LTE Subcarriers, modulation and Frame structure
- LTE subcarrier is the smallest independent part of an LTE signal.
- The smallest defined piece of an LTE signal is a single subcarrier is RE (Resource Element).
- Modulation scheme used in LTE.
LTE Frame Structure in FDD
- Each LTE downlink subcarrier operates in 10 ms long frames.
- Each frame is made up of 10 subframes, each 1 ms.
- Each subframe contains 2 slots, each 0.5 ms.
- Each slot carries seven modulated symbols, which could be QPSK, 16QAM, or 64QAM.
Generic Frame Sequences:
In the frequency domain, 12 subcarriers form one physical resource block (180kHz * 0.5ms). The resource block size is the same for all bandwidths.
2 RB(Resource Block) = 1 Scheduling Block(SB)
1 Scheduling Block(SB)=1 TTI =1 Subframe
- LTE channel bandwidth can be 1.4, 3, 5, 10, 15, 20 MHz.
- The wider bandwidth the higher throughput.