project1

提供实现了（2，1，7）卷积码的维特比译码的源程序，采用了最大似然算法，介绍了软判决维特比译码算法过程的三个步骤：初始化、度量更新和回溯译码。(for achieving a (2,1,7) Convolutional Codes Viterbi decoding of the source, using the maximum- likelihood algorithm, introduced a soft-decision Viterbi decoding algorithm of the three steps : initialization, Metric update and backtracking decoding.)

说明：  lms基础算法，已经经过测试，可以通过。(LMS basic algorithm has been tested and passed.)

QPSK定时同步代码，采用Gardner定时同步算法，Farrow插值算法(QPSK timing synchronization code, using Gardner timing synchronization algorithm, Farrow interpolation algorithm)

在 OFDM 数学原理和收发模型的基础上，本文对帧同步、定时同步、频率同 步和采样同步给 OFDM 系统所产生的影响进行了理论分析，同时讨论了基于循环 前缀或训练符号的典型 OFDM 同步算法。参考 802.11a 突发数据帧结构和系统参 数，分析几种 OFDM 同步算法用于突发分组传输的性能；在分析了几种经典的信 道估计算法基础上,通过对复杂度和性能的折衷，选择一种适合本文系统的估计 算法。最后作者提出一种改进型 LS 信道估计算法，该算法考虑了 LS 算法中噪声 的影响，从而提高了低信噪比下信道估计的精度。仿真结果表明，改进算法在低 信噪比下具有良好的性能。 (OFDM mathematical principles and transceiver model based on frame synchronization, timing synchronization, frequency synchronization and sampling synchronization to the OFDM system, the impact of the theoretical analysis are also discussed based on the cyclic prefix or training symbols typical OFDM synchronization algorithm . Reference 802.11a burst data frame structure and system parameters, analyze several OFDM synchronization algorithm for burst packet transmission performance several classic channel estimation algorithm based on a compromise between complexity and performance, select a suitable estimation algorithm in this article. Finally, the author proposed a modified LS channel estimation algorithm that takes into account the effects of noise in the LS algorithm, thus improving the low SNR channel estimation accuracy. Simulation results show that the improved algorithm has good performance in low signal-to-noise ratio.)

modbus协议栈，供大家参考！ 供大家参考！(modbus connection protocol stack, for your reference! For your reference!)

图形界面实现MQTT通信协议的演示例子程序。(This is an MQTT GUI Demo application,to show how to progrrame with MQTT.)

读取CORS数据，重采样成30秒，计算电离层总电子含量(Read CORS data, resampling into 30 seconds, calculate the total electron content of the ionosphere)

opnet学习资料，提供部分网络仿真模型。一:介绍OPNET 环境。二：执行M/M/1队列模型。三：以太网模型（Aloha，CSMA,CSMA－CD).四：TCP.五：OSPF(OPNET learning materials, providing part of the network simulation model. 1: Introduction OPNET environment. Second: The Executive M/M/1 queue model. III: Ethernet model (Aloha, CSMA, CSMA-CD). IV: TCP. 5: OSPF)

说明：  可实现，线性调频信号的产生，波形显示，波形解调和码字解调功能(Realizable, chirp signal generation, waveform display, waveform demodulation and codeword demodulation)

说明：  pcm编码 有关线性,A律,mu律的pcm编码的matlab实现(Matlab implementation of pcm coding for pcm coding related to Linear, A-Law and mulaw)