Abstract: There is disclosed mechanisms for calibrating a homodyne receiver in a signal distribution network for time division duplex; a corresponding method is performed by a baseband calibration module. The method comprises acquiring a transmission signal being input to a homodyne transmitter of the signal distribution network; acquiring, from a heterodyne transmitter observation receiver of the signal distribution network, a first received version of the transmission signal; acquiring, from a homodyne receiver of the signal distribution network, a second received version of the transmission signal; and, calibrating the homodyne receiver using a comparison of the first received version of the transmission signal and the second received version of the transmission signal, using the first received version of the transmission signal as a reference signal, and using the transmission signal as a calibration signal.

Abstract: There is disclosed mechanisms for calibrating a homodyne receiver in a signal distribution network for time division duplex; a corresponding method is performed by a baseband calibration module. The method comprises acquiring a transmission signal being input to a homodyne transmitter of the signal distribution network; acquiring, from a heterodyne transmitter observation receiver of the signal distribution network, a first received version of the transmission signal; acquiring, from a homodyne receiver of the signal distribution network, a second received version of the transmission signal; and, calibrating the homodyne receiver using a comparison of the first received version of the transmission signal and the second received version of the transmission signal, using the first received version of the transmission signal as a reference signal, and using the transmission signal as a calibration signal.

Abstract: The present invention relates to an analog predistorter (100) having a tunable amplitude (60) and/or phase (80) expansion. The predistorter (100) includes a coupler (110) having an input port (112), an output port (114), a first (116) and a second (118) coupled port separated by 90 degrees. A first compensation circuit (120A) is connected to the first coupled port (116) and comprises a first combination (130A) of linear (132A) and nonlinear (131A) circuit elements and a first impedance adjusting unit (140A) for adjusting the impedance seen by the nonlinear circuit element (131A). A second compensation circuit (120B) is connected to the second coupled port (118) and comprises a second combination (130B) of linear (132B) and nonlinear (131B) circuit elements a second impedance adjusting unit (140B) for adjusting the impedance seen by said nonlinear circuit element (131B).

Abstract: The present invention relates to an analog predistorter (100) having a tunable amplitude (60) and/or phase (80) expansion. The predistorter (100) includes a coupler (110) having an input port (112), an output port (114), a first (116) and a second (118) coupled port separated by 90 degrees. A first compensation circuit (120A) is connected to the first coupled port (116) and comprises a first combination (130A) of linear (132A) and nonlinear (131A) circuit elements and a first impedance adjusting unit (140A) for adjusting the impedance seen by the nonlinear circuit element (131A). A second compensation circuit (120B) is connected to the second coupled port (118) and comprises a second combination (130B) of linear (132B) and nonlinear (131B) circuit elements a second impedance adjusting unit (140B) for adjusting the impedance seen by said nonlinear circuit element (131B).