波道選擇時間 的英文怎麼說
中文拼音 [bōdàoxuǎnzháishíjiān]
波道選擇時間
英文
channel selection time- 波 : Ⅰ名詞1 (波浪) wave 2 [物理學] (振動傳播的過程) wave 3 (意外變化) an unexpected turn of even...
- 道 : Ⅰ名詞(道路) road; way; route; path 2 (水流通過的途徑) channel; course 3 (方向; 方法; 道理) ...
- 選 : Ⅰ動詞1. (挑選) select; choose; pick 2. (選舉) elect Ⅱ名詞(挑選出來編在一起的作品) selections; anthology
- 擇 : 擇動詞(挑選) select; pick; choose
- 時 : shí]Ⅰ名1 (比較長的一段時間)time; times; days:當時at that time; in those days; 古時 ancient tim...
- 間 : 間Ⅰ名詞1 (中間) between; among 2 (一定的空間或時間里) with a definite time or space 3 (一間...
- 選擇 : select; choose; opt; election; choice; culling; alternative
- 時間 : time; hour; 北京時間十九點整19 hours beijing time; 上課時間school hours; 時間與空間 time and spac...
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In this thesis, first, we present the theory of sess system, the generation of the sess spreading code and its characteristics and the acquisition theory of conventional spread spectrum communication system. an efficient acquisition scheme based on periodically transmitting the synchronization head, which is composed of binary chaotic codes, using the matched filter and automatic decision threshold - level control based on a so - called constant false alarm criterion for sess system is present. the acquisition model of sess system is built and simulated in the awgn channel, the raleigh fading channel and imulti - address interfere condition
本文首先概述了自編碼擴頻通信的原理、自編碼擴頻序列的產生方法及其特性和擴頻通信系統編碼同步的理論,然後針對自編碼擴頻通信系統提出了擴頻序列捕獲方案:周期性地加入混沌序列同步碼,並採用恆虛警率匹配濾波器捕獲法;在加性白高斯噪聲通道、瑞利衰落通道和多址干擾情況下進行了模擬,分析了各種捕獲性能:在選擇性能最優的混沌序列、適當的序列長度、虛警概率及門限值的情況下,可以獲得較短的捕獲時間和較大的捕獲概率。The following algorithms have been proposed and tested in the thesis : 1 frequency selective fading : combine the isomorphism between the input space and the output space and propose a new approach to blind equalization of the channel. compared with conventional methods, the new approach offers lower computational complexity, better performance, and more robust against the over - determination of the system order ; 2 time selective fading : a new approach to the equalization of time selective channel based on the zero - forced equalizer is proposed which is more simple in its structure of algorithm ; 3 time - varying channel : using the instantaneous mean value changes of the output signal to extract the information of channel variations and model it using ar model, kalman filter is then employed to track channel variations, it bears faster ability in tracking the variation of tv channels ; based on the isomorphism between the inputs and the outputs and some of the approaches using in mimo system, a new algorithm of equalization of simo time - varying channel is proposed, which also share the merits of being robust against the over - determination of the system order ; model the time - varying channel using the multi - resolution decomposition wavelets, and then a blind identification method based " on the model is proposed ; at last, a new model for equalization and identification of mimo system is proposed
主要工作在以下幾個方面: 1 、針對頻率選擇性衰落通道:結合輸入輸出空間同構關系提出一種新的頻率選擇性通道均衡方法,與傳統方法相比,該方法計算量更小,收斂速度更快,性能更優,且對系統階次的過確定表現穩健,具有實際均衡應用價值; 2 、針對時間選擇性衰落通道:提出一種基於迫零均衡的時間選擇性通道均衡方法,演算法結構簡單; 3 、針對時變色散通道:利用瞬態均值曲線提取通道時變信息,對之ar建模,利用卡爾曼濾波器跟蹤時變通道抽頭變化,可以快速跟蹤通道變化;基於輸入輸出空間之間的同構關系以及多輸入多輸出系統的處理方法,提出了新的單輸入多輸出色散時變通道均衡與識別演算法,同樣具有對通道階次過確定保持穩健的優點;結合小波多解析度分析提出一種基於小波模型的通道盲識別演算法;研究時變的多輸入多輸出系統的盲均衡與盲反卷積問題,給出一種時變系統處理模型。Space - time block codes ( stbc ) based on orthogonal design has attracts enough attentions in its applications in mimo - ofdm systems for its full diversity exploiting and low coding / decoding complexity. these applications include not only system performance improvement, but also reduction of the peak to average power ratio in mimo - ofdm systems. under these backgrounds, this paper first studies space - time block codes under the single carrier, flat fading situation, discusses the encoding / decoding principle and its performance under different channels. then, the author focused on the performance of space - time codes under time selective and frequency selective channels, uncovered the fundamental cause of how maximum doppler shift and power delay profile influences the performance of space - time codes through deduction and simulation
在上述背景下,本文以單載波,平坦衰落通道下的空時分組碼為切入點,深入分析了其編譯碼原理和在不同通道情況下的性能;以此為基礎,後文展開了對空時分組碼在多載波,時間選擇性和頻率選擇性衰落通道下的性能研究,通過理論推導和充分的模擬,揭示了空時/頻分組碼在時頻選擇性衰落通道中的性能變化的根本原因;在以上對多載波系統中空時分組碼的研究的過程中,作者發現了空時分組碼在降低系統峰平比方面應用的可行性,提出了一種降低峰平比的新方法。
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