scholarly journals X-law detection scheme for monobit transmitted-reference ultra wideband receivers

2021 ◽  
Vol 10 (2) ◽  
pp. 75
Author(s):  
Hassan Khani
Keyword(s):  
High Performance ◽  
Low Complexity ◽  
Ultra Wideband ◽  
Detection Scheme ◽  
Performance Loss ◽  
Transmitted Reference ◽  
Optimal Value ◽  
Low Complexity Implementation ◽  
Receiver Performance ◽  
Receiver Complexity

<p>In ultra-wideband (UWB) communications, monobit receivers offer a low complexity implementation but at the same time exhibit a great performance loss. In this paper, a novel detection scheme, denoted as <em>x</em>-law detection (XLD), is proposed to diminish the performance loss caused by employing monobit analog-to-digital converters in transmitted-reference (TR) UWB receivers. Simulation results show that if the optimal value is employed for <em>x</em>, the XLD-based monobit weighted TR (MWTR) receiver can achieve 14.2~15.5 dB and 8~9.2 dB performance gain over the conventional MWTR receiver in LOS and NLOS scenarios, respectively. Moreover, the XLD-based MWTR receiver performance with the optimal value of <em>x</em> is only 1.6~3 dB away from the optimum MWTR receiver performance in intra-vehicle UWB channels. Additionally, the XLD-based MWTR receiver is not sensitive to the summation interval. This feature decreases the receiver complexity and guarantees a robust performance over different multipath channels. The significant performance improvement of the XLD scheme comes at a limited complexity increase. Thus, the XLD approach is a good candidate for TR-based and other training-based monobit receivers requiring low complexity, high performance, and low power consumption.</p>

scholarly journals A Blind Video Watermarking Scheme Robust To Frame Attacks Combined With MPEG2 Compression

2010 ◽  
Vol 8 (03) ◽  
Author(s):  
C. Cruz-Ramos ◽  
R. Reyes-Reyes ◽  
M. Nakano-Miyatake ◽  
H. Perez-Meana
Keyword(s):  
Low Complexity ◽  
Extraction Process ◽  
Video Data ◽  
Video Watermarking ◽  
Blind Detection ◽  
Detection Scheme ◽  
Other Information ◽  
Low Complexity Implementation ◽  
Blind Extraction ◽  
Watermarking Scheme

In this paper, we propose a robust digital video watermarking scheme with completely blind extraction process where the original video data, original watermark or any other information derivative of them are not required in order to retrieve the embedded watermark. The proposed algorithm embeds 2D binary visually recognizable patterns such as company trademarks and owner’s logotype, etc., in the DWT domain of the video frames for copyright protection.Before the embedding process, only two numerical keys are required to transform the watermark data into a noise-like pattern using the chaotic mixing method which helps to increase the security. The main advantages of the proposed scheme are its completely blind detection scheme, robustness against common video attacks, combined attacks andits low complexity implementation. The combined attacks consist of MPEG-2 compression and common video attacks such as noise contamination, collusion attacks, frame dropping and swapping. Extensive simulation results also show that the watermark imperceptibility and robustness outperform other previously reported methods. The extractedwatermark data from the watermarked video sequences is clear enough even after the watermarked video hadsuffered from several attacks.

scholarly journals Calculating the optimal hematocrit under the constraint of constant cardiac power

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michal Sitina ◽  
Heiko Stark ◽  
Stefan Schuster
Keyword(s):  
Blood Flow ◽  
High Performance ◽  
Animal Species ◽  
Normal Values ◽  
Mechanical Load ◽  
The Body ◽  
Trade Off ◽  
Cardiac Power ◽  
Optimal Value ◽  
Good Agreement

AbstractIn humans and higher animals, a trade-off between sufficiently high erythrocyte concentrations to bind oxygen and sufficiently low blood viscosity to allow rapid blood flow has been achieved during evolution. Optimal hematocrit theory has been successful in predicting hematocrit (HCT) values of about 0.3–0.5, in very good agreement with the normal values observed for humans and many animal species. However, according to those calculations, the optimal value should be independent of the mechanical load of the body. This is in contradiction to the exertional increase in HCT observed in some animals called natural blood dopers and to the illegal practice of blood boosting in high-performance sports. Here, we present a novel calculation to predict the optimal HCT value under the constraint of constant cardiac power and compare it to the optimal value obtained for constant driving pressure. We show that the optimal HCT under constant power ranges from 0.5 to 0.7, in agreement with observed values in natural blood dopers at exertion. We use this result to explain the tendency to better exertional performance at an increased HCT.

scholarly journals High Area-Efficient Parallel Encoder with Compatible Architecture for 5G LDPC Codes

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 700
Author(s):  
Yufei Zhu ◽  
Zuocheng Xing ◽  
Zerun Li ◽  
Yang Zhang ◽  
Yifan Hu
Keyword(s):  
High Performance ◽  
Ldpc Codes ◽  
Low Complexity ◽  
Cmos Technology ◽  
Area Efficiency ◽  
Prior Art ◽  
New Radio ◽  
High Area ◽  
Significant Area ◽  
Area Efficient

This paper presents a novel parallel quasi-cyclic low-density parity-check (QC-LDPC) encoding algorithm with low complexity, which is compatible with the 5th generation (5G) new radio (NR). Basing on the algorithm, we propose a high area-efficient parallel encoder with compatible architecture. The proposed encoder has the advantages of parallel encoding and pipelined operations. Furthermore, it is designed as a configurable encoding structure, which is fully compatible with different base graphs of 5G LDPC. Thus, the encoder architecture has flexible adaptability for various 5G LDPC codes. The proposed encoder was synthesized in a 65 nm CMOS technology. According to the encoder architecture, we implemented nine encoders for distributed lifting sizes of two base graphs. The eperimental results show that the encoder has high performance and significant area-efficiency, which is better than related prior art. This work includes a whole set of encoding algorithm and the compatible encoders, which are fully compatible with different base graphs of 5G LDPC codes. Therefore, it has more flexible adaptability for various 5G application scenarios.

UWB Positioning Systsem Design: Selection of Modulation and Multiple Access Schemes

2007 ◽  
Vol 61 (1) ◽  
pp. 45-62 ◽  
Author(s):  
Hui Yu ◽  
Enrique Aguado ◽  
Gary Brodin ◽  
John Cooper ◽  
David Walsh ◽  
...  
Keyword(s):  
Multiple Access ◽  
High Performance ◽  
Ultra Wideband ◽  
Good Time ◽  
Modulation Scheme ◽  
Positioning System ◽  
Indoor Environments ◽  
Signal Design ◽  
Positioning Systems ◽  
Design Selection

In densely-populated cities or indoor environments, limited visibility to satellites and severe multipath effects significantly affect the accuracy and reliability of satellite-based positioning systems. To meet the needs of “seamless navigation” in these challenging environments an advanced terrestrial positioning system is under development. This system is based upon Ultra-Wideband (UWB) technology, which is a promising candidate for this application due to good time domain resolution and immunity to multipath. This paper presents a detailed analysis of two key aspects of the UWB signal design that will allow it to be used as the basis of such a high performance positioning system: the modulation scheme and the multiple access technique. These two aspects are evaluated in terms of spectral efficiency and synchronisation performance over multipath channels. Thus this paper identifies optimal modulation and multiple access techniques for a long range, high performance terrestrial positioning system using UWB.

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