【作者】 王建宏；

【导师】 王志斌；

【作者基本信息】 中北大学 ， 信号与信息处理， 2008， 硕士

【摘要】 为了对付战场上激光测距机目标识别器日益严重的威胁,发展激光告警技术迫在眉睫。目前激光告警系统普遍存在信噪比低、虚警率高等问题,从强背景光中提取微弱的来袭激光信号非常困难。将阿达玛变换用于激光告警接收机时,可以有效地提高系统信噪比。当应用于Sn循环矩阵时,其信噪比提高倍数达到n+1/2n^1/2。论文从阿达玛变换原理出发,分别阐述了液晶空间光调制器和面阵CMOS做编码模板实现信噪比增强技术,详细描述了编码模板的设计,对两种方法实现阿达玛变换分别作了具体的实验研究和数据采集。研究结果表明两种方法都可以在一定程度上实现阿达玛变换,但又各有不足。首先,用液晶空间光调制器做模板可以较好地实现实时解码计算,当信号输入后几秒钟就可以读到实验结果。但信噪比提高倍数与理论计算值出入较大,文中列举了几点原因并作了较详尽的分析。其二,用面阵CMOS代替光调制器充当一个虚拟的用于数据处理的阿达玛编码模板,试验表明其效果很好,与信噪比提高倍数的理论值只有16%的误差,且成本低。但其缺点在于运算量较大,耗时约是前一方法的五倍,实时应用性有待提高。文中也对后一方法做出了详细的误差分析,并给出了解决误差和改进实验的一些建议和方法。更多还原

【Abstract】 In order to meet the increasingly serious threaten of the Laser Range Finder and object identifier in the battlefield,it is important to develop the laser warning technology.Current laser warning system have the problems of low ratio of siginal to noise（SNR） and high False Alarm Rate,it is difficult to get the arriving laser from the intense background light.Applying Hadamard transform in laser warning system,the SNR of it can be improved effectively by n+1/2n^1/2 times,when using the Sn circular matrix.The paper respectively expatiated the SLM and Area Array CMOS served as the coding templet to realize the technology of improving SNR,the design of coding templet was described detailedly,experiment and data acquisition test were carried on using the two kinds of coding templet.The experiment results indicate that this two kinds of method can realize the Hadamard Transform（HT）,but each of them has disadvantages.Firstly,the coding can be realized in real time,by using the SLM,and the result can be read out in a few seconds.But the SNR was not as well as theoretic value,and the reasons were analyzed detailedly. Secondly,the Area Array CMOS replaced the light modulator was used as the Hadamard templet to process the data,ideal results can be got,and only 16%error to the theoretic value of SNR,it also has the advantage of low cost.But it has disadvantage of mass computation capacity,the computing time is quintuplicate of the SLM.Finaly,the error was analyzed,the solutions and improved experiment were put forward.更多还原