Institute of Electronics, Information and Communication Engineers (IEICE)
The decomposition of continuous phase modulation (CPM) signals into a set of PAM waveforms is a very effective approach to reduce the receiver complexity. Recently, CPM signals using rectangular frequency shaping (FS) pulses having the so-called separable phase (SP) property can be reformulated as a compactor connected with an equivalent CPFSK scheme, and was proved to have minimal number of PAM waveforms among the existing PAM approaches. In this letter, we propose a new class of phase separable CPM schemes, which is extended from our previous work. Here FS pulses are constructed by using two-steps overlapping phase separable rectangular pulses. We show that the number of PAM waveforms required to represent this new class of CPM signals can be reduced up to 75 percent compared with other PAM decomposition approaches.