【正文】 Reflective means luminescent tube and pipe parallel with the receiving peacetime, without always receiving tube light, luminescence only in possession of the infrared light reflected from encountered, the receiving tube received from the reflected infrared before work. infrared munication basic tes infrared munication Principle Communication is the use of infrared wavelength of 900 nminfrared waves from 1000 to serve as an information carrier, through infrared technology between the two close munication and confidentiality of information transmitted. Infrared municatio n system structure include : part launcher, channel, the receiver part. Launcher source letter issued after the binary signal from the highfrequency modulated infrared LED sent, receiving device regard the reception of highfrequency signals from the infrared receiver tube after receiving further demodulation photoelectric conversion of the original information of a mass munication lose way. Afterwards the former Information received after receiving part of the drive circuit connected to the expected co mpletion of the various functions. To which the modulation coding style pulse width modulation (by changing the pulse width modulated signal PWM) and pulse modulation time (through change the pulse train interval time between the modulation signal PPM) two. infrared munication system elements (1) Launches : Currently there is a infrared wireless digital munications system sources of information including voice, data, images. Its methods of work for the launch of the receiver can be divided into different layout LOS way (LightofSight , intracardiac way), diffuse (diffuse) mode. LOS way directional, it has good channel characteristics such advantages, but the existence of a shadow effect. difficult to achieve roaming function. Roaming means the main features of nondirectional, and easy to implement roaming function, but its channel quality is better sometimes LOS way. Transmission of signals required for a few of (the sampling was quantified), the general need for baseband modulation, transmission, modulation, sometimes signal source coding, the abovedriven signals from photoelectric converter plete optical signal transmission. Infrared wireless digital munications system and its scope of workforfired power distribution, the quality of the munication. While using various methods to improve optical transmitter power, the other using spatial diversity, holographic films and so on so diffuse light for the launch of space optical power evenly distributed. (2) Channel : infrared wireless digital munication channel refers to the transmitters and receivers in the space between. Due to natural light and artificial light sources such as light signals in the context of intervention, and the source Electrical Equipment, The optical noise and disturbances, infrared wireless digital munications in some occasions, poor quality, At this point needed to channel coding. Infrared wireless munication system, the optical signal reflection, light scattering and background noise and interference effects, Infrared wireless digital channel presence multipath interference and noise, This is to improve the quality and access for highspeed applications should be addressed. Infrared wireless digital munication channel often used by the major optical ponents, optical filter, condenser, their role is : plastic, filter, depending on the field transformation, the band division, the lens can be used as launchray focusing, the use of optical filters filter out stray light, the use of optical lenses to expand the field of view receiver, able to make use of optical ponents for the link frequency division multiplexing, etc.. Infrared wireless munication channel optical noise : the natural noise (sunlight) and anthropogenic 。s ability to control, so in the design of household appliances infrared remote control, wireless remote control as unnecessary, each set (transmitters and receivers) have different frequency or remote coding (Otherwise, wall will control or interference with neighbors household appliances), all similar products in the infrared remote control, The same can control the frequency or coding, and no remote control signal drop. This universal infrared remote control provides a great convenience. Infrared to visible light, is very subtle and confidentiality, therefore, the security, Alert and other security devices have been widely used. Infrared remote control is simple in structure and easy, lowcost, antiinterference capability, high reliability are a number of advantages, is a closeup remote control, especially in indoor remote control optimized manner. infrared diode characteristics Infrared is not visible, people here are not aware of. Electronic technology is used infrared light emitting diode (also known as the IR emission diode) to generate infrared. Infrared remote control transceiver is using nearinfrared transmission control instructions wavelength of ~ 1. 5μm. Nearinfrared remote control as a light source, because there infrared light emitting diodes and infrared receiving device (photodiode. Transistor and PV) and the luminescence peak wavelength of light by the general ~ 0. 94μm. in the nearinfrared band, both of the spectrum is the coincidence to a good match, access to higher transmission efficiency and higher reliability. Commonly used infrared diode, and its shape is similar LED light emitting diodes, Its basic circuit shown in figure 2 2. The triode plans for the switch, when the base added a driving signal, Transistor saturated conduction infrared LED D is also Wizard Link, issued infrared (near infrared about μm). D. The pressure drop of about V and the current general for 1020mA. To adapt to the working voltage of the D loop resistance often