Repeated frames in OFDM

[Antonio_Magma]

Q1:
This is with reference to the white paper by TI entitled, "Power Line Modem with E-meter Platform", 2004 (i'm sorry i can't find the link to the article)

At the part where the paper decribes the Packet Format for the OFDM frames. It says that the data frames are grouped into blocks of 3 frames and each data frame in the block contains identical data but transmitted at different frequency.

Is this a common practice to transmit identical data for multiple times in OFDM or just a choice of transmission methods?

Q2:
The preamble and synchronization data. Is it any binary sequence will do as long as the receiver know what is it? or is there a specific binary sequence for those?

 

[eda_wiz]

Is this a common practice to transmit identical data for multiple times in OFDM or just a choice of transmission methods?

if you are talking abt the preamble .. yes its a common practice to transmit the same symbol repeatedly for packet detection,channle estimation etc..

Q2:
The preamble and synchronization data. Is it any binary sequence will do as long as the receiver know what is it? or is there a specific binary sequence for those?

no its not just a random data.. its carefully selected by simulation to optimize the SNR.

 

[Antonio_Magma]

if you are talking abt the preamble .. yes its a common practice to transmit the same symbol repeatedly for packet detection,channle estimation etc..

I understand the preamble is repeated, i mean the data frames. In the article for every transmission frame. The same data block is repeated 3 times to form a single data frame and transmitted after the preamble. Is it normal to repeat data frames or is it just a choice of methods?

Q2:
no its not just a random data.. its carefully selected by simulation to optimize the SNR.

Is there any papers or articles that have information of such data sequence? The channel i'm transmitting is the power line channel.

 

[varunknp]

hello

Is this a common practice to transmit identical data for multiple times in OFDM or just a choice of transmission methods?

if you are talking abt the preamble .. yes its a common practice to transmit the same symbol repeatedly for packet detection,channle estimation etc..

Q2:
The preamble and synchronization data. Is it any binary sequence will do as long as the receiver know what is it? or is there a specific binary sequence for those?

no its not just a random data.. its carefully selected by simulation to optimize the SNR.