Loopback Transceiver Self-Calibration Design for Wideband RF Impairments

The paper studies the transmitter/receiver (TX/RX) wideband (WB) RF impairment problems, i.e., frequency dependency, frequency independency I/Q imbalance, and DC I/Q offsets. The real-value based parallel structures are proposed to estimate and calibrate the TX/RX WB RF impairment factors. For the calibration procedures, we first deal with the RX impairments estimation and compensation via the frequency offset BPSK (FO-BPSK) training signal. Then, we calibrate the TX impairments via QPSK training signal. The proposed methods can realize the aim of the self-calibration of TX/RXRFIC. Furthermore, for the commercial off-the-shelf (COTS) AD9371 RF module with impairments after the proposed TX/RX calibration, the error vector measurement (EVM) performance of OFDM 64QAM test signal can be improved about 9. 42dB. Summary, the proposed techniques can overcome the WB RF impairments and achieve the high-quality WB communication performances.