Patent ID: 8798209

Claim:
An orthotope sphere decoding method of a multiple antenna system, comprising: tree mapping a node having highest pruning potential that can be predicted at a root of a tree of orthotope sphere decoding to a root level of the tree, among nodes to be mapped to the tree; and performing tree search of the orthotope sphere decoding on the nodes mapped to the tree, wherein the tree mapping comprises: receiving transmission symbols of the multiple antenna system; predicting pruning potential at the tree root for each node that will be mapped to the tree in correspondence to each received transmission symbol; and placing a node having the highest pruning potential at the root level of the tree, and wherein the predicting pruning potential uses, as the pruning potential, a numerical value which expresses possibility of a node to be pruned from the root of the tree through an orthotope constraint test (OC-test), and wherein the predicting pruning potential uses, as the pruning potential, an upper bound of the number of constellation points corresponding to each symbol of the node that will be pruned through the OC-test and removed through tree search.