Explain how an autobaud scheme might work to ensure automatic baudrate detection for the communicating devices?

One company used a known start character that was examined by the receiver micro processor to determine if it was the correct baud rate. If it wasn't, then the received character would translate into an incorrect character, and the receiving micro controller would try the next baud rate and recheck with the new received character. The transmitter would keep retrying until it got an ack back, indicating the receiver had synced with the transmitter's baud rate.