MLTimeFrequencyOffsetOFDM

simulink搭建的卫星姿态动力学仿真，参考书籍是章仁为的卫星鬼道姿态动力学仿真，想学对卫星姿态有兴趣的同学强烈推荐，(simulink to build the satellite attitude dynamics simulation, reference books is Zhang Ren ghosts satellite attitude dynamics simulation, I wanted to learn for students interested in satellite attitude is strongly recommended,)

This document describes about the digital modulation techniques especially about spread spectrum.

Cognitive Radio - Securuty

说明：  频率选择性信道下无编码OFDM系统的误码率曲线。(BER of OFDM signals in FS channel without coding)

《通信系统仿真原理与无线应用》MATLAB源代码，在pudn网上也看到有这个代码，但是那个不全，有好几章代码没有，这个完整版的。(Communication System Simulation principle and wireless applications. "MATLAB source code, in pudn online to see this code, but incomplete, Several chapters code is not the full version.)

说明：  仿真高斯在大气湍流中的传输，研究对其光强和相位影响(Simulation of Gaussian propagation in atmospheric turbulence,Study on the influence of light intensity and phase)

实现通信系统的数字模拟混合预编码，进行干扰抑制，提高系统性能，降低硬件复杂度和实现成本(The digital analog hybrid precoding of the communication system is realized, the interference suppression, the performance of the system, the complexity of hardware and the cost of realizing the system are reduced.)

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.)

this file is used to activate app on startup of nokia mobile.

短信群发系统，在一些业务范围广泛的公司中，当公司有了新的通知要告诉在外地的员工，通常使用拨打电话的方式，这样虽然能把事情说清楚，但是当在外的员工比较多时，工作量很大，为了解决这个问题，可以开发一个企业短信群发管理系统。企业短信群发管理系统主要利用硬件短信猫发送短信，并且可以查看SIM卡中收到的短信。(Mass messaging system, in a number of business a wide range of companies, when the company has a new notification to tell the staff in the field, normally used by calling the way, so although things can make it clear, but when the staff out for a long time compared , the heavy workload, in order to resolve this problem, can develop an enterprise management system for mass text messaging. Short Message management system for enterprises mainly use the hardware to send SMS text messages a cat and can view the SIM card text messages received.)