Howtosignalprocessing
Subframe Structure - Control and Data
| Parameters | 5G | LTE |
|---|---|---|
| Number of GPs | 3 | 2 |
| Number of symbols per frame | 14 | 14 |
| CP duration [us] | 1 | 4.7 (short) |
| GAP duration [us] | 0.89 | 66.67 (min) |
What is CP length?
The CP duration defines how much multiple distance is can support without affecting the Inter symbol interference (ISI) and Inter Carrier Interference (ICI). The distance be calculated using a simple Time, distance formula. For example, let's take 15 KHz having CP for long symbol as 5.2 µs.
How do you calculate CP length?
To keep the subcarrier spacing fixed at 10.9375 KHZ across different channel bandwidth, scalability feature of OFDM chooses 1024 FFT length with 10MHZoccupied bandwidth. Thus, the useful symbol length (Tu) is inverse of the subcarrier spacing ∆f. Then, the CP length is (T g = G*T u), where G is (Tg/Tu) ratio.
What is CP OFDM 5G?
CP-OFDM is used as the access technology for 5G New Radio. Its operation is very similar to that of OFDM used in LTE, however CP-OFDM features variable subcarrier spacing termed “numerology”. Where LTE uses a fixed 15kHz subcarrier separation, CP-OFDM can utilize 15kHz, 30kHz, 60kHz, 120kHz, etc.
What is CP length in LTE?
LTE uses two types of CP, normal CP of 4.7 microseconds and Extended CP of 16.7 microseconds.
