OFDM-MIMO WLAN AP front-end gain and phase mismatch calibration

The work presents a front-end gain and phase mismatch calibration scheme for OFDM-MIMO/TDD WLAN systems using transmit-processing, where complete channel reciprocity and calibration of the access point (AP) hardware is needed. Simulation results for a single-user 2/spl times/2 OFDM-MIMO system with QAM-64 modulation show that our calibration method can reduce the implementation loss to as little as 0.2 dB at a coded BER of 10/sup -5/ The calibration scheme has been implemented and demonstrated by IMEC.