Combination of Space-Time Codes with Forward Error Correction (FEC)

Future wireless communication systems will demand high data rates for delivery of data like multimedia content. The use of MIMO systems with multiple transmit and receive antennas enables the introduction of space-time coding to improve link reliablity and spatial multiplexing to increase spectral efficiency. Recently a class of codes was proposed in [14] which makes it possible to combine space-time coding and spatial multiplexing. The proposed design for the LSD codes includes an optional forward error correction (FEC) element. The goal this work is to investigate the combination of LSD codes with FEC. The results of our simulations show that the combination of LSD codes with FEC yields a significant improvement in terms of a lower bit error rate especially if a weak FEC with a high data rate is performed. In addition, if follows that in order to increase spectral efficiency spatial multiplexing outperforms the choice of a higher symbol-alphabet and diversity. However, the combination of diversity and a higher FEC code-rate even outperforms spatial multiplexing in terms of link reliability. LSD codes and FEC involve a large number of parameters and, consequently, a wide range of optimization. Therefore, this work only covers a small part of the problem. However, the results raise suspicion that the combination of LSD codes with FEC is a reasonable tool in order to improve link reliability and spectral efficiency.