56 bits out of Binary Input Reed Solomon Encoder

Hello,

I am trying to implement a COFDM System which has an IFFT/FFT length
of 64. Out of 64 carriers, 8 are set aside for nulls and pilots (56
remaining).

So, out of Reed Solomon encoder I want to get 56 bits which will
then be convolutionally encoded and modulated using QPSK before
presenting them as inputs to the IFFT. So, in order to 56 bits out of
the Reed Solomon Encoder, I was planning on using a coding structure
of (7,3,2).

But when I implement this in simulink, the number of samples per
frame that I can present as the input to the RS Encoder has to be a
multiple of 9.

My question is: Is there any way I can get 56 bits out of the Binary
Input RS Encoder?

Thanks,
Rohith

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