BPSK Modulation with Unequal Power Allocation Considering A Priori Knowledge
T. Bruggen, Marc Adrat, Peter Vary · 2006
A well known technique to protect bits with different sensitivities against channel errors is unequal error protection (UEP) by selective channel coding. However, some transmission systems such as Bluetooth and DECT include only weak or no channel coding. For those systems modulation with unequal power allocation (MUPA) is an appropriate technique to realize UEP without channel coding, MUPA allocates different transmission power to the modulation symbols according to the individual bit error sensitivities. In this paper we apply the MUPA concept to systems with softbit source decoding and soft demodulation, and enhance the MUPA approach by taking a 1storder Markov model in terms of 1storder a priori knowledge (AK1) into account (MUPA-AK1)