Boosting sphere decoding speed through Graphic Processing Units

Graphic Processing Units (GPUs) have evolved to provide a massive computational power. In contrast to Central Processing Units, GPUs are so-called many-core processors with hundreds of cores capable of running thousands of threads in parallel. This parallel processing power can accelerate the simulation of communication systems. In this work, we utilize NVIDIA´s Compute Unified Device Architecture (CUDA) to execute two different sphere decoders on a graphic card. Both flat fading and frequency selective channels are considered. We find that the execution of the soft-sphere decoder can be accelerated by factors of 6-8, and the fixed-complexity sphere decoder even by a factor of 50.