Papers by Keyword: Auto-Correlation

Abstract: In practical applications, the DSSS signal has very low power spectral density, and its application range is very wide, so in the non cooperative communication, if on the premise that the spread spectrum sequence is unaware, how to detect and estimate the existence of DSSS signal is very important, this has very strong application background. This paper introduces the time domain correlation detection method of DSSS signal, through the simulation can validate that this way can detect the existence of signal; it lays the theoretical foundation for practical application.

Abstract: The paper expounds the basic principle of the weak signal detection on chaotic system at first , according to the actual situation that the signal phase is unknown Received in the communication and radar systems, a new chaos detection model is presented based on traditional chaos system, combined with autocorrelation detection technology , completed the random phase weak sinusoidal signal detection. The simulation analysis indicates that the proposed method succeeds in detecting Random Phase weak sinusoidal signal, and furthermore the signal-to-noise threshold is lower than either autocorrelation or chaotic oscillator.

Abstract: The exciting input signals of the parts in a fatigue life test rig for ball with three point contact and the system’s output signals were analyzed by auto-correlation and cross-correlation with MATLAB software, which eliminated the impact of noise to a certain extent and got the response signals of same frequencies caused by exciting input signals. Finally, the result showed that the text rig was linear by coherent function analysis, which provided the theory basis for modal and dynamic analysis further.

Abstract: The signal characteristics of the biophotons from human hands were studied using correlation and δ-value analyses. Three healthy individuals without any history of disease participated in the measurements, six times every Friday for 52 weeks, while staying in a room with dim lighting to eliminate any delayed luminescence caused by the sun or room lights. Two head-on type photomultiplier tubes inside a dark room were used to simultaneously measure the biophoton emissions from the palm and dorsum of the left and right hand with a 100ms gate time. In view of the signal process, a cross-correlation of the long-term data, i.e. the weekly measurements, revealed a strong correlation between the signals from the left and right hand, yet only a very weak correlation between the palm and dorsum. The non-classical light property of the biophotons, that has a quantum coherence nature, was compared with that of the dark counts of the PMTs using a δ- value analysis. The average δ-value for the biophotons was 0.08±0.07. As such, it was found that the palm emissions were very coherent, while the dorsum emissions showed an occasional lack of coherence.