Getting Closer to MIMO Capacity with Non-Binary Codes and Spatial Multiplexing

In this paper, we discuss the combination of non-binary channel coding with higher-order modulation and MIMO transmission in the form of spatial multiplexing. In addition to the benefits of non-binary LDPC codes on the AWGN channel, we identify an inherent advantage for non-binary coding in multiple antenna schemes. By comparing binary and q-ary information processing at the receiver, we highlight the intrinsic advantages of non-binary coding. A performance comparison based on simulation results shows that, at similar system complexity, non-binary information processing can actually outperform the Shannon limit of its binary counterpart.