譯碼噪聲 的英文怎麼說
中文拼音 [yìmǎzàoshēng]
譯碼噪聲
英文
decoding noise-
Turbo codes represent the new code structures, which consist of pccc ( parallel serially convolutional code ) and sccc ( serially concatenated convolutional code ). in this paper, the background of turbo codes are firstly introduced, which includes the base principle of error correction code 、 block code and convolutional code ; the principle of turbo code and the iterative decoding is secondly expanded ; the key decoding algorithm : a revised map algorithm and iterative decoding theory are detailed ; then, a new turbo code structure : hccc ( hybrid concatenated convolutional code ) is presented, and the capacity of this code method is analyzed, the average capacity upper bound is derived ; at last, this code is simulated on awgn ( additive white gaussian noise ) channel and rayleigh fading channel
本文首先介紹了turbo碼的背景知識，包括差錯控制的基本原理、分組碼和卷積碼；然後闡述了turbo碼的基本原理，包括turbo編譯碼器結構及迭代譯碼原理；較為詳細地描述了關鍵的譯碼演算法： ?種改進的最大后驗概率（ map ）譯碼演算法及迭代譯碼演算法；提出了一種新的turbo碼結構：混合turbo碼（混合級聯卷積碼） ；並用編碼性能聯合界分析方法對混合turbo碼進行了性能分析，得出了其平均性能上界；並在高斯白噪聲通道和瑞利衰落通道上分別作了一些應用研究及計算機模擬實驗。Many of communication systems take the convolutional code and viterbi algorithm as the channel coding scheme. the viterbi algorithm decoding is a kind of maximum likelihood decoding, and its performance is good over additive white gaussian noise ( awgn ) channel, but when burst errors occur, the decoding performance may be greatly degraded
維特比譯碼演算法是最大似然譯碼，在由高斯白噪聲引起的隨機錯誤的通道中有良好的性能，但當通道錯誤集中或為突發錯誤通道時，維特比譯碼演算法則性能急劇下降。To verify their effectiveness, simulation studies are conducted to test the performance of the proposed turbo codes in awgn channels and flat fading channels. in these simulations, the modified max - log - map decoding algorithm and the golden - spread interleaver are applied
模擬研究了採用優選擴散交織與改進的max - log - map譯碼演算法的turbo碼在加性白高斯噪聲（ awgn ）通道以及平衰落通道上的性能。After the analysis of viterbi decoding, we conclude that the adverse effect of impulsive noise on recognition is that the impulsive noise introduces unreliable
通過對viterbi譯碼過程的分析，得出沖激噪聲對語音識別的影響在於其引入了不可靠的概率差距。Second, this paper design the simulation scheme of bicm for comparing the performance over fading channel and awgn channel that combine 2 / 3 rate, 4 states punctured convolutional code with 8psk modulation, matching block interleave or random interleave, transform through rayleigh channel or awgn channel and use the way that combine coherent demodulation with viterbi decoding in receiver. design the scheme of bicm _ id that use the iterative decoding technique and the scheme of tcm for compare
為了驗證bicm和bicm _ id在衰落通道和加性高斯白噪聲通道（ awgn ）下的性能，設計了一個2 / 3碼率， 4狀態的鑿孔卷積碼經過塊交織或隨機交織，與8psk調制相結合，在rayleigh通道下或awgn通道下傳輸，接收端採用相干解調與維特比譯碼相結合的bicm方案，在接收端引入迭代反饋譯碼的bicm _ id方案，以及與之相比較的tcm方案。Qr code is a kind of 2d matrix barcode. it has high density, great capacity that will influent coding of 2d - barcode. a rs code is cyclic symbol error - correcting code, which can correct lost or missing data for damaged symbols
Qrcode是一種矩陣二維碼，具有信息密度大、容量高的優點，因此，譯碼時受噪聲的干擾大，採用糾錯能力比較強的非二進制bch碼中的一類? rs碼進行編碼，可以有效地抗除干擾進行糾錯。Deriving formulas of map algorithm and its modified algorithms in the log domain ( including max - log - map and log - map ), and simulating the performances of turbo codes over additive white gaussian noise ( awgn ). 2
詳細推導了map譯碼演算法，以及map演算法在對數域中的修正演算法（ max - log - map和log - map演算法） ，並對turbo碼在高斯白噪聲通道下的性能進行了模擬分析。After a great amount of detailed computer simulations and concise qualitative and quantitative theoretical analysis, the turbo codes " parameters and fpga specific hardware implementation architecture suitable for being integrated into dtv systems are determined. furthermore, the codec is completely designed with verilog hdl, ending with an occupation of less than a 600 - thousand - gate fpga chip. at this lowest hardware cost, a white noise snr threshold of 1. 8db at a net stream rate of 6mbps is achieved, which exceeds all other existent dtv systems " performance
經過大量詳細的計算機軟體模擬和簡明扼要的定性與定量的理論分析，最終確定了數字電視系統中適合採用的turbo碼參數及針對fpga特殊構架的硬體實現結構，並用verilog硬體描述語言完成了turbo碼編譯碼器的完整設計，以佔用不到一片60萬門fpga晶元的較少的硬體資源取得了在6mbps凈碼率下1 . 8db的白噪聲信噪比門限這一遠遠超過現有任何數字電視系統的性能。分享友人