实现信号处理中QAM调制、过信道、解调部分。其中QAM调制部分可改符号点数，M阶数，信道加高斯白噪声、时延、多径，调制解调均有星座图。通过本代码，可学习QAM调制解调，或者通信系统的知识。-To achieve QAM modulation, signal processing over channel, a demodulation section. QAM modulation section can be changed symbolic points M order channel additive white Gaussian noise, delay, multipath, the modem has constellation diagram. QAM modulation and demodulation, or communication system knowledge through this code, you can learn.