Near-Capacity Three-Stage Downlink Iteratively Decoded Generalized Layered Space-Time Coding with Low Complexity

This paper presents a low complexity iteratively detected space-time transmission architecture based on Generalized Layered Space-Time (GLST) codes and IRregular Convolutional Codes (IRCCs). The GLST combines the benefits of the Vertical Bell-labs LAyered Space-Time (V-BLAST) scheme and Space-Time Coding (STC). The GLST is serially concatenated with a Unity-Rate Code (URC) and an IRCC which are used to facilitate near-capacity operation with the aid of an EXtrinsic Information Transfer (EXIT) chart based design. Reduced-complexity iterative Successive Interference Cancellation (SIC) is employed in the GLST decoder, instead of the significantly more complex Maximum Likelihood (ML) detection. For the sake of approaching the maximum achievable rate, iterative decoding is invoked to achieve decoding convergence by exchanging extrinsic information across the three serial component decoders. Finally, it is shown that the SIC-based iteratively detected IRCC-URC-GLST system is capable of providing a trade-off between the affordable computational complexity and the system throughput.