METHOD FOR ENUMERATING VISITED LATTICE POINTS, AND SPHERE DECODER FOR IMPLEMENTING SAME

摘要

The present invention relates to a method for enumerating lattice points for determining a search order of the lattice points according to the Schnorr-Euchner enumeration at a visiting level when the sphere decoder searches a tree. The method comprises the steps of: searching for a first candidate lattice point of a visiting level in a tree and then calculating, for the next visit, a first enumeration distance for searching for a second candidate lattice point, i.e. a candidate lattice point for the next visit; setting an enumeration distance calculating mode to be used when a second enumeration distance is calculated from the second candidate lattice point to a third candidate lattice point, i.e. a next candidate lattice point, on the basis of a tree search direction and the first candidate lattice point; and enumerating valid lattice points at a corresponding level by calculating an enumeration distance on the basis of the enumeration distance calculating mode set at the corresponding level while searching the tree by going upward from the level or going downward to a non-visited level according to the result of a comparison between a path distance to the first candidate lattice point and a limiting condition.