The channel estimation algorithm which has excellent performance is necessary for Single Carrier Frequency Division Multiple Access (SC-FDMA) system. The traditional Least Square (LS) algorithm and Linear Minimum Mean...
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ISBN:
(纸本)9781467372459
The channel estimation algorithm which has excellent performance is necessary for Single Carrier Frequency Division Multiple Access (SC-FDMA) system. The traditional Least Square (LS) algorithm and Linear Minimum Mean-Square (lmmse) algorithm exist many problems. The problem of the lmmse algorithm which is too complex is found to be applied effectively by researching lmmse algorithm. The traditional lmmse algorithm can be improved with the help of Jacobi iterative algorithm for solving linear equations. Meantime, theoretical analysis and simulation results indicate that: The improved lmmse algorithm has more superior performance at low SNR, it not only can reduce the computational complexity, but also has more precise estimation result.
In wavelet packet modulation (WPM) system, the application of the linear minimum mean square error (lmmse) channel estimation algorithm is limited by the nonlinearity of the fading WPM signal. To solve the problem, a ...
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ISBN:
(纸本)9783319527307;9783319527291
In wavelet packet modulation (WPM) system, the application of the linear minimum mean square error (lmmse) channel estimation algorithm is limited by the nonlinearity of the fading WPM signal. To solve the problem, a simplified linear signal model (SLSM) matching with the lmmse algorithm is established in the paper. The establishing of the SLSM is based on the fading channel and the orthogonality of WPM signals. The analysis and simulation results show that, the SLSM is matched with the lmmse algorithm, and the SLSM based lmmse algorithm can improve the WPM system performance effectively in frequency-selective fading environment.
To cope with the growth of traffic and the need for high-speed transmission, the next-generation aviation communication technology considers deploying the L-bond digital aeronautical communication system (L-DACS1) bas...
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ISBN:
(纸本)9781728195940
To cope with the growth of traffic and the need for high-speed transmission, the next-generation aviation communication technology considers deploying the L-bond digital aeronautical communication system (L-DACS1) based on orthogonal frequency division multiplexing (OFDM) in ground-to-air scenarios. But the aviation channel with strong multipath, long-distance, Doppler frequency shift and other characteristics is likely to cause severe channel fading, which affects the reliability of the system and requires channel equalization. At present, the traditional one-time equalization algorithms are generally used in the research of channel equalization in aviation communication systems, but the performance is not ideal. This paper firstly introduces the idea of iteration to the aviation communication system, proposes to use SISO (soft input soft output) equalizer and SISO decoder at the receiving end, and design the iterative receiving algorithm of joint equalization and decoding to realize signal reception. After an in-depth study of linear minimum mean square error (AIMSE) algorithm and Gaussian approximate message passing (AMP-G) algorithm, simulations were built to analyze system performance. The results show that both algorithms can significantly reduce the bit error rate, improve the system reliability, obtain 0.6 dB gain through iteration, save receiver power, and increase the flight radius. The iterative receiving algorithm can improve flight safety, optimize user experience in civil systems, and resist interference, increase the combat range in military systems, so it has broad applications.
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