Broadband transmission, signal is sent by modulating a carrier

In summary, the conversation is discussing the difference between baseband and broadband transmission and how information is transmitted through voltage changes on a grounded wire. The speaker is trying to understand how this method of information transmission works and is questioning the effectiveness of using a grounded wire for this purpose. They also mention the use of antennas and voltage references in the transmission process.
  • #1
beckett
11
0
Hi folks,

quick question, i have just read a small snippet on data transfer that has sparked some thoughts. Basically it was this:

Baseband transmission, one carrier frequency is used and the electrical signal is applied directly to the wires.

Broadband transmission, signal is sent by modulating a carrier (eg amplitude or frequency etc).

Now, if for example i am connected to an earthed wire and i raise and lower the voltage on the point of connection to represent a sequence of 0's and 1's what exactly is going on? Would this be considerered as amplitude modulation of some sort, what frequencies are involved, what is the signal exactly. I can understand modulating a certain frequency and sending this over the air where it may then be demodulated and useful info is extracted but i can't grasp what is going on in a wire using voltage changes as a means for information transmission.

Thanks in advance
 
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  • #2


Originally posted by beckett
Now, if for example i am connected to an earthed wire and i raise and lower the voltage on the point of connection to represent a sequence of 0's and 1's what exactly is going on?

well, it's not very clear what are you trying to do, but if you're trying to output something on a grounded wire all that's going on is burning the transmitter.

I can understand modulating a certain frequency and sending this over the air where it may then be demodulated and useful info is extracted but i can't grasp what is going on in a wire using voltage changes as a means for information transmission.

well, before sending something over the air there has to be an antenna and before that it's just electrical signal traveling on a wire.
basically let's say you want to transmit digital info on a wire. then you use a wire and a voltage reference (that's the ground). When you want to send the bit '1' you rise the voltage on the wire and the other party detects this voltage by coparing it to the reference. When you want to send the bit '0' you put the wire at the same voltage as the ground and the other party detects the lack of voltage on the wire.
You could say that this is one basic type of modulation. You could also do that with two wires and no ground. So that is why your question with the grounded wire is a bit confusing...
 

What is broadband transmission?

Broadband transmission is a method of sending data over a wide range of frequencies simultaneously. This allows for a larger amount of information to be transmitted at a faster rate compared to traditional methods.

How does broadband transmission work?

In broadband transmission, a signal is sent by modulating a carrier wave with the data to be transmitted. This means that the data is encoded onto the carrier wave, which is then transmitted through a physical medium, such as a cable or through the air.

What is the purpose of modulating a carrier wave?

Modulating a carrier wave allows for the transmission of data over a larger range of frequencies. This means that more data can be transmitted at once, resulting in faster transfer rates.

What are the advantages of broadband transmission?

Broadband transmission offers several advantages, including faster data transfer rates, the ability to transmit larger amounts of data simultaneously, and less susceptibility to interference compared to traditional methods.

What are some examples of broadband transmission?

Some examples of broadband transmission include cable internet, satellite internet, DSL, and fiber optic internet. Wireless technologies such as Wi-Fi and 4G/5G networks also utilize broadband transmission methods.

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