A new layered space-time-frequency architecture with LDPC coding for OFDM MIMO multiplexing
This paper is focused on the study of layered space-time-frequency (LSTF) architectures with channel coding for orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) multiplexing system in high speed wireless transmission under frequency-selective fading channel. In order to achieve the available spatial, temporal and frequency diversity, and at the same time make the system implementation feasible for ultra high data rate OFDM MIMO multiplexing, we propose a new LSTF architecture with each independently coded layer being threaded in the three-dimensional space-time-frequency transmission array. List sphere decoding is used for MIMO multiplexing detection, and the irregular low-density parity-check code (LDPC) is chosen as the channel code. Three construction rules are adopted to generate high coding rate irregular LDPC codes with low encoding complexity and little performance loss. Simulation results show that the proposed LSTF architecture can significantly outperform the LSTF assuming each independently coded layer being transmitted through a permanently assigned antenna, and get almost the same performance as the LSTF applying coding across the whole information stream. On the other hand, due to its structure of multiple parallel lower-speed codecs with shorter codeword length, the proposed LSTF architecture is more realizable for ultra high data rate transmission than the LSTF applying coding across the whole information stream