Leclère, Botteron, and Farine Figure 24. Timing diagram of the implementation of the pre-FFT secondary code removal in a sequential way using the new technique for the combinations (Figure 11) with NS = 4. R denotes the ratio between the number of nonzero values in s′ and NS (R = 0.5 here). The processing time to compute K times the full 2 correlation is K × [2NPNS + (2NPNSR)NS] + NZ + L + NFFT + L + NP = NP[2K( N S R + NS) + 3] + 2NZ + 2L. AUGUST 2017 IEEE A&E SYSTEMS MAGAZINE 63