# The term OFDM symbol in Wireless Communication / Radio frequency in LTE

Thread Starter

#### JimmyCho

Joined Aug 1, 2020
97
Hi guys, I've already read and understand what does OFDM mean and what does it stand for and why we use it in our wireless technology today.
My question that I didn't understand is what does it mean number of "OFDM symbol per frame is 1 or two or 3 ..whatever"?
to clear more, lets assume I have pattern of data to transmit : [0 1 0] , and at each frame number of OFDM symbols is 2.
so what does it mean? is it mean the following claim on the data:
the data [0 1 0] will be stored in three frames and at each frame there's two OFDM symbols? so for is instance
0 is stored in frame and it has two OFDM symbols
1 is stored in frame and it has two OFDM symbols
0 is stored in frame and it has two OFDM symbols
So if that's true , what does it mean that 0 have two OFDM symbols? I need to understand what does it mean that certain frame has N OFDM symbols.

Appreciated for any help.

#### crutschow

Joined Mar 14, 2008
27,243
0 is stored in frame and it has two OFDM symbols
1 is stored in frame and it has two OFDM symbols
0 is stored in frame and it has two OFDM symbols
Where does that come from?

#### nsaspook

Joined Aug 27, 2009
8,400
Thread Starter

#### JimmyCho

Joined Aug 1, 2020
97
Where does that come from?
I just understand that it might be like this .. so maybe I concluded something is incorrect ..that's why I posted here my question .. could you help me to understand the terminology of saying "one frame has 4 OFDM symbols" for instance? what does that actually mean ..

thanks alot

Thread Starter

#### JimmyCho

Joined Aug 1, 2020
97
I appreciate your links, much appreciated. but I'm still confused about the term "one frame has 4 OFDM symbols" ..what does that actually mean?

Once again I really understand the OFDM technique but what does that mean for instance one frame has 4 OFDM symbols?
I chose 4 OFDM per subframe or frame just as an example to understand actually what does that mean ..

Last edited:

#### nsaspook

Joined Aug 27, 2009
8,400
I appreciate your links, much appreciated. but I'm still confused about the term "one frame has 4 OFDM symbols" ..what does that actually mean?

Once again I really understand the OFDM technique but what does that mean for instance one frame has 4 OFDM symbols?
I chose 4 OFDM per subframe or frame just as an example to understand actually what does that mean ..
Each OFDM symbol (from what I can tell there are several types in LTE) is the information encoding method for X number of data bits expressed into a RF signal for a period of time.

https://en.wikipedia.org/wiki/Symbol_rate

#### andrewmm

Joined Feb 25, 2011
1,498
I appreciate your links, much appreciated. but I'm still confused about the term "one frame has 4 OFDM symbols" ..what does that actually mean?

Once again I really understand the OFDM technique but what does that mean for instance one frame has 4 OFDM symbols?
I chose 4 OFDM per subframe or frame just as an example to understand actually what does that mean ..
what do you understand is the difference / relationship between symbols and bits ?

Thread Starter

#### JimmyCho

Joined Aug 1, 2020
97
what do you understand is the difference / relationship between symbols and bits ?
Assume I mean that symbol equal to 1 bit (assumption), so I can say one frame has 4 OFDM symbols is actually the same as saying one frame has 4bits? just want to understand.

Yes ofcourse I understand the difference between symbol and bits, symbol may have more than bit ..not always 1bit.

#### andrewmm

Joined Feb 25, 2011
1,498
Assume I mean that symbol equal to 1 bit (assumption), so I can say one frame has 4 OFDM symbols is actually the same as saying one frame has 4bits? just want to understand.

Yes ofcourse I understand the difference between symbol and bits, symbol may have more than bit ..not always 1bit.
well thats a totlay confusing answer.
I was just asking at to what level of support you required,