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Fifth generation (5G) cellular networks would include millimeter wave (mmWave) for communication which gains the advantage of extensive frequency reuse and directive propagation. The recent trends in device-to-device (D2D) communication have escalated the importance of proximity based services for next generation cellular systems. The integration of mmWave and D2D technology will improve the performance...
We report on the role of digital pre-emphasis in facilitating 64 Gbaud DP-64QAM coherent optical systems based on currently available commercial 32 Gbaud transceiver components. In particular, we vary the extent of digital pre-emphasis together with digital-to-analog converter bandwidth and resolution, and show the optical back-to-back performance and transmitter output power trade-offs. Our results...
In this paper, we investigate rate adaptive radio resource allocation in visible light communication systems (VLC), to maximize the total output data rate. The proposed allocation algorithm assigns power and subcarriers to each user based on its downlink channel gain and rate constraint, while satisfying the total power constraint. The performance of the proposed algorithm on multi cell VLC systems...
A reliable feedback channel is vital to report decoding acknowledgments in retransmission mechanisms such as the hybrid automatic repeat request (HARQ). While the feedback bits are known to be costly for the wireless link, a feedback message more informative than the conventional single-bit feedback can increase resource utilization efficiency. Considering the practical limitations for increasing...
Orthogonal Frequency Division Multiplexing based M-ary Frequency Shift Keying (OFDM-MFSK) is a non- coherent modulation scheme that was proposed for robust transmission over fast fading environments. It combines the MFSK modulation scheme with OFDM. In this paper, the Generalised Frequency Division Multiplexing (GFDM) waveform is considered to use with MFSK to take the advantages of the low out of...
In this paper, we investigate the relay selection (RS) problem in power splitting (PS) based energy- harvesting (EH) half-duplex (HD) relay networks, where the relays are wirelessly powered by harvesting a portion of the received RF signal power. We expand the relay selection problem in PSEH-HD relay networks to allow multiple relays to cooperate simultaneously. Furthermore, the optimal PS factor...
Nonlinear wavelength up-conversion from the infrared (IR) to the visible spectrum appears as an interesting alternative for imaging applications. Since early demonstrations [1], work is being done to improve significantly features of up-converted images in terms of the efficiency by intra-cavity continuous wave up-conversion [2] and resolution and field-of-view by incoherent illumination [3]. Direct...
In this paper, we investigate the performance of mobile vehicle positioning based on signal propagation delay estimation in the uplink case for a realistic propagation environment. In order to optimize the ranging performance, we introduce a parametric waveform. This waveform contains a scalar parameter for adjusting the distribution of the available signal power over the frequency. The optimization...
In this paper, we address the need for motivating applications, such as mission critical industrial control and medical applications, to operate under the Ultra-Reliable Communication (URC) mode in the future 5th Generation (5G) cellular wireless networks, while also under strict Quality of Service (QoS) constraints such as ultra-low latency. Reliability has been shown to improve by using Hybrid Automatic...
Machine-type communications (MTC), considered as one of potential technologies in 5G, has attracted more and more attention in recent years. Massive MTC connection density but with small data rate leads to preamble deficiency and network congestion in the network. In order to solve this problem, we jointly utilize the back off strategy and the hierarchical access control method. We formulate a Quality...
This paper proposes a unified design of log likelihood ratio (LLR) quantization and joint reception (JR) to reduce the mobile fronthaul (MFH) bandwidth in the split-physical (PHY) processing (SPP). SPP is one of the schemes that redefine the base station (BS) functional split between a baseband unit (BBU) and a remote radio head (RRH) in cloud radio access network (C-RAN). SPP splits the BS functions...
We consider a continuous-time bandlimited additive white Gaussian noise channel with 1-bit output quantization. On such a channel the information is carried by the temporal distances of the zero-crossings of the transmit signal. The set of input signals is constrained by the bandwidth of the channel and an average power constraint. Under a set of assumptions, we derive a lower bound on the capacity...
The problem of modulating the value of a parameter onto a band-limited signal to be transmitted over a continuous-time, additive white Gaussian noise (AWGN) channel, and estimating this parameter at the receiver, is considered. The performance is measured by the mean power-α error (MPαE), which is defined as the worst-case αth order moment of the absolute estimation error. The optimal exponential...
Dynamic time-division duplexing (TDD) is considered a promising solution to deal with fast-varying traffic often found in ultra-densely deployed networks. At the same time, it generates more interference which may degrade the performance of some user equipment (UE). When base station (BS) utilization is low, some BSs may not have an UE to serve. Rather than going into sleep mode, the idle BSs can...
A two-path time-interleaved third-order ΣΔ modulator is presented. A domino-free solution moves a part of the required processing in the second path from the digital domain to the analog domain and relaxes the timing constraints of the second path ADC. Simulation results, achieved in a 65 nm CMOS technology, show that it is possible to achieve 90-dB SNR with a −6 dBFS input signal, a 4-bit quantizer,...
This paper introduces a 16 element, 1GHz IF input, digital beamformer (DBF) that generates 4 independent simultaneous beams, with 100MHz bandwidth. Although DBF has several advantages over analog beamforming, including higher accuracy and multiple beam generation, application of on-chip DBF has been limited due to high power consumption and large die area. The proposed architecture addresses these...
This paper presents a new method for ring amplifier biasing to improve their stability while maintaining high slew rate. A multi-path ring amplifier is proposed for switched capacitor applications that allows accurate charge transfer at high speeds. Dynamic biasing improves large signal slewing without affecting residue amplifier settling performance. Stable operation is possible because the auxiliary...
In spectrum sharing networks with relay cooperation, primary users can benefit from the assistance of secondary users while secondary users accessing the primary bandwidth to transmit their signals. Reasonable relay selection strategy can improve the performances of both primary and secondary users in terms of higher transmission data rate and lower outage probability, and at the same time, frequent...
In this work, it is studied the performance of a scheduling algorithm where the Mobile Terminals (MTs) may be turned off if they cause a level of interference greater than a given threshold. This approach, which is referred to as Interference Aware Muting (IAM), may be regarded as an interference-aware scheme that is aimed to reduce the level of interference. The performance of IAM is studied in terms...
Relay selection is a simple yet effective means to improve the reliability and coverage of wireless cooperative networks. However, it suffers from inefficient use of the available bandwidth resources. This paper introduces the use of content caching at relays in order to tackle this problem and improve the performance of relay selection. Three cache placement schemes are considered: one based on the...
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