In this thesis, we propose some original examples of radar waveform design via convex optimization theory. After an initial section introducing some basic concepts about waveform design (chapter 2), we analyze in detail code design for a stand-alone radar in case of temporal (chapter 3) or spatial-temporal processing (chapter 4), and for a networked radar with constraints on the induced interference (chapter 5). Finally, some concluding remarks are presented (chapter 6).