The beat frequency characteristic of a He-Ne laser with an activity plate in its cavity is studied.

The Research of Time Delay Estimation Method of General Cross Correlation with Frequency Difference;

In the real three station TDOA locating system,there is frequency difference between IF output of the receiver receiving direct signal and IF ouput of the receiver recieving indirect signal ,which decreases the TDOA estimation precision.

A Method of Dual-Satellites Geolocation Using TDOA and FDOA and Its Precision Analysis;

The low orbit dual-satellites passive location method for electronic reconnaissance using TDOA(time difference of arrival) and FDOA(frequency difference of arrival) was studied and presented which locates ground emitter from space satellites.

The locating principle on TDOA&FDOA with twin satellites is discussed in this paper.

Performance evaluation of NOrth-MDPSK with frequency offset in single path slow fading channel model;

In the QPSK demodulation′s system,many factors can cause the carrier′s frequency offset and phase error,such as Doppler frequency offset,the central frequency offset of the receiver′s local oscillator and the phase noise.

A scheme for joint frequency offset and spread spectrum code time delay acquisition was proposed,and the noise and interference estimation algorithm was put forward based on peak windows.

The Application of Difference-frequency Detection System in Electrochemistry;

In HF spread spectrum system,because of the low rate of pseudo code,coupled with instability of the frequency source and the Doppler frequency shift,some frequency difference is often exit there between the carrier of transceiver and receiver,the frequency difference makes the PN code failed to establish synchronization.