Differential trellis coded modulation with state dependent mappings

Differential encoding (DE) is a classical technique without channel coding at the transmitter that allows simple noncoherent detection at the receiver. In this paper, we propose a new trellis coding extension of DE, called differential trellis coded modulation (DTCM), which extends our earlier work and consists of both design and distance analysis. DTCM is TCM with DE defined in states where distinct states may have distinct DE functions. We propose design methods of DE functions for noncoherently non-catastrophic DTCM. For MPSK signals, an additive distance measure and set partitioning are proposed. In addition, trellis diagrams of DTCM are designed and their minimum distances are analyzed.