Mismatch Detection and Compensation Method for the LINC System Using a Closed-Form Expression

This paper proposes a simple and straightforward path mismatch detection method with a closed-form expression for linear amplification with nonlinear components (LINC) system implementation. In this work, a test vector signal set with three phase differences and one amplitude difference is employed to detect the amplitude and phase mismatches at the same time. The proposed method can predict the exact mismatch value without any iterations, because the mismatch value has a unique solution with a closed-form expression with the proposed test signal set. Moreover, the sensitivity of the proposed method to the measurement noise is also analyzed for practical implementation of LINC system. The LINC system is realized with the proposed mismatch detection method and the performance is evaluated with a IEEE 802.16 WiMAX signal, which has 7 MHz channel bandwidth and 16-QAM. The error vector magnitude (EVM) of -37.4 dB is obtained through performance testing, which meets the performance requirement of -24 dB EVM. The proposed mismatch detection method is validated to improve the LINC system performance.