Patent ID: 8270520

Claim:
A low complexity sphere decoding method for spatial multiplexing (SM) multiple input multiple output (MIMO) communication systems, comprising: A. Computing a linear zero forcing (ZF) decoder matrix H + wherein: {dot over (s)}=H + y =( {dot over (H)}H ) −1 {dot over (H)}y for each of K SM inputs, wherein {dot over (s)} is a ZF solution and y is a received vector; B. Calculating or providing a condition number for all of the K matrices; C. Ordering the K matrices according to the condition number of step B in descending order (largest first), wherein the more problematic matrices in term of decoding are first in order; D. Selecting a matrix from the ordered matrices, each time beginning from the first remaining matrix, wherein the selection can be done in parallel, so that more than one matrix is processed at the same time; E. Performing sphere decoding (SD) for the selected matrix as long as clock budget remains, else proceed to step G; F. If there are matrices left, of the K matrices, returning to step D for the next matrix; G. Providing K output matrices, wherein matrices that have not undergone SD will be provided with their existing ZF solution, while matrices that have undergone SD will be provided with the SD solution.