rayleigh&MIMO

说明：  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. .)

一种频率估计方法，短时傅里叶变换，很基础，适合初学者。(A frequency estimation method, short-time Fourier transform，it is based, suitable for beginners. )

说明：  5. 在三条径的瑞利信道中，对于直接序列扩频： (1) 请设计DS-CDMA一种具体的码分导引辅助的信道估计方法，接收机分别采用等均益合并、最大比合并。用Simulink进行仿真，画出比特信噪比与信道估计均方误差的关系曲线和比特信噪比与误码率的关系曲线。 (2) 设频率已经同步，请设计DS-CDMA一种具体的单停顿滑动相关时间同步方法，用Simulink进行仿真，画出比特信噪比与捕获概率的关系曲线。 (3) 设时间已经同步，请设计DS-CDMA一种具体的频率同步方法，用Simulink进行仿真，画出比特信噪比与频率同步误差的关系曲线。(5. In three-path Rayleigh channel, for direct sequence spread spectrum: (1) please design a specific code division navigation aided channel estimation method for ds-cdma, and adopt equal-beneficial combination and maximum ratio combination for receivers respectively.Simulink is used to simulate and draw the relationship curve between bit SNR and channel estimation mean square error and the relationship curve between bit SNR and bit error rate. (2) assuming that the frequency has been synchronized, please design a specific single-stop sliding correlation time synchronization method ds-cdma, Simulink simulation, draw the relationship between the bit SNR and the acquisition probability curve. (3) if the time has been synchronized, please design a specific frequency synchronization method ds-cdma, Simulink simulation, draw the relationship between the bit SNR and frequency synchronization error curve.)

16QAM 在AWGN信道中的BER表现(BER performance of 16QAM in AWGN channel)

使用verilog实现全数字16QAM调制器，载波频率1MHZ，数据比特流的速率为100Kbps,(the modulation of 16QAM based on FPGA)

B-IFDMA pdf document

C#串口，以太网通信代码,很详细的代码。可以使用(C# serial and Ethernet communication code, very detailed code. You can use)

功率谱密度的估计算法，simulink实现，现代信号处理第三章仿真实现。(Power spectral density estimation algorithm, simulink realization of modern signal processing Chapter Simulation.)

说明：  一种PC与单片机多机RS232串口通信设计应用(A PC with a single-chip multi-machine RS232 serial communication design application)

重点研究 了低信噪比﹑多径瑞利衰落信道条件下，基于高阶累积量的OFDM信号盲识别技 术。提出了利用奇数阶累积量区分OFDM信号与单载波信号的方法，并对基于三 阶和五阶累积量的算法进行了仿真分析。 (﹑ Focus on the low SNR multipath Rayleigh fading channel conditions, based on cumulant OFDM signal blind identification technology. Made a distinction between the use of odd-order cumulants single-carrier OFDM signal with the signal approach, and based on the cumulative amount of third-order and fifth-order algorithm for the simulation.)