When Does Periodicity in Discrete-Time Imply that in Continuous-Time?
Palghat P. Vaidyanathan, Srikanth Venkata Tenneti · 2018
If the sampled version x(n)=xc(nT) of a continuous-time signal xc(t) is periodic, it does not necessarily imply that xc(t) is periodic. This paper presents some conditions under which periodicity of xc(t) is indeed implied. The conditions for this implication are more relaxed than bandlimitedness. The results place in evidence a multriate method to estimate the period of xc(t) from the samples x(n). The method works better than DFT based methods when the available data segment is short and multiple hidden periods are to be estimated.