Let's say we have a matrix
$ H= \begin{bmatrix} 0 & 0 & 0 & 1 & 1 & 1 & 1 \\ 0 & 1 & 1 & 0 & 0 & 1 & 1 \\ 1 & 0 & 1 & 0 & 1 & 0 & 1 \end{bmatrix} $
Which is a hamming code parity check matrix
I need to find code generator matrix and then find code words if sequence being sent is $ 0 0 0 0 0 1 1 1 1 0 0 1 1 1 1 0$
Now, when i find code generator matrix, its dimensions are supposed to be 4x7. Since i have a sequence of twelve numbers. How am i supposed to determine the code words when number of elements in a given sequence is not equal to number of rows of generator matrix so multiplication of that vector and generator matrix is not possible? Any help appreciated!