Fiber Bragg grating-based, 511 chip, 500 Gchip/s encoders-decoders are experimentally demonstrated by the reconstruction equivalent-chirp (REC) method. Encoding-decoding efficiency close to the theoretical value is ac...
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Fiber Bragg grating-based, 511 chip, 500 Gchip/s encoders-decoders are experimentally demonstrated by the reconstruction equivalent-chirp (REC) method. Encoding-decoding efficiency close to the theoretical value is achieved. Without any real phase shifts, the encoders-decoders are fabricated by use of the traditional setup. Highly precise phase control requires only submicrometer precision. The encoding-decoding performance can be further improved by REC-based correction. (c) 2006 Optical Society of America.
This paper provides a comprehensive review on transducer technologies for underwater communications. The popularly used communication transducers, such as piezoelectric acoustic transducers, electromagnetic acoustic t...
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ISBN:
(纸本)9781510660793;9781510660809
This paper provides a comprehensive review on transducer technologies for underwater communications. The popularly used communication transducers, such as piezoelectric acoustic transducers, electromagnetic acoustic transducers, and acousto-optic devices are reviewed in detail. The reasons that common air communication technologies are invalid die to the differences between the media of air and water are addresses. Because of the abilities to overcome challenges the complexity of marine environments, piezoelectric acoustic transducers are playing the major underwater communication roles for science, surveillance, and Naval missions. The configuration and material properties of piezoelectric transducers effects on signal output power, beamwidth, amplitude, and other properties are discussed. The methods of code and decode communication information signals into acoustic waves are also presented. Finally, several newly developed piezoelectric transducers are recommended for future studies.
In order to solve the problem of coded targets matching caused by the roll and split structure of external stores model in wind tunnel, this paper proposed an improved code and decode algorithm based on encircled code...
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ISBN:
(纸本)9781728100647
In order to solve the problem of coded targets matching caused by the roll and split structure of external stores model in wind tunnel, this paper proposed an improved code and decode algorithm based on encircled coded targets with template points. Compared to traditional encircled coded targets, the improved algorithm can realize the fast recognize and high precision match in the complex environment of wind tunnel without opening holes, destroying the aerodynamic shape, changing the strength and stiffness of the structure or increasing the manufacturing cost. The coded targets decode according to the distance relation between the two circular targets, and the angle relation between the circular targets vectors and the template points vectors. The experimental result shows that the recognition accuracy is higher than 98%, the ratio of unrecognized targets is below 2%, and the error rate is almost 0%.
This paper addresses the performance of the new Range Extensions profile of HEVC standard for professional UHDTV contribution services, where 4:2:2 color format, a bit depth of 10-bits, and high bit rates are required...
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ISBN:
(纸本)9781629938370
This paper addresses the performance of the new Range Extensions profile of HEVC standard for professional UHDTV contribution services, where 4:2:2 color format, a bit depth of 10-bits, and high bit rates are required in order to achieve excellent video quality. — With the aim to carry out a neutral technology comparison for the 4k format, we have conducted some simulations using the HM reference software of HEVC, under the new “Main 422 10-bits” profile, and JM reference software of H.264 under the “High 422”” profile. The experiment results show that for the same objective quality obtained by H.264, HEVC can achieve a bit rate saving in the range of 30% to 50%, reaching the best performance for the most complex sequences. — We have repeated the experiment to gather the HEVC robustness in a cascaded encoding-decoding 4K contribution scenario, implementing a new HEVC simulation with two re-encoding stages. The results reveal that the average quality losses for second generation are really low, around 0.3dB, but the bit rate penalty is over 20%. These results can help network operators and broadcasters to estimate efficiently the bandwidth services.
This paper extends the well-known source coding problem of multiple descriptions, in its general and basic setting, to analog source-channel coding scenarios. Encoding-decoding functions that optimally map between the...
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ISBN:
(纸本)9781479999897
This paper extends the well-known source coding problem of multiple descriptions, in its general and basic setting, to analog source-channel coding scenarios. Encoding-decoding functions that optimally map between the (possibly continuous valued) source and the channel spaces are numerically derived. The main technical tool is a non-convex optimization method, namely, deterministic annealing, which has recently been successfully used in other mapping optimization problems. The obtained functions exhibit several interesting structural properties, map multiple source intervals to the same interval in the channel space, and consistently outperform the known competing mapping techniques.
In this paper, the leaderless and leader-following consensus problems are considered for a class of discrete-time multi-agent systems with limited communication data rate. Under a connected undirected communication ne...
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ISBN:
(纸本)9781467357159
In this paper, the leaderless and leader-following consensus problems are considered for a class of discrete-time multi-agent systems with limited communication data rate. Under a connected undirected communication network, a quantized observer-based encoding-decoding scheme is designed and a distributed control law based on the outputs of the encoders and decoders is proposed. With the help of the perturbation analysis of matrices and quantization technique, it is shown that n bits of information exchange between agents are enough to guarantee the quantized leaderless and leader-following consensus with an exponential convergence rate, when each agent is in the form of the n-th order integrator and observable with one measurable state.
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