Passive sensor frequency conversion transmitting method, system time division polling method and system

The invention belongs to the technical field of passive sensor networks, and particularly discloses a passive sensor frequency conversion transmitting method, a system time division polling method and a system, in the system time division polling method, a wireless base station transmits an excitation signal in a transmitting period, and in a receiving period, the wireless base station transmits the excitation signal to a wireless base station; the wireless base station receives reflection frequencies of a plurality of passive sensors in the coverage range of the wireless base station, the wireless base station presets local oscillation frequencies adopted by the passive sensors in the receiving period, and the difference between the reflection frequencies and the local oscillation frequencies of the different passive sensors is a fixed value in the receiving period; and the wireless base station respectively switches the local frequency to local frequencies corresponding to different sensors in different tim