【摘要】：隨著無(wú)線通信的發(fā)展,對(duì)低信噪比信號(hào)的接收得到越來(lái)越多的重視。在微弱信號(hào)環(huán)境下,利用單個(gè)天線難以進(jìn)行有效接收,一種有效的解決方法是采用多天線信號(hào)合成技術(shù)提高信噪比。在傳統(tǒng)的以固定單路信號(hào)為參考的合成方案中,參考信號(hào)如果信噪比更低或者經(jīng)歷了更惡劣的衰落信道,將嚴(yán)重影響參數(shù)估計(jì)精度,從而降低合成性能。因此,從構(gòu)造更優(yōu)參考信號(hào)的角度提高信號(hào)合成性能具有重要研究意義。本論文圍繞多天線信號(hào)合成中構(gòu)造更優(yōu)參考信號(hào)的目標(biāo),針對(duì)高斯信道下多天線信號(hào)時(shí)延對(duì)準(zhǔn)問題和頻率選擇性衰落信道下多天線信號(hào)合成問題展開研究。論文主要工作及創(chuàng)新點(diǎn)如下:1.針對(duì)高斯信道下多天線信號(hào)時(shí)延對(duì)準(zhǔn)中參考信號(hào)構(gòu)造問題,首先借助匹配濾波器界,理論推導(dǎo)了時(shí)延對(duì)準(zhǔn)誤差對(duì)合成性能影響的顯式表達(dá)式,結(jié)果表明在保證合成信噪比增益的前提下,天線數(shù)目越多對(duì)時(shí)延對(duì)準(zhǔn)性能要求越高;然后,在分析合成參考算法收斂性的基礎(chǔ)上,通過(guò)構(gòu)造聯(lián)合參考,將合成輸出信號(hào)作為參考信號(hào),提出了一種基于部分補(bǔ)償?shù)亩嗵炀�信號(hào)時(shí)延對(duì)準(zhǔn)算法(部分補(bǔ)償算法),并證明了算法的恒收斂特性。理論分析和仿真實(shí)驗(yàn)表明,該算法能夠克服合成參考算法中時(shí)延交替震蕩現(xiàn)象,具有更強(qiáng)的魯棒性。2.在非均勻天線組陣條件下,針對(duì)部分補(bǔ)償算法中補(bǔ)償系數(shù)最優(yōu)化問題,以算法收斂速度最快為目標(biāo)函數(shù)建立數(shù)學(xué)模型。通過(guò)對(duì)模型進(jìn)行求解,推導(dǎo)得到最優(yōu)補(bǔ)償系數(shù)和時(shí)延中心的顯式表達(dá)式。理論推導(dǎo)表明,最優(yōu)補(bǔ)償系數(shù)由各路信號(hào)信噪比決定,信噪比越大,最優(yōu)補(bǔ)償系數(shù)越小;而時(shí)延中心為初始信號(hào)時(shí)延的加權(quán)平均,加權(quán)值即為信號(hào)信噪比。仿真結(jié)果顯示,與合成參考算法相比,部分補(bǔ)償算法具有更快的算法收斂速度和更高的時(shí)延對(duì)準(zhǔn)性能。3.針對(duì)頻率選擇性衰落信道下多天線信號(hào)合成中參考信號(hào)構(gòu)造問題,首先從均衡器輸出均方誤差的角度證明了空間分集均衡器(SDE)與基于頻域分量最大比合并算法(FMRC)的接收結(jié)構(gòu),這兩者性能上的等價(jià)性,從而在理論上證明了FMRC算法的有效性;然后,對(duì)FMRC算法中固定參考信道的相頻響應(yīng)特性對(duì)合成信號(hào)盲均衡性能的影響進(jìn)行分析。從避免固定參考帶來(lái)合成信號(hào)盲均衡性能下降的角度,構(gòu)造平均相位參考,同時(shí)利用兩路信號(hào)合成不存在信道間相位模糊的優(yōu)點(diǎn),提出了一種基于兩兩逐路合成的平均相位參考算法。該算法計(jì)算量?jī)H與天線數(shù)目成正比,復(fù)雜度較低,并且通過(guò)仿真實(shí)驗(yàn)驗(yàn)證了該算法的有效性。4.設(shè)計(jì)并實(shí)現(xiàn)了8天線信號(hào)合成系統(tǒng),達(dá)到預(yù)期設(shè)計(jì)指標(biāo)要求。首先根據(jù)系統(tǒng)指標(biāo)要求,設(shè)計(jì)了8天線信號(hào)合成系統(tǒng)總體設(shè)計(jì)方案;然后,針對(duì)實(shí)際應(yīng)用環(huán)境給出了軟、硬件實(shí)現(xiàn)方案,并完成了部分補(bǔ)償算法等參數(shù)估計(jì)算法的DSP程序設(shè)計(jì)和實(shí)現(xiàn)、PC端合成器控制軟件設(shè)計(jì)與實(shí)現(xiàn)、FPGA與DSP高速接口設(shè)計(jì)與實(shí)現(xiàn)等主要工作;最后,通過(guò)合成性能測(cè)試與實(shí)際業(yè)務(wù)測(cè)試對(duì)系統(tǒng)進(jìn)行了檢驗(yàn),達(dá)到預(yù)期指標(biāo)要求。
[Abstract]:With the development of wireless communication, more and more attention has been paid to the reception of low signal-to-noise ratio (SNR) signals. In weak signal environment, it is difficult to receive effectively with a single antenna. An effective solution is to improve SNR by using multi-antenna signal synthesis technology. If the signal has a lower signal-to-noise ratio or undergoes a worse fading channel, the parameter estimation accuracy will be seriously affected and the synthesis performance will be reduced. Therefore, it is of great significance to improve the signal synthesis performance from the perspective of constructing a better reference signal. The main work and innovations of this paper are as follows: 1. Aiming at the problem of reference signal construction in time delay alignment of multi-antenna signals in Gaussian channel, the time delay alignment is theoretically deduced by means of matched filter bound. Explicit expression of the effect of errors on synthesis performance shows that the more antenna number, the higher delay alignment performance is required under the premise of guaranteeing the gain of synthetic signal-to-noise ratio (SNR); then, based on the analysis of convergence of synthetic reference algorithm, a joint reference is constructed to take the synthetic output signal as the reference signal, and a part-based approach is proposed. Theoretical analysis and simulation results show that the proposed algorithm can overcome the time-delay oscillation phenomenon in the synthetic reference algorithm and has stronger robustness. 2. Compensation for the partial compensation algorithm under the condition of non-uniform antenna array. The mathematical model is established with the fastest convergence speed as the objective function. The explicit expressions of the optimal compensation coefficient and the delay center are derived by solving the model. The simulation results show that compared with the synthetic reference algorithm, the partial compensation algorithm has faster convergence speed and higher delay alignment performance. 3. To solve the problem of reference signal construction in multi-antenna signal synthesis under frequency selective fading channels, the first step is equalization. From the point of view of the output mean square error, the performance equivalence between the spatial diversity equalizer (SDE) and the frequency domain component maximum ratio combining (FMRC) algorithm is proved, which proves the effectiveness of the FMRC algorithm theoretically. Then, the blind equalization of the synthetic signal to the phase frequency response characteristics of the fixed reference channel in the FMRC algorithm is given. An average phase reference algorithm based on two-to-two path synthesis is proposed to avoid the degradation of blind equalization performance of synthesized signals due to the fixed reference band. 4. A 8-antenna signal synthesis system is designed and implemented to meet the expected design requirements. Firstly, according to the system requirements, the overall design scheme of the 8-antenna signal synthesis system is designed. Then, the software and hardware implementation schemes are given for the practical application environment. The DSP program design and implementation of the partial compensation algorithm and other parameter estimation algorithm, the PC synthesizer control software design and implementation, the design and implementation of the high-speed interface between FPGA and DSP are completed. Finally, the system is tested by the synthetic performance test and the actual business test, and the expected target is achieved.
【學(xué)位授予單位】：解放軍信息工程大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN820

