A simultaneous TX and RX I/Q imbalance calibration method

Digital I/Q compensation allows the transceivers to achieve high performance with relatively low-cost analog front-end. This paper presents a method that digitally calibrates both TX and RX I/Q imbalances. Unlike those methods that calibrate the TX and RX separately, with TX (or RX) alone being calibrated first using additional analog circuits, the proposed method simultaneously estimates the TX and RX I/Q imbalance parameters, assisted by a low-cost phase-shifter. Estimation of the TX and RX I/Q parameters is achieved by sending test signals and measuring the received signals entirely in baseband, in the digital domain. No RF/analog test signal or measurements are needed.