A novel and low-cost analog front-end mismatch calibration scheme for MIMO-OFDM WLANs

This paper presents a novel and low-cost analog front-end gain and phase mismatch calibration scheme for MIMO-OFDM TDD WLAN systems with transmit-processing, where the complete channel reciprocity and calibration of the access point hardware is needed. It is shown by analytical derivations that the novel scheme has similar performance to that of the older scheme. The new scheme also has the advantage of lower implementation cost by removing the necessity of having a calibration transceiver. In addition, it is demonstrated that the new scheme can easily be extended towards an arbitrary number of multi-antenna transceivers.