There are three different bit identifiers

Start bit: It consists of a 9ms high phase followed by a 4.5ms low phase.
0-Bit: A bit with a value of 0, is represented by an equal-long high and low phase. The length is in each case 0.55 ms. The bit thus has a total length of 1.1 ms.
1 bit: A bit with a value of 1, represents a 0.55 ms long high pulse followed by a 1.7 ms low phase. The total length is therefore 2.25 ms.

A command consists of 4 bytes, whereby in my interpretation the LSB (least significant bit) of each byte is sent first.

1st byte: always CA hex.
2nd byte: always 34 hex.
3. Byte: The command which is evaluated.
4. Byte: Again the command with inverted bit.

The bit sequence "01010011 00101100 01111000 10000111" can be seen in the figure above. This corresponds to the hexadecimal representation "CA 34 1e e1". In this case, the radio has indicated that the next track should be played.