Iterative decoding of low-complexity space-time codes

In this work, we study the iterative decoding of a lowcomplexity space-time architecture proposed by [1, 2] employing per-survivor-processing at the receiver with the soft-output viterbialgorithm (SOVA, [3]). At the transmitter, the space-time architecture is serially concatenated with an outer code. With the availability of extrinsic information at the receiver delivered by the SOVA, it is now possible to use a novel receiver scheme performing iterative (turbo) decoding in order to improve the performance of the architecture. According to the ZF or to the MMSE criterion, linear feedforward and -backward filters of the decision-feedback spacetime (ST) decoder are derived. Furthermore, the decision metric of the SOVA employing per-survivor-processing is developed and the performance of the scheme is analyzed and compared with the scheme in [2].