频域不同导频密度的信道估计在被研究，并且在高低时延信道其信道估计被固定了导频分配时域。频域信道估计是基于插补，多项式的广义线性模型（或最小二乘法）和维纳滤波（或线性最小均方误差法）的方法。时域的信道估计是用线性插补完成的。我们通过测量在基于克拉克散射模型的瑞利衰落信道上并带有QPSK调制的粗误码率，已经比较了所有这些方案的结果。-Different pilot density in frequency domain channel estimate to research, and its hi

QPSK调制与解调，低通滤波器采用了时域和频域两种实现方式，截止频率fc = 200hz,采样频率fs= 1000hz,欢迎下载参考！-QPSK modulation and demodulation, using a low-pass filter with a time domain and frequency domain implemented way, the cutoff frequency fc = 200hz, the sampling frequency fs = 1000hz

分别编写BPSK与QPSK调制解调系统的Matlab仿真程序，要求：发送滤波器与接收滤波器均为根升余弦滚降滤波器；信道噪声为加性高斯白噪声 绘制BPSK与QPSK调制下的误码率与信噪比曲线图，并与理论曲线比较对比-They were written BPSK and QPSK modulation and demodulation system Matlab simulation program requirements: a transmission filter and a recept