Performance Analysis of Dipole Antenna Based Planar Arrays With Mutual Coupling and Antenna Position Error in mmWave Hybrid System

In this work, a hybrid architecture called fully connected sub-array (FCSA) is considered for uplink data decoding with mutual coupling and space constraints at the base station (BS). The above architecture achieves the same system performance with a lower hardware complexity than a fully connected array. The packing of many antenna elements on a small surface area leads to the mutual coupling effect. Moreover, having antenna elements at the BS with finite directivity is more practical than having isotropic antenna elements at the BS. In the present work, we have considered uplink data decoding with dipole antennas arranged in a uniform planar array (UPA) grid at the BS with the error in separation between the antenna elements and mutual coupling as additional impairments. An approximate expression for the mutual coupling matrix (MCM) is derived and verified. A geometry-based stochastic model (GBSM) for the channel is considered between the user equipment (UE) and the BS. The performance of the hybrid architecture in terms of spectral efficiency (SE) and bit error rate (BER) of the system, with the mutual coupling effect and antenna separation error, is analyzed. Numerical simulations show that when the BS has no information on the MCM, SE and the system's BER performances with the FCSA architecture degrade. In the absence of any information on the coupling effect, the system performs better when a more extensive array size is used at the BS. Both the SE and BER degraded when longer dipoles were used in the array.