Determining Length of Sequence for Modulation Techniques

[hananl]

Hello,
I need help with modulation techniques.
If I have a sequence I want to transmit, and need to be modulated, how do I know its length? :
I know the time duration of the sequence=t => t/T(carrier period)=number of cycles per sequence.

(number_cycles_per_sequence/number_periods_per_symbol)*number_bit_per_symbol = total number of bits per sequence.

1) So, now my question is, how do I decide the value of number_periods_per_symbol?
I guess I also need this value for the symbol clock when demodulation, no?

2) when I create modulation - I modulate the sequence of bits. How long will take each 2 bits (one symbol=2 bits for qpsk)? that's exactly the question in 1, right? - deciding number_periods_per_symbols?

So this value I guess must be somewhere in the formula for creating the qpsk modulation?
Regards,
Hanan.

 

[anorlunda]

It is a two step process.

First, figure out how to express your message in binary.

Then, look for a digital communication protocol. Each protocol has overhead to allow for start/stop off the messsage, error correction, routing and so forth. TCP/IP is a very complicated protocol for sending data over the Internet. RS232 and USB are simpler serial protocols. You must choose one.