Joint Radar and Communication: A Survey (2103.00496v1)

Abstract: Joint radar and communication (JRC) technology has become important for civil and military applications for decades. This paper introduces the concepts, characteristics and advantages of JRC technology, presenting the typical applications that have benefited from JRC technology currently and in the future. This paper explores the state-of-the-art of JRC in the levels of coexistence, cooperation, co-design and collaboration. Compared to previous surveys, this paper reviews the entire trends that drive the development of radar sensing and wireless communication using JRC. Specifically, we explore an open research issue on radar and communication operating with mutual benefits based on collaboration, which represents the fourth stage of JRC evolution. This paper provides useful perspectives for future researches of JRC technology.

• The paper establishes a comprehensive survey of JRC integration, categorizing systems as coexistence, cooperation, co-design, and collaboration.
• It details the evolution from separate radar and communication systems to fully integrated dual-function platforms that optimize spectrum use and reduce costs.
• The survey outlines future directions, emphasizing multi-dimensional signal processing, cooperative detection, and networked system challenges.

Joint Radar and Communication: A Comprehensive Survey Overview

The paper "Joint Radar and Communication: A Survey," authored by Zhiyong Feng et al., provides an extensive examination of the field of Joint Radar and Communication (JRC) technologies. JRC has been a focal point for advancing both civil and military radio frequency (RF) applications due to its potential to address spectrum scarcity and enhance system performance. This paper positions itself as an all-encompassing survey that delineates key concepts, characteristics, advantages, and categorization of JRC technologies while offering a forward-looking perspective on ongoing research challenges and possible technological advancements.

Foundational Concepts and Technological Evolution

JRC technology represents an overview of radar and communication systems designed to capitalize on common hardware platforms while performing dual functions without mutual interference. This approach fosters cost-effective system integration and spectrum efficiency. Historically, these systems were designed in isolation due to their different signal processing and operational requisites. The convergence of radar and communication technologies has been facilitated by advancements in digital signal processing, phased array systems, and MIMO technology, thus rendering JRC more practical and appealing.

Four-Fold Categorization of JRC Systems

The paper categorizes JRC developments into four distinct paradigms: coexistence, cooperation, co-design, and collaboration.

1. Coexistence: In this initial stage, radar and communication systems operate independently, treating each other as sources of interference. Strategies here focus on interference mitigation and resource sharing without shared information processing.
2. Cooperation: This mode involves a level of interaction between systems whereby components are coordinated to enhance performance collectively. Through techniques like beam sharing and waveform permutation, systems can jointly leverage capabilities to optimize their overall efficiency.
3. Co-Design: At this higher stage of integration, radar and communication systems are conceived together from inception. Techniques like waveform design, signal coding, and advanced modulation schemes are employed here. This stage represents a significant leap towards achieving dual-purpose systems that maximize spectrum utilization and minimize costs.
4. Collaboration: This advanced level heralds a networked approach where multiple JRC units coordinate to perform tasks that are beyond the capabilities of single units. Collaborative JRC leverages networked nodes to improve detection, data fusion, and communication reliability. Applications such as vehicle-to-vehicle networks and flying ad-hoc networks exemplify this collaborative potential.

Implications and Future Directions

Practical implications of JRC are vast, spanning military applications like naval combat systems and avionics, to commercial sectors including intelligent transport systems and drone surveillance networks. The paper highlights significant cost savings in equipment and maintenance, alongside improved signal security and system resilience in hostile environments.

The critical open research issues identified in this paper include communication-aided multi-radar cooperative detection, radar-assisted channel estimation and beam alignment, resource sharing optimizations, and multidimensional signal processing paradigms. Addressing these complex problems holds the potential to substantially elevate the capabilities and applicability of JRC systems.

Moreover, as 5G and beyond technologies mature, they present unparalleled opportunities for JRC systems to exploit expanded bandwidths and advanced network structures. This survey outlines the necessity of a robust theoretical framework to underpin future JRC research activities, suggesting that a multi-dimensional signal modeling approach will be instrumental in forging new paths in this domain.

Conclusion

In conclusion, the survey by Feng et al. offers valuable insights and a holistic view of the significant strides made in JRC technologies. It encapsulates the current state, categorization, applications, and unresolved research challenges, thereby serving as a crucial resource for practitioners and researchers in the domain. The research prognosticates a future where JRC plays a pivotal role in optimizing spectrum usage and system performance across multiple applications, both commercially and militarily.