本文關(guān)鍵詞：非協(xié)作FSK和CPM信號(hào)解調(diào)方法和實(shí)現(xiàn)　出處：《電子科技大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 連續(xù)相位調(diào)制 參數(shù)盲估計(jì) 復(fù)合網(wǎng)格解調(diào)

【摘要】：在調(diào)制相關(guān)信息未知的情況下,接收機(jī)對(duì)接收信號(hào)進(jìn)行解調(diào),稱之為非協(xié)作信號(hào)盲解調(diào)。關(guān)于非協(xié)作FSK信號(hào)的盲解調(diào)問(wèn)題已有大量的研究,調(diào)制參數(shù)估計(jì)和解調(diào)算法都很成熟。為了避免了FSK振蕩器突發(fā)式切換產(chǎn)生較大的頻譜旁瓣,由FSK演變出連續(xù)相位鍵控(CPFSK)。它是后續(xù)CPM信號(hào)的先驅(qū)。連續(xù)相位調(diào)制(CPM)顯著特點(diǎn)是包絡(luò)恒定,同時(shí)相位是連續(xù)變化的,為它帶來(lái)了高的頻譜利用率。CPM信號(hào)調(diào)制方式是非線性的。同時(shí)CPM信號(hào)隨著設(shè)置不同的調(diào)制參數(shù),例如調(diào)制指數(shù)、相關(guān)長(zhǎng)度,各類CPM信號(hào)表現(xiàn)出不同的性質(zhì)。所以針對(duì)這些特點(diǎn)研究相關(guān)的解調(diào)技術(shù),實(shí)現(xiàn)非協(xié)作CPM信號(hào)盲解調(diào)很有意義。本論文將CPM信號(hào)盲解調(diào)方法分為調(diào)制參數(shù)估計(jì)算法和解調(diào)算法,對(duì)它們都進(jìn)行了深入的分析和研究。主要工作內(nèi)容有：1、根據(jù)循環(huán)平穩(wěn)特性,分析了針對(duì)載頻／調(diào)制指數(shù)／符號(hào)周期估計(jì)算法的代價(jià)函數(shù),研究了針對(duì)CPM信號(hào)相位展開(kāi)的方法,為接下來(lái)調(diào)制指數(shù)調(diào)整奠定了基礎(chǔ),仿真驗(yàn)證了該算法的性能,表明該算法估計(jì)性能穩(wěn)定。2、分析推導(dǎo)了多進(jìn)制CPM信號(hào)的二進(jìn)制表達(dá)形式和其與二進(jìn)制CPM信號(hào)的頻域關(guān)系。研究了基于信號(hào)的循環(huán)譜,根據(jù)它的離散譜線結(jié)構(gòu)進(jìn)行調(diào)制階數(shù)估計(jì)。仿真驗(yàn)證該算法不受調(diào)制指數(shù)和頻率成形脈沖限制,具有較高的正確識(shí)別率。3、利用CPM信號(hào)符號(hào)之間有相關(guān)性,從而根據(jù)信號(hào)自相關(guān)函數(shù)實(shí)現(xiàn)相關(guān)長(zhǎng)度估計(jì)。利用先前估計(jì)出的調(diào)制階數(shù),仿真驗(yàn)證了適用于任意調(diào)制指數(shù)的相關(guān)長(zhǎng)度估計(jì)算法性能,表明該算法實(shí)現(xiàn)簡(jiǎn)單,估計(jì)精度高。4、在相關(guān)解調(diào)算法的基礎(chǔ)上,重點(diǎn)研究了利用復(fù)合網(wǎng)格的思想,進(jìn)行非相下解調(diào)的算法。該算法引入旋轉(zhuǎn)網(wǎng)格圖和狀態(tài)耦合轉(zhuǎn)移,實(shí)現(xiàn)了解調(diào)中對(duì)多普勒頻移的有效跟蹤。理論分析和仿真表明,該算法可以得到優(yōu)于差分的非相干解調(diào)性能,可以很好的接近最佳解調(diào)性能,同時(shí)它具有抗初相和頻偏跟蹤的優(yōu)點(diǎn)。5、在完成調(diào)制參數(shù)估計(jì)和解調(diào)算法分析之后,設(shè)計(jì)了非協(xié)作CPM信號(hào)盲解調(diào)器結(jié)構(gòu),對(duì)盲解調(diào)器進(jìn)行模塊劃分,針對(duì)DSP實(shí)現(xiàn)給出了程序流程和算法代碼優(yōu)化方法。同時(shí)分析了復(fù)合網(wǎng)格解調(diào)算法中關(guān)于Viterbi算法和網(wǎng)格之間耦合的算法復(fù)雜性,提出了基于多核DSP的復(fù)合網(wǎng)格解調(diào)方案,利用多個(gè)處理器核的并行運(yùn)算,實(shí)現(xiàn)大量數(shù)據(jù)的并行處理。
[Abstract]:In the case of unknown modulation related information, the receiver demodulates the received signal, which is called non-cooperative signal blind demodulation. There has been a lot of research on the blind demodulation of non-cooperative FSK signal. Modulation parameter estimation and demodulation algorithms are very mature in order to avoid the FSK oscillator burst switching to generate large spectrum sidelobe. The continuous phase keying (FSK) is the precursor of the subsequent CPM signal. The continuous phase modulation (CPM) is characterized by constant envelope and continuous phase variation. It brings high spectral efficiency. CPM signal modulation mode is nonlinear, and CPM signal with different modulation parameters, such as modulation index, correlation length. All kinds of CPM signals show different