How do you choose subcarrier spacing in OFDM?
Choosing the first subcarrier to have a frequency such that it has an integer number of cycles in a symbol period, and setting the spacing between adjacent subcarriers (subcarrier bandwidth) to be BSC = B/L, where B is the nominal bandwidth (equal to data rate), and L is the number of subcarriers, ensures that all …
What is the subcarrier spacing?
The subcarriers can be spaced from 15 kHz to 240 kHz apart. In general, due to the characteristics of the channel bands, 15 kHZ to 60 kHz is used in carrier channels below 6 GHz, and 60 kHz to 120 kHz is used for higher frequency channels.
What is OFDM subcarrier?
OFDM is a frequency-division multiplexing (FDM) scheme that was introduced by Robert W. Chang of Bell Labs in 1966. In OFDM, multiple closely spaced orthogonal subcarrier signals with overlapping spectra are transmitted to carry data in parallel. Demodulation is based on fast Fourier transform algorithms.
What is subcarrier in modulation?
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.
Why are there 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.
Why subcarrier spacing is 15 KHz in LTE?
Simply, It is because 3G and LTE have the same clock timing for multi technology handsets.
What is subcarrier spacing in 5G?
5G NR can choose subcarrier spacing from 15kHz to 240kHz, with a maximum 3300 subcarriers in simultaneous use on one channel. However, channels can be no more than 400MHz wide. The standard is frequency agnostic, meaning any subcarrier configuration can be used on any band.
What is subcarrier mapping?
Sub-carrier mapping is one of the major considerations for LTE as multiple mobile terminals i.e. users are assigned by partitioned subcarriers in OFDMA system. In LTE uplink a subsets of subcarriers are used to transmit its own data.
Which subcarrier spacing is not supported for 5G?
I find this part of 5G fascinating and think it will be a key part of 5G to support a wide range of frequencies and scheduling for many diverse services. The top five features of 5G flexible numerology are: 1. Subcarrier spacing is no longer fixed to 15 kHz.
Which subcarrier spacing is not supported for Sync 5G?
However, unlike LTE, extended cyclic prefix is supported only for µ value of 2 (i.e., for subcarrier spacing of 60 kHz). The subcarrier spacings of 15 kHz to 120 kHz are used for shared channels, such as those carrying user traffic, while the subcarrier spacing of 240 kHz is available for synchronization signals.
What is subcarrier spacing SCS?
Numerology-4 : 240 kHz sub-carrier spacing can be used to provide broadcast signals at millimeter-wave. All other Sub-carrier spacing are supported for data and signaling except 60 KHz which is for data Physical channels only. Numerologies 0 and 1 (15/30 KHz) can be used only in FR1 (Frequency Range 1 – sub 6 GHz)
What is subcarrier mapping in LTE?