## FANDOM

186 Pages

We consider a precoded multiple-antenna broadcast system which consists of a AP with $N_t$ transmit antennas and $K$ users each with single receiver antenna. Then, the received signal at user $k$ is described as

$y_k = \mathbf{h}_k^T\mathbf{x}+n_k, \quad k=1,2, \ldots, K$

where $\mathbf{x} = \sum_{i=1}^K s_i P_i \mathbf{w}_i$ is the $N_t \times 1$ vector of transmit symbols, $n_k$ is the noise signal at user $k$ respectively, $\mathbf{h}_k$ is the $N_t \times 1$ vector of channel coefficients and $\mathbf{w}_i$ is the $N_t \times 1$ linear precoding vector.