Threshold Analysis of Loop-Delay Estimation Using Correlation Functions for Double-Carrier Signals in Digital Predistortion Subsystem

• Published in: IEEE communications letters Vol. 19; no. 3; pp. 479 - 482
• Main Authors: Zhu, Shitao, Zhang, Anxue, Xu, Zhuo, Dong, Xiaoli
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-03-2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Bandwidth; Correlation; Data models; Delays; Digital predistortion subsystem; Equivalent bandwidth; Estimation; Loop delay estimation; Predistortion; Threshold analysis; equivalent bandwidth; loop delay estimation; Digital predistortion subsystem; threshold analysis
• ISSN: 1089-7798; 1558-2558
• DOI: 10.1109/LCOMM.2014.2386880

For wideband configuration double carrier (WCDC) signals, a novel phenomenon is analyzed in this paper, i.e., when the data rate is lower than a threshold, the integer loop-delay estimation (ILDE) accuracy sharply declines when traditional time-delay estimation methods are used in a digital predistortion subsystem. Assisted by the equivalent bandwidth of a single-carrier signal, a proposed cross-correlation model for WCDC signals is built to analyze the low data-rate threshold in the ILDE. The relationship between a low data-rate threshold, carrier spacing, carrier bandwidths, and the power difference is analyzed. The proposed method is qualified to estimate the low data-rate threshold for the ILDE methods, including the state of the art. Experiments and simulations are presented to validate the proposed method using three typical communication signals.