Simulation of Digital Optical Receiver of Intensity Modulation and Direct Detection
Manuel Vítor Martingo Coelho
Issue:
Volume 3, Issue 1, January 2015
Pages:
1-10
Received:
21 February 2015
Accepted:
15 June 2015
Published:
2 July 2015
Abstract: This article presents the implementation of an interactive software that integrates various functional blocks of an optical receiver of intensity modulation and direct detection (IM-DD), with OOK (on-off keying) digital modulation and NRZ (non-return-to-zero) pulse format. The software allows for the isolated simulation of each block, as well as the complete simulation of the whole system. We underline the following results presented by the simulator: theeye diagram, the probability density functions of the samples, Bode diagram, bandwidth, transimpedance gain, signal-to-noise ratio, power of the different noise sources and the bit error probability of the simulated system.
Abstract: This article presents the implementation of an interactive software that integrates various functional blocks of an optical receiver of intensity modulation and direct detection (IM-DD), with OOK (on-off keying) digital modulation and NRZ (non-return-to-zero) pulse format. The software allows for the isolated simulation of each block, as well as th...
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Investigating Space Overhead by IPSec on IPv4 and IPv6 Communication Protocols
Muhammed Nura Yusuf,
Ali Mohammed Baba
Issue:
Volume 3, Issue 1, January 2015
Pages:
11-23
Received:
4 July 2015
Accepted:
13 July 2015
Published:
25 July 2015
Abstract: IPsec, an internet layer three-security protocol suite is often characterised with introducing an additional space and processing overhead when implemented on a network for secured communication using either IPv4 or IPv6. The use of IPsec on IPv4 is an alternative that offers solutions and addresses the security vulnerabilities in network layer of the OSI and TCP/IP protocol stack. In IPv6, IPsec is one among many other features added to the earlier internet protocol to enhance efficiency and security. Analysis in this research aim at observing the effect of additional space overhead incurred by internet protocols version 4 and 6 (IPv4, IPv6) as a result of selected IPsec configuration in relation to payload size in transport and tunnel mode of IPsec. It was observed that the cost of IPsec added overhead is relatively small when smaller packet sizes are involved for both protocols comparison with large packet sizes that were IPsec protected with the same configuration as the smaller packet, unless in the cases whereby the packet was very large which has to be fragmented. It is therefore, a guide for network administrators to trade up between processing cost and larger address space among other improvements specifically for transmission involving larger IP packets.
Abstract: IPsec, an internet layer three-security protocol suite is often characterised with introducing an additional space and processing overhead when implemented on a network for secured communication using either IPv4 or IPv6. The use of IPsec on IPv4 is an alternative that offers solutions and addresses the security vulnerabilities in network layer of ...
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