ASK4

说明：  2. 关于无线信道的多普勒谱，请回答以下问题： (1) 在某些无线信道中，多普勒频移会引起无线信道输出信号的混叠。请描述产生混叠的各种原因； (2) 无线信道中的多普勒谱有一种经典谱(classic spectrum)，请解释产生这种谱形状的机理； (3) 请用Simulink工具编写代码(S-Function方式)，产生一单径瑞利信道，其多普勒谱为经典谱，其中移动速率为120km/h。并请回答：证明自己用计算机产生的经典谱是正确的可能方法。 (On the wireless channel of the Doppler spectrum, please answer the following questions: (1) In some radio channels, the Doppler frequency shift will cause the output signal of the wireless channel aliasing. Please describe the aliasing produced a variety of reasons (2) wireless channel in the Doppler spectrum has a classical spectrum (classic spectrum), please explain the mechanism of produce such spectral shape (3), please use the Simulink tool to write code ( S-Function mode), resulting in a single-path Rayleigh channel, the Doppler spectrum for the classical spectrum, including mobile rate of 120km/h. And requested the answer: that they used computer-generated classical spectrum is the right possible way.)

optisystem与MATLAB之间的联合编程(the link of optisystem and matlab)

说明：  ofdm qpsk 添加循环前缀 信道估计 补偿与均衡 信号星座图(OFDM QPSK add cyclic prefix channel estimation compensation and equalization signal constellation)

车载诊断仪，在线OBD，ECU通信协议技术规范，是诊断仪，ECU开发者必备文档 (Car diagnostic online the OBD ECU communication protocol technical specifications, diagnostic ECU developers required documentation)

用有限差分法求电场电势分布，金属盒子接地，电位是0，中间三分之一处有电位是1的长方体，求解其电场电势分布(The electric potential distribution of the electric field is calculated by the finite difference method. The metal box is grounded, the potential is 0, and the 1/3 of the rectangular bodies with the potential is 1, and the electric potential distribution of the electric field is solved.)

希尔伯特变换测试，使用希尔伯特变换对信号处理，相位偏移90°(The Hilbert transform test uses Hilbert transform to process the signal with a phase shift of 90 degrees)

说明：  实现雷达信号处理仿真，LFMMTIMTD(radar signal processing,including MTI,MTD,LFM signal)

DRM 外辐射源雷达的杂波抑制算法代码，LMS RLS ECA 有问题。(The code of clutter suppression algorithm for DRM external emitter radar has some problems with LMS RLS ECA.)

QPSK调制解调程序仿真程序，非常有参考价值(QPSK modulation and demodulation process simulation program, very useful)

COM技术内幕，com这方面的技术资料，找了很久··希望对大家有所帮助吧··(COM technology insider com, this technical information, looking for a long time we hope to help)