Spectrum Estimation for Very High Frequency RF Systems

Emerging applications in the radar and communication fields (e.g. 5G cellular communications, automotive radar, etc.) need to use very high frequencies (in particular millimetre waves) and wide bandwidth, in order to achieve high efficiency at relatively short distance at affordable costs. When performing spectrum estimation for different purposes, these systems have to cope with very high frequency signals, whose samples need to be collected at sub-Nyquist rate, as the direct sampling at Nyquist rate would not be advisable. This paper explores the applicability of a new technique, namely the Hybrid Folding Receiver (HFR) and evaluates its performance in spectrum estimation for very high frequency signals. The results obtained by examining typical case studies demonstrate that the implementation of the HFR technique gives good performances in the above mentioned application areas.