本文選題：空域干擾抑制　切入點：通道不一致性　出處：《電子科技大學》2014年碩士論文

【摘要】：隨著全球衛(wèi)星導航系統(tǒng)(GNSS,Global Navigation Satellite System)處于日益惡劣的電磁干擾環(huán)境下,抗干擾型導航接收機起著越發(fā)重要的作用。它利用自適應陣列進行空域干擾抑制(DBF)有效地避免干擾,提高信干噪比,從而有利于接收機后端的信號捕獲、跟蹤、位置解算功能。然而,在實際應用中,DBF抗干擾性能深受陣列通道不一致性問題的影響。因此,為了保證導航接收機抗干擾能力,對于接收機通道不一致性校正方法的研究要求也越來越迫切。論文圍繞GNSS導航接收機自適應陣列通道不一致性的問題展開了深入的研究,目的是提出結合導航接收機特性的通道不一致性校正方法。論文主要工作和具體內容如下:1.研究了衛(wèi)星導航接收機通道不一致性的特性,發(fā)現接收機通道的天線部分是通道不一致性的重要組成部分,不容忽視。而常用的通道不一致性校正方法僅僅考慮了射頻前端部分的不一致性。因此,必須針對GNSS自適應陣列通道不一致性研究校正方法。2.研究了通道不一致性對衛(wèi)星導航接收機的影響。首先從不同的抗干擾性能衡量標準的角度出發(fā),研究發(fā)現通道不一致性會造成抗干擾性能惡化,表現為陣列方向圖零點深度減小,干擾抑制度減小以及捕獲過程中最高峰與次峰比值減小。然后研究發(fā)現通道的非理想頻率特性會造成衛(wèi)星信號偽隨機碼的碼元高度、碼相位延遲發(fā)生變化,進而造成相關峰峰值變化、相關峰出現總體上延遲以及發(fā)生傾斜,給碼延遲估計帶來誤差,而通道不一致性則會導致經過不同通道的衛(wèi)星信號變化不一致。最后通過理論推導發(fā)現衛(wèi)星信號經過各通道后的不一致性變化會造成空域干擾抑制模塊輸出的衛(wèi)星信號與本地參考信號的相關峰發(fā)生畸變,并且畸變情況隨DBF權向量變化,造成碼延遲估計誤差隨加權系數變化,不易補償,最終導致偽距測量誤差。3.研究接收機通道不一致性的窄帶模型,提出了一種用于GNSS自適應陣列的通道不一致性窄帶校正方法。該方法充分利用導航接收機能夠提供位置信息的優(yōu)勢,并且結合導航信號自相關特性以及正交投影原理,在不依賴于任何輔助源的情況下實現了通道不一致性的校正。首先對該方法進行了理論分析,然后通過仿真證明了該方法可以準確估計出表征通道不一致性的誤差矩陣的參數,利用該方法校正后的自適應陣列進行DBF時,抗干擾性能得到大大地提升。同時分析了校正過程中的接收信號信噪比SNR以及相關時間T這兩個因素對方法性能的影響。最后研究了方法的容差性,分析了衛(wèi)星信號來波方向這一先驗信息的誤差來源,通過仿真證明在該先驗信息存在最大角度誤差時,該方法仍能夠很好地實現通道不一致性校正。4.研究接收機通道不一致性寬帶模型,提出了一種用于衛(wèi)星導航接收機的通道頻域均衡方法。該方法的關鍵點是在通道頻域均衡前,利用接收衛(wèi)星信號與本地參考信號的相關峰值及其附近足夠多的點,結合在頻域上對通道特性進行泰勒級數展開的方式,采用最小二乘求解出泰勒級數系數實現了通道頻率特性的在線估計。它有效地避免了常用通道均衡方法中采用線性調頻信號(LFM)作為輔助校正信號的諸多缺點。在獲取各通道頻率響應后,采用逆傅里葉變換頻域均衡算法實現了通道不一致性校正。首先對在線估計算法進行了深入的理論分析和仿真驗證,證明它能準確估計出通道頻率特性,同時分析了算法性能受泰勒級數展開階數N以及在相關峰值附近取值方式的影響。然后仿真驗證了經過逆傅里葉變換頻域均衡后的各通道能夠達到一致性。最后分析了進行通道均衡后衛(wèi)星信號碼延遲估計誤差的來源以及誤差補償方案。
[Abstract]:With the development of global navigation satellite system (GNSS, Global Navigation Satellite System) in the electromagnetic interference environment deteriorating, anti-jamming navigation receiver plays an increasingly important role. It uses adaptive array spatial interference suppression (DBF) can effectively avoid interference, improve the SINR, which is conducive to the acquisition of signal receiver, tracking, position calculation function. However, in the practical application effect of DBF anti jamming performance by array channel inconsistency. Therefore, in order to ensure the ability of anti-jamming navigation receiver, receiver for channel mismatch correction method research also more and more urgent. The GNSS navigation receiver channel adaptive array the consistency problem is studied deeply, the purpose is proposed combining the characteristics of navigation receiver channel mismatch correction method. The main work and The specific contents are as follows: 1. research on the channel of satellite navigation receiver inconsistency characteristics, found that part of the receiver channel channel antenna is an important part of inconsistent, can not be ignored. But the common channel mismatch correction method only considers the inconsistency of the RF front-end. Therefore, according to the GNSS adaptive array Channel Study on the inconsistent impact of channel difference on satellite navigation receiver.2. correction research. First, from the anti-jamming performance of different measure angle, the study found that inconsistency of channels will cause deterioration of the anti-jamming performance, performance for the array nulls depth decreases, the peak time and peak interference suppression ratio in the system of reducing and capture process. Then the study found that non ideal channel frequency will cause the height of the satellite