for it. Section \[sec:sim\] presents numerical results to evaluate the performance of the proposed protocol and designs. Finally, Section \[sec:con\] concludes the paper.

*Notation:* For ease of reference, Table \[table:not\] summarizes the main variables which will be used throughout this paper. Furthermore, vectors and matrices are denoted by bold-face lower-case and upper-case letters, respectively. Sets are designated by upper-case calligraphic letters. $[\boldsymbol{x}]_{a:b}$ denotes the subvector that contains the $a$-th to $b$-th elements of $\boldsymbol{x}$. $\Re({\cdot})$, $\Im({\cdot})$, $(\cdot)^*$ and $\arg(\cdot)$ denote the real part, imaginary part, conjugate, and angle of a complex number, respectively. For a matrix $\boldsymbol{M}$ of arbitrary size, $\boldsymbol{M}^H$ denotes the conjugate transpose, and $\boldsymbol{M}_{i,j}$ denotes the entry in the $i$-th row and $j$-th column. $\mathrm{Tr}(\cdot)$ denotes the matrix trace. $\boldsymbol{F}_N$ and $\boldsymbol{F}_N^H$ refer to the $N\times N$ discrete Fourier transform (DFT) and inverse DFT (IDFT) matrices, respectively. $\boldsymbol{0}_{a \times b}$ denotes an all-zero matrix of size $a\times b$, $\boldsymbol{1}_{a \times b}$ denotes an all-one matrix of size $a\times b$, $\boldsymbol{I}_M$ denotes the identity matrix of size $M\times M$, and $\boldsymbol{e}_m$ denotes the $m$-th column of $\boldsymbol{I}_M$. $\mathrm{diag}(\boldsymbol{x})$ denotes a square diagonal matrix with the elements of $\boldsymbol{x}$ on the main diagonal, whereas $\mathrm{Diag}(\boldsymbol{X})$ denotes a column vector 