Cross-layer Radio Resource Management Research Articles

Primal–Dual Learning for Cross-Layer Resource Management in Cell-Free Massive MIMO IIoT

The use of cell-free massive multiple-input–multiple-output (MIMO) is regarded as a novel technique in the Industrial Internet of Things (IIoT) networks, and many studies have been reported on its cross-layer optimization, including random access and power allocation. Nevertheless, the cooperation of deep reinforcement learning (DRL) and cell-free massive lacks of deep study. In this article, a primal–dual deep deterministic policy gradient (DDPG) algorithm is designed to obtain cross-layer radio resource management, including power allocation in the physical layer and random access in the medium access layer. Different from the current studies, the random access and power allocation is formulated in cell-free massive MIMO IIoT networks, utilized by the stochastic ergodic optimization. In contrast to the stochastic policy gradient algorithm, a primal–dual DDPG algorithm is designed for the cross-layer optimization. Moreover, a multiagent primal–dual DDPG algorithm is proposed to different scenarios in the cell-free massive MIMO IIoT networks. Simulations are presented to verify the effectiveness of the primal–dual DDPG algorithm for random access and power allocation in the cell-free massive MIMO IIoT networks.

Performance of OFDMA Multicell Systems with Opportunistic Beamforming

The opportunistic beamforming (OB) technique in multicellular OFDMA networks is investigated in this paper. Three cross-layer radio resource management (RRM) algorithms for OFDMA operational scenarios are considered. These algorithms build upon typical network planning practices for OFDMA systems. The first two implement an OFDMA network with opportunistic rate adaptation while the third one aims at a network which guarantees QoS provision through power control on carrier basis. The RRM algorithms are based on typical OFDMA resource allocation targets such as minimization of transmit power, maximization of throughput and interference averaging. Then, the OB concept is combined with the considered RRM algorithms and a comparative performance analysis between the two types of networks (omni and opportunistic beamforming) is performed in terms of throughput, blocking probability and fairness. The paper aims at providing a useful insight into the way the OB technique affects the performance of different OFDMA networks based on large scale simulations. The simulation results suggest that OB is preferred for OFDMA systems with opportunistic rate adaptation rather than power controlled systems which offer QoS provision. According to the presented results, OB provides to OFDMA systems with opportunistic rate adaptation a ~13% throughput gain and ~75% gain in terms of blocking probability. In addition, it is shown that the combination of OB with interference averaging RRM algorithms has a minor beneficial impact only on the system fairness.

Cross-layer radio resource management in integrated WWAN and WLAN networks

This paper proposes a mobility adaptive network selection scheme in the context of wireless wide area network (WWAN) and wireless local area network (WLAN) radio access technologies (RATs) that supports both real-time (RT) and non-real-time (NRT) service classes. Physical layer information based call admission control (CAC) is considered for the two RATs to enforce service specific QoS requirements. The effectiveness of the cross-protocol-layer information for radio resource management (RRM) in integrated WWAN and WLAN networks is assessed analytically for individual service classes in a multi-service environment using the theory of Markov chains. The impact of non-uniform user and mobility distributions due to the existence of hotspot in the macro-cell area and the effect of network selection parameter measurement errors on the RRM performance are also evaluated. Numerical results show that the proposed network selection scheme minimizes the rate of unnecessary vertical handoffs, thereby providing stable communication without degrading the call blocking probability and call outage probability performance metrics.

Cross‐layer protocols for satellite communication networks: part I

Cross‐layer protocols for satellite communication networks: part I