The paper presents a square wave modulation scheme based on TDMA signal system to resolve the problem. Also it can avoid the high speed system clock.

For specific square wave modulation modes and typical ionospheric conditions, oscillations process of ionospheric conductivity and electrojet are studied in details.

In the study of circuit detection scheme for the low-cost Fiber Optic Gyroscope (FOG), a closed-loop scheme for analog demodulation, square wave modulation and step wave feedback was put forward.