Multi-beam Transmissions for Blockage Resilience and Reliability in Millimeter-Wave Systems

Multi-beam Transmissions for Blockage Resilience and Reliability in Millimeter-Wave Systems

5G mobile communication

analog beamforming

Antenna arrays

Array signal processing

beam scanning

blockage

Decision trees

initial access

Millimeter wave communication

Millimeter-wave

multi-lobe beams

Directionality in millimeter-wave (mmW) systems make link establishment and maintenance challenging, due to the search-time overhead of beam scanning and the vulnerability of directional links to blockages. In this paper, we propose a communication protocol called SmartLink, which exploits the clustering phenomenon at mmW frequencies to establish a multi-beam link between a base station and a user. By utilizing multiple clusters, SmartLink enables efficient link maintenance and sustained throughput. We develop a logarithmic-time search algorithm called multi-lobe beam search (MLBS), which is used in SmartLink to discover the clusters. MLBS probes several directions simultaneously, using multi-lobe beam patterns. The number of simultaneous lobes is selected to minimize the search time of the clusters. We provide detailed analysis of the false alarm and misdetection probabilities for the designed beam patterns. Following cluster discovery, SmartLink divides antennas into sub-arrays to generate the optimal multi-lobe beam pattern that maximizes the average data rate under blockage. Extensive simulations using actual channel traces obtained by utilizing phased-array antennas at 29 GHz are used to verify the efficiency of SmartLink. MLBS decreases the discovery time by up to 88% compared to common existing search schemes, and exploiting multiple clusters improves the average data rate by 10%.

2772-2785

I. Aykin

B. Akgun

M. Krunz

IEEE Journal on Selected Areas in Communications

2019

journalArticle

1558-0008