High performance homodyne six port receiver using memory polynomial calibration

This paper proposes an optimized memory polynomial (MP) based calibration technique for a homodyne six-port receiver. The performance and complexity of the proposed calibration technique allows for an easy implementation and high linearity performance of the homodyne receiver. For validation purpose, a six-port receiver was implemented and tested using a 3G (WCDMA) signal in the case of a multipath fading channel. The MP calibration technique was implemented and tested. By sending a training I/Q data into the receiver, the calibration constants were estimated from the diode output voltages using the least square algorithm. Subsequent analysis using a 3D plot of the error vector magnitude (EVM), non-linearity order (N) and memory depth (M) of the MP was done to optimize the complexity in terms of the number of calibration constants to ensure a good receiver performance. A bit error rate profile of the communication system was finally plotted to show the viability of the SPR front-end in a high data rate communication system even in the presence of a multipath fading channel.