properties. Therefore, the demodulation technology is studied according to these characteristics. It is very meaningful to realize blind demodulation of non-cooperative CPM signal. In this paper, the blind demodulation method of CPM signal is divided into modulation parameter estimation algorithm and demodulation algorithm. The main work is: 1. According to the characteristics of cyclic stationary, the cost function of carrier frequency / modulation index / symbol period estimation algorithm is analyzed. The method of phase unwrapping for CPM signal is studied, which lays a foundation for the modulation exponent adjustment. The performance of the algorithm is verified by simulation, which shows that the estimation performance of the algorithm is stable. 2. The binary expression of multiary CPM signal and its frequency domain relationship with binary CPM signal are analyzed and deduced. The cyclic spectrum based on the signal is studied. The modulation order is estimated according to its discrete spectral line structure. The simulation results show that the algorithm is not limited by modulation exponent and frequency shaping pulse and has a high recognition rate of 3. 3. The correlation length is estimated according to the autocorrelation function of the signal by using the correlation between the symbols of the CPM signal, and the modulation order is estimated by the previous estimation. The performance of the correlation length estimation algorithm suitable for arbitrary modulation exponents is verified by simulation. It shows that the algorithm is simple in implementation and has high estimation accuracy. 4. The algorithm is based on the correlation demodulation algorithm. The algorithm of non-phase demodulation based on the idea of composite mesh is studied, which introduces the rotating grid graph and the state coupling transfer. The theoretical analysis and simulation show that the proposed algorithm can obtain better performance than the differential non-coherent demodulation and approach the best demodulation performance. At the same time, it has the advantages of anti-initial phase and frequency offset tracking. After completing the modulation parameter estimation and demodulation algorithm analysis, a non-cooperative CPM signal blind demodulator structure is designed, and the blind demodulator is divided into modules. The optimization method of program flow and algorithm code for DSP implementation is given, and the complexity of Viterbi algorithm and grid coupling algorithm in complex mesh demodulation algorithm is analyzed. A multi-core DSP based complex mesh demodulation scheme is proposed. The parallel processing of a large number of data is realized by using the parallel operation of multiple processor cores.
【學(xué)位授予單位】：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)】：TN911.3
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本文編號(hào)：1437339