Efficient Detection Ordering Scheme for MIMO Transmission Using Power Control

In this letter, an efficient ordering scheme for an ordered successive interference cancellation detector is determined under the bit error rate minimization criterion for multiple antenna systems using transmission power control. From the convexity of the Q -function, we derive the ordering strategy that makes the channel gains converge to their geometric mean. Based on this approach, the fixed ordering algorithm is first designed, for which the geometric mean is used for a constant threshold. To further improve the performance, the modified scheme employing adaptive thresholds is developed using the correlation among ordering results. Theoretical analysis and simulation results show that proposed ordering schemes using QR-decomposition not only require a reduced computational complexity compared to the conventional scheme, but result in improved error performance.