ofdm

Multiple input multiple output techniques combined with orthogonal frequency division multiplexing (MIMO-OFDM) provide a promising approach for wireless systems. However, a serious drawback of the OFDM system is the high peak-toaverage power ratio (PAPR), which may severely affect the power efficiency of RF power amplifiers. In this paper, we propose a simple method to reduce the PAPR of MIMO-OFDM signals based on the use of unused subcarriers. Instead of processing the signals at each transmitter separately, a peak cancelling signal is generated at one antenna and is then applied to all the others with only simple modifications. Simulation has shown that a minimum 2 dB reduction in PAPR can be achieved for all transmit signals using this approach. As the signal processing is nearly all done at a single transmitter, repetition of the operations at each transmitter is avoided, and therefore the overall cost of the system can be significantly reduced.

循环谱估计算法，SSCA，FAM，可以运行，结果不错，你值得拥有(Cyclic spectrum estimation algorithm, SSCA, FAM, you can run, and the results are good, you deserve)

通信基本仿真3,适合初学者学习的代码,包括了调制,分析等等:使用IIR filter的经典模拟滤波器（巴特沃斯Butterworth,切比雪夫Chebyshev）,Bartlett周期图谱，加窗Bartlett周期图谱，基带波形仿真，IIR的贝塞尔滤波器Bessel Filter，二进制对称信道Binary Symmetric Channel仿真，比特序列，Remez滤波，BPSK复合基带信号仿真，载波生成器，椭圆滤波器Elliptical Filter，FFT,FSK调制及解调，高斯噪声Gaussian仿真，直方图，理想AM，线性PLL，BP混淆器，理想MPSK，正交振幅调变（QAM，Quadrature Amplitude Modulation），正交相移键控(QPSK)，Rayleigh Noise瑞利噪声，Yule-Walker Psd功率谱密度函数。(matlab simulte)

说明：  Ber performance for MIMO using SIC

说明：  This program is for division of natural semiconductor

说明：  语言的文法规则 说明 对原编译程序作了如下修改,增加了输入文件(The grammar rules of the language have been modified as follows to add input files to the original compile)

接收端采用的算法和程序流程与发送端发送的OFDM符号的帧结构有关系。具体的帧结构，以及定时估计，频偏估计，剩余误差跟踪的算法可参考算法说明文档。这里对程序的流程进行说明。 首先根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。 (good)

一个CMA算法程序，可以对CMA算法进行一些仿真研究(A CMA algorithm procedures, CMA algorithm can carry out some simulation studies)

说明：  51单片机，通过人体红外热释电模块检测人数，并计数。(51 single chip computer, through the human body infrared pyroelectric module to detect the number of people, and count.)

本程序为CDMA系统中基于MMSE的多用户检测技术，供有相关人士下载(This procedure for the CDMA system based on the MMSE multi-user detection techniques for those who have related downloads)