Chia-han Lee

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Consider a cognitive radio network with two types of users: primary users (PUs) and cognitive users (CUs), whose locations follow two independent Poisson point processes. The cognitive users follow the policy that a cognitive transmitter is active only when it is outside the primary user exclusion regions. We found that under this setup the active cognitive(More)
Battery lifetime is critical for wireless video sensors. To enable battery-powered wireless video sensors, low-power design is required. In this paper, we consider applying multi-view summarization to wireless video sensors to remove redundant contents such that the compression and transmission power can be reduced. A low-complexity online multi-view video(More)
This paper proposes two energy-efficient techniques suitable for cooperative spectrum sensing for cognitive radios. Cooperative spectrum sensing collects information from different users to make final decisions. The simplest information to be collected is the decision of each user, and this method is analogous to voting. First of all, we propose a voting(More)
Extension from the single-measurement vector (SMV) problem to the multiple-measurement vectors (MMV) problem is critical for compressed sensing (CS) in many applications. By increasing the number of measurement vectors, a k-jointly-sparse signal can be recovered with less stringent requirements on the signal sparsity. Simultaneous orthogonal matching(More)
Molecular communications emerges as a promising scheme for communications between nanoscale devices. In diffusion-based molecular communications, molecules as information symbols diffusing in the fluid environments suffer from molecule crossovers, i.e., the arriving order of molecules is different from their transmission order, leading to intersymbol(More)
The advance in nanotechnology has enabled the fabrication of nanomachines for health applications. Recently, molecular communication has become a promising communication paradigm that allows nanomachines to exchange information by using messenger molecules in fluid environments. To enable molecular communications, the knowledge of distance between(More)
Low-power wireless video sensor nodes play important roles for applications in machine-to-machine (M2M) network. Several design issues to optimize the power consumption of a video sensor node are addressed in this paper. For the video coding engine selection, the comparison between conventional video coding system and distributed video coding (DVC) system(More)