Performance study of an OFDM visible light communication system based on white LED array

By introducing orthogonal frequency division multiplexing (OFDM) technology, a visible light communication (VLC) system using a 5x5 white LED array is studied in this paper. The OFDM transmitter and receiver are modeled through MATLAB/Simulink tool. The electrical-optical-electrical (EOE) response of the VLC channel, which is also the response of the detector, is derived based on Lambert’s lighting model. Then the modeling on the overall OFDM/VLC system is established by combining the above three models together. The effects of the factors which include the digital modulation, Reed-Solomon (RS) coding, pilot form, pilot ratio (PR) and communication distance on the bit error rate (BER) of the system are discussed. The results show that through the use of RS coding, block pilot, quadrate phase shift keying (QPSK) modulation and a suitable pilot ratio about 1/3, under the communication rate about 550 kbit/s, the BER can be dropped to below 10-5, and the communication distance can reach 0.9 m.     

低渗透油田注水效果分析

对于注水开发,如何注好水,实现油田的稳油控水成为关键。通过对低渗透油区贝301区块注水开发效果的分析,总结出适合该类油田注水开发的措施,为实现低渗透油田稳油控水提供一定的借鉴。     

微生物驱油技术应用效果分析

微生物采油技术(MEOR)是利用微生物及其代谢产物增加原油产量的石油开采三次采油技术,具有改善吸水剖面和提高洗油效率的双重效果。通过在低渗、特低渗区块开展了微生物驱油工艺技术研究应用,为高压注水井剖面改善难题找到一条解决办法。