【摘要】：隨著信息時代的到來，人們需要的信息量也越來越來，而隨著DVB-S2標(biāo)準(zhǔn)的確立，更高的靈活性，更強的糾錯性能，更大的傳輸容量的接收機擁有更好的市場空間。而在無線通信系統(tǒng)中，當(dāng)碼率一定的情況下，接收端設(shè)計的好壞關(guān)系到解碼端解碼性能。 本文主要工作包括如下幾部分： （1）基帶處理中的定時同步，載波恢復(fù)，DAGC（自動增益控制），均衡以及SNR（信噪比）估計都對直流分量敏感，因此在數(shù)字處理之前需要進(jìn)行去直流分量的操作。本文結(jié)合系統(tǒng)的特征，通過對分塊平均求值法和滑動平均求值法進(jìn)行深入的分析，找出一種在資源和性能上平衡的新算法。 （2）數(shù)字信號是以幀為單位來進(jìn)行發(fā)送，而解碼端正確解碼必須知道幀的起始位置，因此幀同步的實現(xiàn)是系統(tǒng)正常運行的首要條件。由于本系統(tǒng)有一部分輔助信號，在合理利用輔助信號的基礎(chǔ)上，本文設(shè)計出既能在低信噪比（最低可到0dB）,又能在有頻偏相偏條件下的幀同步方法。 （3）接收端將接收到的有用信號首先經(jīng)過模擬AGC，將信號放大到一個合適的范圍，再將信號輸送給后面的基帶處理。但是由于模擬AGC的性能所限，并不能滿足解碼端的需求，為了更精準(zhǔn)的還原信號，，在利用已知信號的基礎(chǔ)上，利用拉格朗日插值方法設(shè)計DAGC算法，為后面的解碼模塊提供更好的數(shù)據(jù)。 （4）SNR估計可以使系統(tǒng)解調(diào)性能得到有效提高。本文在充分利用輔助信息的基礎(chǔ)上，根據(jù)輔助信息的特性，設(shè)計出較低復(fù)雜度和較高性能的SNR估計方法。 本文提出的上述方法，可以有效的提高無線傳輸系統(tǒng)的接收端解碼性能。
[Abstract]:With the arrival of the information age, people need more and more information, and with the establishment of DVB-S2 standards, higher flexibility, stronger error-correcting performance, larger transmission capacity of the receiver has a better market space. In wireless communication system, when the bit rate is fixed, the design of the receiver is related to the decoding performance of the decoder. The main work of this paper is as follows: (1) timing synchronization, carrier recovery DAGC, equalization and SNR estimation are sensitive to DC components in baseband processing. Therefore, the operation of dedirect current component is needed before digital processing. According to the characteristics of the system, this paper analyzes the block average evaluation method and the moving average evaluation method, and finds out a new algorithm to balance the resource and performance. (2) the digital signal is transmitted in the unit of frame. The decoder must know the starting position of the frame correctly, so the realization of frame synchronization is the most important condition for the system to run normally. Because the system has a part of auxiliary signal, on the basis of reasonable utilization of auxiliary signal, In this paper, a frame synchronization method is designed, which can achieve low signal-to-noise ratio (0dB) and frequency offset. (3) the useful signal received by the receiver is first simulated to amplify the signal to a suitable range. The signal is then transmitted to the subsequent baseband processing. However, due to the performance limitation of analog AGC, it can not meet the needs of decoder. In order to restore the signal more accurately, the Lagrange interpolation method is used to design the DAGC algorithm based on the known signal. (4) SNR estimation can effectively improve the demodulation performance of the system. On the basis of making full use of auxiliary information and according to the characteristics of auxiliary information, a low complexity and high performance SNR estimation method is designed in this paper. The proposed method can effectively improve the receiver decoding performance of wireless transmission systems.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN92;TN791

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本文編號：2168040