Energy minimization of wireless sensor networks based on modulation and coding optimization under finite frame length constraint

Recent hardware advances allow more signal processing functionality to be integrated into a single chip. In sensor networks, the wireless nodes are typically operated with small batteries for which their replacement, when not impossible, is very difficult and expensive. Thus, minimizing the energy consumption of transmitting sensor nodes is an important issue on the design of such communication systems. The previous work in the literature proposes modulation as well as coding optimization considering uncoded and coded bit error rate (BER) of M-ary QAM as well as its average mutual information. However, these approaches do not address the coded case with finite frame length, which is always the case in practical systems. In this paper, we consider a design of coding and modulation that minimizes the transmit circuit energy under finite codeword length constraint of capacity-approaching channel codes and analyze its performance through simulation using regular low-density parity-check (LDPC) codes in a point-to-point communication link. The results are also compared with those of information-theoretic analysis based on the mutual information rate.