Latency and reliability aware radio resource allocation for multi-antenna systems

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

L10, Linnanmaa

Topic of the dissertation

Latency and reliability aware radio resource allocation for multi-antenna systems

Doctoral candidate

Master of Technology Dileep Kumar

Faculty and unit

University of Oulu Graduate School, Faculty of Information Technology and Electrical Engineering, Centre for Wireless Communications (CWC) - Radio Technologies Research Unit

Subject of study

Communications Engineering

Opponent

Associate Professor Taneli Riihonen, Tampere University, Finland

Custos

Professor Antti Tölli, University of Oulu, Finland

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Latency and reliability aware radio resource allocation for multi-antenna systems

Millimeter wave (mmWave) and sub-terahertz (sub-THz) communication systems rely mainly on the availability of dominant links between the transmitters and receivers. The sensitivity of high-frequency radio links to random blockages, however, challenges the achievable positioning, reliability, and latency requirements. Moreover, the provision of a sustainable and reliable energy source in mobile devices has to be addressed.

We explore the viability of using Coordinated Multi-Point (CoMP) schemes, which facilitate multi-user processing across spatially distributed remote radio units (RRUs), to ensure accurate positioning and latency-constrained reliable mmWave communication, even if one or more dominant links are blocked. We design a blockage-aware algorithm for the weighted sum-rate maximization problem in mmWave based system. A robust downlink beamformer design, with the parallel beamformer processing across distributed RRUs, is proposed by exploiting the spatial macro-diversity and a pessimistic estimate of rates over potential link blockage combinations. This problem is extended by considering the user-specific latency requirements in a dynamic access network for the sum-power minimization objective. The time-average stochastic problem is transformed into a sequence of deterministic and independent subproblems using the Lyapunov optimization, and a dynamic control algorithm is then proposed, which enables an efficient implementation of low-complexity closed-form iterative beamformer design. Furthermore, by exploiting the queue backlogs and channel information, we propose a proactive and dynamic selection of the serving set combinations of CoMP RRUs.

In the simultaneous wireless information and power transfer (SWIPT) systems, we consider the interdependence of latency-battery queue dynamics, and propose the joint beamforming and power splitting optimization to minimize the sum-power of the transmitter under user-specific latency and energy harvesting requirements. The battery depletion phenomenon is avoided by preemptively incorporating information regarding the receivers’ battery state and energy harvesting fluctuations into the resource allocation designs. Finally, for the cellular-based localization, we propose a robust uplink CoMP receive beamforming strategy to combat the unavailability of dominant links. Furthermore, we derive the Cramér-Rao Lower Bound, which is subsequently solved to obtain the bound on positioning accuracy, and provide a synergy between accurate positioning and highly-reliable mmWave communication.
Last updated: 16.6.2022