*3.3. Computational Complexity of the Proposed Method*

The computational complexity is measured in terms of number of complex multiplications and additions. It is considered that removal of the CPI is negligible in complexity, divisions are equivalent to multiplications, and performing an IFFT/FFT of size *N* requires (*N*/2)log2(*N*) number of complex multiplications and *N*log2(*N*) number of complex additions [27]. Table 1 provides the complexity of the proposed method and the conventional OFDM-based sensing. The complexity of the proposed method is higher by a factor of

≈*QN*<sup>s</sup> because whole chain of operation, for range detection, is performed after each shift in *k* with maximum shifts as *QN*s. For speed, *N* number of *M*-point FFTs is increased to *QN*s.


**Table 1.** Computational complexity of the proposed method.
