With an extensive growth in user demand for high throughput, large capacity, and low
latency, the ongoing deployment of Fifth-Generation (5G) systems is continuously exposing …

The fifth-generation (5G) of cellular networks and beyond requires massive connectivity,
high data rates, and low latency. Millimeter-wave (mmWave) communications is a key 5G …

Multiple antenna technologies have attracted much research interest for several decades
and have gradually made their way into mainstream communication systems. Two main …

The recent concept of massive multiple-input multiple-output (MIMO) can significantly
improve the capacity of the communication network, and it has been regarded as a …

Channel estimation is very challenging when the receiver is equipped with a limited number
of radio-frequency (RF) chains in beamspace millimeter-wave massive multiple-input and …

Orthogonal time frequency space (OTFS) modulation outperforms orthogonal frequency
division multiplexing (OFDM) in high-mobility scenarios. One challenge for OTFS massive …

Beamforming (BF) design for large-scale antenna arrays with limited radio frequency chains
and the phase-shifter-based analog BF architecture, has been recognized as a key issue in …

A 3-D-printed Luneburg lens with a novel simplified geometry is presented. The rod-type
structures are employed as the unit cell of the gradient-index material to realize the required …

Millimeter-wave massive multiple-input multiple-output (MIMO) can use a lens antenna array
to considerably reduce the number of radio frequency (RF) chains, but channel estimation is …

This paper proposes a novel direction-of-arrival (DOA)-aided channel estimation for a hybrid
millimeter-wave (mm-wave) massive multiple-input multiple-output system with a uniform …