zhaidai

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.)

采用循环前缀的OFDM信道盲估计算法,经典的忙估计(Cyclic prefix OFDM blind channel estimation algorithm)

在MATLAB上设计一个（2，1，3）卷积编码器和对应的采用维特比译码算法的译码器。编码器的生成多项式为：[1 0 1；1 1 1]。将编码器的输出经过一个高斯白噪声信道的结果作为译码器的输入，观察比较译码器输出和编码器输入，了解卷积码的容错性，并计算译码结果的误比特率.(A convolutional coder (2, 1, 3) and corresponding decoder using Vitby decoding algorithm are designed on MATLAB. The generating polynomial of encoder is: [1 01; 11 1]. The output of the encoder through a Gauss white noise channel as a result of the decoder input, compare the output of the decoder and encoder input, understand the fault tolerance of convolutional code, and calculate the decoding results of bit error rate.)

关于nrf24L01的开发设计资料，内含源码分析，可做为设计2.4G无线通信的开发参考(About nrf24L01 development and design information, containing source code analysis can be used as design 2.4G wireless communication development reference)

基于相关性分析的OFDM系统信干噪比盲估计，一种利用循环前缀进行信道计数估计，和信噪比盲估计的新方法(Correlation analysis based on OFDM system SINR blind estimation, a use of cyclic prefix for channel count estimates, and SNR estimation method of blind)

说明：  这是关于多输入多输出正交频分复用索引的代码(Multiple input multiple output orthogonal frequency division multiplexing index modulation simulation code)

说明：  TCP/IP通信截取指定IP和port的数据包(packet sniffer)

说明：  实现了8PSK的调制，画出了时域及频域信号波形，以及8PSK的星座图。(The 8PSK modulation is realized, and the time domain and frequency domain signal waveforms, as well as the 8PSK constellation diagram are drawn.)

有关多普勒频移与距离的关系的matlab仿真(doppler shift)

低信噪比条件下的高分辨DOA估计算法,提出一种基于多级维纳滤波器(MSWF)的信号波达方向(DOA)估计算法。通过测试信号子空间的估计值与噪声子空间的正交性实 现 DOA粗估计，通过测试MSWF 分解的互相关函数实现信号 DOA 的精估计。仿真实验表明，在低信噪比条件下，该算法比已有的子空 间类算法有更好的分辨率和误差性能。(Put forward a kind of multistage Wiener filter (MSWF) based on the signal direction of arrival (DOA) estimation algorithm. By testing the orthogonality between the estimated values of the signal subspace and the noise subspace Now DOA coarse estimation, by testing the MSWF decomposition of the cross-correlation function to achieve accurate estimation of signal DOA. Simulation results show that the proposed algorithm is more efficient than the existing subspace in low SNR conditions The inter class algorithm has better resolution and error performance.)