Ofdm subcarrier spacing

OFDM and subcarriers allow Wi-Fi to be more fault tolerant and carry data more reliably. Older Wi-Fi standards, such as 802.11ab/g/n/ac, use 64 subcarriers. Each Wi-Fi channel is 20 MHz. Therefore, each subcarrier is spaced 312.5 kHz apart.

1. Why subcarrier spacing is 15 kHz in LTE?
2. How many subcarriers are in OFDM?
3. How to calculate number of subcarriers in OFDM?
4. Why only 12 subcarriers in LTE?
5. What is the space between a subcarrier and the next sub carrier in an LTE network?
6. Why different subcarrier spacing in 5G?

Why subcarrier spacing is 15 kHz in LTE?

Simply, It is because 3G and LTE have the same clock timing for multi technology handsets.

How many subcarriers are in OFDM?

A single OFDM symbol contains 52 subcarriers; 48 are data subcarriers and 4 are pilot subcarriers.

How to calculate number of subcarriers in OFDM?

If you divide the channel bandwidth (20 MHz) by the subcarrier bandwidth (312.5 kHz) you will see that 802.11a/g comprises 64 subcarriers.

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.

What is the space between a subcarrier and the next sub carrier in an LTE network?

The LTE OFDM subcarrier spacing equals 15 kHz for both downlink and uplink.

Why different subcarrier spacing in 5G?

Wider subcarrier spacing would provide better resistance to such increased Doppler shifts at higher frequency bands. Furthermore, 5G NR provides a flexible solution to support various applications by choosing an appropriate configuration. For example, when higher Δf is used, it results in a shorter slot duration.