signal symbol of pseudo random code, the code phase. Late changes, causing the correlation peak changes of correlation peaks on the whole delay and tilt to the code delay estimation error, and channel mismatch will lead to change after the satellite signals from different channels are not consistent. Finally through the theoretical derivation that correlation peak satellite signal after the inconsistency of the passage. The change will cause the spatial interference suppression module output of the satellite signal and local reference signal distortion, and distortion with DBF weight vector changes caused by the code delay estimation error changes with the weighted coefficient to compensate, resulting in the pseudorange measurement error of.3. receiver channel inconsistent narrowband model, a method is presented for GNSS adaptive array channel mismatch correction method for narrowband. The method makes full use of the navigation receiver can provide location information advantage, and combined with the air guide The number of self correlation and orthogonal projection principle, does not depend on any auxiliary source is realized under the condition of channel mismatch correction. Firstly, the theoretical analysis of the method, and then the simulation proved that the method can accurately estimate the characterization of channel mismatch error matrix parameters, using the adaptive array the correction method of DBF, anti jamming performance is greatly improved. At the same time analyzed the correction process receiving signal to noise ratio of these two factors SNR and T on time method performance. Finally the tolerance method, analyzed the error sources of satellite signals to the prior information of wave direction the simulation results show that the maximum angle error exists in the prior information, the method can well realize the channel mismatch correction.4. receiver channel inconsistency broadband model, A method for channel frequency domain equalization method for satellite navigation receiver is proposed. The key point of this method is in the channel frequency domain equalization, using the correlation peak to receive the satellite signal and the local reference signal and its near enough points, combined with the Taylor series expansion of channel characteristics in the frequency domain, using the least squares solution of Taylor coefficient the series achieves online channel frequency estimation. It can effectively avoid the LFM signal used in channel equalization method (LFM) as many disadvantages. In the auxiliary correction signal to obtain the channel frequency response, the realization of channel inconsistency correction inverse Fourier transform frequency domain equalization algorithm. Firstly, online estimation algorithm the theoretical analysis and Simulation of verification, show that it can accurately estimate the frequency characteristics of the channel, and the performance of the algorithm was analyzed by Taylor The number of expansion order N and impact on the correlation peak value near the way. Then the simulation verified through inverse Fourier transform frequency domain equalization after each channel can achieve consistency. Finally analyzes the channel equalization after the satellite channel number delay estimation error sources and error compensation scheme.

【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN967.1

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本文編號：1713031