论文部分内容阅读
数字通信比摸拟通信具有多方面的优点,而数字通信比摸拟通信最突出的缺点则是占用信道的带宽太宽,一路话音信号,用摸拟方式通信,占用的带宽只有4KHZ,而一路话音信号数字通信方式,占用的带宽将为48KHZ;这就是实现数字通信的最大障碍,为此人们对数字通信压缩频带成了主要的研究课题。人们在长期的研究过程中,找出了压缩频带在信息论中的依据,我们知道话音信号的概率分布是指数形式的,当经过非线性变换,改变其概率分布为等概率的特性,就可大大提高传输的信息量,而大大压缩冗余信息量,这样就可将频带宽度48
Compared with analog communication, digital communication has many advantages. However, the most prominent disadvantage of digital communication over analog communication is that the bandwidth of the occupied channel is too wide. All the way the voice signal is transmitted in analog mode, and the occupied bandwidth is only 4KHZ. The digital communication mode of the voice signal, the occupied bandwidth will be 48KHZ; This is the biggest obstacle that realizes the digital communication, therefore people compress the digital communication band to become the main research topic. In the long-term research, people find out the basis of compressed frequency band in information theory. We know that the probability distribution of speech signal is exponential form. When nonlinear transformation is used to change its probability distribution to equiprobability, Increase the amount of information transmitted, and greatly reduce the amount of redundant information, so that the bandwidth can be 48