Fig. 3
From: BlueFMCW: random frequency hopping radar for mitigation of interference and spoofing
Frequency hopping by permutation and its beat signal. a shows an example of the transmitted BlueFMCW signal (\(N=4\)). The sub-chirps are permuted by \(\sigma\). b shows the beat signals in the time-domain. \(x_{align}\) is achieved by inverse-permuting \(x_{naive}\). c shows the conventional FMCW and its beat signal. d shows an example of frequency hopping in BlueFMCW and the phase discontinuity in its beat signal