Windowed Overlapped frequency-domain Block Filtering Approach for Direct Sequence Signal Acquisition

TL;DR

This paper introduces a windowed frequency-domain overlapped block filtering method for direct sequence signal acquisition, enhancing spectrum sensing and synchronization across various signal types with improved performance and flexibility.

Contribution

It proposes a universal, windowed frequency-domain receiver that enables pulse shaping, spectrum sensing, and synchronization for diverse signals, including multi-carrier and long-code signals, with robustness to Doppler shifts.

Findings

Improved spectrum sensing performance in cognitive radios.

Effective initial synchronization for various signal types.

Robustness to Doppler shifts demonstrated.

Abstract

This paper applies a windowed frequency-domain overlapped block filtering approach for the acquisition of direct sequence signals. The windows, as a novel viewpoint, not only allow pulse shaping without a front end pulse shaping filter, but also improve the performance of the spectrum sensing unit which can efficiently be implemented into this frequency-domain receiver and may further be used for spectrum sensing in cognitive radios or narrowband interference cancellation in military radios. The proposed receiver is applicable for initial time synchronization of different signals containing a preamble. These signals include single carrier, constant-envelope single-carrier, multi-carrier and even generalized-multi-carrier signals, which makes the proposed receiver structure a universal unit. Furthermore, the receiver can be used to perform filtering with long codes and compute the sliding correlation of an unknown periodic preamble. It can further be modified to handle large Doppler shifts. We will also demonstrate the computational complexity and analysis of the acquisition performance in Rayleigh and Rician fading channels.