Information Diversity in Coherent MIMO Radars

Abstract

In this paper, the concept of information diversity in both the space and frequency domains is investigated for multiple-input multiple-output (MIMO) radars with widely separated antennas. Compared to phased-antenna arrays and multistatic radars, they can exploit more degrees of freedom, allowing them to maximize the information content upon centralized data fusion, thus granting unprecedented target detection and localization capabilities.This analysis proceeds in parallel with the running progresses of microwave photonics (MWP), which could represent, in the near future, a new paradigm for the development of centralized MIMO radar architectures.Thus, understanding the implications of information diversity becomes essential to foretell the system effectiveness in detecting and resolving closely spaced targets, as well as in suppressing sidelobes which may lead to false alarms. Performance metrics are proposed and evaluated to characterize the effects that information diversity has on centralized MIMO radars with widely separated antennas. On the other hand, the proposed methodology could reveal precious for designing the optimum system configuration.

On the design of an optimal coherent multistatic radar network configuration

“…For a small number of sensors, this linear estimation approach is known to give rise to significant spatial ambiguities due to the sparse spatial sampling (see e.g. [5, 42, 43]). More generally, estimating can be regarded as a 3‐D spectral estimation problem, a topic of intense current interest within the signal processing community, in particular using modern sparse approximation/compressive sensing techniques (e.g.…”

“…There has been increasing interest in recent years in the topic of operating networks of radars multistatically by more closely coordinating their control and integrating their data at a lower level than traditionally carried out so as to achieve greater utility in the resulting information [1][2][3]. Potentially significant benefits that are commonly quoted are those arising from spatial diversity and higher spatial resolution due to the large aperture induced by the physical separation of transmitters and receivers [4][5][6]. This separation can exploit spatially-diverse targets and clutter radar cross-sections (RCS), which provide the possibility of enhanced detection of low-observable targets and improved target-clutter discrimination.…”

“…[39][40][41], with analyses of their performance. However, linear processing techniques have the drawback of creating spatial ambiguities in the form of phantom targets when more than one target is present, creating false alarms, as revealed by the Ambiguity Function analysis [5,42,43]. It was demonstrated that coherent spatial integration techniques are superior to noncoherent techniques in being able to reduce the amplitude of such phantom targets, although not entirely eliminating them.…”

“…With the development of the Statistical, or Distributed, Multi-Input Multi-Output (MIMO) Radar System [9][10][11] and Netted Radar System [12,13] concepts, partially coherent processing techniques were proposed, eventually leading to the investigation of fully-coherent techniques requiring that stringent synchronisation requirements be met. The concept of a Distributed Coherent Aperture [14][15][16][17][18] was proposed as a way of achieving coherence spatially through appropriate waveform transmission timings, and recently there has been considerable interest in the use of Microwave Photonics as a means of attaining spatial coherence using a hardware-based approach [5,[19][20][21][22][23][24][25].…”