Turbo Product Code-Aided Spatiotemporal 2-D Coded MIMO for URLLC

The ultra-reliable low-latency communication (URLLC) scenario beyond the fifth-generation mobile networks requires latency to shift from ms-level to ms-level while maintaining low packet error rates. Short block-length codes can reduce latency but suffer from performance degradation. Asymptotic analyses indicate that increasing spatial degrees of freedom in multiple-input multiple-output (MIMO) systems help to achieve target error rates with a fixed block length and signal-to-noise ratio. To approach the upper bound of the average maximal achievable information rate in massive MIMO systems, spatiotemporal 2-D channel coding has been proposed. However, a considerable gap remains between the performance of the existing coding scheme and the theoretical capacity bound. To bridge this gap, this article introduces turbo product codes aided spatiotemporal 2-D coded MIMO systems (TPCAS-MIMO). Multi-level design on the baseband MIMO transceiver, involving encoding, interleaving, modulation, detection, and decoding schemes, is explored to boost the performance of TPCAS-MIMO with low latency for URLLC. In comparison to prior arts, this work achieves a 5.5 dB SNR gain at a frame error rate of 10–5 using (64, 42)2 polar turbo product codes in a 64 x 128 MIMO system, narrowing to a mere 2.5 dB gap from the theoretical capacity bound.