In an optical wireless scattering communication network, the receiver needs to periodically listen to the channel to detect whether the channel is occupied by other transceiver pairs. It falls into the spectrum sensing category of the cognitive radio. In this work, we adopt the sequential detection for the spectrum sensing, for both the photon-counting receiver and the photomultiplier tube (PMT) receiver. For the PMT receiver, to reduce the computational complexity, we propose the one-term approximation for the log-likelihood ratio computation. From simulations, it is seen that the one-term approximation can show virtually the same number of samples as that for the exact log-likelihood ratio (LLR) computation to achieve certain miss detection(MD) and false alarm (FA) probabilities, significantly fewer than that required by the Gaussian approximation.
['Xiaona Liu', 'Chen Gong', 'Zhengyuan Xu']
Sequential detection for optical wireless scattering communication