發(fā)布時(shí)間：2018-05-27 01:08

  本文選題：參數(shù)估計(jì) + Alpha穩(wěn)定分布��； 參考：《西安電子科技大學(xué)》2014年碩士論文

【摘要】：近年來(lái),隨著通信環(huán)境的日趨復(fù)雜,基于高斯白噪聲環(huán)境的數(shù)字信號(hào)處理方法在實(shí)際通信環(huán)境下存在很多弊端。實(shí)際通信系統(tǒng)中的噪聲往往具有顯著的尖峰脈沖特性,且通常以Alpha穩(wěn)定分布模型進(jìn)行建模。PSK信號(hào)憑借其較強(qiáng)的抗干擾能力,廣泛應(yīng)用于高、中速數(shù)據(jù)傳輸。研究非高斯Alpha穩(wěn)定分布噪聲下PSK信號(hào)的參數(shù)估計(jì)可以為信號(hào)的解調(diào)、識(shí)別、恢復(fù)等后續(xù)工作提供依據(jù),是非合作通信信號(hào)處理過(guò)程中必不可少的環(huán)節(jié)。因此,本文對(duì)Alpha穩(wěn)定分布噪聲下的PSK信號(hào)的部分參數(shù)進(jìn)行估計(jì),所取得的主要研究成果如下:1.針對(duì)Alpha穩(wěn)定分布噪聲下PSK信號(hào)的載頻估計(jì)方法在低信噪比條件下性能較差的問(wèn)題,提出了一種基于循環(huán)共變譜的PSK信號(hào)載頻估計(jì)新方法。該方法通過(guò)構(gòu)建信號(hào)的循環(huán)共變函數(shù),推導(dǎo)出了其循環(huán)共變譜,并通過(guò)譜截面特征的提取以及該特征與載頻之間的特定關(guān)系,實(shí)現(xiàn)非高斯Alpha穩(wěn)定分布噪聲下PSK信號(hào)的載頻估計(jì)。此外,本文還從理論上分析了Alpha穩(wěn)定分布噪聲下的PSK信號(hào)載波頻率估計(jì)的克拉美羅界(CRLB)。仿真結(jié)果表明,在Alpha穩(wěn)定分布噪聲下,該方法的估計(jì)性能在低信噪比下較好。2.針對(duì)Alpha穩(wěn)定分布噪聲下PSK信號(hào)的碼元速率估計(jì)困難的問(wèn)題,提出了一種基于分?jǐn)?shù)低階離散域累加平均的PSK信號(hào)碼元速率估計(jì)新方法。該方法首先對(duì)離散時(shí)域點(diǎn)及其累加值進(jìn)行分?jǐn)?shù)低階運(yùn)算,然后構(gòu)建分?jǐn)?shù)階離散域累加平均時(shí)域圖,則相位跳變的位置點(diǎn)會(huì)出現(xiàn)峰值特性,再通過(guò)搜索并計(jì)算任意相鄰峰值譜線的時(shí)間距離,確定最小時(shí)間距離,從而得出PSK信號(hào)的碼元速率。此外,本文還從理論上分析了Alpha穩(wěn)定分布噪聲下PSK信號(hào)的碼元速率估計(jì)的克拉美羅界。仿真結(jié)果表明,在Alpha穩(wěn)定分布噪聲下,該方法的估計(jì)性能較好且計(jì)算復(fù)雜度較低。
[Abstract]:In recent years, with the increasing complexity of communication environment, the digital signal processing method based on Gao Si white noise environment has many drawbacks in the actual communication environment. The noise in practical communication system often has the characteristic of sharp spike pulse, and the model of Alpha stable distribution model is usually used to model .PSK signal, because of its strong anti-jamming ability, it is widely used in high and medium speed data transmission. The parameter estimation of PSK signal under non-Gao Si Alpha stable distributed noise can provide basis for signal demodulation, identification, recovery and so on. It is an essential link in the process of non-cooperative communication signal processing. Therefore, this paper estimates some parameters of PSK signal under Alpha stable distributed noise, and the main research results are as follows: 1. A novel carrier frequency estimation method for PSK signals based on cyclic covariant spectrum is proposed to solve the problem that the carrier frequency estimation method of PSK signals with stable distribution of Alpha noise is of poor performance under low SNR. By constructing the cyclic covariant function of the signal, the cyclic covariant spectrum of the signal is derived, and the carrier frequency estimation of the PSK signal under the non-Gao Si Alpha stable distribution noise is realized by extracting the spectral cross-section feature and the specific relationship between the characteristic and the carrier frequency. In addition, in this paper, the Clemero bound for the carrier frequency estimation of PSK signals under the stable distributed noise of Alpha is analyzed theoretically. The simulation results show that the estimation performance of this method is good at low SNR under the condition of Alpha stable distribution noise. Aiming at the difficulty of estimating the symbol rate of PSK signals under the stable distributed noise of Alpha, a new method for estimating the rate of PSK number elements based on the accumulative average of fractional low order discrete domain is proposed. In this method, the discrete time domain points and their accumulative values are first performed fractional low order operations, and then the fractional discrete domain accumulative mean time domain maps are constructed, and the peak value of the position points of the phase jump will appear. Then the minimum time distance is determined by searching and calculating the time distance of any adjacent peak line, and the symbol rate of PSK signal is obtained. In addition, this paper theoretically analyzes the Clemero bound for the estimation of the symbol rate of PSK signals under the stable distribution of Alpha noise. The simulation results show that the proposed method has better estimation performance and lower computational complexity under the stable distribution of Alpha noise.
【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】：2014
【分類號(hào)】：TN911.23

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 姚帥;方世良;王曉燕;;有色噪聲背景下的水聲跳頻信號(hào)參數(shù)估計(jì)[J];東南大學(xué)學(xué)報(bào)(自然科學(xué)版);2014年01期

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本文編號(hào)：1939726