Tiva-C Launchpad - Sending a Tx signal over long distance
Consider using RS485 drivers and receivers and a properly terminated twisted pair. The old SN75176 is one choice- there are newer products. 

Assuming you're talking about a unidirectional one-wire type interface, you can use a single pair from Ethernet cable, for example. You can use some or all the other wires for the (required) ground. 

You would need a transceiver at each end (you can enable both continuously) and a suitable termination resistor at each end - for CAT5 100 ohm resistors would be better than the usual 120 ohms used for RS485. 

Using the above arrangement, a few hundred feet should be no problem. 

The 75176 will work with a 0/3.3V input signal from the Tiva so you don't need a voltage translator.