A composite impulse radio ultra-wideband (IR-UWB) communication system is presented. The proposed system model aims to transmit UWB pulses over several kilometers through free-space optical (FSO) links and depending on the link design, the electrical estimates of the FSO system can be directly used or distributed to end-user through radio-frequency (RF) links over short ranges. However, inhomogeneities on the FSO transmission path cause random fluctuations in the received signal intensity and these effects induced by atmospheric turbulence closely effect the system performance. Several distinct probability distributions based on experimental measurements are used to characterize FSO channels and using these probabilistic models, detection error probability analysis of the proposed system for different link designs are carried out under weak, moderate and strong turbulence conditions. The results of the analysis show that depending on the atmospheric conditions, system performance of the composite link can have high error floors due to the false estimates of FSO link. The system performance can be improved by employing error control coding techniques. One simple solution employing a convolutional encoder and Viterbi decoder pair is also analyzed in this thesis. Another important system parameter that is the average channel capacity of the FSO system is analyzed under weak and moderate turbulence conditions. Theoretical derivations that are verified via simulation results indicate a reliable high data rate communication system that is effective in long distances.
Dynamic Dispersion Accumulation in Fiber Loops for Realizing Record-High Frequency Resolution or Ultra-Low Signal Sampling Rate in Dispersion-Based Photonics-Assisted Wideband Microwave Measurement Systems
Shanghai Key Laboratory of Multidimensional Information Processing, East China Normal University（上海多维信息处理重点实验室，华东师范大学）
Analog Time-Frequency Analysis and Frequency Measurement of Ultra-Wideband Microwave Signals via Dual-Comb Channelization
Shanghai Key Laboratory of Multidimensional Information Processing, School of Information and Electronic Engineering, East China Normal University（华东师范大学信息电子工程学院多维信息处理上海市重点实验室）；National Key Laboratory of Microwave Photonics, Nanjing University of Aeronautics and Astronautics（南京航空航天大学微波光子学国家重点实验室）
Single-scatter channel impulse response model of non-line-of-sight ultraviolet communications
Key Laboratory of Digital TV System of Guangdong Province and Shenzhen City, Research Institute of Tsinghua University in Shenzhen（深圳市清华研究院广东省及深圳市数字电视系统重点实验室）
