In synchronous communication how the clock signal is sent with the main signal?

CLk pulse is a trigger pulse what is your sync circuit you have

Why do you want to transmit it ?

In general only signal restorers are sent in transmission

If clk is transmitted then it will be used for triggering or activating some pulse or part of circuit

in practice clock information is transmitted rather than the clock signal.

the purpose of sending the clock information may be to synchronize different parts of the system that are distant apart, or to determine the timing when a particular circuit should be come operational in its true sense etc.

usually depending upon the physical separation between the transmitter and the receiver, there are two fundamental techniques to send the clock information.

• when the transmitter and the receiver are closely situated(as in a laboratory), the two could be supplied by a common clock. in this case the clock source is connected to the two individual components( of course transmitter and the receiver).
• when the units are situated far from one another we make use two codings techniques:- manchester coding and differential coding. these are basically used to convert or to encode the clock information(digital data) into an equivalent digital signal. this encoded information is embedded in the modulated signal and then sent from transmitter to be received at the receiver.

hope that will help you. for further reference you can visit wikipedia to get to know the pros and cons of the two encoding schemes discussed above.

regards,
proffy