MIMO-OFDM Linear approximation signal detection apparatus using MIMO-OFDM system and method thereof

摘要

The present invention relates to a linear approximation signal detection apparatus using a MIMO-OFDM system and a method thereof. According to the present invention, a linear approximation signal detection method comprises the following steps of: obtaining a reception signal having a channel matrix of N×N size in response to a transmission signal of a transmission terminal; decomposing the reception signal into L (L=N/2) signals having a channel matrix of 2×2 size by using a partial ZF technique; early-detecting first and second symbols included in decomposition signals for each of the decomposition signals by applying a DFE technique to each of the L decomposition signals; selecting each of M (M K) first candidate symbols and M second candidate symbols within a set distance from the first symbol and the second symbol among K symbols in a modulation constellation; and re-detecting the first and second symbols by applying a QRD-M technique to the decomposition signals, and detecting the first and second symbols by individually applying the M first candidate symbols and the M second candidate symbols to first and second signal detection layers for the QRD-M technique, respectively. According to the present invention, since one large MIMO system is decomposed into several small MIMO systems by using a ZF technique, complexity is reduced, and implementation is facilitated. Also, complexity is not high even when a DFE and a QRD-M, which are complex signal detection techniques, are applied to the decomposed several small MIMO systems, thereby providing low complexity and high error performance.