Unequal error protection by modulation with unequal power allocation

In digital communication systems for speech, audio or video signals the individual bits of the transmitted parameters u exhibit different bit error sensitivities. Usually channel coding with unequal error protection (UEP) is applied. However, some transmission systems do not include channel coding for several reasons. For this situation, a novel concept is proposed which achieves UEP by allocating different transmission power to individual bits according to their bit error sensitivities. The optimization criterion for unequal power allocation is the mean square of the error between the original parameter-u and the decoded parameter u which has a strong correlation with subjective perception.