A Fast Accurate Time Delay Estimation Method in the Digital Predistortion Subsystem

The traditional time delay methods cannot obtain the time delay efficiently in the digital predistortion subsystem (DPDS) when the wide bandwidth, multi-carrier signals with large frequency space is used in the communication system. A time delay estimation method, which can estimate the loop delay between the time delayed feedback signal and the input signal in DPDS with high accuracy and high efficiency, is proposed in this paper. The piecewise-parabolic filter and the bisection method are used to change the sampling start of the feedback signal and to choose the loop delay adjustment range, respectively. Compared with the conventional, the proposed loop delay estimation method can obtain the accurate loop delay using various configuration communication signals in DPDS. Results from experiments validate the proposed method.