Implementation of an SDFG based parallel depth-first complex sphere decoding algorithm

Iterative tree search algorithms like K-Best or sphere decoder algorithms are promising candidates for the upcoming wireless communications systems. In this paper a square root and division free Givens rotation (SDFG) algorithm is merged into a common sphere decoder algorithm to decrease the entire complexity. Furthermore, the algorithm is speeded up due to parallelizing the computation by taking the orthogonality of the real and imaginary parts of the complex transmit symbols into account.