Author: Poomathi DuraisamyPublisher:
ISBN: 9781267805416
Category : Spread spectrum communications
Languages : en
Pages :
Book Description
Performance Improvements in Self-encoded Spread Spectrum
Author: Poomathi DuraisamyPublisher:
ISBN: 9781267805416
Category : Spread spectrum communications
Languages : en
Pages :
Book Description
Performance of Self-encoded Spread Spectrum Under Worst-case Jamming
Author: Casey L. DeyleSelf Encoded Spread Spectrum Synchronization and Cooperative Diversity
Author: Kun HuaPublisher: LAP Lambert Academic Publishing
ISBN: 9783846536094
Category :
Languages : en
Pages : 132
Book Description
The main theme of this research is to improve data quality and security, optimize wireless networking system performance over wireless networks. concerned a novel self-encoded spread spectrum (SESS) network. It provides a feasible practical implementation for random spreading codes. The traditional transmit and receive PN code generators are not needed. Instead, the spreading codes are extracted from the user's information bits itself. Comparing to conventional CDMA, SESS completely abandons the use of pseudo-random spreading codes. The code variability doesn't depend on the spreading length like pseudo-random codes. SESS can achieve 3dB performance gain comparing to the conventional uncoded direct sequence spread spectrum system. The author considers initial acquisition as a global optimization problem and employ genetic search algorithm for converging to the global optimization efficiently. In the tracking phase, Markov chain analysis is used to examine the mean tracking time. SESS is incorporated with cooperative diversity (CD) technique (SESS-CD) to achieve spatial diversity gain with the number of relays.It's stability in highly correlated rayleigh channels has been observed.
Self-encoded Spread Spectrum with Enhanced Diversity in Flat Fading Channels
Author: Liang ChiPublisher:
ISBN: 9781303049545
Category : Spread spectrum communications
Languages : en
Pages : 111
Book Description
In our dissertation, we focus on the SESS application with enhanced diversity in different transmission scenario such as multiple access, multichannel and multi-carrier techniques. Unlike the single user situation, there are two major sources of interference in the multiple access transmission system: one is multiple access interference (MAI) and the other is multipath interference (MI). The former occurs due to the cross correlation of CDMA codes and the latter is caused by the combined effect of out-of-phase autocorrelation and cross correlation of spreading codes used by the system in a multipath channel. The performance of the SESS based CDMA with two major impairing effects will be discussed in this dissertation.
2002 IEEE 7th International Symposium on Spread Spectrum Techniques and Applications
Author: Publisher: IEEE Computer Society Press
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 378
Book Description
Coded-sequence Self-encoded Spread Spectrum Communications
Author: Poomathi DuraisamySelf-encoded Spread Spectrum Synchronization and Cooperative Diversity
Author: Kun HuaPublisher:
ISBN: 9780549651413
Category : Spread spectrum communications
Languages : en
Pages :
Book Description
Journal of Communications and Networks
Author: Multi-Carrier Spread-Spectrum
Author: Khaled FazelPublisher: Springer Science & Business Media
ISBN: 940170502X
Category : Technology & Engineering
Languages : en
Pages : 515
Book Description
The benefits and success of multi-carrier (MC) modulation on one side and the flexibility offered by the spread spectrum (SS) technique on the other side have motivated many researchers to investigate the combination of both techniques since 1993. This combination known as multi-carrier spread spectrum (MC-SS) benefits from the advantages of both systems and offers high flexibility, high spectral efficiency, simple detection strategies, narrow-band interference rejection capability, etc. The basic principle of this combination is straightforward: The spreading is performed as direct sequence spread spectrum (DS-SS) but instead of transmitting the chips over a single carrier, several sub-carriers are employed. The MC modulation and demodulation can easily be realized in the digital domain by performing IFFT and FFT operations. The separation of the users' signals can be performed in the code domain. MC-SS systems can perform the spreading in frequency direction, which allows for simple signal detection strategies. Since 1993, MC-SS has been deeply studied and new alternative solutions have been proposed. Meanwhile, deep system analysis and comparison with DS-CDMA have been performed that show the superiority of MC-CDMA.
Author: Youn Seok Kim