Abstract: The primary reasons for leading to the impairment of frequency hopping communication system are studied, the analytic relations between the impairment ratio and the parameters of the frquency hopping system are given, and the low bound of the frequency hopping system loss is achieved. The conclusion not only explains the difference in performance between frequency hopping communication and frequency fixing communication, but also clarifies the misunderstanding about FH systems.

Key words: impairment of frequency hopping, frequency hopping communication, frequency fixing communication