Extensive Comparison of Blind I/Q Imbalance Estimator Hardware Requirements

In wireless communications, in-phase (I) and quadrature-phase (Q) imbalance is a well-understood issue, and an extensive body of different I/Q imbalance estimation algorithms exists in literature. The focus in many of these algorithms, as well as in this work, lies on the I/Q imbalance on the receiver side. We consider frequency-independent (FID) estimators that operate as so-called blind algorithms, where little to no knowledge about the transmitted data is required. For this set of algorithms, however, barely any effort was made towards a comparison regarding their required resources when implementing them in hardware. In this work we compare a comprehensive list of such algorithms with regard to their logic utilization, required registers, and embedded multipliers when implementing them on a field-programmable gate-array (FPGA). To provide meaningful results, we optimize the individual estimators' fixed-point bit-widths to make them achieve a common performance target for a typical orthogonal frequency-division multiplexing (OFDM) signal scenario.