Performance of Hybrid Beamforming for mmWave Systems with Massive MIMO in Dense Urban Scenarios

It is expected that 5G systems will bring a great increase of the system data rate, which motivates the key role of massive MIMO cellular solutions operating in mmWave bands. However, the huge cost and complexity of fully digital schemes applied to massive MIMO systems has boosted the interest on hybrid beamforming solutions with unclear performance when it comes to their use in a cellular system. This paper assesses with simulations the behavior of a hybrid beamforming scheme in a cellular system, comparing its performance against the fully digital option with an increasing number of radiofrequency chains. Results show that hybrid beamforming can reach the performance of a fully digital precoder when working under line of sight conditions and with an enough number of parallel radiofrequency chains. However, hybrid schemes are shown to be more sensitive to interference and more degraded in non line of sight conditions, but still offering huge potential as compared with current 4G technologies.