in many texts about modulators I have seen there is a component called "Serial to Parallel Converter". For instance, let's consider this scheme and let's focus on the second block (reference):
The text about that block says:
The input serial data stream is formatted into the word size required for transmission, e.g. 2 bits/word for QPSK, and shifted into a parallel format. The data is then transmitted in parallel by assigning each data word to one carrier in the transmission.
Somewhere I have read also that this device converts a signal from serial to parallel by halving the transmission rate.
- I do not understand what serial to parallel conversion exactly means, and if I have to see it from and electronic and circuital point of view (from a signal between a wire and GND we get two signals between two wires and GND) or from a signal theory point of view (but I do not know how to see it).
- Which is the math relationship of the output signals (between them and between them and the input signal)?