Methods of converting or reconverting a data signal and method and system for data transmission and/or data reception

A method (RC) for reconverting a converted data signal (Y), the method comprising processes of

• providing an input bit stream (IB′) of input bits (IBj′), the input bit stream (IB′) directly or indirectly being representative for an underlying converted data signal (Y) to be reconverted or a derivative thereof;
• and
• applying to said input bit stream (IB′) or to a derivative thereof an inverse distribution matching process (DM−1) to generate and output a final output bit stream (OB′);
• wherein
• the inverse distribution matching process (DM−1) is formed by an inverse quadrant shaping process (QS−1) and configured to map a respective constellation point of a four-dimensional 24·m-QAM constellation, in particular being configured to convey two distinct polarizations for each of an in-phase component and a quadrature component, to a partial output bit sequence (OBk′) of a length of k output bits (OBj′);
• m is a fixed natural number fulfilling the relation 4·m≥k;
• and
• the consecutive partial output bit sequences (OBk′) are disjunct and form and output a (re)converted signal (V).