Table 2 Different representations of CSI in different stages
From: A limited feedback scheme for massive MIMO systems based on principal component analysis
Representations | Implications |
|---|---|
h | Original high-dimensional CSI estimated by MS |
Low-dimensional CSI after normalization | |
\({\bar {\mathbf {h}}}\) | and compression, that is \({\bar {\mathbf {h}} = \frac {{{\mathbf {h}\bar {\mathbf {U}}}}}{{\left \| {{\mathbf {h}\bar {\mathbf {U}}}} \right \|}}}\) |
\({\hat {\mathbf {h}}}\) | Quantized low-dimensional CSI |
h⌢ | High-dimensional CSI recovered from \({\hat {\mathbf {h}}}\) |
High-dimensional CSI recovered from \({\bar {\mathbf {h}}}\) | |
\({\tilde {\mathbf {h}}}\) | (with no quantization error of low-dimensional CSI) |