Achievable Rate Region of Gaussian Broadcast Channel With Finite Input Alphabet and Quantized Output
In this paper, the authors study the achievable rate region of two-user Gaussian Broadcast Channel (GBC) when the messages to be transmitted to both the users take values from finite signal sets and the received signal is quantized at both the users. They refer to this channel as Quantized Broadcast Channel (QBC). They first observe that the capacity region defined for a GBC does not carry over as such to QBC. Also, they show that the optimal decoding scheme for GBC (i.e., high SNR user doing successive decoding and low SNR user decoding its message alone) is not optimal for QBC. They then propose an achievable rate region for QBC based on two different schemes.