基于3KHz带宽的短波高速数传均衡算法设计与实现

发布时间：2018-06-19 15:27

本文选题：码间串扰(ISI) + 信道估计　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：短波通信是中远距离无线通信的重要方式,在实际中得到了广泛的应用;但是由于短波信道存在的多径干扰、衰落和多普勒频移等信道特性,使得传送信号发生了严重的码间串扰以及信号失真,从而导致系统传输性能大大降低。针对短波信道的这些特性,本文在短波高速数传的基础上,通过研究信道估计技术和均衡技术以提高系统的抗多径衰落的能力。首先介绍了三种信道估计算法,即自相关信道估计算法、最小均方误差算法和递归最小二乘法,并结合美军标MIL_STD_188_110C中规定的数据帧结构,讨论了采用信道插值算法的信道估计方法。其次研究了基于MMSE准则的频域Turbo均衡技术,将时域的卷积计算转换为频域的点乘计算,从而减小了运算量,降低了实现的复杂度;研究了采用软干扰抵消(SIC)的均衡技术,以软信息迭代的方式来提高系统的传输性能。然后,针对传输帧中未知数据较长的情况,给出了将数据块组合的高阶插值信道估计方法,提高了估计精度和频域均衡的性能。最后,仿真验证了本文所给出的方法,结果表明:性能比美军标提升了3dB。还介绍了小数抽头均衡器,该均衡器采用不低于奈奎斯特(Nyquist)速率的采样速率,以弥补整数间隔抽头均衡器对于定时信息敏感、无法完全补偿信道失真而需要额外匹配滤波器的特性;给出了一种简化算法,以减少小数抽头均横算法的运算量。仿真表明,达到了美军标的指标要求。
[Abstract]:Short wave communication is an important way of the medium and far distance wireless communication, which has been widely used in practice. However, due to the characteristics of multipath interference, fading and Doppler frequency shift in the short wave channel, the transmission signal has serious inter code crosstalk and signal distortion, which causes the transmission performance of the system to be greatly reduced. These characteristics of the wave channel, based on the high speed number transmission of short wave, through the study of channel estimation and equalization technology to improve the ability to resist multipath fading. Firstly, three channel estimation algorithms are introduced, namely, autocorrelation channel estimation algorithm, minimum mean square error algorithm and recursive least square method, combined with American Standard MIL_STD_. The channel estimation method using channel interpolation algorithm is discussed in the data frame structure specified in 188_110C. Secondly, the frequency domain Turbo equalization technology based on MMSE criterion is studied. The time domain convolution calculation is converted to the frequency domain point multiplication calculation, thus the computation is reduced and the complexity of the realization is reduced; the average of the soft interference cancellation (SIC) is studied. In order to improve the transmission performance of the system with the soft information iteration, the high order interpolation channel estimation method, which combines the data blocks, is given to improve the estimation accuracy and the performance of the frequency domain equalization. Finally, the simulation results show that the performance ratio is compared. 3dB. also introduces a small number tap equalizer, which uses a sampling rate of not less than the Nyquist (Nyquist) rate to make up for the timing information sensitive to the integer spacer equalizer, which can not completely compensate for the channel distortion, and requires the characteristics of the additional matching filter. A simplified algorithm is given to reduce the small size of the equalizer. The number of taps algorithm is calculated. The simulation shows that it meets the requirements of the US military standard.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN925

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