Viterbi Demodulation for Continuous Phase Modulation (CPM)

This content discusses Viterbi demodulation for Continuous Phase Modulation (CPM). CPM is a modulation technique widely used in digital communications that efficiently utilizes bandwidth resources while providing strong interference resistance. The Viterbi demodulation method employs maximum likelihood criterion to recover original signals, demonstrating excellent performance even under complex channel conditions. In practical implementations, the Viterbi algorithm typically tracks the phase states through a trellis structure, where each node represents possible phase states and branches correspond to phase transitions. Key implementation aspects include: generating a state trellis based on modulation index and pulse length, calculating branch metrics using correlation receivers or matched filters, and performing path metric updates through additive comparisons. The algorithm's core function involves maintaining path metrics for each state and selecting the most probable path through traceback operations. Therefore, employing Viterbi demodulation for CPM in online communication systems presents a viable solution for achieving efficient and reliable data transmission with robust error performance.