时频分析

北斗卫星导航系统空间信号接口控制文件，这是正式版(BeiDou Navigation Satellite System Interface Control Document)

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，测量BPSK的误码率性能，画出比特信噪比与信道估计均方误差的关系曲线，画出比特信噪比与误码率的关系曲线，请解释在误码率为0.01时，两种合并方式所表现的不同的物理意义。 (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(自己编写代码S-Function方式)，分析所设计方案的时间同步精度，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一种具体的频率方法，用Simulink进行仿真(自己编写代码S-Function方式)，画出比特信噪比与频率同步误差的关系曲线。 (err)

说明：  实现了lfm信号的仿真，可以对其频谱和时域波形进行分析，并且仿真了其模糊函数，可以分析其雷达性能。(The simulation of LFM signal is realized, and its spectrum and time domain waveform can be analyzed, and its ambiguity function can be simulated to analyze its radar performance.)

MATLAB MIMO-OFDM信道估计仿真.m文件。基于梳状导频环境。(MATLAB MIMO-OFDM channel estimation simulation. M file. Comb based pilot environment.)

基于非线性压扩的降低OFDM信号PAPR的算法(Reduction based on nonlinear companding algorithm for OFDM signal PAPR)

说明：  北斗通信设备通用的协议，串口通信与北斗卫星的通信协议，(The general protocol of Beidou communication equipment, serial communication protocol with Beidou satellite)

Computes BER v EbNo curve for convolutional encoding / soft decision Viterbi decoding scheme assuming BPSK. Brute force Monte Carlo approach is unsatisfactory (takes too long) to find the BER curve. The computation uses a quasi-analytic (QA) technique that relies on the estimation (approximate one) of the information-bits Weight Enumerating Function (WEF) using A simulation of the convolutional encoder. Once the WEF is estimated, the analytic formula for the BER is used.(Computes BER v EbNo curve for convolutional encoding/soft decision Viterbi decoding scheme assuming BPSK. Brute force Monte Carlo approach is unsatisfactory (takes too long) to find the BER curve.The computation uses a quasi-analytic (QA) technique that relies on theestimation (approximate one) of the information-bits Weight Enumerating Function (WEF) usingA simulation of the convolutional encoder. Once the WEF is estimated, the analytic formula for the BER is used.)

针对数字卫星常用的 7 种通信信号调制方式(QPSK、8PSK、16QAM、32QAM、64QAM、16APSK、32APSK)，对零中心归一化瞬时幅度谱密度最大值、四次方谱、幅度、高阶累积量四种特征参数进行了分析，提出了一种联合特征参数的信号调制识别方法．(Aiming at seven communication signal modulation modes commonly used in digital satellite (QPSK, 8PSK, 16QAM, 32QAM, 64QAM, 16APSK and 32APSK), four characteristic parameters of zero-center normalized instantaneous amplitude spectral density, quadratic spectrum, amplitude and high-order cumulant are analyzed, and a signal modulation recognition method of joint characteristic parameters is proposed. Method.)

A simulator for wireless sensor networks using omnet ++ framework

基于matlab-GUI制作的数字通信信号的调制仿真，包括时域、功率谱显示，仿真的调制方式有：ASK、FSK、PSK、QPSK、OQPSK、1/4piQPSK、8PSK、MSK，比较直观易懂，可供需要的同胞参考(this process mainly simulate varity of digital signal modulation,such as ASK、FSK、PSK、QPSK、OQPSK、1/4piQPSK、8PSK、MSK)