2,312 publications from this institution
Multiresolution M-ary differential chaos shift keying (MR-M-DCSK) modulation using nonuniformly spaced phase constellation is a promising technique that can satisfy different bit-error-rate (BER) requirements within one symbol over multipath fading channels. However, the BER performance always deteriorates as the modulation order M becomes larger. To overcome this shortcoming, a new hierarchical square-constellation-based M-DCSK communication system using non-uniformly spaced distance constellation is proposed, which can be easily extended to other-constellation scenarios, e.g., rectangular, star, and asymmetrical square constellations. Furthermore, an adaptive transmission scheme is designed by modifying the distance between the two constellation points in the last hierarchical level. In addition, theoretical BER expressions of the proposed systems are derived over multipath Rayleigh fading channels, which are consistent with the simulated results. Analytical and simulated results show that the proposed system not only can provide lower energy consumption as compared with the conventional MR-M-DCSK system but also can efficiently adjust BER performance based on the signal-to-noise ratio information. Therefore, the proposed system can serve as a desirable alternative for energy-efficient short-range wireless-communication applications.
Perceptron is one of the most important aspects of artificial neural networks (ANN), while cellular neural networks (CNN) are biologically inspired systems in which computation emerges from the collective behavior of some locally coupled simple cells. However, whether the minimal number of the neurons in the hidden layer of a perceptron needed or a CNN template design for performing a prescribed task has not been completely characterized today. This article summarizes several algorithms for decomposing linearly non-separable Boolean function, specially a DNA-like decomposing algorithm and a shortest distance decomposing algorithm, with emphasis on the relationship between universal perceptron (UP) and CNN, and provides some examples to show the powerful ability of these algorithms in decomposing non-LSBF. Moreover, a new concept named CNN-UP is developed, which may lead to a useful new PC software in designing CNN and perceptron in the near future.