QPSKsimulat

说明：  5. 在三条径的瑞利信道中，对于直接序列扩频： (1) 请设计DS-CDMA一种具体的码分导引辅助的信道估计方法，接收机分别采用等均益合并、最大比合并。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) 设频率已经同步，请设计DS-CDMA一种具体的单停顿滑动相关时间同步方法，用Simulink进行仿真，画出比特信噪比与捕获概率的关系曲线。 (3) 设时间已经同步，请设计DS-CDMA一种具体的频率同步方法，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。(5. In three-path Rayleigh channel, for direct sequence spread spectrum: (1) please design a specific code division navigation aided channel estimation method for ds-cdma, and adopt equal-beneficial combination and maximum ratio combination for receivers respectively.Simulink is used to simulate and draw the relationship curve between bit SNR and channel estimation mean square error and the relationship curve between bit SNR and bit error rate. (2) assuming that the frequency has been synchronized, please design a specific single-stop sliding correlation time synchronization method ds-cdma, Simulink simulation, draw the relationship between the bit SNR and the acquisition probability curve. (3) if the time has been synchronized, please design a specific frequency synchronization method ds-cdma, Simulink simulation, draw the relationship between the bit SNR and frequency synchronization error curve.)

接收端采用的算法和程序流程与发送端发送的OFDM符号的帧结构有关系。具体的帧结构，以及定时估计，频偏估计，剩余误差跟踪的算法可参考算法说明文档。这里对程序的流程进行说明。 首先根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。 (good)

Test for DatagramChannel Source Code for Andriod.

An e book on channel coding

see the attachments- cusat

这是一个C语言实现的一阶到六阶的IIR滤波器程序,用于TI TMS320C5416 Texas 工具(This is a C-language-implemented first-to-sixth-order IIR filter program for the TI TMS320C5416 Texas tool)

用 MATLAB 对基带数字通信系统进行仿真。整 个系统模拟了发送和接收的全过程。其中调制部分采用 16QAM，并且采用基带传输(Using MATLAB for baseband digital communication system simulation. The system simulates the entire process of sending and receiving. Where the modulation part is 16QAM, and using the base band transmission)

基于盲波束形成的波达方向──多普勒稳健估计(Based on Blind Beamforming DOA ─ ─ Doppler robust estimation)

数字调制解调信号ask fsk bpsk qpsk 16qam 64qam(digital modulation and demodulation )

ML Estimation of frequency, phase, and amplitude of a sinusoid from discrete time samples MLEsim.m (ML Estimation of frequency, phase, and amplitude of a sinusoid from discrete time samples MLEsim.m)