llr_Bp2

编译原理的学习资料，我们上课用的，没有源码传，但又想下载东西，只好传了学习资料(Compilation Principle of learning materials, we used in class, there is no source Chuan, but want to download things, but to learn from the information passed)

说明：  OFDM多径信道的仿真和模拟,有效的仿真了多径信道(simulation of OFDM through multipath channel)

关于polar codes的源码，简单的仿真。(An Brief Introduction to Polar Codes)

用于信捷PLC与Labview之间的通信，可以作为学习的初版(Used for the communication between Sinjie PLC and Labview, it can be used as the first edition of learning.)

（1） 分析QPSK调制、解调原理，并画出其系统框图； （2） 产生等概率且相互独立的二进制序列，作为待传输的信号，并画出其波形； （3） 进行8PSK调制，分别画出I、Q两支路信号经过乘法器后的波形以及8PSK调制波形； （4） 产生均值为0，方差为1的加性高斯随机噪声，画出其时域波形及频谱； （5） 将加性高斯随机噪声作为传输信道的干扰，画出接收端信号的时域图； （6） 进行8PSK解调，输出解码序列，画出解调后信号波形； （7） 计算系统信噪比、传输误码率。((1) analysis of QPSK modulation, demodulation, and draw the system block diagram (2) have equal probability and independent binary sequence as a signal to be transmitted, and draw the waveform and (3) 8PSK modulation, Draw the I, Q two way signal multiplier waveform and 8PSK modulation waveform (4) to produce zero mean and variance of an additive Gaussian random noise, to draw the time-domain waveform and spectrum ( 5) the additive Gaussian random noise interference as a transmission channel, to draw the time-domain diagram of the receiver signal (6) 8PSK demodulator output decoding sequence, draw the demodulation of the signal waveform computing system (7) signal-to-noise ratio, the transmission bit error rate.)

相位和载波估计的算法，用于通信中的同步估计。(And carrier phase estimation algorithm is used for communication synchronization estimation.)

说明：  最简单的收发程序，可以用于超宽带测距，信道通信等等(The simplest transceiver program can be used in UWB ranging, channel communication and so on)

基于matlab实现的循环谱估计算法，可以对具有循环平稳特点的信号进行参数估计(Matlab-based spectral estimation algorithm to achieve the cycle, you can have the characteristics of the signal cyclostationary parameter estimation)

说明：  采用Mackay构造H矩阵的LDPC码仿真。(LDPC code simulation of H matrix constructed by Mackay)

说明：  设计一个巴特沃兹数字低通滤波器，其技术指标为：3dB带宽为0.2π，阻带截止频率为0.3π，通带纹波为1dB，阻带衰减大于30dB，采样间隔T=10ms。 1）采用冲激响应不变法； 2）采用双线性变换法设计； 3）采用FIR的窗函数（Hanning窗、Hamming窗或Blackman窗）设计。(A Butterworth digital low-pass filter is designed. Its technical specifications are: 3 dB bandwidth is 0.2 pi, stopband cut-off frequency is 0.3 pi, passband ripple is 1 dB, stopband attenuation is more than 30 dB, sampling interval T=10 Ms. 1) Impulse response invariance method is adopted. 2) Design by bilinear transformation method; 3) FIR window function (Hanning window, Hamming window or Blackman window) is used to design.)