Does anybody know what this cable is/does?

Last night, out of nowhere, my iPhone 5 started acting up and getting real glitchy. I locked/unlocked it and the LCD had a grid pattern behind my normal wallpaper and the digitizer isn't responsive.

Thought it was just a bad session, so I hard reset it...still no response and flawed picture.

Thought it may be a problem with iOS 7.0.3, so I restored and went back down to 7.0.2...still no response and I lost everything (couldn't back my phone up because Find My iPhone was running and I couldn't unlock my phone to turn it off)

Thought the LCD must just be bad, swapped it out and it still had the problem.

Sooooo I tore the whole phone down and found that this cable (See linked picture) was screwed in, but tore in half. It's one of the two that are at the top of the LB next to the camera.

Does anybody know what this cable is? What this cable does? And how could I go about fixing it? Looks to be soldered in, which I'm about to try doing. But I don't even know what to begin searching for in order to find somebody who can. Help help help

Tearing my hair out with this one :/