DoA Estimation Using Reconfigurable Antennas in Millimiter-Wave Frequency 5G Systems

To achieve low latency and high throughputs, future 5G systems will have to utilize complex antenna systems able to provide beamforming and direction-of-arrival (DoA) estimation capabilities. Most of the concepts available in the literature rely on analog or digital beamforming, which is well developed and can be used both at a base station and in a user terminal. However, in applications, in which energy-efficiency or cost is one of the key concerns, the use of traditional beamforming systems is limited. To overcome this limitation, reconfigurable antennas can be used as they rely on a simple but effective concept, in which a transceiver is connected to a single input port and beamforming capabilities are enabled by a number of passive elements electronically switched via transceiver's digital input-output ports. In the article, we show how simple single-input mm-wave reconfigurable antenna can be used to provide not only beamforming but also DoA capabilities relying on received signal strength measurements. Therefore, the proposed approach can be applied in future 5G millimeter-wave nodes or gateways, in which low-cost and power-efficiency are important.