phonemic system; phoneme system
Linguistics term referring to the set of phonemes and their organizational rules in a language.
It is said that the phonemic system of Japanese is relatively simple.
Analysis of the phoneme system is fundamental to phonology.
音韻体系 (phonological system) is a broader term encompassing all sound patterns, while 音素体系 focuses specifically on the inventory and organization of phonemes.
Compound of 音素 (phoneme) and 体系 (system). The exact historical derivation is uncertain, but the term is a modern linguistic coinage.