Design and Analysis of 1.28 Terabit/s DWDM Transmission System for Free Space Optical Communication

In this paper, the implementation of a dense wavelength division multiplexing (DWDM) 32 × 40 Gbps (1.28 Tera bit/s) for the free-space optical (FSO) communication system is investigated. Analysis is performed for return-to-zero (RZ) and non-return-to-zero (NRZ) line codes for 1 km free space optic length. Motivation to the current analysis is to compare RZ and NRZ lines codes in the DWDM-FSO communication system and it is found that the NRZ line code is better than RZ code. A 1.28 Tb/ps wavelength division multiplexed communication system for free space optic channel workplace has been discovered in which 32 channel each of 40 Gbps data streams are combined using wavelength division multiplexed. The study includes the attenuation caused by atmospheric effect and beam divergence. Bit-error rate (BER), quality factor (Q), and eye diagram are indicator of performance evaluation. By comparing one can get a promising system to the high capacity access network with more bandwidth, cost effective and good flexibility.

Design and Analysis of 1.28 Terabit/s DWDM Transmission System for Free Space Optical Communication

In this paper, the implementation of a dense wavelength division multiplexing (DWDM) 32 × 40 Gbps (1.28 Tera bit/s) for the free-space optical (FSO) communication system is investigated. Analysis is performed for return-to-zero (RZ) and non-return-to-zero (NRZ) line codes for 1 km free space optic length. Motivation to the current analysis is to compare RZ and NRZ lines codes in the DWDM-FSO communication system and it is found that the NRZ line code is better than RZ code. A 1.28 Tb/ps wavelength division multiplexed communication system for free space optic channel workplace has been discovered in which 32 channel each of 40 Gbps data streams are combined using wavelength division multiplexed. The study includes the attenuation caused by atmospheric effect and beam divergence. Bit-error rate (BER), quality factor (Q), and eye diagram are indicator of performance evaluation. By comparing one can get a promising system to the high capacity access network with more bandwidth, cost effective and good flexibility.

HỆ THỐNG PHÂN PHỐI KHÓA LƯỢNG TỬ ĐA KÊNH TỪ VỆ TINH SỬ DỤNG SCM-WDM

Phân phối khoá lượng tử QKD (Quantum Key Distribution) là giải pháp có khả năng đảm an ninh vô điều kiện nhờ áp dụng luật cơ lượng tử để phân phối khóa an toàn giữa hai bên hợp pháp với sự hiện diện của kẻ nghe lén. Sử dụng vệ tinh để phân phối khóa lượng tử tới các trạm mặt đất qua kênh quang không gian tự do FSO (Free Space Optic) là giải pháp hứa hẹn tạo ra một mạng QKD phạm vi toàn cầu. Tuy nhiên, do ảnh hưởng của kênh FSO, đặc biệt là nhiễu loạn khí quyển, tốc độ truyền khóa bí mật SKR (Secret Key Rate) của các hệ thống QKD hiện tại bị hạn chế. Do đó, nghiên cứu này đề xuất mô hình hệ thống QKD đa kênh dựa trên ghép kênh phân chia theo bước sóng WDM (Wavelength Division Multiplexing) và ghép kênh sóng mang phụ SCM (Sub Carrier Multiplexing) nhằm tăng SKR. Sử dụng phương pháp phân tích lý thuyết với các công cụ giải tích và xác suất, nhóm tác giả đã xây dựng các công thức tính toán SKR và tỉ lệ lỗi bit lượng tử của hệ thống đề xuất. Kết quả khảo sát hiệu năng cho thấy, hệ thống QKD đa kênh cho phép cải thiện SKR so với hệ thống đơn kênh trong khi vẫn đảm bảo yêu cầu về QBER (Quantum Bit Error Rate).

Performance of orthogonal frequency division multiplexing based 60-GHz transmission over turbulent free-space optical link

In this paper, radio-over-free-space optic (RoFSO) transmission is investigated for the next-generation wireless networks. Here, the 60 GHz based radio frequency (RF) system is demonstrated using 16-quadrature amplitude modulation with orthogonal frequency division multiplexing scheme. System performance for FSO link is evaluated by modeling the channel with the gamma-gamma fading. The optical spectrum and constellation diagram of the received signals are analyzed. The improvement reported for error vector magnitude is 3.8–0.6% and symbol error rate of 0.03–0.005 for free-space range of 0.2–1 km. Proposed work claims that orthogonal frequency division multiplexing can be helpful for the FSO systems by providing robustness to adverse atmospheric turbulence.

Optical wireless systems with ASK & PSK using coupler-based delay line filter

In free space optics (FSO) optics, the tweaked optical sign is transmitted at different climate conditions like day off, Mist, and Haze, which is a new paragon to the field of optical communication. Further to realize the same, the present research analyzes the framework performance by executing two adjustment strategies amplitude shift keying (ASK) and Phase shift keying (PSK). Moreover, article investigates the performance of applied modulation-based free space optic system using a coupler-based delay line filter. Aside this, the recreation results are examined and natter about the dependent of quality factor, bit error rate (BER), and eye outline of various FSO parameters pertaining to the same. The outcomes of the research bestow on the recreation results acquired for quality factor and BER against various conditions with respect to the both adjustment techniques and PSK offers better execution.