22222feedback

实现信号的上变频和信号的下变频，经过仿真实验后确定正确。(Signal up-conversion and signal down-conversion, and after a simulation to determine the correct.)

H桥级联多电平逆变器载波层叠SPWM调制(H bridge cascaded multilevel inverter carrier cascaded SPWM modulation)

这是一个完整的OFDM通信系统仿真代码。包括信源编码信源调制，信道编码，信道估计，峰均抑制比等。实际程序可用直接运行。(This is a complete OFDM communication system simulation code. Including the source modulation source coding, channel coding, channel estimation, peak to average ratio suppression. The actual procedure can be run directly.)

说明：  3. 瑞利信道中的调制解调、信道估计： (1) 请推导出单径瑞利信道中的BPSK相干解调的理论误码率性能，并画出比特信噪比与误码率的关系曲线。 (2) 在单径瑞利信道中，请设计一种时分的导引辅助的信道估计方法，用Simulink进行仿真，测量BPSK的误码率性能，画出比特信噪比与误码率的关系曲线，并与理论误码率曲线进行对比。(3. Modulation demodulation and channel estimation in Rayleigh channel: (1) deduce the theoretical bit error rate performance of BPSK coherent demodulation in single-path Rayleigh channel, and draw the relationship curve between bit signal-to-noise ratio and bit error rate. (2) in single-path Rayleigh channel, please design a time-division guidance assisted channel estimation method, Simulink simulation, measure the bit error rate performance of BPSK, draw the relationship curve between bit SNR and bit error rate, and compare with the theoretical bit error rate curve.)

卫星导航关键知识，必备文档。 需要掌握的报文，定位信息，卫星信息等等(GNSS essential knowledge, first document to keep)

计算图像的各个指标，很有用，希望大家喜欢，谢谢(Calculated images of the various indicators, very useful, I hope you like it, thank you)

说明：  6. 在三条径的瑞利信道中，对于OFDM： (1) 请设计一种具体的导引辅助的信道估计方法，用Simulink进行仿真。画出比特信噪比与信道估计均方误差的关系曲线和比特信噪比与误码率的关系曲线。 (2) 设频率已同步，请设计OFDM一种具体的采用循环前缀进行时间同步方法，用Simulink进行仿真，画出比特信噪比与捕获概率的关系曲线。 (3) 设时间已同步，请设计OFDM一种具体的采用循环前缀进行频率同步方法，用Simulink进行仿真，画出比特信噪比与频率同步误差的关系曲线。(6. In the three-path Rayleigh channel, for OFDM: (1) please design a specific navigation-assisted channel estimation method and use Simulink for simulation.The relation curves of bit signal-noise ratio and channel estimation mean square error and the relation curves of bit signal-noise ratio and bit error rate are drawn. (2) if the frequency has been synchronized, please design a specific method of time synchronization using cyclic prefix in OFDM. Simulink is used for simulation to draw the relationship curve between bit-snr and acquisition probability. (3) if time has been synchronized, please design a specific method of frequency synchronization using cyclic prefix in OFDM. Simulink is used for simulation to draw the relationship curve between bit signal-to-noise ratio and frequency synchronization error.)

说明：  本方法采用pca进行特征提取，knn分类器进行人脸识别。(The method of feature extraction using pca, knn classifier for face recognition.)

迭代法阈值分割图像，可以实现精确地像素级分割。(Iterative threshold segmentation of images)

说明：  对磁通切换电机的矢量控制仿真，仿真效果很好，可以快速跟踪转速，版本要求是2016b(Vector Control Simulation of Flux Switching Motor)