question: powerline communications

[subroutine]

howdie all:..

I am a bachelor student electronics in holland,

I have a question about powerline communications.

I think FSK as a modulation type is the best choise, because it is more immume to the ampitude noise from the switching of home aplieances.

the thing is in most ann notes I only see data trasmitted at the zero crossing of the 50Hz( europe powerline) signal.

why not transmit more often then only at the zero crossings... max data transfer when only transmitting at zero crossing point is 100 bits a second??

greetz jason (newbe)

[charan langton]

Hello Greetz,

I am not sure about your question. But here is an answer any way. The data rate on any carrier is limited by the bandwidth allowed. Theoretically it is possible to tranmit 2 bits per Hz if there is no contraint on bandwidth. From there it only goes down. The only way to increase data rate is to transmit bits per symbol. In FSK, we can make go M-FSK to increase bit rate. A binary FSK is limited by the bandwidth just as are all modulation schemes.

As far as transmitting at zero crossing, I am not exactly sure what you are asking. May be you can elaborate on it.

Charan Langton