The use of optical fiber which offers large bandwidth in the telecommunication sector has shown a lot of developments in the last decade mainly in television cables and cell phone cables. But these are not fully efficient and to do this, the fiber should allow multiple access which means allowing various users to send and receive data in the fiber at the same time. There are three main schemes ...

A DOCDMA (dynamic optical code division multiple access) communication system is projected for high-bandwidth communication systems. At the receiver, a synchronized TOF with the same function is used as a decoder. In this system, an electrically controlled tunable optical filter (TOF) is used to encode the modulated broadband light source. This technique dynamically modulates the central wavele...

This paper presents a novel 160 Gbps free space optics (FSO) communication system for 6G applications. Polarization division multiplexing (PDM) is integrated with an optical code multiple access (OCDMA) technique to form PDM-OCDMA hybrid. There are two polarization states: one X-polarization generated from adjusting the azimuthal angle of light source at 0° while other Y-polarization which by 9...

The data that is to be sent through any network across the globe vulnerable various kinds of threats. One such threat eavesdropping which should seriously viewed. Eavesdropping secretly gathering two parties without their consent. In Optical fiber communication this has become trend and been accessed by unauthorized user. To overcome these issues researchers have suggested many ways includes en...

In this work, the performance of the hybrid system that combines the distributed power control algorithm (DPCA) with the random access protocol as a novel and simple scheme of achieving a high performance in decentralized optical code division multiple access (OCDMA) networks has been investigated. The multiple access interference (MAI) and the near-far problem effects have been considered. The...

In this paper, we study the performance of the multiuser detection in a direct sequence optical code division multiple access (DS-OCDMA) system using novel periodic optical encoder applied to fiber-to-the-X (FTTX) passive optical network (PONs). The performance of our system is analyzed in a synchronous network using multilevel periodic codes (ML-PC) with a conventional receiver model and the r...

هدف: این پژوهش با هدف ارائه مدل چالش‌های پرورش کودکان کم‌شنوای پیش‌دبستانی از دیدگاه مادران و متخصصان بر اساس نظریه داده‌بنیاد انجام ‌شده است. روش: نمونه 15 مادر کودک کم‌شنوا 4 تا 6 ساله انجمن والدین شهر تهران 5 متخصص حوزه ناشنوا بودند که در سال 1400 استفاده روش نمونه‌گیری هدفمند انتخاب شدند. چالش ­های طریق مصاحبه نیمه ساختاریافته عمیق رسیدن به اشباع نظری جمع‌آوری کدگذاری (کدگذاری باز، محوری ان...