DatagramChannelTest

costas环matlab仿真，已经通过验证可行(Costas ring matlab simulation, has been verified feasible)

本文以12个例程详细介绍了opnet的使用，尤其适合初学者。(This paper details the 12 routines opnet use, especially for beginners.)

一整套OFDM系统的实现程序，基于梳状导频图案的OFDM系统估计，采用LS信道估计方法，和线性插值法，信道采用瑞丽多径信道。(A whole set of OFDM system, the implementation of the program of OFDM system based on comb pilot pattern, estimates using the LS channel estimation method, and the linear interpolation method, use ruili channel multipath channel. )

百度手机地图 实例集合，应用程序编程源码，很好的参考资料。(Set Baidu mobile phone map example, application programming source code, a good reference.)

默认产生（0，1）的高斯随机数，参数可调(Gauss random number (0,1) is generated by default with adjustable parameters.)

BPSK调制，采用（15,11）汉明码对信号编码；然后对信号加噪，解调，译码。(BPSK modulation (15,11) Hamming code signal encoding then added noise to the signal, demodulation, decoding.)

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.)

说明：  51MODBUS从机程序源码希望对有用的人有用，，(51MODBUS,welcom to here,thank you very mouch.)

用simulink实现电力电子技术中的降压电路，可应用于光伏发电(Implementation of buck circuit with Simulink)

多元ldpc编译码matlap程序，采用bp译码算法(Multiple LDPC coding and decoding)