Survey on coherent multiband splicing techniques for wideband channel characterization

Abstract

Coherent multi-band splicing is an optimal solution for extending existing band-limited communication systems to support high-precision sensing applications. Conceptually, the communication system performs narrow-band measurements at different centre frequencies, which are then concatenated to increase the effective bandwidth without altering the sampling rate. This can be done in parallel for multiple non-contiguous subbands or by hopping across the different bands. However, multi-band splicing poses significant challenges, particularly in compensating for phase offsets and hardware distortions before stitching the acquired samples, which can be distributed in contiguous or non-contiguous manners. This survey paper studies the state of the art in coherent multi-band splicing and identify open research questions. For beginners in the field, this review serves as a guide to the most relevant literature, enabling them to quickly catch up with the current achievements. For experts, open research questions that require further investigation are highlighted.