本文關(guān)鍵詞： 重疊復(fù)用 OvTDM 波形編碼 級(jí)聯(lián)OvTDM 迭代檢測(cè)　出處：《北京郵電大學(xué)》2014年博士論文　論文類型：學(xué)位論文

【摘要】：重疊復(fù)用原理是通信系統(tǒng)最本質(zhì)的現(xiàn)象。利用重疊復(fù)用原理,不僅可以實(shí)現(xiàn)高頻譜效率傳輸,還能夠獲得遠(yuǎn)優(yōu)于奈奎斯特系統(tǒng)的性能。重疊時(shí)分復(fù)用(OvTDM)系統(tǒng)是對(duì)重疊復(fù)用原理最直接的應(yīng)用,該技術(shù)利用傳輸數(shù)據(jù)符號(hào)之間的移位重疊,通過(guò)在相鄰符號(hào)之間人為引入ISI的方式提高系統(tǒng)頻譜效率。論文主要從理論和實(shí)現(xiàn)兩個(gè)方面對(duì)OvTDM進(jìn)行了分析和仿真驗(yàn)證。 理論方面在第三章詳細(xì)分析了時(shí)域重疊復(fù)用系統(tǒng)的頻譜效率、功率譜特性、信道容量和差錯(cuò)概率。證明了相鄰符號(hào)之間的移位重疊不僅不會(huì)擴(kuò)展系統(tǒng)帶寬,而且相比于奈奎斯特傳輸系統(tǒng)不存在過(guò)剩帶寬的問(wèn)題,因此可以提高系統(tǒng)頻譜效率。OvTDM的實(shí)質(zhì)是一個(gè)并行傳輸系統(tǒng),因此相比于奈奎斯特系統(tǒng)可以成倍的提高系統(tǒng)的頻譜效率。與相同譜效率下的正交傳輸系統(tǒng)(例如PSK和QAM)傳輸相比,OvTDM編碼輸出信號(hào)電平數(shù)僅隨著頻譜效率線性增加,而正交調(diào)制的信號(hào)電平數(shù)則是隨著頻譜效率指數(shù)式增加。所以,相同頻譜效率條件下OvTDM系統(tǒng)具有更低的峰平比和更大的信號(hào)節(jié)點(diǎn)歐式距離。信道容量方面證明了OvTDM系統(tǒng)可以達(dá)到波形信道的容量,而且嚴(yán)格優(yōu)于奈奎斯特系統(tǒng)的信道容量。證明了OvTDM系統(tǒng)是一種真正意義上的波形編碼方案。 差錯(cuò)概率方面,將ISI信道的差錯(cuò)概率性能界應(yīng)用到OvTDM系統(tǒng),得到了OvTDM系統(tǒng)采用矩形復(fù)用波形的差錯(cuò)概率。與正交調(diào)制相比,OvTDM在差錯(cuò)概率方面有兩大優(yōu)勢(shì),一方面OvTDM可以提供較高的編碼增益；另一方面相同頻譜效率下OvTDM所需的星座點(diǎn)比較少,因此具有較大的星座點(diǎn)距離。 第四章為了提高OvTDM編碼在低頻譜效率區(qū)域的性能,給出了OvTDM的級(jí)聯(lián)模型及其迭代檢測(cè)算法。由于OvTDM可以等效為一個(gè)復(fù)數(shù)域的卷積編碼模型,因此,OvTDM也具有類似于卷積碼的不同結(jié)構(gòu)。文中分別給出了三種不同的級(jí)聯(lián)方案：并行級(jí)聯(lián)OvTDM、串行級(jí)聯(lián)OvTDM以及混合級(jí)聯(lián)OvTDM系統(tǒng)。三種結(jié)構(gòu)分別在OvTDM編碼之間以及OvTDM和信道編碼之間進(jìn)行了級(jí)聯(lián)。由仿真結(jié)果可以看出,級(jí)聯(lián)結(jié)構(gòu)可以有效的增加OvTDM的編碼約束長(zhǎng)度,從而顯著提升OvTDM的系統(tǒng)性能。 多載波OvTDM解決了OvTDM的寬帶傳輸問(wèn)題。若直接將OvTDM應(yīng)用到OFDM系統(tǒng),除了自身的ISI,還會(huì)引入子載波間干擾,破壞子載波間的正交性,大大增加了接收機(jī)的復(fù)雜度。為了克服這個(gè)問(wèn)題,文中構(gòu)造了一種旋轉(zhuǎn)正交互補(bǔ)碼對(duì)偶。利用旋轉(zhuǎn)正交互補(bǔ)碼對(duì)偶實(shí)現(xiàn)了多載波OvTDM的傳輸。從而使得各路OvTDM可以獨(dú)立譯碼,該方案在不增加OvTDM檢測(cè)復(fù)雜度的基礎(chǔ)上實(shí)現(xiàn)了各子載波間的獨(dú)立傳輸。 最后給出了OvTDM的多小區(qū)組網(wǎng)方案和多用戶傳輸系統(tǒng)。首先利用四色原理給出了OvTDM的四色組網(wǎng)方案,利用該方案,實(shí)現(xiàn)了相鄰小區(qū)間的無(wú)干擾傳輸。而對(duì)于多用戶的OvTDM傳輸問(wèn)題,文中首先給出了多用戶OvTDM的矩陣卷積模型。給出了一種和多用戶數(shù)成線性關(guān)系的并行迭代多用戶檢測(cè)算法。該算法不僅算法復(fù)雜度低,而且能夠快速收斂到最優(yōu)算法性能。
[Abstract]:Overlapping multiplexing principle is the most essential communication system phenomenon. By overlapping multiplexing principle, can not only realize the transmission of high frequency spectrum efficiency, but also be able to obtain better performance than the Nyquist system. Overlapped time division multiplexing (OvTDM) system is the most direct application of overlapped multiplexing principle, the shift between the transmission of data symbols overlap using the technology, improve the system the spectral efficiency between adjacent symbols artificially introduced ISI. The main realization from the theory and the two aspects of the analysis and Simulation of OvTDM.
The theory in the third chapter detailed analysis of the spectral efficiency of time-domain overlapped multiplexing system, power spectrum, channel capacity and error probability. It is proved that the displacement between adjacent symbols overlap will not only extend the system bandwidth, but compared to the Nyquist transmission system does not have the excess bandwidth, so it can improve the spectrum efficiency of the.OvTDM is the essence of the system a parallel transmission system, so compared to the Nyquist system can improve the spectrum efficiency of the system. With the