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One of the significant challenges of the Radio over fibre (RoF) Medium Access Control (MAC) protocol is the propagation delay. This delay can lead to serious issues, such as higher propagation delay resulting in collisions and unnecessary retransmissions. Quantum entanglement is an excellent candidate to overcome the propagation delay of the RoF MAC protocol. A new quantum MAC protocol is proposed, named the Quantum Entanglement‐based MAC protocol (QE‐MAC), in which Quantum Teleportation is utilised to address the propagation delay. Four entanglement states are employed to represent the control packets of the classical MAC protocol, and data is transmitted over the classical channel. Instead of using control packets such as acknowledgement, request to send, and Clear to send, state transitions are employed. This approach avoids the delay and collision issues associated with control packets, resulting in a significant improvement in network performance. The delay, duty cycle (DC), and power consumption of the proposed QE‐MAC protocol are formulated and derived. The protocol is evaluated in terms of delay, DC, and power consumption, demonstrating superior performance compared to the classical RoF MAC protocol. In comparison to published works, our proposed approach has successfully reduced both delay and power consumption by 35%. IoT‐RoF QE‐based: MAC Protocol Delay Study.

In fifth-generation (5G) relay networks, the network blockage situation upsurges owing to inadequate penetration capability of the radio waves or interruption due to tall buildings and obstacles. To improve the network coverage and spectrum efficiency, a cooperative cognitive relay network with mutated beamforming is proposed. This work introduces mutation and replacement-strategy-based beamforming to enhance the opportunistic throughput and spectral efficiency. The proposed model employs imperfect channel state information (CSI) with consideration of the CSI error due to interfering signal. The mutated beamforming technique is implemented for the cognitive radio environment postefficient spectrum sensing. The proposed mutated beamforming mitigates CSI error via performing beamforming with minimized sidelobes and placing nulls in the desired direction. The mutated beamforming in 5G relay network achieves a spectral efficiency of 30 b/s/Hz at SNR = 20 dB.

This article proposes a simple sparse imaging scheme using a linear sparse aperiodic array and a new fast Fourier transform matched filtering (FFTMF) algorithm for a THz multistatic multiple-input and multiple-output (MIMO) imaging system. The simple linear sparse aperiodic array and multipass interferometric synthetic aperture focusing technique are used to achieve fast sampling, low system cost, and high imaging performance. Unlike a traditional generalized synthetic aperture focusing technique (GSAFT) for multistatic MIMO imaging, which is time-consuming and exhibits increased reconstruction time with increased data volume, the proposed FFTMF image reconstruction algorithm is capable of providing comparable image quality but significantly reducing the reconstruction time. For example, we show that for an image of 300 $\times320$ mm with a pixel size of $0.75\times0.83$ mm, the reconstruction time is reduced from about 1.50 min to 0.25 s in the 220-GHz five-pass synthetic imaging experiments. The proposed imaging algorithm uses internal zero padding, a multipass interferometric synthetic aperture focusing technique, and a wideband imaging technique to improve the imaging performance under a low-cost, sparse sampling scheme. It shows a strong antinoise ability and a high tolerance to target focusing distance. In addition, integrated with an algorithm of principal component pursuit by alternating directions method (PCPADM), sparse imaging is available to further save system cost and sampling data without a loss of image quality while the novel use of an error matrix provides an additional detection capability for imaging systems.

This paper presents a field measurement campaign carried out by the IST PLUTO project to quantify the advantages that can be achieved practically if transmit delay diversity is applied to DVB-T/H systems. An extensive field trial was performed in Uxbridge (UK) to validate transmit diversity gain predictions obtained previously from theoretical modelling and laboratory measurements. DVB-T/H transmissions were performed in the 730 MHz frequency band. It is concluded that transmit delay diversity achieves significant improvement in the reception quality in difficult to reach areas without impacting the standard or increasing the complexity of receivers.