Repeat Audio EDGE and Interference

Tripling the data transmission rate on the Air-Interface by applying 8-PSK seems like an obvious step forward. However, it has some inherent disadvantages, in particular, through the unpredictable environment of radio transmission. With increasing interference, the clearly distinguishable symbols of 8-PSK, as shown in the animation, become more and more diffused. At a certain stage, the receiver is no longer able to distinguish between different symbols. Obviously, 8-PSK with 8 different symbols is more vulnerable to such interference than e.g. GMSK.