In this paper, we present a code-division multiple access (CDMA) system with a spreading factor of N that can accommodate up to mN users, where m 2. The m sets of orthogonal spreading sequences are constructed by overlaying the same N orthogonal Walsh-Hadamard sequences with a set-specific pseudonoise (PN) sequence. Interference between user signals from different sets is cancelled by means of ...

This research proposes the architecture of a SAC-OCDMA–OFDM–DWDM system using flat optical frequency comb generator and coherent communication. Its aim is to create new OCDMA communication that specifically intended for multiservice networks. The suggested architectural design numerically simulated analyzed OptiSystem MATLAB. To quantify performance proposed system, SNR, EVM, BER were used as m...

: Optical code division multiple access OCDMA is one of the promising optical technologies due to its worth-mentioning features, such as asynchronous access, and high security. In this paper, author performed an analytical-based comparison between three commonly used spectrum amplitude coding SAC-based codes, namely: Modified Frequency Hopping MFH, Hadamard, Enhanced Double Weight EDW. The was ...

The performance of M-ary optical code division multiple access (OCDMA) is analytically investigated in presence of chromatic dispersion. The study is carried out for single mode dispersion shifted and non dispersion shifted fibers. Walsh code is used as user address. The p-i-n photodetector is used for optoelectronic conversion process. In our proposed model 16 different symbols are modulated w...

The flexible cross correlation (FCC) code algorithm for optical code division multiple access (OCDMA) systems has been developed. The FCC approach has advantages, such as flexible cross-correlation property at any given number of users and weights, as well as effectively suppressed the impact of phase-induced intensity noise (PIIN) and multiple-access interference (MAI) cancellation property. T...

Passive Optical Network (PONs) are becoming a mature concept for the provision of enormous bandwidth to endusers with low cost. In this paper we study the call-level performance of two PON configurations: the OCDMA-PON and the Hybrid WDM-OCDMA PON. We propose analytical models for calculating connection failure probabilities (due to unavailability of a wavelength) and call blocking probabilitie...

در این مقاله یک مدل ریاضی برای مسئله سیستم تولیدی همکارانه ساخت بر اساس سفارش با رعایت انصاف تخصیص بار‌های تولید طراحی شده است. اهداف اصلی مدل، کمینه‌سازی هزینه‌‌های کل و حداکثر استفاده از منابع به‌منظور عادلانه شرایط عدم­قطعیت کنترل پارامتر‌های غیرقطعی روش برنامه‌ریزی فازی ‌شده نتایج نشان می‌دهد افزایش نرخ عدم‌قطعیت، می­یابد. ازآنجاکه ظرفیت کارخانه‌ها ثابت است، مقدار تقاضا، هر کارخانه نیز می­ی...

سابقه و هدف: در کشور ایران از حدود 5/88 میلیارد مترمکعب آب استحصال‌شده منابع سطحی زیرزمینی، ۸۳ یعنی 5/93 درصد به بخش کشاورزی اختصاص می‌یابد، بزرگ‌ترین مصرف‌کننده است. مصرف رو افزایش معلول جمعیت، سطح زیر کشت تولیدات هست که به‌تبع آن سبب کاهش دسترسی افت ایستابی تخلیه آبخوان‌ها شده آمارها نشان می‌دهند این استراتژیک، تهدید کمیت کیفیت است ­طوری ­که هم ­اکنون تعداد زیادی دشت­ های شرایط بحرانی قرار دا...

The performances of time-domain Optical Code Division Multiple Access (OCDMA), using Gaussian model for the optical amplified channel, are evaluated. The interest of spectral spreading to take benefit of low cost optical filtering conditions is point out and the simultaneous effects of Multi Access Interferences (MAI) and optical noises on the optical detection are demonstrated. To generate OCD...