Subcarrier meaning

1. What is carrier and subcarrier?
2. What is the meaning of subcarrier?
3. What is subcarrier in OFDM?
4. Why only 12 subcarriers in LTE?

What is carrier and subcarrier?

A subcarrier is a secondary modulated signal frequency modulated into the main frequency (the carrier) to provide an additional channel of transmission. It allows for a single transmission to carry more than one separate signal.

What is the meaning of subcarrier?

A subcarrier is a sideband of a radio frequency carrier wave, which is modulated to send additional information. Examples include the provision of colour in a black and white television system or the provision of stereo in a monophonic radio broadcast.

What is subcarrier in OFDM?

OFDMA subdivides a channel into smaller frequency allocations, called resource units (RUs). Both OFDM and OFDMA divided a channel into subcarriers through a mathematical function known as an inverse fast Fourier transform (IFFT).

Why only 12 subcarriers in LTE?

In the downlink, the subcarriers are split into resource blocks. This enables the system to be able to compartmentalise the data across standard numbers of subcarriers. Resource blocks comprise 12 subcarriers, regardless of the overall LTE signal bandwidth. They also cover one slot in the time frame.