Some may say that peak data rate for LTE is 300mbps.

How did they arrive at this number? In this chapter we shall make it clear.

WKT:

1 frame = 10 subframe = 10ms

1 subframe = 2 slots = 0.5ms

1 slot = 12 sub carriers & 7 symbols

1 slot = Resource Block

Hence, 1RB = 12 x 7 = 84 Resource Elements

Bandwidth of 1 Resource Block = 180 Khz

Bandwidth of 1 Sub Carrier = 15 Khz (spacing)

WKT LTE will work on below bandwidths and has the resource blocks:

Channel bandwidth Resource BLocks: 1.4 MHz 6 3 MHz 15 5 MHz 25 10 MHz 50 15 MHz 75 20 MHz 100

So in LTE uses OFDM in downlink and SC-FDMA in uplink.

In OFDMA it is possible to have below 3 modulation techniques.

QPSK 2 bits per symbol

16QAM 4 bits per symbol

64QAM 6 bits per symbol

## Some of the parameters to be considered while calculating bandwidth are:

Some Parameters to be considered:

1. Cyclic prefix

2. Available Resource

3. Modulation and coding scheme

4. MIMO

## So in our example let us assume below parameters:

20 Mhz channel bandwidth, normal CP & 4×4 MIMO

**Step 1:**Calculate the number of RE in each subframe of 20Mh

12 subcarriers x 7 symbols x 100 RB x 2 slots (each subframe has 2 slots) = 16800 RE’s per subframe.

**Step 2:**Assume 64QAM modulation & no coding, 1 modulation symbol will carry 6bits.

so 16800 modulation symbols x 6bits/modulation symbol = 100800bits = 100.8Mbps is the data rate

**Step 3:**With 4×4 MIMO, peak data rate = 4×100.8 = 403Mbps

**Step 4:**Estimating 25% is for signaling such as PDCCH, reference signal, sync signal, PBCH & some coding we get,

= 403Mbps x 0.75 = 302Mbps