UART signal recovery from PCM data
This signal looks pretty good, so that a simple sign decision gives you &quot;low&quot; or &quot;high&quot; periods.
Then, you just start at the beginning, and count samples until you find your start bit.
From the start bit, you just sample your signal in 1 bit period, 2 bit periods, ... and get your transmit data stream. Remember, UART is by definition unsynchronized.