Massive multiple input multiple output(MIMO)-based fully-digital receive
antenna arrays eventuate a huge amount of circuit costs and complexity to
direction of arrival(DOA) estimation, which is hard to satisfy the needs of
high precision and low cost in future green wireless communication. To address
this challenge, a novel heterogeneous hybrid MIMO receiver is proposed in this
paper and a high performance DOA estimator called heterogeneous cross-minimum
distance (HCMD) is developed based on the structure. The antenna arrays are
first divided into multiple groups, and each group adopts a different hybrid
structure. The virtual antenna arrays of these groups are then used for DOA
estimation to generate multiple candidate angle sets, where each set contains a
unique true solution and multiple pseudo-solutions. Finally, the cross-distance
minimization method is applied to the multiple candidate angle sets to select
the corresponding true solution for each group, and the final DOA estimation is
given by combining the multiple true solutions. Simulation results show that as
the number of antennas tends to large-scale, the proposed method can rapidly
find the true solution for each group and achieve excellent estimation
performance