A first approach to concatenation of coding and spreading for CDMA-systems
Thomas L. Frey, Martin Bossert · 2002
This paper presents an approach to combine error correcting coding with spreading in CDMA (code division multiple access) systems. The spreading is described in a very general way by means of block coding, that includes the 'normal' antipodal direct-sequence (DS) spreading and also the spreading with orthogonal sequences (M-ary transmission), but is not restricted to them. Applying this description of spreading as coding, the complete system can be regarded as a concatenated code, consisting of the outer channel code and the inner spreading code. This allows an overall optimization of coding and spreading by constructing powerful codes as well as delivering good decoding algorithms.