Search

Copyright of Journal of Signal Processing is the property of Journal of Signal Processing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the current anti-jamming communication, the spread spectrum communication has been studied deeply with the advantages of strong anti-jamming ability and good security performance. In this paper, the code index modulation and multi-ary spread spectrum technology are analyzed and compared. Code index modulation technology is based on the development of direct sequence spread spectrum, in the transmitter information bits are mapped to the pseudo noise(PN) code index and the modulation symbol respectively. The in-phase and orthogonal parts of the modulation symbol select PN codes activated to spread spectrum, and then transmitted through an antenna. The difference between multi-ary spread spectrum technology and code index modulation technology is that the multi-ary spread spectrum technology does not have modulation symbols, and only sends out the activated spread spectrum code through the antenna. This paper will introduce the basic models, spread spectrum gain analysis and complexity analysis of the two kinds of spread spectrum technology. The simulation results show that the code index modulation system has higher spectral efficiency and anti-interference ability.

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Because of the complicated environment, various types of users, random time of power consumption and so on, the low-voltage power line communication has interference, which causes communication failure seriously. In this paper, the characteristics and laws of load and interference in low voltage power lines are studied. A channel noise model is established, and an intelligent active anti-interference technique for low voltage power line carrier communication is proposed. This technique matches the impedance of the transceiver controller with the impedance of the low voltage power communication line to a maximum, and broadens the spread spectrum technology. We further propose a method of actively selecting a high reliability band to communicate on the basis of spread spectrum, so as to overcome the strong attenuation and strong interference defects of low voltage power line. The experimental environment is set up, and the communication experiments are carried out for low voltage power lines, such as white noise, periodic noise and impulsive noise. The results show that the method is feasible. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to set up the large-scale network of electronic detonators, high-voltage AC carrier spread spectrum communication mode is proposed in this paper. Based on this technology, the network size of electronic detonators could be enlarged. The spread spectrum communication brings many advantages, such as high-speed transmission of information, anti-jamming and so on. Adopting high working voltage could enhance the ability of anti-jamming and enlarge the size of detonation network. Based on this mode, transmission channel of the mode was analyzed. Besides, the spread spectrum communication system was designed and simulated. The complete system was simulated and the results verify the feasibility of the proposed mode. [ABSTRACT FROM AUTHOR]