Consider a generator matrix \( G \) = \(\begin{bmatrix} 1 & 0 & 0 & 1 & 1 & 0 \\ 0 & 1 & 0 & 0 & 1 & 1 \\ 0 & 0 & 1 & 1 & 0 & 1 \end{bmatrix}\), find the dimensions of corresponding parity-check matrix \( H\), identity matrix \(I_{n-k}\), and sub-matrix \(P^T \).