Nate Dogg -- Performing at Coachella ... From Beyond the Grave

Nate Dogg isn't letting a little thing like death keep him away from Coachella this weekend -- sources tell TMZ, the rapper will be making a very special guest appearance on stage ... in the form of a HOLOGRAM.

Sources tell us, Dr. Dre didn't want to leave Nate out of his Sunday performance -- so he's incorporating his old friend using hologram technology ... the same technology that broadcast Mariah Carey's image across Europe last year ... at 5 simultaneous concerts.

We're told an image of Nate will be projected onto the Coachella stage -- alongside Dre, Snoop Dogg, Kurupt, Warren G, and Daz Dillinger -- to make it appear as though he's actually performing on stage.

According to sources, Nate will perform several songs.

The singer passed away last March -- just weeks before last year's Coachella festival.