Wideband OFDM system for radar and communications

Abstract

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.