Predicting the pruning potential in sphere decoding for multiple-input multiple-output detection

In this work, a method for predicting the pruning potential of a sphere constraint (SC) for sphere decoding (SD) is developed. Because the direct prediction of the pruning potential is not easy, the orthotope constraint (OC), an approximation of SC, is used instead of SC. This pruning potential prediction makes it possible to increase pruning at the root of the search tree in SD, considering it is the most desirable location for pruning.