Huangfu Wei

Performance analysis for amplify-and-forward relay selection with outdated channel state information

The impact of outdated Channel State Information (CSI) on the performance of relay selections, including the partial relay selection and the best relay selection, is studied, with respect to Amplify-and-Forward (AF) mode cooperative systems. The proposed method is analysed by deriving the asymptotic closed-form expressions for some figures of merit such as the outage probability and the Symbol Error Probability (SEP). Moreover, the validity of the proposed theoretical analysis is proven via simulations. Numerical results prove that the performance of the proposed scheme is impacted considerably by various parameters such as the number of candidate relays and the end-to-end Signal-to-Noise Ratio (SNR). In the presence of cooperative networks with outdated CSI feedback, a performance improvement of more than 3 dB in terms of either outage probability or SEP can be observed by utilizing the Source-to-Destination (S→D) link rather than the method of simply increasing the number of relays.

Sea Route Monitoring System Using Wireless Sensor Network Based on the Data Compression Algorithm

The wireless sensor network (WSN) plays an important role in monitoring the environment near the harbor in order to make the ships nearby out of dangers and to optimize the utilization of limited sea routes. Based on the historical data collected by the buoys with sensing capacities, a novel data compression algorithm called adaptive time piecewise constant vector quantization (ATPCVQ) is proposed to utilize the principal components. The proposed system is capable of lowering the budget of wireless communication and enhancing the lifetime of sensor nodes subject to the constrain of data precision. Furthermore, the proposed algorithm is verified by using the practical data in Qinhuangdao Port of China.