mqtt收发

Performace analysis of Zero Forcing detection in (2,2) MIMO system using 4 QAM modulation in Rayleigh Flat Fading Channel

802.16协议标准，中文版，非常实用，可与英文版对照(802.16 protocol specification)

说明：  温度报警系统程序，已经调试成功的，没有问题。(emperature alarm system program, has been successfully debugged, no problem.)

这是看完一本通信仿真手册后我自己写的一点程序，包括ASK FSK PSK的调制和解调程序，不过是比较简单的 ，因为用了公式的()

在实际的调谐解调电路中，采用的是非相干载波解调，本振信号与发射端的载波信号存在频率偏差和相位抖动，因而解调出来的模拟I、Q基带信号是带有载波误差的信号。这样的模拟基带信号即使采用定时准确的时钟进行取样判决，得到的数字信号也不是原来发射端的调制信号，误差的积累将导致抽样判决后的误码率增大，因此数字QPSK解调电路要对载波误差进行补偿，减少非相干载波解调带来的影响。(In the actual tuning and demodulating circuit, non-coherent carrier demodulation is adopted, and the frequency deviation and phase jitter of the local oscillator signal and the carrier signal of the transmitting end are present, and thus the demodulated analog I and Q baseband signals are signals with carrier error.)

文件中包括括了Multipath fading Channel和RAleigh Fading Channel 的MATLAB实现方式，程序可以直接运行(Documents, including including a Multipath fading Channel and RAleigh Fading Channel implementations of MATLAB, the program can be directly run)

NLMS for channel equalization

OFDM中降低峰均比的方法，将传统的SLM法，改进的SLM法和限幅加改进SLM法进行比较(Compare OFDM PAPR reducing methods in the traditional SLM method, improved SLM method and limiter plus improved SLM method)

vc++开发的socket通信类（含客户端和服务端）(socket communication(include client and server))

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.)