# Communication Systems/Space-Division Multiplexing

This page is all about **Space-Division Multiplexing** (SDM).

-   What is SDM: When we want to transmit multiple messages, the goal is
    maximum reuse of the given resources: time and frequency.
    Time-Division Multiplexing (TDM), operates by dividing the time up
    into time slices, so that the available time can be reused.
    Frequency-Division Multiplexing (FDM), operates by dividing up the
    frequency into transmission bands, so that the frequency spectrum
    can be reused. However, if we remember our work with directional
    antennas, we can actually reuse both time and frequency, by
    transmitting our information along parallel channels. This is known
    as **Space-Division Multiplexing**.

## Technical categorisations

### Spatial Coding

## Multipathing

## Application systems

### MIMO Systems

### Smart antenna
