It adds support for stereo signals and higher sampling rates.

He thought it would help if we could feed a stereo signal to a satellite and get it back," Schafer said.

This is exactly what a stereo signal does - it constantly reverses the flow of electricity.

However, stereo signals tend to have some correlation between the two channels that can be further exploited.

The ability to separate sources from stereo signals requires different techniques than those usually applied in communications where multiple sensors are available.

If you're really on a budget, you can rig your own surround-sound setup with four speakers and a regular stereo signal.

Some eyes had a separate small display to light up indicating a stereo signal on FM.

For many broadcasts - especially the evening news and movies made in Western countries - the stereo signal is split in two.

This technique can produce phase issues when the stereo signal is mixed to mono.

But many people whose television sets do not accommodate stereo signals could not take advantage of this refinement anyway.