An Analog Module for Hybrid Massive MIMO Testbeds Demonstrating Beam Alignment Algorithms

Thomas Kühne • Giuseppe Caire

14:00 - 18:10 | Wednesday 14 March 2018 | ID 04/459 & ID 04/471



Hybrid analog-digital beamforming for massive MIMO is an important technology for millimeter-wave communication systems. Current experimentation of massive MIMO is based mainly on full digital solutions and in the sub-6 GHz frequency range. The technology for millimeter-wave massive MIMO systems is not yet available to the broad research community. Due to the high path loss, sparsity of the channel, and restrictions of the hardware in the millimeter-wave band, new challenges in signal processing arise. One of these problems is the initial link acquisition also called beam alignment (BA). We present a hybrid analog-digital massive MIMO testbed with 64 antennas not in the millimeter-wave band but in the sub-6 GHz range. This testbed enables the investigation of challenges connected to a hybrid analog-digital architecture like the BA problem with the mature technology of the sub-6 GHz range. We demonstrate multiple BA algorithms to show their advantages and disadvantages. The testbed is based on a self developed analog module with a high resolution of phase and magnitude settings.