例句與造句

1. it combines the advantages of ofdm and cdma . it can convert the frequency selective channel propagation of the broadband to flat channel of the subcarrier
   它結(jié)合了ofdm和cdma技術(shù)的優(yōu)點，能夠把寬帶頻率選擇性衰落轉(zhuǎn)化為每子載波的平坦信道。
2. the protoplasts of arabidopsis were isolated and the voltage-dependent k +-selective channels in the plasma membrane were recorded by whole-cell configuration
   o。的產(chǎn)生部位。我們分離了擬南芥保衛(wèi)細(xì)胞原生質(zhì)體并記錄在不同處理條件下全細(xì)胞內(nèi)向k”電流的變化情況。
3. causes small transmission delay, but computation is complex . the other is called dsova, which does not need to know csi, with low-computation complexity and small transmission delay, and is more suitable in the case when side information is unknown . these two algorithms effectively combine the ofdm technology and the sova algorithm in rayleigh channel, resulting in an efficient sova decoding under frequency-selective channel
   另一種是不含信道估計的差分sova算法(簡稱dsova)，該算法不必知道csi，計算復(fù)雜度低，傳輸時延小，適用于邊沿信息(sideinformation，si)未知的情況，這兩種算法將ofdm技術(shù)和rayleigh信道下的sova譯碼算法有機(jī)的結(jié)合起來，很好地實現(xiàn)了頻率選擇信道下的sova譯碼。
4. so far, there is not much research on the signal detection of da-mimo system, and the general frequency selective channel is not taken into consideration . in chapter 3 of this dissertation, the coherent signal detection algorithms for da-mimo system under both flat fading and frequency selective fading channels are derived . and the analysis of the factors which affect the performance of the detection algorithms is also illustrated through computer simulations
   針對分布mimo信號檢測目前研究較少,并且沒有考慮一般意義下的頻率選擇性信道的情況,本文在第三章分別推導(dǎo)了基于平坦衰落和頻率選擇性衰落信道環(huán)境的分布mimo信號相干檢測算法,并通過計算機(jī)仿真,對影響算法檢測性能的因素進(jìn)行了分析討論。
5. 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,平坦衰落信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信道情況下的性能;以此為基礎(chǔ),后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信道下的性能研究,通過理論推導(dǎo)和充分的仿真,揭示了空時/頻分組碼在時頻選擇性衰落信道中的性能變化的根本原因;在以上對多載波系統(tǒng)中空時分組碼的研究的過程中,作者發(fā)現(xiàn)了空時分組碼在降低系統(tǒng)峰平比方面應(yīng)用的可行性,提出了一種降低峰平比的新方法。
6. It's difficult to find selective channels in a sentence. 用selective channels造句挺難的
7. combined with the data-selected schemes proposed, the computational complexity of this method can be lowered . the performance of the presented rls method is analyzed by simulations, and it is shown that this method is interesting for application . 4 time-selective channel signal model based on multipath-doppler diversity representation is given in multi-path fast fading channel, and rls space-time receiver algorithm based on time-varied constraint condition is presented and the computational complexity of this method is analyzed
   4、針對多徑快衰落信道下的ds-cdma系統(tǒng)，給出了基于多徑-多譜勒觀點描述的1百安電弓卜科東兔j憶學(xué)協(xié)士學(xué)位論文時間選擇性信道的信號模型，提出了基于變約束條件下的遞歸最小二乘空時接收機(jī)算法并分析算法的運算量，最后通過仿真分析了所提出的方法的性能。
8. 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信道：結(jié)合輸入輸出空間同構(gòu)關(guān)系提出一種新的頻率選擇性信道均衡方法，與傳統(tǒng)方法相比，該方法計算量更小，收斂速度更快，性能更優(yōu)，且對系統(tǒng)階次的過確定表現(xiàn)穩(wěn)健，具有實際均衡應(yīng)用價值；2、針對時間選擇性衰落信道：提出一種基于迫零均衡的時間選擇性信道均衡方法，算法結(jié)構(gòu)簡單；3、針對時變色散信道：利用瞬態(tài)均值曲線提取信道時變信息，對之a(chǎn)r建模，利用卡爾曼濾波器跟蹤時變信道抽頭變化，可以快速跟蹤信道變化；基于輸入輸出空間之間的同構(gòu)關(guān)系以及多輸入多輸出系統(tǒng)的處理方法，提出了新的單輸入多輸出色散時變信道均衡與識別算法，同樣具有對信道階次過確定保持穩(wěn)健的優(yōu)點；結(jié)合小波多分辨率分析提出一種基于小波模型的信道盲識別算法；研究時變的多輸入多輸出系統(tǒng)的盲均衡與盲反卷積問題，給出一種時變系統(tǒng)處理模型。