Efficient Cross-Correlation Algorithm and Architecture for Robust Synchronization in Frame-Based Communication Systems

Abstract

Wireless communication in high-mobility environments is usually frame-based burst communication. Preamble sequences are generally used for time and frequency synchronization. Recently, Zadoff–Chu sequences have gained popularity for this purpose. In this paper, we propose an efficient cross-correlation-based algorithm and its implementation architecture for robust synchronization in systems with multiple preambles. The proposed method is well suited for systems experiencing carrier frequency offsets and operating in high-mobility environments. Synchronization is achieved by cross-correlation of local preamble replica with the segmented and decimated samples of the received preamble. The proposed architecture has been synthesized and implemented on Xilinx FPGA platform for validation and performance evaluation. The system-level simulation under additive white Gaussian noise, in Long-Term Evolution channels with frequency offsets and Doppler shifts, has also been carried out to find the efficacy of the proposed approach. The inherent parallelism of the proposed scheme results in a fast and energy-efficient implementation. One such implementation of the correlator structure in Xilinx FPGA is presented and is shown to have $\approx 28\%$ reduction in power consumption, capable of clocking $\approx 1.5{\times }$ higher clock speed with $\approx 73\%$ reduction in the usage of FPGA hardware resources such as DSP blocks and logic resulting in an overall reduction in energy consumption by $\approx 57\%$, when compared to full-parallel cross-correlator-based synchronization.