What type of modulation is used by the D-Star digital voice standard?

The D-Star digital voice standard utilizes Gaussian Minimum Shift Keying (GMSK) for its modulation. GMSK is a type of continuous-phase frequency shift keying that is particularly efficient in terms of bandwidth and power. This makes it well-suited for digital voice applications, as it allows for high-quality voice transmission with low latency while minimizing the potential for interference.

GMSK helps to maintain signal integrity and reduces adjacent channel interference, which is crucial for effective communication in crowded radio frequency environments. The technique is effective in maintaining a robust connection even when the signal strength is weak, making it ideal for portable and mobile operation typical in amateur radio applications.

This choice stands out for D-Star as it effectively combines efficiency and performance, providing clear voice quality and reliable communication. Therefore, from the given options, it is the correct modulation type associated with D-Star technology.