Towards self-clocked gated OCDMA receiver

A novel incoherent OCDMA receiver with incorporated all-optical clock recovery for self-synchronization of a time gate for the multi access interferences (MAI) suppression and minimizing the effect of data time jitter in incoherent OCDMA system was successfully developed and demonstrated. The solution was implemented and tested in a multiuser environment in an out of the laboratory OCDMA testbed with two-dimensional wavelength-hopping time-spreading coding scheme and OC-48 (2.5 Gbp/s) data rate. The self-clocked all-optical time gate uses SOA-based fibre ring laser optical clock, recovered all-optically from the received OCDMA traffic to control its switching window for cleaning the autocorrelation peak from the surrounding MAI. A wider eye opening was achieved when the all-optically recovered clock from received data was used for synchronization if compared to a static approach with the RF clock being generated by a RF synthesizer. Clean eye diagram was also achieved when recovered clock is used to drive time gating

Investigation of All-Optical Switching OCDMA Testbed under the Influence of Chromatic Dispersion and Timing Jitter

First part of this paper presents an all-optical switching OCDMA testbed investigation under the influence of the residual chromatic dispersion resulted from different locations of the receiving terminal. The investigation was carried out using incoherent 2D-WH/TS OCDMA codes based on picosecond pulses at OC-48 2.5Gb/s) data rate. The testbed itself is based on a fully chromatic dispersion compensated (with sub-picosecond accuracy) 17 km bidirectional fiber link connecting University of Strathclyde and Glasgow University. We have found that a high performance penalty in the form of BER deterioration was incurred when even a relatively short length of optical fiber was added to a fully compensated transmission link in order to relocate the receiving terminal (we tested increments up to 275m of SMF- 28). Second part of this paper reports on the testbed performance when an OCDMA receiver with built in all-optical clock recovery was implemented to mitigate the detrimental effects of the link timing jitter on the picosecond switching based all-optical time gate

Network scaling using OCDMA Over OTDM

We present analysis and proof-of-concept field demonstration of an incoherent optical code-division multiple access over an optical time-division multiple access system. The performance analysis which includes power budget and scalability calculations show scalability improvements without any significant system performance degradation

Investigating the influence of thermal coefficients on 2-D WH/TS OCDMA code propagation in optical fiber

In this paper we present an extension of our previous investigation of the effect of environmental temperature variation on the bit error rate (BER) performance of multiwavelength 2- dimensional wavelength hopping time spreading optical code division multiple access (2D-WH/TS OCDMA) signals that utilises picosecond pulses for code formation

SOCIO-CULTURAL STRUCTURE AND DEVELOPMENT OF ARÁMOKǪ LAND: A HISTORICAL REFLECTION

This paper examined the socio-cultural composition and development in pre-colonial Arámokǫ-land. It describes and analyzes the various social stages recorded during the pre-colonial era as well as the human adaptive measure put in place for the various established structures. It further opined that the community; Arámokǫ, possess in large extent, the various social and cultural formations as well as a good climate to sustain its inhabitants and future generations from going into extinction. The value of marriage, family as well as other social and cultural habits i.e. hairdo, arts and craft are considered in the paper. The paper however derives its data from both primary and secondary sources.  Article visualizations