الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 57 |  |  |
| | | from | 57 | | |
Abstract
In this thesis, an overview on the multi-core fibers (MCFs) and the effect of inter-core crosstalk (XT) between neighboring cores is presented. In order to explore whether the deterioration is < possible or not, we study the inter-core XT in multi-core fiber (MCF). The inter-core XT of the MCF was shown to be sensitive not only on fiber structure, but also on the distances between various cores, such as fiber bending and twisting. After that, in order to reduce the fiber nonlinear effects, we suggested a receiver diversity utilizing maximum ratio combining (MRC) for MCFs-based systems. The concept of using MRC is extended from wireless communications to optical communications systems, as this combining technique allows increasing the transmitted optical power and hence enhancing the system performance without any increase in the fiber nonlinear effects. Since the launched power is divided between the different cores in the MCF which reducing the peak power and hence the nonlinear fiber effects. The obtained simulation results showed that the system’s quality-factor (Q-factor) is enhanced by 2.5 and 5 dB when using two and four diversity cores in MCF, while the eight diversity cores achieved 6 dB when compared to the single-mode fiber (SMF). The effect of inter-core XT is introduced in the simulation model of the MCF with four diversity cores. The Q-factor degrades when increasing the XT levels compared to the case without XT. Also an improvement in the system transmission reach is acquired when increasing the number of diversity cores compared to the achievable transmission reach of the conventional SMF. Finally, we investigate how to achieve a balance between spatial capacity and spatial diversity in multi-core fiber using MRC receiver diversity without the need for a complex MIMO-DSP system. In addition to a conventional MCF and the standard signal fiber mode (SMF), we explain how users may share Multi-core fiber core values while also improving the rate of bit-error values, and enhance system performance. In addition, we examine the effect of inter-core XT in MCF, where system performance for every user is limited, but improved compared with SMF due to the existence of the MRC receiver. Our study is focused on the case of five and seven cores MCF. The simulation results showed that the BER is decreased with the increase of the diversity order.