Antenna Array Calibration Using Frequency Selection in OFDMA/TDD Systems

This paper proposes a new antenna array calibration using frequency selection in OFDMA/TDD systems. In the proposed method, subbands or frequencies of good channel conditions are initially selected for accurate channel measurement. Next, the relative calibration is performed at the selected subbands, in which mismatch of analog gains in multiple antennas is compensated by use of measured channel parameters on uplink and downlink. Third, the calibration parameters are interpolated in frequency domain for whole bandwidth. The proposed method keeps more accurate channel reciprocity for whole bandwidth than the conventional method which does not use the frequency selection. The proposed method is effective in exploiting channel reciprocity at both base station and terminals keeping feasible feedback amount and low-cost operation.