光通信系统设计

摘要

LED作为冷光源和节能光源，正在不断发展和普及。所以利用这个新的光源来通信，也变成了目前研究的热门课题之一。LED光传输技术就是利用常见的LED等室内照明设备，发出肉眼感觉不到的高速明暗闪烁的通信信号，以无线通信的方式来传输数据。采用无线光通信最大的特点就是它的波长范围大，可以将可见光讯号用不同的波长来进行信号的传输。可见光还有无电磁辐射、易保密等特点，尤其搭借了照明平台，所以不需要采用另外的传输介质，采用广播方式，受体的数量即容量受到的制约小，但是其缺点是不易实现双向的通信。

这次毕业设计的主要内容是尝试设计并制作一个LED通信试验系统，通过对频率的调制，发出特定的编码信号，接收方利用光电敏感器件接收调制光，解调后还原成数据信号。最后，本次毕业设计完成了基本功能的LED发射管、接收管的发射和接收工作，并且尝试将其时分复用和频分复用。在发送端添加了温度传感器和超声波测距传感器，数码管显示，在接收端用1602液晶屏幕显示出来。两者的对比，反应出通信的正确性。

本设计是基于两个89C51单片机，利用红外led发射装置和HS0038接收装置设计的简单慢速通信。目标是熟悉单片机的编程思路和学习通信的基本原理。基本的慢速光通信在传感器与单片机之间的通信上有着广泛的应用。

关键词：LED;调解;解调;频分复用;时分复用

I

Abstract

As a cold light and energy-saving light source, LED is rapidly developing and being popularization. So using this new light source to communicate has become a hot research topic nowadays. The technology of LED light transmission is to using common LED indoor lamps. Communication signal of high speed light by the naked eye can not feel the flashing, in a way of wireless communication to transmit data. The most special characteristic of light communication is that the light wavelength range is very long, and visible light can be signal transmission in different wavelength. Visible light and no electromagnetic radiation, such as confidentiality, especially a borrowed lighting platform, so do not need to use the transmission medium, the broadcast, the number that is restricted by receptor capacity is small, it is not easy to achieve two-way communication.

The main purpose of this paper is to try to design a LED communication system, through the modulation of the frequency coding signal, the photoelectric sensitive device receives the light modulation, demodulation back into the data signal. Finally, the graduation design, completed the basic function of the LED launch tube, receiving tube emission and reception work, and try to time division multiplexing and frequency division multiplexing. The temperature sensor and the ultrasonic ranging sensor is added in the transmitter, the digital tube display, the receiver with 1602 LCD screen display. The contrast of the two, reflect the correctness of communication.

The design is based on two MCUs, simple slow communication using infrared LED emission device and HS0038 receiver design. The target is the basic principle of the programming ideas and learning communication with single-chip microcomputer. Slow light communication basic is widely used in communication between sensor and MCU.

Keywords: LED; mediation; demodulation; frequency; division;

II

目录

摘要........................................................................................................................ I Abstract ......................................................................................................................... II 第1章绪论 (1)

1.1光通信发展的简要回顾 (1)

1.2课题的意义和发展趋势 (1)

1.3课题的主要任务和预期目标 (2)

第2章总体方案设计 (3)

2.1设计思路 (3)

2.2系统设计方案 (3)

2.2基本光通信原理的介绍和通信方式的设计 (3)

2.2.1基本光通信方式的介绍 (3)

2.2.2复用技术的介绍 (5)

2.2.3通信方式的选择 (6)

2.2.4码原理设计 (8)

第3章光通信硬件电路的设计 (9)

3.1单片机的选择和单片机的工作原理介绍 (10)

3.1.1单片机的选择 (10)

3.1.2单片机89C51介绍 (10)

3.1.3单片机89c51最小系统 (10)

3.2发射端的设计 (11)

3.2.1发射管的选择 (11)

3.2.2红外LED的原理 (11)

3.2.3红外LED的设计 (11)

3.2.4传感器的设计 (12)

3.2.5发射端整体的设计 (12)

3.3接收端的设计 (13)

3.3.1接收端的选择： (13)

3.3.2 HS0038的介绍(引用器件产品说明书部分) (13)

3.3.3红外接收装置HS0038的设计 (15)

3.3.4接收电路整体的设计 (16)

3.4温度传感器ds18b20的介绍和使用（部分引用说明书） (16)

3.5超声波传感器的介绍和使用（部分应用说明书） (19)