Patent ID: 7333734

Claim:
A method of transmitting data, comprising the steps of: encoding said data to obtain a code of order n for transmission from a transmitter to a receiver in a communications system; operating an encoder to obtain a coded signal x(t) which represents binary data which are constituted by sequences of information bits {u k } with rate T, the code having N= 2 n states named Σ i , for i =1, 2, . . . , N for the encoder, and predetermined elementary signals s i (t) which are combined in the coded signal x(t): if, at the time t =kT, the code is in a state Σ m of the N states for the encoder, forcing a transition to the state Σ q of the N states upon arrival of information bit u k of the sequence of information bits {u k }; selecting the elementary signals s i (t) as x(t), where q and i are given by the following equations: d 1 = ( m - 1 ⁢ ) ⁢ ⁢ mod ⁢ ⁢ 2 d 0 = ( d 1 + u k ) ⁢ ⁢ mod ⁢ ⁢ 2 r = 2 ⁢ ( m - 1 ) + d 0 q = ( r ⁢ ⁢ mod ⁢ ⁢ N ) + 1 i ⁢ = r + 1 if ⁢ ⁢ r < N i ⁢ = r - 2 ⁢ N otherwise ⁢ ; wherein the elementary signals s i (t), for i =±1, ±2, . . . , ±N, are such that s −i (t)=−s i (t) and, for i≧1, in which: s i ⁡ ( t ) = { ∑ k = 0 n ⁢ ( b k - 0.5 ) ⁢ g ( t + ( k - n + 1 2 ) ⁢ T ) 0 ≤ t ≤ T 0 otherwise ⁢ ⁢ where ⁢ ⁢ b k = [ i - 1 2 k ] ⁢ ⁢ mod ⁢ ⁢ 2 k = 0 , 1 , … ⁢ , n and g(t) is a pulse of time length D=(n+1)T centered in the origin such that g(t)=g (−t) and having constant values over time intervals of length T/2; wherein the elementary signals s i (t), for i=±1, ±2, . . . , ±N, constitute couples of signals s −i (t)=−s i (t), have levels not zero in a time interval of length T, and have levels zero elsewhere, and wherein each couple of the signals has a level different for the level of other couples of the signals.