Joint Estimation of Transmitter IQ Imbalance and Nonlinearity with Multipath in OFDM Systems

Radio frequency (RF) fingerprint has been an emerging research topic since the last decade. Numerous algorithms for recognition have been proposed. However, algorithms for accurate extraction of in-phase/quadrature phase imbalance (IQI) and power amplifier (PA) nonlinearity are hardly available especially when multipath is considered. This paper presents a joint estimation of transmitter IQI and PA nonlinearity with multipath in OFDM systems. Using sequential iterative estimation algorithm, transmitter IQI, PA nonlinearity and multipath are jointly and separately estimated efficiently. After obtaining these parameters, a compensation approach for IQI, PA nonlinearity and multipath is given via equalization operation at receiver. Simulation results show that the proposed algorithm has a significant estimation accuracy advantage compared to the other two algorithms that already exist.