Patent ID: 8194527

Claim:
A block interleaving method with a block size K and with N iterations of index j, N being greater than or equal to 1, for use with digital data items indexed by a variable k={0, . . . , K−1} in a block interleaver for positioning input digital data items X in an output sequence made up of output digital data items Y in an order determined by an interleaving law I (j) (k) such that Y(k)=X(I (j) (k)), wherein the method comprises the steps of: calculating an intermediate value I 0 (j) (k) of the interleaving law that for a first iteration (j=1) is a result of applying a first algebraic function f 0 (a, b) modulo K with two variables a and b to input indices k, with a=b=k such that ƒ 0 (a, b)=[−a−pb] K , wherein for the intermediate value from the first iteration: I 0 (1) (k)=[−k−pk] K and for each subsequent iteration j, j=2 to N, is the result of applying the first algebraic function f 0 (a, b) to the input indices k and to an output value I (j-1) (k) obtained during the preceding iteration: I 0 (j) (k)=[−k−p·I (j-1) (k)] K ; calculating the output value I (j) (k) of the interleaving law that, for a given iteration j, is the result of applying a second algebraic function f 1 (a, b) modulo K with two variables a and b to the input indices k and to the intermediate value I 0 (j) (k) calculated in the same iteration j, with a=k and b=I 0 (j) (k) such that ƒ 1 (a, b)=[αp+a+qpb] K , wherein for the output value I (j) (k) after each iteration j: I (j) (k)=[αp+k+q·p·I 0 (j) (k)] K , where p and q are natural integer parameters and [X] K signifies X modulo K; and positioning the input digital data items X, using the block interleaver, in the output sequence made up of the output digital data items Y in the order determined by the interleaving law I (j) (k) and outputting the output digital data items Y from the block interleaver as a bit stream for modulation.