基于小波包變換的多載波調(diào)制系統(tǒng)性能分析
發(fā)布時(shí)間：2018-07-31 11:07
【摘要】：小波包多載波調(diào)制系統(tǒng)(WPDM),就是小波包變換應(yīng)用于多載波調(diào)制系統(tǒng)而產(chǎn)生的一種新的多載波調(diào)制技術(shù)。具有時(shí)頻域都正交特點(diǎn)的小波包函數(shù)結(jié)合具有內(nèi)在的抗多徑衰落優(yōu)點(diǎn)的多載波調(diào)制技術(shù),使得WPDM系統(tǒng)具有頻率利用率高和良好的抗衰落、抗干擾,以及易于實(shí)現(xiàn)多速率傳輸?shù)奶攸c(diǎn),相比于傳統(tǒng)的OFDM系統(tǒng)有一定的優(yōu)勢(shì)。本文的主要目的在于WPDM系統(tǒng)的最優(yōu)小波基的選擇,分析了不同系的小波的時(shí)頻特性,根據(jù)最優(yōu)小波的選取原則,以及仿真結(jié)果的驗(yàn)證,選取出最適合本文WPDM系統(tǒng)的小波基。同時(shí)結(jié)合小波分析在信號(hào)去噪方面的應(yīng)用,對(duì)基于小波去噪的信道估計(jì)算法進(jìn)行了仿真研究,重點(diǎn)分析了小波去噪閾值選擇和小波去噪小波基的選擇對(duì)信道估計(jì)性能的影響,通過對(duì)比小波去噪信道估計(jì)和常見的幾種信道估計(jì)算法,體現(xiàn)出小波去噪信道估計(jì)的優(yōu)越性。最后通過MATLAB實(shí)現(xiàn)信道建模與仿真,分析比較WPDM系統(tǒng)和OFDM系統(tǒng)的多方面性能。通過理論分析和實(shí)驗(yàn)結(jié)果可知,綜合各方面因素,通過選用Db4作為最優(yōu)小波基可以使WPDM系統(tǒng)的性能能夠改善明顯,而且能夠使用等效濾波器算法實(shí)現(xiàn)。信道估計(jì)算法方面,基于小波去噪的信道估計(jì)算法不僅減少了運(yùn)算量,也大大的提高了系統(tǒng)的性能,是一種有效的信道估計(jì)算法。
[Abstract]:Wavelet packet multicarrier modulation system (WPDM),) is a new multicarrier modulation technique which is generated by wavelet packet transform applied to multi-carrier modulation system. The wavelet packet function with orthogonal time-frequency domain combined with the multi-carrier modulation technology which has the inherent advantages of anti-multipath fading makes the WPDM system with high frequency utilization and good anti-fading and anti-interference. Compared with the traditional OFDM system, it has some advantages. The main purpose of this paper is to select the optimal wavelet basis of WPDM system. The time-frequency characteristics of different wavelets are analyzed. According to the principle of optimal wavelet selection and the verification of simulation results, the wavelet bases that are most suitable for this WPDM system are selected. At the same time, combining the application of wavelet analysis in signal denoising, the channel estimation algorithm based on wavelet denoising is simulated, and the influence of wavelet denoising threshold selection and wavelet base selection on channel estimation performance is analyzed. By comparing wavelet denoising channel estimation with some common channel estimation algorithms, the superiority of wavelet de-noising channel estimation is demonstrated. Finally, channel modeling and simulation are realized by MATLAB, and the performance of WPDM system and OFDM system is analyzed and compared. The theoretical analysis and experimental results show that the performance of WPDM system can be improved obviously by using Db4 as the optimal wavelet basis, and the equivalent filter algorithm can be used to realize it. In the aspect of channel estimation algorithm, the channel estimation algorithm based on wavelet denoising not only reduces the computation, but also greatly improves the performance of the system. It is an effective channel estimation algorithm.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN761
本文編號(hào)：2155393
[Abstract]:Wavelet packet multicarrier modulation system (WPDM),) is a new multicarrier modulation technique which is generated by wavelet packet transform applied to multi-carrier modulation system. The wavelet packet function with orthogonal time-frequency domain combined with the multi-carrier modulation technology which has the inherent advantages of anti-multipath fading makes the WPDM system with high frequency utilization and good anti-fading and anti-interference. Compared with the traditional OFDM system, it has some advantages. The main purpose of this paper is to select the optimal wavelet basis of WPDM system. The time-frequency characteristics of different wavelets are analyzed. According to the principle of optimal wavelet selection and the verification of simulation results, the wavelet bases that are most suitable for this WPDM system are selected. At the same time, combining the application of wavelet analysis in signal denoising, the channel estimation algorithm based on wavelet denoising is simulated, and the influence of wavelet denoising threshold selection and wavelet base selection on channel estimation performance is analyzed. By comparing wavelet denoising channel estimation with some common channel estimation algorithms, the superiority of wavelet de-noising channel estimation is demonstrated. Finally, channel modeling and simulation are realized by MATLAB, and the performance of WPDM system and OFDM system is analyzed and compared. The theoretical analysis and experimental results show that the performance of WPDM system can be improved obviously by using Db4 as the optimal wavelet basis, and the equivalent filter algorithm can be used to realize it. In the aspect of channel estimation algorithm, the channel estimation algorithm based on wavelet denoising not only reduces the computation, but also greatly improves the performance of the system. It is an effective channel estimation algorithm.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN761
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 郝久玉;王小梅;齊振豪;李惠敏;;小波包多載波調(diào)制算法及DSP實(shí)現(xiàn)[J];天津大學(xué)學(xué)報(bào);2006年03期
2 楊慰民,畢光國;基于小波包變換的多址通信[J];通信學(xué)報(bào);1999年03期
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