In LTE:
Each Resource Block refers to
0.5 msec
12 Sub carriers (Each Sub Carrier is of 15khz)
7 Symbols (Normal Cyclic Prefix)
Which makes 84 Resource elements per Resource Block.
1 Sec = 2 Slots = 2 Resource Blocks
So For 20Mhz is the Bandwidth:
Number of RBS X 2 Slot (per Sec) * Number of RES
= 100 * 2 * 84
=16800 Resource Elements
So, per sec eNodeB total resources are 16800 Resource Eleements
Considering 64 QAM is the Modulation, Each Resource Element carries 6 Bits
=16800 * 6
= 100800 bits per milli second
= 100800 * 1000 =
= 100800K
= ~100 Mbits per second
Considering 4 X 4 DL MIMO = ~400 Mbits per second
As we know that DL Grid also possess other entities like PDCCH, PSS, SSS, MIB, PHICH,Reference Signals, etc., and other Factors like Modulation,etc.,
Considering 25% of 400 Mbits occupies the above
It brings down to ~300 Mbits per second
References:
TS 36.213 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures
Section 7.1.7 - Modulation order and transport block size determination
No comments:
Post a Comment