Improved Tensor-MODE Based Direction-of-Arrival Estimation for Massive MIMO Systems

Mobile data traffic is expected to have an exponential growth in the future. To meet the challenge of mobile data traffic exponential growth, massive multiple input, multiple output (MIMO) has been proposed as one of the enabling technologies for future wireless systems. Due to the huge number of antennas at the base station, it is more reasonable to rely on direction-of-arrival (DOA) estimation to perform downlink precoding. This is one of the main reasons why direction information becomes critical for such a system. The measurement of 2D massive MIMO can be expressed as a 3D tensor. In this letter, we propose an improved tensor method of direction estimation (IT-MODE) based DOA estimation algorithm. It is a modification of the conventional tensor method of direction estimation (T-MODE) algorithm, and the threshold performance is improved. Asymptotic efficiency is achieved for the proposed estimator even when the source signals are highly correlated or coherent.