Therefore,kinds of methods for frequency refinement for C/A code can\' t work well for P code,especially under low C/NO.

Signal synchronization and compensation of meteor for extremely low SNR;

Modeling and simulation of meteor extremely low SNR communication system based on SPW;

Research and Implementation on HF Technology in Strong Single-frequency-interference under the Condition of Extremely Low SNR;

CNR Analysis of CDMA used in Fiber to the Railway;

Effect of Initialization Conditions on the Reflectivity and CNR of Ge_2Sb_2Te_5 Phase-change Optical Disk;

The influence of the ionosphere,rain,multipath distortion,Doppler shift,the CNR of received signal and the design of the antenna used in the satellite are described.

The noise figure of erbium-doped fiber amplifiers (EDFAs) can be derived from the degradation of carrier-to-noise ratio by the cable TV analyzer.

The computational formula and every influence factor of the carrier-to-noise ratio of CATV system are discussed, the concrete methods of lifting carrier-to-noise ratio are put forward.

Then the multiplex efficiency and the influence of intermodulation term on receivers\' carrier-to-noise ratio are thoroughly analyzed.

Influence of Output Level to Modulator C/N;

Primary Research on C/N Rate of Fibre-optical Network and Nonlinear Distortion;

This paper describes three points:it s hard to measure C/N accurately,video signal from far-front- end makes the relation between C/N and S/N_(w) dis-corresponding,DTV demands C/N lower than analog TV for receiving a good quality picture.