NFDMcpdeOFDM

说明：  MIMO-OFDM系统降低PAPR的天线旋转取反算法(Antenna rotation inversion algorithm for reducing PAPR in MIMO-OFDM system)

一种基于信号二阶四阶矩的信噪比估计方法，该文件中包含该方法的文章以及matlab程序。(This estimation method is based on the signal second-order signal-to-noise ratio of the fourth moment. The file contains a paper and a code.)

说明：  实现了一个直接扩频系统，使用BPSK作为调制解调方法。并比较白噪声AWGN及瑞利衰落(rayleigh fading)环境下，误码率的影响。(There are two files in the zip folder. bpsk_spread.m and jakesmodel.m Steps for simulation: 1] Run jakesmodel.m first 2] Then run bpsk_spread.m . 3] Note that during the first run bpsk_spread.m has no rayleigh fading.This is because the corresponding code has been commented 4] The resulting performance is stored in BER_awgn. 5] Now uncomment the Rayleigh Fading code in bpsk_spread.m file. 6] Same time comment BER_awgn (line 112) and uncomment BER_ray variable. 7] Run the simulation. To compare the perfromances of the receiver using DSSS plot the BER_awgn and BER_ray >>semilogy([1:8],BER_awgn(1:8), g* ) hold on semilogy([1:8],BER_ray(1:8), -.b* ) hold on grid on )

当今世界电子对抗日益激烈，对于雷达低截获和抗干扰能力的研究越来越受到关注。OFDM (Orthorgonal Frequency Division Multiplexing，正交频分复用)雷达具有大时宽带宽积、波形设计方法灵活、频谱利用率较高以及低截获性能好的特性，因此逐渐成为雷达领域的重点研究方向。除此之外，OFDM信号时域和频域波形都比较复杂，当雷达信号采用OFDM技术时，敌方很难精确估计发射信号波形和瞬时频率，使得截获机不容易分析出检测到的雷达信号。当面对敌方的欺骗式干扰时，对于同样具有大时宽带宽积的线性调频信号，OFDM信号具有更好的抗欺骗式干扰的性能，因此OFDM技术在雷达上的运用愈来愈得到关注。(As electronic warfare becomes increasingly fierce, low intercept probability radar has become an important research filed in electronic countermeasures. OFDM (Orthorgonal Frequency Division Multiplexing) radars have gradually emerged due to their high spectrum efficiency, large time-bandwidth product, flexible waveform design methods, and low intercept probability.In addition, because of the complex time-frequency characteristics of the transmitted signal in OFDM radar, the enemy is difficult to estimate the transmitted signal waveform and instantaneous frequency.When faced with enemy deception interference, OFDM signals have better anti-spoofing performance for LFM signals that also have a large time-bandwidth bandwidth product. Therefore, the use of OFDM technology in radar is attracting more and more attention. .)

支持IEC60870-5-104: 2000 IEC104规约软件包 实现104规约主站侧链路层的功能(IEC_Master_104.lib: void Init_SockServerport(WORD port=2404) void Init_Linkpara(int t0=30,int t1=15,int t2=10,int t3=20,int k=12,int w=8) virtual void On_init_Link_process() virtual void On_init_Sock_process() virtual void On_ErrorMsg(char*msgbuf) void slave_start() void slave_close() )

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.)

MATLAB仿真，对比OFDM与F-OFDM性能(Compare F-OFDM with OFDM using MATLAB)

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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.)

the file is implimented in C++ for wimax network it is explication of qualitie of service