1. A method for pairwise distance computation, comprising: transforming a first signal into a first mapped signal using an absolute distance preserving mapping; and transforming a second signal into a second mapped signal using the absolute distance preserving mapping, such that a k-norm distance between the first mapped signal and the second mapped signal represents an absolute distance between the first signal and the second signal, wherein elements of the first signal and the second signal are selected from a finite alphabet, wherein the absolute distance preserving mapping maps an element of a first or a second signal to a vector having a size equals to a cardinality of the finite alphabet, wherein steps of the method are performed by a processor, and wherein the absolute distance preserving mapping comprises: determining a position N of the element in an ordered sequence of symbols of the finite alphabet; determining values for each of N elements of the vector as a fractional power 1/k of positive increments in the finite alphabet, wherein k is a positive number, and determining values for subsequent elements of the vector as zero.