Codes over a ring modulo-m: an alternative for combined coding and modulation

The main idea of the schemes that utilize coded modulation is to transmit q information bits per channel symbol by using a modulator with m>2^q waveforms (usually m=2^q+1) and thus exploit the redundancy produced by using a suitable set of 2^q channel symbols. This proceeding must establish a correspondence between binary q-tuples and symbols of the m-ary alphabet. An alternative coding method based on a ring of integer modulo-m (m is a nonprime integer number) which is suitable for coded modulation schemes is presented. Some classes of block codes are also presented together with some of their interesting properties. It is important to reinforce that such codes can be used not only in m-PSK modulations but also in m-QAM modulations by making a simple adaptation