Parallel Architecture of List Sphere Decoders

Sphere decoding has been used for maximum likelihood (ML) detection of multiple-input-multiple-output (MIMO) communication systems. In order to combine the sphere decoder with the outer channel code decoder, researchers have proposed to include a candidate list in the sphere decoder to provide soft information to the channel code decoder. This algorithm is called list sphere decoder (LSD). With LSD, it takes many cycles to decode a vector. In this paper, the architecture of applying parallel processing technique in LSD is presented, with detailed discussions on the individual building blocks.