Patent ID: 7190730

Claim:
A method of sending an original information sequence, including: an encoding operation, of encoding the original information sequence by means of an error correction code, so as to obtain a sequence of encoded symbols; a frequency mapping operation, of associating with the sequence of encoded symbols K frequency symbols in a frequency space consisting of an ordered series of 2 p increasing frequencies, periodically spaced apart and associated with an amplitude, each of the K frequency symbols representing N encoded symbols, p, K and N being strictly positive integers; an inverse transformation operation, of applying to the K frequency symbols a reversible transformation including a multiplication by an invertible matrix of size N×N, so as to obtain inverse transform signals; and a transmission operation, of sending over a transmission channel signals obtained from the inverse transform signals in which there exists a K-tuplet of positive integers n 1 , n 2 , . . . , n K , at least one of which is strictly positive, such that, for an integer i varying from 1 to K, after periodic extraction of one frequency out of 2 ni amongst the frequencies of the i th of the K frequency symbols, thus forming a reduced frequency symbol with 2 p−ni frequencies, a set of K reduced frequency symbols is obtained, representing the original information sequence, with a view to a complete or partial decoding.