What is the Spacing Between 4G and 5G Subcarriers?
When discussing 4G and 5G networks, one of the key differences that affects their performance is the spacing between subcarriers. These subcarriers are used in Orthogonal Frequency Division Multiplexing (OFDM) systems, which are the basis for both 4G (LTE) and 5G networks. Let’s break this down and understand the differences in subcarrier spacing between these two technologies.
Subcarrier Spacing in 4G (LTE): In 4G LTE networks, the standard subcarrier spacing is 15 kHz. This means that each subcarrier is spaced 15 kHz apart within the frequency band. This subcarrier spacing works well for LTE, providing a good balance between data throughput and the ability to handle different channel conditions. The 15 kHz spacing allows LTE to perform well in a wide range of deployment scenarios, from urban areas to rural environments.
Subcarrier Spacing in 5G (NR): In 5G New Radio (NR), the subcarrier spacing is significantly more flexible and scalable. 5G can use different subcarrier spacings depending on the frequency range and use case. The typical subcarrier spacings in 5G are:
- 15 kHz (same as LTE) for low-frequency bands (sub 1 GHz).
- 30 kHz for mid-frequency bands (1 GHz to 6 GHz).
- 60 kHz, 120 kHz, and 240 kHz for high-frequency bands (above 24 GHz).
The ability to use larger subcarrier spacings in 5G is one of the reasons why 5G can deliver higher data rates and lower latency, especially in high-frequency bands (such as millimeter-wave bands). With larger subcarrier spacings, 5G can better handle high bandwidth and support more users simultaneously without congestion.
To make this clearer, let’s consider that in LTE, with its 15 kHz spacing, it is optimized for long-range coverage and lower-frequency bands. But in 5G, when you’re using higher frequency bands (like mmWave), the subcarrier spacing increases to ensure that the network can handle the large amount of data transmitted in a small amount of time, resulting in higher throughput and lower latency.
Why does this matter? The larger subcarrier spacing in 5G is beneficial for improving performance in high-demand scenarios, such as dense urban environments or situations where ultra-low latency is required, like in autonomous vehicles or industrial applications. The increased spacing helps to better resolve signal interference and provides greater efficiency in processing high-frequency signals.
As we saw in earlier articles on LTE and 5G technologies, these advancements in subcarrier spacing are just one part of how 5G improves upon 4G. It’s all about optimizing the network to meet the ever-growing demand for faster speeds, lower latency, and the ability to handle more devices simultaneously. Subcarrier spacing is one of the key factors contributing to this evolution.