From: Application of cell-free massive MIMO in 5G and beyond 5G wireless networks: a survey
Notations | Definitions |
---|---|
K, M, Nap | Number of UEs, APs, and antennas per AP |
(·)T, (·)D, (·)∗ | Transpose, conjugate transpose, and the complex conjugate of a matrix |
tr(R), ‖R‖, |R| | Trace, Euclidean norm, and the determinant of matrix R |
⊗ | Kronecker product between two matrices |
In | n×n identity matrix |
\( \mathbbm{E} \) | Expectation operator |
k, l | Index of the UEs and index of the APs |
Ï„c, Ï„s | The length of the channel coherence time, length of the UL training phase |
Boldface lower case x | Column vectors |
Boldface upper case X | Matrices |
\( w\sim \mathcal{N}\left(0,{\sigma}^{{}^2}\right) \) | Real-valued Gaussian random variable |
\( w\sim C\mathcal{N}\left(\mu, {\sigma}^{{}^2}\right) \) | Circularly symmetric complex Gaussian random variable with mean μ and variance σ² |