analog_modulation

本程序利用改进的CHOW算法，仿真了自自适应OFDM系统的性能，并画出了SNR (This program makes use of improved CHOW algorithm simulates the performance of self-adaptive OFDM system, and draw the SNR)

用C++实现BPSK的仿真，包括信源，调制，信道，解调，计算误比特率(Using C++ implementation BPSK simulation, including source, modulation, channel, demodulator, bit error rate calculation)

automatic link establishment radio software

DRM(Digital Radio Mondiale)系统采用OFDM调制方式， 引入了先进的信源信道编码和调制技术，使得AM波段的音频广播质量大大提高，在保持现有10kHz带宽时接近了FM广播的质量[5](DRM (Digital Radio Mondiale) system uses OFDM modulation, the introduction of advanced source-channel coding and modulation techniques, making AM-band audio broadcast quality greatly improved, while maintaining the existing 10kHz bandwidth close to the quality of FM broadcasting [5])

对当前通信信号中常用的数字调相信号BPSK、QPSK、1／4一QPSK、8PSK的调制识别问题，提出了一种基于信号差分高阶累积量的识剐算法。该算法分两个层次进行调制识别，首先利用信号的四阶累积量特征对BPSK、QPSK和{1／4一QPSK、8PSK}信号进行识别，然后再利用信号差分的四阶和八阶累积量特征对1/4-QPSK、8PSK信号进行识别。从理论上分析了的该算法的有效性，并通过计算机仿真验证了算法具有良好的性能。(A recognition algorithm based on differential high-order cumulant is proposed for the modulation recognition problems of BPSK, QPSK, 1/4-QPSK and 8PSK, which are commonly used in current communication signals. The algorithm is divided into two levels for modulation recognition. Firstly, BPSK, QPSK and {1/4-QPSK, 8PSK} signals are identified by using the fourth-order cumulant characteristics of signals, and then 1/4-QPSK and 8PSK signals are identified by using the fourth-order cumulant and eighth-order cumulant characteristics of signal difference. The validity of the algorithm is analyzed theoretically, and the good performance of the algorithm is verified by computer simulation.)

说明：  常用的两种信道估计算法，基于matlab，可以正常运行(Channel estimation algorithm, based on MATLAB)

生成2KHz和8KHz的混合信号,使该信号通过上述滤波器,观察滤波前后的波形变化和频谱分布情况, 在改信号中加入高斯白噪声,(The mixed signal of 2KHz and 8KHz is generated so that the signal passes the above filter, the waveform change and spectrum distribution before and after filtering are observed, and Gao Si white noise is added to the modified signal.)

QPSK ALmouti 2x2 mimo figure

MIMO系统中基于压缩感知的有限反馈方法研究,D对研究有限反馈有很好的帮助。(MIMO systems with limited feedback based compressive sensing method study, D finite feedback of good help.)

UWB_Channel_IEEE_802_15_3a.rar是用MATLAB对UWB信道进行仿真的实例，所仿真的信道是UWB的标准信道模型。(UWB_Channel_IEEE_802_15_3a.rar is used for UWB channel MATLAB simulation examples, the channel simulation is the standard UWB channel model.)