Improvement of the sphere decoding complexity through an adaptive OSIC-SD system

Sphere decoding is a decoding technique able to achieve the maximum likelihood error performance in fading environments; nevertheless, it exhibits a high complexity, especially in poor channel conditions. In this paper, we present an adaptive hybrid algorithm which reduces the complexity of conventional sphere decoding without sacrificing its error performance. Through simulations, we prove that the proposed system maintains almost the same bit error rate of the conventional sphere decoding, and exhibits a lower, quasi-constant complexity.