Satellite-FDM-examples

说明：  OFDM信道估计的主要程序，算法研究等。(OFDM channel estimation algorithm for the main program, etc.)

说明：  matlab实现的信道指标计算求误码率低的信道(Calculation of channel index realized by MATLAB to find the channel with low bit error rate)

PPM调制信号的产生，产生随机信号。亲测可用(The generation of PPM modulation signal)

说明：  Zero forcing - with interference cancellation

说明：  设计一个巴特沃兹数字低通滤波器，其技术指标为：3dB带宽为0.2π，阻带截止频率为0.3π，通带纹波为1dB，阻带衰减大于30dB，采样间隔T=10ms。 1）采用冲激响应不变法； 2）采用双线性变换法设计； 3）采用FIR的窗函数（Hanning窗、Hamming窗或Blackman窗）设计。(A Butterworth digital low-pass filter is designed. Its technical specifications are: 3 dB bandwidth is 0.2 pi, stopband cut-off frequency is 0.3 pi, passband ripple is 1 dB, stopband attenuation is more than 30 dB, sampling interval T=10 Ms. 1) Impulse response invariance method is adopted. 2) Design by bilinear transformation method; 3) FIR window function (Hanning window, Hamming window or Blackman window) is used to design.)

用于监控PLC，针对的是modbus协议(monitoring PLC with modbus protocol)

修正的CMA盲均衡算法，用于盲信道均衡，不依赖与训练序列(Modified CMA blind equalization algorithm for blind channel equalization, and training sequences do not depend)

高速DDR存储器数据接口设计实例. 1. 将文件拷入硬盘 2. 产生DQS模块 3. 产生DQ模块 4. 产生PLL模块 5. 拷贝以上步骤生成的文件到子目录【Project】中 6. 打开子目录【Project】中的DataPath.qpf工程，设计顶层模块 7. 编译并查看编译结果 (High-speed DDR memory interface design data. 1. Copyed into the document hard disk 2. DQS generated module 3. Have a DQ module 4. Have a PLL module 5. Copies of the above steps to generate a document to a subdirectory 【Project】 6. Open the subdirectory 【Project】 DataPath.qpf in engineering, design top-level module 7. compilers to compile the results and see)

利用MATLAB实现多用户的扩频通信的发送和接受，程序可以直接跑，不需要改动！(The use of MATLAB implementation of multi-user spread spectrum communication send and receive, the program can be directly run, no changes!)

说明：  前已提出的频谱感知方法主要包括匹配滤波器检测、 能量检测、 循环平稳特征检测以及多分辨率频谱感知. 这些方法均为单节点感知方法.然而，在阴影和深度衰落情况下， 单个节点的感知结果并不可靠， 因此， 需要对多个节点的感知结果进行融合，以提高检测可靠性， 即协作感知技术. 文献采用“或” 准则对各个 CR 感知结果进行融合. 文献则提出了基于 D-S 证据理论的协作频谱感知算法，虽然该算法的性能比“或” 准则或“与”准则要好， 但需要存储大量历史信息， 算法的计算复杂度也很高. 文献中分析了采用似然比检测(likelihood ratio test， LRT) 的软判决与采用“与” 准则的硬判决的性能， 结果表明采用软判决的协作感知性能更优(Previously proposed spectrum sensing methods mainly include matched filter detection, energy detection, cyclostationary feature detection and multi-resolution spectrum sensing. These methods are all single node sensing methods. However, in the case of shadow and deep fading, the sensing results of single node are not reliable, so, It is necessary to fuse the sensing results of multiple nodes to improve the detection reliability, i.e. cooperative sensing technology. In the literature, "or" criterion is used to fuse the CR sensing results. In the literature, a cooperative spectrum sensing algorithm based on D-S evidence theory is proposed. Although the performance of the algorithm is better than "or" criterion or "and" criterion, a large amount of historical information needs to be stored, The computational complexity of the algorithm is also very high. In the literature, the performance of the soft decision based on the likelihood ratio test)