Structured light vision systems are based on the fact that the pixel location of light in an image has a unique association with the object depth. However, their applications are mainly limited to the properties of the object surface and the lighting conditions. This paper presents a robust vision system for accurate acquisition of 3-D surface data based on optimal structured light. To achieve depth measurement for a dynamic scene, the data acquisition must be performed with only a single image. Our special arrangement makes the image of the light stripe remaining sharp while the background becomes blurred. Moreover, a dynamic programming approach is proposed to track the optimal path while the laser beam is invisible or divergent under extreme condition. The principle and necessary mathematics for implementing the algorithm are presented. The robustness of the system against uncalibrated errors is demonstrated.

The Bluetooth system provides point-to-point or point-to-multipoint communications with no peer-to-peer communication. For peer-to-peer communication, a slave should be able to communicate with other slaves as well as a master. To do this, the master should indirectly forward the packets. However, the end-to-end delay of forwarding packets may be increased because the packets should be forwarded at network layer. Forwarding packets for peer-to-peer communications may also bring about some needless waste of wireless resource. In this paper, we propose the addressing policy for efficient peer-to-peer communications in Bluetooth. We also address the dynamic master selection policy in which a master is dynamically selected in order to minimize the average channel occupancy. To dynamically change master in a piconet, the master-slave switching should be executed as soon as possible. Therefore, we propose the fast master-slave switching mechanism in order to minimize the switching delay. It is observed from the simulations that our proposed policies perform better than the naive Bluetooth specification.

This letter proposes a low-complexity soft-detection algorithm for modified dual-carrier modulation (MDCM) in WiMedia ultra-wideband (UWB) systems. In order to reduce the complexity of soft-output maximum-likelihood detection (soft-MLD), which gives the optimal performance for MDCM symbols, the proposed algorithm utilizes the following three methods: real/imaginary separation, multiplierless distance calculation, and candidate set reduction. Through these methods, the proposed algorithm reduces the complexity of soft-MLD by 97%, while preventing the deterioration of its optimality. The performance of the proposed algorithm is demonstrated by simulations of 640–1024 Mbps transmission modes of the latest Release 1.5 standard of the WiMedia UWB.