A High-Performance Measure for Non-Line-of-Sight Identification in MIMO-OFDM-Based Sensor Networks

This paper proposes a new measure for non-line-of-sight (NLOS) identification in wireless localization systems. The measure is defined based on the space-frequency correlation of multi-input-multi-output orthogonal frequency division multiplexing systems. Here, space correlation refers to the correlation across antenna elements, and frequency correlation refers to the correlation across subcarriers. In this technique, the mean value and standard deviation of space-frequency correlation over multiple transmit and receive antenna combinations are used as the measure for NLOS identification. This method requires minimal variation of spatial correlation across different multipath components. The channel model satisfying this requirement is studied. It is depicted that the proposed technique is applicable to many indoor and outdoor environments in which sensor networks operate. The probability of detection performance of the new NLOS identification method is investigated.