Transmission Restriction and Suppression of Radio over Fiber Communication System

This article puts forward long-reach and high-performance Radio over Fiber (RoF) Communication Systems.Two schemes are proposed for solving the transmission restriction factors of the RoF system and verifies the system through experiments.One scheme is 40GHz RoF system based on external modulation with odd-order sideband-suppressed.The other one is 40GHz Optical Frequency Division Multiplexing (OFDM) system based on Optical Carrier-Suppression (OCS),external modulation.Both theory and experiment prove that the two systems allow not only low chromatic dispersion,but also long-distance transmission.

Torpedo car tracking system at China Steel Corporation

Torpedo cars,for the hot metal transportation by rail,play an indispensable role in China Steel Corporation (CSC)'s production.In order to meet the requirements of continual progress in hot metal production and safety management,the torpedo car tracking system suitable for our identification has been built up.This system not only combines the applications of of radio frequency identification(RFID) for accurately locating and radio modems to transmit the torpedo car position data,but also integrates the monitoring of railway switch machines and level crossings as well as the torpedo cars management system.Accordingly all torpedo car positions and operation data of railway equipments can be displayed in the control center for the reference of the effectively monitoring of torpedo cars and the dispatching of missions.

Optimization Design and Experiment of the Radio Frequency Transmission Utilized in Video Capsule Endoscope

In view of fuzzy and unstable images received in video capsule endoscopy, and the poor communication effect, an improved radio frequency(RF) transmission circuit module with low power consumption and helix antenna is designed to improve the performance of video transmission and to extend the working time of the capsule. Simulation and analysis of the circuits and antenna with HFSS12 and ADS2011 software are highlighted.Video capsule endoscope prototypes are made and evaluated to verify the feasibility of the proposed design. In vitro tests and animal experiments show that the results of the antenna tests basically meet the simulation, and the power consumption of RF circuit is 15.9 mV. The video capsule endoscope works well with the receiver with multiple receiving antennas, and the working time is more than 9 h. It can realize the wireless transmission of the video data, and images received are clear and stable in comparison with the previous designs.

Gigabit-converged wired and wireless networks for simultaneous multi-services transmission

A novel architecture of converged radio-over-fiber （RoF） and wavelength division multiplexed passive optical network （WDM-PON） system, namely RoF-WDM-PON, is demonstrated. 20-GHz 1-Gb/s radio frequency （RF） signals and 1-Gb/s baseband （BB） signals are simultaneously generated and transmitted using optical carrier suppression （OCS） modulation techniques. The proposed scheme is compatible with the conventional RoF and PON system. 25-km single-mode fiber （SMF） transmission is successfully achieved.

Design and analysis of flexible colorless remote node using RSOA-assisted Michelson interferometer

A scheme of flexible colorless remote note with reflective semiconductor optical amplifier （RSOA） assisted Michelson interferometer is proposed. This is capable of generating an optical carrier suppressed signal at a specific radio frequency to suppress the penalty brought about by Rayleigh backscattering and reflection in a full-duplex single fiber transmission network. Simulations are conducted, and the validation of the proposal is discussed by observing the penalty eye opening factor. The results are useful for designing cost-effective multi-wavelength passive optical network （PON） or radio-over-fiber （RoF） systems.

Novel pricing model for spectrum leasing in secondary spectrum market

According to the property rights model of cognitive radio,primary users who own the spectral resource have the right to lease or trade part of it to secondary users in exchange for appropriate profit.In this paper,an implementation of this framework is investigated,where a primary link can lease the owned spectrum to secondary nodes in exchange for cooperation （relaying）.A novel pricing model is proposed that enables the trading between spectrum and cooperation.Based on the demand of secondary nodes,the primary link attempts to maximize its quality of service （QoS） by setting the price of spectrum.Taking the price asked by primary link,the secondary nodes aim to obtain most profits by deciding the amount of spectrum to buy and then pay for it by cooperative transmission.The investigated model is conveniently cast in the framework of seller/buyer （Stackelberg） games.Analysis and numerical results show that our pricing model is effective and practical for spectrum leasing based on trading spectral resource for cooperation.