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.