Yan Gan Zhang

Design and Implementation of Long Distance Visible Light Communication System Based on Embedded ARM Platform

In this paper, a long-distance optical communication system based on Embedded ARM platform is presented and demonstrated. The system is composed of two parts: LED/PD application terminal and its drive circuit. Terminal has a 4-inch touch screen with interactive interface based on Android system. The performance of data transfer in our prototype shows up to 50 m range at the transmission rate of 50kbps. This system is supposed to reach the distance of 2km or higher in the coming months.

The Mobile Manager of Network Management System Based on Android Platform

This paper presents a new network management system which contains a user-friendly wireless mobile manager. Compared with traditional network management system, the new system realizes the mobile management of network.

A Polarization Stabilization Control System Based on DSP

A polarization stabilization control system based on digital signal processor (DSP) is proposed in this paper. The system uses low frequency radio frequency (RF) power as control signal for polarization stabilization, and it does not need high-speed circuit to track fast polarization change. Modified particle swarm optimization algorithm is utilized and the effectiveness of polarization stabilization control is experimentally verified.

Application of a Novel Modulation Scheme of PS-RZ-QPSK Signal in High-speed Optical Transmission System

Modulation principle of dual-polarization quadratu-re phase shift keying signal and polarization-switched QPSK signal are demonstrated and advantages of PS-QPSK are proved in theoretically. A novel modulation scheme of PS-RZ-QPSK signal is proposed in this paper. The scheme reduces transmitter cost by less use of Mach-Zehnder modulator, but also presents similar performance as traditional structure for PS-RZ-QPSK. The simulate result indicates PS-RZ-QPSK can achieve a better transmission performance than DP-RZ-QPSK at the same bit rate (84Gb/s) and baud rate (28GBd), and proves showing the feasibility of novel modulation scheme.

Design and Implementation of Buffer Control in EoS System

We propose an optimization approach to EoS (Ethernet over SDH) buffer control which the objective is to dynamically adjust the EoS buffer management registers. We will present the improved model of the traffic buffer management based on embedded MCU to control the SDRAM of the EoS chip, and setup the end-to-end system to illustrate the feasibility and advantage of the solution in buffer management when the data transport rate suddenly exceed the bandwidth of Ethernet port.

Discuss the Number of Sub-Channels and Quantization Bits in a DCO-OFDM VLC System

This paper introduces an integrated simulation system for visible light communications (VLC) which is based on DC-biased optical OFDM (DCO-OFDM). By simulating a VLC system with an equalizer, we optimize the parameters for a real-time system: the number of sub-channels and quantization bits. It could be concluded that a 128 sub-channels system is suitable when the signal bandwidth exceeds 100MHz and 6 quantization bits should be enough for a VLC system, which would be useful when it comes to a hardware only system.

A Software-Based and Dither-Less Modulators Bias Control Technique

A software-based bias control system of push-pull Mach-Zehnder Modulators (MZMs) without dither tone is described in this paper. The slope of the average optical output power respect to the bias voltage is used to control the operating bias points in the automatic control system. The paper analyses the theory of automatic bias control intensively and verifies the effectiveness of the proposed technique which is a modulation-format-free method under the RF signal through testing and contrasting the BER (bit error rate) between the new technique and manual measure on the experimental platform.

Design and Implementation of Real-Time Polarization Measurement System Based on LabVIEW

A rapid real-time polarization measurement system was designed and implemented in this paper. The system is centered round a laptop running application developed for the purpose. The paper illustrates how to build such an excellent application with National Instruments graphical programming language LabVIEW, a synchronized high speed multi-channels data acquisition card and some photoelectric conversion module in detail. With simple and friendly user interface, the experimental result shows that the measurement system has high computational efficiency, high precision calibration matrix, which can be efficiently utilized in experiments relating to the measurement of polarization.

Design and Realization of 10Gbps DPSK System for Free Space Optical Communication

The performance of atmospheric communication system is limited by the atmospheric turbulence. In this paper, we present a practical 10Gbps DPSK transmission system for free space optical (FSO) communication with low error probability and wide-opening eye diagram. Compared to OOK modulation, DPSK format is a more effective way to resist the atmospheric turbulence. In addition, we designed parameters of this modulation system to be varied as the channel situation changed to achieve an optimized performance. The experiment results show that such a DPSK system could greatly overcome the atmospheric turbulence.

Design and Implementation of New Embedded Network Management and Monitoring System

Embedded devices are confined to be agents although they have been deployed in network management system for decades. We shed light on this situation by designing and implementing a new full-featured embedded network management system. On one hand, this system can still be an agent; on the other hand, this system provides a friendly GUI and I/O devices such as mouse and keyboard, which allows administrators to conveniently monitor and configure the managed equipment. The new system is developed on ARM with Linux using multithreading method, and it is deployed on ROADM equipment in optical network. SNMP is applied to be the network management protocol.