Thermal Noise Effect in FTTH Communication Systems

Thermal noise is generated naturally by thermal agitation of electrons in a conductor commonly found in opto-electronic devices. The fact that the optical medium is totally immune to noise does not exclude its occurrence in receiver parts. In communication, thermal noise has a major influence to the quality of the receiver. The lower the thermal noise the higher and more expensive is receiver sensitivity. This paper starts with a tutorial on thermal noise in common communication technologies. The major contribution factor to thermal noise power is also discussed analytically. For more comprehensive view, the includes a study on thermal noise effects network performance in terms of BER, maximum Q-factor, eye height and maximum distance. The fiber-to-the-home network is used as a test field to study the impact of two different values of thermal noise on network parameters. At the end of this paper, thermal noise minimizing techniques are also listed.