The mm-wave technology is a promising technology for next-generation wireless cellular systems (5G NR) which can offer multi-gigabit per second speeds. However, the use of mm-wave frequencies for wireless communication requires versatile antenna topologies to address the propagation losses. The free space pathloss being directly proportional to λ² (operating wavelength) is more prominent at mm-wave frequencies which restricts the communication to short-range distances. To compensate for the propagation losses, high gain antennas with compact footprint are quite essential for future generation wireless systems. However, beam alignment is quite difficult with such high gain antennas thus requiring antennas with reconfigurable wide-scan radiation characteristics/beam switching antennas for Line of sight (LOS) communication. For non-LOS communication and shadowing, the outage probability (p) can be significantly reduced by using mm-wave MIMO antennas (p^nM) with multi-beam radiation characteristics. Also due to the smaller wavelengths at mm-wave frequencies, a large number of antennas can be accommodated in small space to enable massive MIMO. To exploit the full potential of the MIMO technique, MIMO is usually implemented digitally with one RF chain for each transmitter/receiver antenna. However, implementing one RF chain for each antenna would increase cost tremendously and the power consumption would deuterate the SNR significantly at mm-waves. The signal processing complexity and hardware cost can be reduced significantly by employing lens antenna arrays for massive MIMO systems. Due to the limited scattering of mm-wave signals, the communication channel matrix between transmitter and receiver is typically sparse which means the signal only reaches the receiver only along with a few distinct directions (less than 5). Therefore, efficient and reliable communication protocols are required for mm-wave systems to find such directions in the least possible time and maintain the link under random blockage. Such protocols can be experimentally evaluated using a mm-wave 5G testbed by creating LOS and non-LOS communication links between the transmitter and the receiver using reflectors.