The Experts below are selected from a list of 34236 Experts worldwide ranked by ideXlab platform
Mohsen Guizani - One of the best experts on this subject based on the ideXlab platform.
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random access preamble design and detection for mobile satellite communication systems
IEEE Journal on Selected Areas in Communications, 2018Co-Authors: Li Zhen, Bin Song, Rui Ding, Xiaojiang Du, Mohsen GuizaniAbstract:Reasonable design and effective detection of the random access preamble has become a challenging task due to the unique characteristics of mobile satellite communications. To tackle this challenge, we first design a universal long Sequence structure by concatenating multiple short Zadoff–Chu Sequences that are insensitive to carrier frequency offset (CFO), and then propose the new principles of parameter selection for short Sequences to ensure the minimum utilization of Root Sequence and the independence of the cyclic shift offset on the beam radius. To further reduce the detection complexity and improve the multi-user access performance, a fast timing detection approach is also presented by leveraging the piecewise cumulative detection and the multi-peaks joint estimation to obtain an accurate timing advance for each access user. Simulation results and complexity analysis validate the effectiveness of the new preamble in a typical satellite communication environment, and reveal that the proposed timing detection can achieve the robustness to CFO and offer outstanding performance improvements especially in multi-user scenarios while having a notably reduced computational complexity.
Huang Wei - One of the best experts on this subject based on the ideXlab platform.
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k-th Root Sequence Average Value Asymptotic Formula
Journal of Jishou University, 2010Co-Authors: Huang WeiAbstract:Let bk(n) be positive integer(n=1,2,…),that is the k-th Root part.The main purpose of this paper is to study the asymptotic properties of the Sequence {bk(n)}.Using the elementary method,two interesting hybrid asymptotic formulas involving this Sequence {bk(n)} and the generalized Mangoldt function are given.
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Average Value Asymptotic Formula of K Root Sequence
2009Co-Authors: Huang WeiAbstract:The elementary method and analytical method are used to study the nature of K Root Sequence function;the average value nature of the K-th power Root series and the related Asymptotic formula are obtained,thus developing further the research work of Professor F.Smarandache in his book "Only Problems,Not solutions".
Li Zhen - One of the best experts on this subject based on the ideXlab platform.
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random access preamble design and detection for mobile satellite communication systems
IEEE Journal on Selected Areas in Communications, 2018Co-Authors: Li Zhen, Bin Song, Rui Ding, Xiaojiang Du, Mohsen GuizaniAbstract:Reasonable design and effective detection of the random access preamble has become a challenging task due to the unique characteristics of mobile satellite communications. To tackle this challenge, we first design a universal long Sequence structure by concatenating multiple short Zadoff–Chu Sequences that are insensitive to carrier frequency offset (CFO), and then propose the new principles of parameter selection for short Sequences to ensure the minimum utilization of Root Sequence and the independence of the cyclic shift offset on the beam radius. To further reduce the detection complexity and improve the multi-user access performance, a fast timing detection approach is also presented by leveraging the piecewise cumulative detection and the multi-peaks joint estimation to obtain an accurate timing advance for each access user. Simulation results and complexity analysis validate the effectiveness of the new preamble in a typical satellite communication environment, and reveal that the proposed timing detection can achieve the robustness to CFO and offer outstanding performance improvements especially in multi-user scenarios while having a notably reduced computational complexity.
Zachary F. Burton - One of the best experts on this subject based on the ideXlab platform.
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Rooted tRNAomes and evolution of the genetic code.
Transcription, 2018Co-Authors: Daewoo Pak, Yunsoo Kim, Yanni Sun, Zachary F. BurtonAbstract:ABSTRACTWe advocate for a tRNA- rather than an mRNA-centric model for evolution of the genetic code. The mechanism for evolution of cloverleaf tRNA provides a Root Sequence for radiation of tRNAs and suggests a simplified understanding of code evolution. To analyze code sectoring, Rooted tRNAomes were compared for several archaeal and one bacterial species. Rooting of tRNAome trees reveals conserved structures, indicating how the code was shaped during evolution and suggesting a model for evolution of a LUCA tRNAome tree. We propose the polyglycine hypothesis that the initial product of the genetic code may have been short chain polyglycine to stabilize protocells. In order to describe how anticodons were allotted in evolution, the sectoring-degeneracy hypothesis is proposed. Based on sectoring, a simple stepwise model is developed, in which the code sectors from a 1→4→8→∼16 letter code. At initial stages of code evolution, we posit strong positive selection for wobble base ambiguity, supporting convergen...
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Rooted tRNAomes and evolution of the genetic code
2018Co-Authors: Daewoo Pak, Yunsoo Kim, Yanni Sun, Zachary F. BurtonAbstract:We advocate for a tRNA- rather than an mRNA-centric model for evolution of the genetic code. The mechanism for evolution of cloverleaf tRNA provides a Root Sequence for radiation of tRNAs and suggests a simplified understanding of code evolution. To analyze code sectoring, Rooted tRNAomes were compared for several archaeal and one bacterial species. Rooting of tRNAome trees reveals conserved structures, indicating how the code was shaped during evolution and suggesting a model for evolution of a LUCA tRNAome tree. We propose the polyglycine hypothesis that the initial product of the genetic code may have been short chain polyglycine to stabilize protocells. In order to describe how anticodons were allotted in evolution, the sectoring-degeneracy hypothesis is proposed. Based on sectoring, a simple stepwise model is developed, in which the code sectors from a 1→4→8→∼16 letter code. At initial stages of code evolution, we posit strong positive selection for wobble base ambiguity, supporting convergence to 4-codon sectors and ∼16 letters. In a later stage, ∼5–6 letters, including stops, were added through innovating at the anticodon wobble position. In archaea and bacteria, tRNA wobble adenine is negatively selected, shrinking the maximum size of the primordial genetic code to 48 anticodons. Because 64 codons are recognized in mRNA, tRNA-mRNA coevolution requires tRNA wobble position ambiguity leading to degeneracy of the code.
Xiaojiang Du - One of the best experts on this subject based on the ideXlab platform.
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random access preamble design and detection for mobile satellite communication systems
IEEE Journal on Selected Areas in Communications, 2018Co-Authors: Li Zhen, Bin Song, Rui Ding, Xiaojiang Du, Mohsen GuizaniAbstract:Reasonable design and effective detection of the random access preamble has become a challenging task due to the unique characteristics of mobile satellite communications. To tackle this challenge, we first design a universal long Sequence structure by concatenating multiple short Zadoff–Chu Sequences that are insensitive to carrier frequency offset (CFO), and then propose the new principles of parameter selection for short Sequences to ensure the minimum utilization of Root Sequence and the independence of the cyclic shift offset on the beam radius. To further reduce the detection complexity and improve the multi-user access performance, a fast timing detection approach is also presented by leveraging the piecewise cumulative detection and the multi-peaks joint estimation to obtain an accurate timing advance for each access user. Simulation results and complexity analysis validate the effectiveness of the new preamble in a typical satellite communication environment, and reveal that the proposed timing detection can achieve the robustness to CFO and offer outstanding performance improvements especially in multi-user scenarios while having a notably reduced computational complexity.
