Orthogonal Space-time Block Coding for Wireless Sensor Networks : Performance Results

Diversity, i.e. transmitting multiple replicas of a signal, may mitigate fading in wireless sensor networks. Among other diversity techniques, the space diversity systems are particularly interesting since it can complement other forms of diversity. The paper presents design and analysis of orthogonal space time block codes which provide a new concept for transmission over rayleigh fading channels. Data is encoded using an orthogonal space-time block code, and the encoded data is split into n streams which are simultaneously transmitted using n transmit antennas. In the structure, the noise added by the channel is considered as additive white gaussian noise. The system performance is evaluated using the Maximum likelihood (ML) decoding. Numerical and simulation results show that orthogonal space time block codes in wireless sensor networks exhibits significant performance improvement over Alamouti STBC, especially in interference limited conditions.