Frame synchronization in frequency uncertainty

• Published in: IEEE transactions on communications Vol. 58; no. 4; pp. 1235 - 1246
• Main Authors: Pedone, R., Villanti, M., Vanelli-Coralli, A., Corazza, G.E., Mathiopoulos, P.T.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Approximation; Complexity; Costs; Couplings; Detectors; Exact sciences and technology; Frame synchronization; Frames; frequency error; Frequency synchronization; Information, signal and communications theory; Links; Mathematical models; Maximum likelihood detection; Multiplexing; post detection integration; Robustness; Signal and communications theory; Signal to noise ratio; Studies; Switching and signalling; Synchronism; Synchronization; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Time division multiple access; Time division multiplexing; Transmission and modulation (techniques and equipments); Uncertainty; Performance evaluation; Packet switching; Frame synchronization; Time division multiplexing; Robust estimation; Correction factor; Numerical method; Frame rate; Synchronization; Modeling; Time division multiple access; Maximum likelihood; Burst switching; frequency error; Signal to noise ratio; post detection integration
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2010.04.080350

This paper addresses the problem of robust frame synchronization for TDM/TDMA systems in the presence of frequency errors, accomplished through data-aided recognition of the Unique Word (UW) preamble in the transmission flow. Robust detection design is performed applying, through approximations, the Maximum Likelihood (ML) criterion coupled to Post Detection Integration (PDI), to obtain a novel detector identified as Balanced-GPDI (B-GPDI). This new approach considerably outperforms other schemes available in the literature, at the cost of a moderate complexity increase. This is possible thanks to an optimized use of coherent accumulation, which enhances the correlation term in the decision variable, along with highly accurate modeling of the energy correction factor. To limit complexity increase and memory requirements, several approximations of the exact B-GPDI are proposed and discussed in the paper, to provide the designer with practical solutions that are still able to outperform other approaches in specific application scenarios. In particular, approximations for low and high Signal-to-Noise Ratio (SNR) are presented. Different application scenarios are considered in the paper for numerical analysis. In particular, the cases of forward link Continuous Transmission (CTX) and return link Burst Transmission (BTX) are addressed.