1. A method of analyzing an electrocardiogram (ECG) signal, the method comprising: receiving the ECG signal; segmenting the received ECG signal into a set of cycle segments; aligning the set of cycle segments along a relative time axis to obtain aligned cycle segments; generating a set of cross-sectional signals from the aligned cycle segments, wherein each cross-sectional signal is a time-slice signal representing a cross-section of the aligned cycle segments along a relative time of the aligned cycle segments, said each cross-sectional signal corresponding to a different relative time; separating, using a signal separation process, the set of cross-sectional signals into a set of statistically substantially independent components; and detecting, using the set of components, an abnormal cardiac signal; wherein the steps of receiving, segmenting, aligning, generating, separating, and detecting are performed by a processor-based cardiac signal detection system.