same spectral efficiency under the orthogonal transmission system (such as PSK and QAM) compared with OvTDM transmission, encoding the output signal level only with the spectral efficiency of linear increase, while the number of quadrature modulation signal level is with spectral efficiency index to increase the peak level. So, OvTDM system under the condition of the same spectral efficiency is lower than and greater signal node Euclidean distance. The channel capacity In terms of volume, it is proved that the OvTDM system can achieve the capacity of the waveform channel, and it is superior to the Nyquist system's channel capacity. It is proved that the OvTDM system is a true waveform coding scheme.
The error probability, ISI channel error probability performance bound is applied to the OvTDM system, the error probability of OvTDM system using rectangular waveform multiplexing. Compared with orthogonal modulation, OvTDM has two major advantages in the error probability, on the one hand, OvTDM can provide high encoding gain; on the other hand, the constellation points the same spectral efficiency under OvTDM the required is relatively small, so it has the constellation points greater distance.
The fourth chapter in order to improve the performance of OvTDM encoding spectral efficiency in the low-frequency region, given the cascade model and iterative detection algorithm OvTDM. Because OvTDM convolutional encoding model, equivalent to a complex domain so that OvTDM has a different structure similar to convolutional codes. This paper respectively presents three different schemes of cascade parallel concatenated OvTDM, serial concatenated OvTDM and hybrid cascade OvTDM system. Three structures were between OvTDM and between OvTDM encoding and channel encoding of the cascade. The simulation results show that the cascade structure can effectively increase the OvTDM encoding constraint length, thus greatly improve the system performance of OvTDM.
Multi carrier broadband transmission OvTDM solves the problems of OvTDM. If the OvTDM is applied to the OFDM system, in addition to their own ISI, will introduce intercarrier interference, destroy the orthogonality between subcarriers, greatly increasing the complexity of the receiver. In order to overcome this problem, this paper constructs a dual rotating orthogonal code by rotating orthogonal code to achieve dual transmission of multi carrier OvTDM. So that each OvTDM can be independently decoded, the scheme on the basis of not increasing the complexity of OvTDM detection based on the independent transmission of each sub carrier.
Finally, the multi cell network scheme OvTDM and multi-user transmission system are given. The first principle is given four four-color networking scheme of OvTDM by using this scheme, the interference free transmission between adjacent cells. The OvTDM transmission problem of multiple users, this paper gives a matrix convolution model of multi user OvTDM is given. A multi user and a linear relationship between the number of parallel iterative multiuser detection algorithm. The algorithm not only the complexity of the algorithm is low, and can quickly converge to the optimal performance of the algorithm.

【學(xué)位授予單位】：北京郵電大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN911.2

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本文編號(hào)：1519236