利用伪随机序列作为发送信号 dppl

利用C++实现的一个即时通讯系统的客户端。传输层采用的是TCP协议。这是本科时候的毕业设计，最后评定为优，希望对一些朋友能有所帮助。(The use of C++ implementation of an instant messaging system client. Transport layer protocol used is TCP. This is the time of undergraduate graduation project, and finally classified as gifted, in the hope that some of my friends can be helpful.)

TCM with BCJR (Log-Map) & channel Encoder Coded_Modulation

卫星信道删除卷积码的优化译码算法，介绍打孔卷积码的应用(Satellite channel to remove the convolutional code optimization Decoding Algorithm)

说明：  VC++编程环境下的USB编程(接收和发送数据）(VC++ Programming environment under the USB programming (receiving and sending data))

利用MATLAB软件对OFDM系统做出仿真。仿真中采用QPSK调制技术，并加入高斯白噪声，最终得到QPSK星座映射图以及BER曲线图。由仿真结果可以看出，OFDM在高斯信道具有良好的抗噪声性能，误码率较低。(MATLAB software is used to simulate the OFDM system. In the simulation, QPSK modulation technology is used, and Gauss white noise is added, and the map of the QPSK constellation and the BER curve are finally obtained. It can be seen from the simulation results that OFDM has good anti noise performance and low error rate in Gauss channel.)

主要用于各种实际中的定位运算，如TDOA等，可以在很短的时间内进行精确定位(It used in positioning calculation of the actual environment,for example ,TDOA.It can know the exact positioning in a short time.)

这是整套的ldpc-ofdm仿真模拟代码，可以运行的，输出的是误码率图像(This is the whole set of ldpc-ofdm simulation code, you can run the output image is the bit error rate)

LTE系统中信道的加扰调制部分,子载波建立的必要过程( LTE, modulate ,scrambing,16QAM,64QAM,QPSK,)

AM调制与解调，信息信号和载波信号经过AM调制并加噪得到AM信号的频谱，再经过带通滤波器，相干解调，低通滤波后得到解调后的信号。(AM modulation and demodulation, information signal and carrier signal through AM modulation and noise to get the spectrum of AM signal, then through band-pass filter, coherent demodulation, low-pass filter to get the demodulated signal.)

its a matlab code for ofdm with 16 qam