junyun_FFT_1031

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。并请描述：自己用计算机产生的经典谱是正确的依据。(2. Regarding the doppler spectrum of the wireless channel, please answer the following questions: (1) in some wireless channels, doppler frequency shift will cause aliasing of the output signals of the wireless channel.Describe the various causes of aliasing; (2) there is a classic spectrum in the doppler spectrum in the wireless channel, please explain the mechanism of producing this spectrum shape; (3) please use Simulink tool to write code (s-function mode) to generate a single-path Rayleigh channel, whose doppler spectrum is the classical spectrum, in which the moving rate is 120km/h.And please describe: your own computer generated classical spectrum is the correct basis.)

网上找的一些同步资料网上找的一些同步资料(Some synchronization information online to find)

本代码介绍了OFDM/OQAM 多径信道下，理想信道估计的系统仿真，给出了不同信噪比下的ber性能。介绍了多载波系统的均衡。(This code describes the OFDM/OQAM multipath channel, system simulation, ideal channel estimation, given the ber performance under different signal to noise ratio. The equilibrium of the multi-carrier system.)

this is for calculate qam and it is very good to practice so good u can play

dac8568驱动程序编程，可以控制dac8568进行输出(Dac8568 driver programming)

利用MATLAB实现多用户的扩频通信的发送和接受，程序可以直接跑，不需要改动！(The use of MATLAB implementation of multi-user spread spectrum communication send and receive, the program can be directly run, no changes!)

设计了差分编码移相键控(2DPSK)调制解调系统的工作流程图,并利用 Matlab 软件对该系统的动态进行了模拟仿真。利用仿真的结果,从基带信号的波形图可以衡量数字信号的传输质量 由系统的输入和输出波形图可以看出,仿真实验良好 。(Design of a differential phase shift keying encoding (2DPSK) modulation and demodulation system working flow chart of the system using Matlab software to simulate the dynamics simulation. Using simulation results, from the baseband signal waveform can be measured digital signal transmission quality by the system' s input and output waveforms can be seen that simulation is good.)

103转modbus协议C程序，支持多个485端口并能够配置(103 turn modbus protocol C program, more than 485 ports and supports the ability to configure)

这个程序除了接收机同步、信道编码没有加入外，基本上反映了一个OFDM系统的特性： 1. qpsk/16qam/64qam映射、解映射 2. OFDM调制解调（循环前缀，FFT等） 3. 非整数采样时刻多径时延的多径信道 4. Rayleigh或者Rician多径信道 5. 信道的连续时变（非block fading） 6. 线性插值信道估计 7. FFT变换域插值信道估计(In addition to this program receiver synchronization, channel coding have not joined, the basically reflect the characteristics of an OFDM system: 1. Qpsk/16qam/64qam mapping, mapping solution 2. OFDM modulation and demodulation (cyclic prefix, FFT, etc.) 3. Non- integer sampling instant multi-path delay of multi-path channel 4. Rayleigh or Rician multipath channel 5. a continuous time-varying channel (non-block fading) 6. linear interpolation channel estimation 7. FFT transform domain interpolation channel estimation)

计算非平稳随机信号的WVD时频谱的matlab程序(Calculation of non-stationary random signal WVD time-frequency spectrum of the matlab program)