Binary and nonbinary LDPC-coded modulations for generalized fading channels

In this paper, we compare binary and nonbinary LDPC-coded modulation schemes with high-rate component codes, which are more suitable for high-speed wireless communication applications than schemes employing low-rate codes. In order to test the performance of these schemes under various fading conditions, we use two generalized fading distributions, namely the a-μ distribution and the K-μ distribution. By adjusting the parameters a, k, and μ, we simulate the conventional Rician, Rayleigh, and Nakagami-m fading cases. Further, to provide an example for cases where the field measurements may exhibit better fit to nonconventional distributions, we also study a heuristic fading scenario. Using QPSK modulation, we observe that binary and nonbinary LDPC-coded modulation schemes perform closely under all fading conditions considered. However, in terms of receiver latency, the nonbinary LDPC-coded modulation scheme may lower receiver latency especially when complex equalization schemes are employed since NB-LDPC-CM avoids using iterative equalization and decoding which is a crucial component in binary LDPC-coded modulation schemes.