Is there a variable change I could do in order to transform the matrix inequality below
$$A^T P A - P + Q + K^T B^T P A + A^T P B K + K^T(B^T P B + R) K \leq 0$$
into an LMI? My variables are positive definite matrix $P$ and non-invertible matrix $K$. In my specific case, $K$ is a $3 \times 6$ matrix. All other matrices are given. Thank you all very much!