2DPSK数字调制器研究与设计 毕业论文 答辩版11405010125 李恒.doc

华中师范大学武汉传媒学院毕业论文(设计) 2DPSK数字调制器的研究与设计 院 系： 传媒技术学院 专 业： 电子信息工程 班 级： B1101班 姓 名： 李 恒 学 号： 11405010125 指导教师： 谈 新 权 2015年5月7日  2DPSK数字调制器的研究与设计 The Research and Design of 2DPSK Digital Modulator 摘 要 数字相位调制广泛应用于通信领域。2DPSK是一种基本的相移键控。PSK调制通常有两种实现方法：乘法器法和相位选择法。本文采用相位选择法实现PSK调制。文章首先介绍了两种实现方法的电路框图。接着论述了相位选择法实现2DPSK调制的各部分电路设计。相位选择开关采用了集成芯片74HC4051，这种模拟开关可通过三位数字信号的控制从8路模拟信号中选通其中的一路输出。本文中只用了二选一开关。用一位数字信号的高低电平选 出其中的一路信号，即选出初始相位为0°或180°的载波。从而实现了2DPSK的调制。文中还详细介绍了其他单元电路的设计，包括低通滤波电路，载波放大和形成电路，以及调制输出电路。论文最后完成了用Protel设计的总体电原理图。 关键词：数字通信 数字调制 相移键控 相对相移键控 Abstract Digital phase modulation is widely used in the field of communication.2DPSK is a kind of basic phase shift keying.PSK usually have two ways to realize the modulation:multiplier method and the phase selection method.The phase selection method is adopted to realize PSK modulation in this paper.Two methods are introduced to realize circuit diagram first.Then discussesed design of circuit that is the phase selection method to realize 2DPSK modulation.The integrated chip 74HC4051 is adopted as the phase selection switch which can be controlled by 3bit digital signals so that a channel signal is selected from eight analog signnals.One of two switch is only used for this paper .High and low level of a digital signal are used to choose one of the signals, that selectes the initial carrier phase that is 0 degrees or 180 degrees.In order to the modulation of 2DPSK modulation is achieved.And the design of the other circuit unit are introduced in this paper,including low pass filter circuit, amplifying circuit and the formation of carrier modulation, and the output circuitof modulation.Finally,The whole design of the electrical schematic diagram is completed by using the Protel. Key word: Digital Communication Digital Modulation Phase Shift Keying Relative Phase Sh