Non-Line-of-Sight Identification Via Space-Frequency Correlation in MIMO-OFDM Systems: A Preliminary Study
This paper presents a preliminary study on a Non-Line-of-Sight (NLOS) identification technique that exploits space frequency correlation features of multiple-output Orthogonal Frequency Division Multiplexing (OFDM) systems. Here, space correlation refers to the correlation across antenna elements and frequency correlation refers to the correlation across subcarriers. In this technique, a measure, Subcarrier Correlation Difference (SCD), is introduced and used to identify NLOS conditions. SCD is defined as the difference of cross-antenna subcarrier correlation and single antenna subcarrier correlation. The impact of the fading channel K-factor, spatial subchannel correlation and channel estimation error on the proposed techniques is investigated.