transceiver transmitting the first signal using a first polarization and receiving the second signal using a second polarization; and - the second mode of operation comprises the transceiver transmitting the first signal using a third polarization and receiving the second signal using a fourth polarization; the transceiver characterized in that the at least one receiver module is adapted to detect interruption in the received second signal and interpret the interruption as initiation of alternation of the mode of operation (640, 661); and the mode alternator is adapted to alternate the mode of operation responsive to detection of the interruption (630, 640, 662). at least one antenna (110, 110a, 210, 211, 310, 311, 410, 411) adapted to simultaneously transmit the first signal and receive the second signal, wherein the first and second signals have equal carrier frequencies and different polarizations, wherein the second signal is for determining a channel characterization of a communication channel over which the second signal is received, and wherein the channel characterization is for determination of transmission parameters for the first signal; at least one transmitter module (120, 220, 221, 320, 321, 325, 326, 420, 421) adapted to process the first signal before transmission by the at least one antenna; at least one receiver module (130, 230, 231, 330, 331, 335, 336, 430, 431) adapted to process the second signal after reception by the at least one antenna; and a mode alternator (160, 260, 261, 360, 361, 460, 461) adapted to alternate a mode of operation of the transceiver between at least a first and a second mode of operation, wherein: - the first mode of operation comprises the transceiver transmitting the first signal using a first polarization and receiving the second signal using a second polarization; and - the second mode of operation comprises the transceiver transmitting the first signal using a third polarization and receiving the second signal using a fourth polarization; - the first mode of operation comprises the transceiver transmitting the first signal using a first polarization and receiving the second signal using a second polarization; and - the second mode of operation comprises the transceiver transmitting the first signal using a third polarization and receiving the second signal using a fourth polarization; the transceiver characterized in that the at least one receiver module is adapted to detect interruption in the received second signal and interpret the interruption as initiation of alternation of the mode of operation (640, 661); and the mode alternator is adapted to alternate the mode of operation responsive to detection of the interruption (630, 640, 662).