A Space-Time Code Design for Partial-Response CPM: Diversity Order and Coding Gain

Using a linear decomposition of continuous phase modulated (CPM) signals with tilted-phase, sufficient conditions are derived under which M-ary partial-response CPM space-time codes will attain both full spatial diversity and optimal coding gain. A rank criterion for M-ary partial-response CPM that specifies the set of allowable modulation indices is identified. Furthermore, optimization of the coding gain for CPM space-time codes is shown to depend on the CPM frequency/phase shaping pulse, modulation index, and codewords. The modulation indices and phase shaping functions that optimize the coding gain are specified. Finally, optimization of CPM space-time codewords is discussed.