Spatial Diversity vs Spatial Multiplexing - MIMO

Hello Experts,
What is the differece between Spatial Diversity and Spatial Multiplexing - MIMO?
Can someone clarify please?

The main difference between Diversity and Multiplexing is:

  1. Spatial Diversity is a technique to overcome probability of error, P_e

  2. Spatial Multiplexing is a technique to increase data throughput

Spatial Diversity:

We all know transmitted data in wireless is received through multipath propagation i.e., Fading

If the channel is worse, P_e is high this implies channel is in deep fade

Transmission of multiple copies of the same information over independent channels, thereby reduces the chance of information loss

Even if one or more channels are in deep fade remaining channels will decode data correctly

Spatial Diversity can be employed in 3 ways

  1. Transmit Diversity
  2. Receive Diversity
  3. Switching Diversity

Spatial Multiplexing:

Transmission of multiple copies of the different information over independent channels i.e., transmitting information in parallel

Since transmitting multiple parallel streams in space through different spatial modes it is known as Spatial Multiplexing

Spatial Multiplexing is employed when P_e < Threshold, this implies channels are good and not in deep fade

Integration of Diversity and Multiplexing:

Whenever P_e > Threshold we have to adjust it by implementing spatial diversity technique