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張凱;于宏毅;沈彩耀;沈智翔;;隨機(jī)布局多天線信號(hào)聯(lián)合時(shí)差估計(jì)Cramer-Rao下界[J];信號(hào)處理;2013年04期

2 沈彩耀;于宏毅;胡峗鵬;;頻率選擇性信道下的多天線信號(hào)分量合成算法[J];信息工程大學(xué)學(xué)報(bào);2012年01期

3 沈彩耀;于宏毅;;天線組陣中SUMPLE算法的合成相位漂移補(bǔ)償[J];飛行器測(cè)控學(xué)報(bào);2011年06期

4 沈彩耀;胡峗鵬;于宏毅;;天線組陣中基于SUMPLE算法的故障天線分析[J];宇航學(xué)報(bào);2011年11期

5 史學(xué)書;王元?dú)J;;深空組陣Eigen算法及其低信噪比合成性能分析[J];宇航學(xué)報(bào);2009年06期

6 孔德慶;施滸立;;非均勻天線組陣SUMPLE權(quán)值信噪比及信號(hào)合成性能分析[J];宇航學(xué)報(bào);2009年05期

7 孔德慶;施滸立;;非均勻天線組陣SUMPLE合成相位補(bǔ)償及信號(hào)強(qiáng)度估計(jì)[J];電波科學(xué)學(xué)報(bào);2009年04期

8 朱婕;郭業(yè)才;;基于最大比合并空間分集判決反饋盲均衡算法[J];系統(tǒng)仿真學(xué)報(bào);2008年11期

9 鐘曉玲;周三文;李海濤;盧滿宏;;天線組陣信號(hào)合成技術(shù)的研究[J];遙測(cè)遙控;2007年S1期

10 趙洪林;童玲玲;王鋼;王磊;;海上微波信道的傳輸特性[J];哈爾濱理工大學(xué)學(xué)報(bào);2006年02期

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