Survey of RF Communications and Sensing Convergence Research <s> B. RECONFIGURABLE SYSTEMS <s> The paper describes a modelling scenario aimed at exploring high-resolution imaging, communication and in-band coexistence with other signals potential of a multi-carrier radar/communication system based on ultra-wideband waveforms obtained via orthogonal frequency division multiplexing (OFDM). Imaging performance is simulated for a well-studied scenario of stripmap SAR, for which backprojection algorithm is used in image reconstruction. The case of two airborne platforms is considered and image data communication between the platforms is modelled. This feasibility study lays foundation for subsequent analysis of a multi-platform sensor network scenario based on novel ultra-wideband radar architectures. <s> BIB001 </s> Survey of RF Communications and Sensing Convergence Research <s> B. RECONFIGURABLE SYSTEMS <s> This paper describes the design and architectural composition of a radar system built on OFDM platform. The radar signal is generated digitally by forming an arbitrary-length vector of OFDM sub-carrier amplitudes and translating it in analog format via 1000 Ms/s D/A conversion. The resultant baseband signal has a bandwidth of 500 MHz, and variable number and composition of sub-carriers, which may be changed on a pulse-to-pulse basis. The signal is upconverted to 7.5 GHz carrier frequency and emitted via small-form horn antenna. The receiver includes 1 Gs/s A/D converter and processing is performed in frequency domain. The system is currently configured for short-range applications (3–5 m) and can be used as radar or communication unit without any changes to hardware and with very minimal changes to software. Experimental results from high-resolution range profile imaging and broadband data communications are presented and discussed. <s> BIB002 </s> Survey of RF Communications and Sensing Convergence Research <s> B. RECONFIGURABLE SYSTEMS <s> A multimodal radar varies its bandwidth (and hence resolution) based on the arrangement of target scattering features, possibly leaving unused bandwidth for other applications. In this paper, we explore bandwidth sharing scenarios between radar and communications. We divide the surveillance space into sectors and use fuzzy logic to arrive at priorities for each sector. Multi-objective optimization is used to arrive at solutions making the best use of available bandwidth between radar and communications. We also consider the problem of scheduling between tracking and surveillance for the multimodal radar. Smart scheduling is necessary to make the best use of available radar resources. We look at algorithms for special target scenarios. Tracking is performed using the particle filter algorithm. <s> BIB003
As a step toward joint systems, many researchers have focused on developing algorithms, waveforms, and other components to modern radio systems that can be reconfigured for either communications or radar at any given time. For example, OFDM platforms that can execute broadband communications or radar imaging depending on configuration BIB002 , BIB001 . Others have used fuzzy logic to dynamically allocate bandwidth at the system level to either radar or communications depending on target dynamics BIB003 .