Spread spectrum transmission on residential power line

Spread spectrum data transmission on residential electric power lines is investigated. As a fundamental problem transmission characteristics of a residential power line has been studied. First, the active impedance characteristics of various electric apparatus used in the ordinary customers house are measured and simulated by lumped constant impedance. Configurations of the residential power line network are statistically studied next. A novel approach to construct an artificial transmission line of the residential electric power line using these results is shown. Various noise arising from electric apparatus used in the residence are measured and classified according to its amplitude, time duration and time intervals statistically. Besides these, several experimental spread spectrum data transmission systems are constructed and trial tests are carried out. Several novel techniques such as, spread time spread spectrum system to suppress impulsive noise, system using a reference PN signal to cope with sudden change of the transmission line characteristic, parallel combinatory spread spectrum system to improve spectral efficiency are tested in the trial test. Some of the experimental results are shown