unable to perform assignment because the left and right sides have a different number of elements , vect problem

can some one plz explain tome that !

[amani]

i do vec_SNR_dB(i) = vec_EbN0_dB (i) + 10( mod_order)

it word but i don't know if it is correct or no !

[Torsten]

Maybe you should pass MATLAB Onramp, an introductory course free of costs to learn the basics of the new language:

https://matlabacademy.mathworks.com/details/matlab-onramp/gettingstarted

Answer 1

[Walter Roberson]

vec_EbN0_dB is an entire vector.

On the statement

vec_SNR_dB(i)  = vec_EbN0_dB + log10( mod_order)

you are using the entire vector vec_EbN0_dB on the right hand side, so the right hand side is an entire vector. The left hand side can only store a single element.

However,

vec_SNR_dB(i)  = vec_EbN0_dB (i) + 10( mod_order) 

is an incorrect expression because it is not possible to index the constant 10 at a particular location mod_order, and MATLAB has absolutely no implied multiplication.