Grouping-Based Channel Estimation and Tracking for Millimeter Wave Massive MIMO Systems

Algorithm 2

Grouping Scheme

1: Initialization: divide UTs into groups. Different UTs in the same group are allocated with different pilot sequences;

2: UTs in the same group transmit the pilots in the same time slot. The BS distinguishes the received signals from different UTs;

3: The BS estimates the initial DoA angles of different UTs;

4: If the minimum difference on the DoA angles between any two UTs is bigger than a threshold denoted as , they are put into the same group;

5: The UTs in the same group will use the same pilot sequence.