Multi-input Single-output communication system
Multi-input single-output (MISO) is describing the inputs and outputs of the system. In communication, this is the channel, so if you have a single-output it means that the received vector is $1 \times 1$.
The general model for a MISO system is:
\begin{split}
y &amp;= \mathbf{h^Tx}+\text{noise} \\
  &amp;= (h_1x_1+h_2x_2+...+h_Nx_N)+\text{noise}
\end{split}
The single output in a MISO system is a combination of the multiple inputs plus the noise.