Improved soft de-mapping scaling for a constrained MMSE receiver in OFDM MIMO systems

Since different spatial streams in MIMO systems experience different SINRs, the soft bits of each spatial stream should be scaled according to its SINR. In this paper, we introduced the idea of soft demapping scaling according to SINR and proposed an improved scaling method using a constrained MMSE approach for OFDM MIMO systems. Based on IEEE 802.11n examples, good system performances are observed in various modulation and coding schemes using the proposed soft demapping scaling while computational efficiency is preserved.