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It is well known that low-cost RF front-end implementation such as direct conversion transmitter suffers from serious in-phase/quadrature phase (IQ) imbalance. Most existing works in single carrier transmission employ linear compensation methods, such as Least Square and minimum mean square error, to combat the interference caused by IQ imbalance. Actually, for single carrier transmission, it is possible...
Well established cable network diagnosis systems rely on reflectometry and transferometry principles to detect faults using specific signals within a frequency spectrum of a few hundreds MHz only. Huge performance improvements in terms of precision and sensitivity can be achieved with higher frequencies and signal modulation, hence revealing phase and amplitude response of the potential impedance...
3GPP has recently introduced new features to the long term evolution (LTE) cellular technology enabling direct vehicle-to-vehicle (V2V) communications, also known as LTE-V2V. This new technology aims at supporting a large number of applications, most of them based on the broadcasting of periodic messages by all vehicles to inform the neighborhood about relevant information such as vehicle position,...
Filter bank-based multicarrier (FBMC) systems have been considered as a prevalent candidate for replacing the long established cyclic prefix (CP)-based orthogonal frequency division multiplexing (CP-OFDM) in the physical layer of next generation communications systems. In particular, offset quadrature amplitude modulation (OQAM)-based FBMC has received increasing attention due to, among other features,...
Reconfigurable terminals capable of adapting their transmission parameters such as modulation scheme, data and coding rates are desired to enhance the quality of service along with energy and spectral efficiency. However, spectrum bandwidth and time delay constraints limit the explicit sharing of these parameters and hence, they need to be estimated blindly. Though significant work has been done in...
Machine type communication (MTC) is a typical scenario in 5G communication systems, and massive machine type communication (MMTC) is a main type of MTC. One prominent characteristic of MMTC is massive connections and sporadic transmission with short packets. To embrace the new challenge in 5G emerging scenarios, flexible filterbased waveforms have been widely studied recently. In this paper, we evaluate...
LTE is the most recent standard for the mobile cellular communication. To achieve high speed communications, multi-carrier modulations have been adopted both for the downlink and the uplink. In the LTE downlink, OFDMA (the multi-user version of OFDM) has been chosen. The LTE uplink uses instead SC-FDMA modulation, an OFDM alternative. In this work, the use of CB-FMT, jointly with SC-FDMA, is analyzed...
It is indispensable to take a low complexity and high accuracy channel estimation algorithm into account under rapidly growth in wireless communication. In this paper, we propose an algorithm for channel estimation using complementary sequence (CS). By utilizing the fantastic autocorrelation property of CS, time domain channel estimation can be easily achieved. We analyzed the complementary sequence,...
Orthogonal frequency division multiplexing (OFDM) based on the use of discrete fractional Fourier transform (DFrFT) has recently gained interest due to its lower sensitivity to synchronization errors in comparison with conventional OFDM based on the use of the discrete Fourier transform (DFT). Although this higher robustness to synchronization errors is a well-recognized fact, only few works are available...
In this paper we consider multi-user multicarrier transmissions with flexible subcarrier spacings. In a scenario of multiple users access with different subcarrier spacings the orthogonality between subcarriers is disrupted. The paper presents the Intercarrier Interference (ICI) that occurs between two users with different subcarrier spacings in a Universal Filtered Multicarrier (UFMC) system. We...
In addition to high data rate, millimeter-wave technology has great potential to provide extremely high localization accuracy. In this paper, we outline the benefits of this technology for positioning and their main applications, which are no longer confined to services only but also to improve communication. We shall focus on the trade-off between data communication and positioning looking the reconfiguration...
The development of telecommunications system in modern technology is increasing widely so that the process can take place more quickly and efficiently, one of which was the use of Software Defined Radio (SDR). SDR is a radio communication system where the components that have been typically implemented in hardware (mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead...
In this paper, we investigate the physical layer (PHY) performance of generalized frequency division multiplexing (GFDM) for high throughput wireless communication. For comparison purposes, orthogonal frequency division multiplexing (OFDM)-based IEEE 802.11ac PHY is used as a benchmark. Harnessing the flexibility of GFDM, we propose a novel configuration, being compliant to the IEEE 802.11ac PHY for...
We have proposed a novel hybrid software and hardware equalization scheme based on digital zero-padding pre-equalization and differential reception. We have experimental demonstrated a red LED based visible light communication system over 1-meter free space transmission with the measured BER below 7% FEC threshold. The signal is QAM-DMT modulated and the modulation level is varying from 32QAM to 128QAM...
We compared the performance of the asymmetric and direct current bias limiting optical orthogonal frequency division multiplexing (ADO-OFDM), asymmetric limiting optical orthogonal frequency division multiplexing (ACO-OFDM), and the direct current bias limiting optical orthogonal frequency division multiplexing (DCO-OFDM) in visible light communication (VLC) systems. We optimize the power ratio between...
One of the main issues, in the specification of the 5G radio access network (RAN) technology, is the design of a new waveform, overcoming the limitations of the CP-OFDM in terms of frequency localization, spectral efficiency and robustness to users asynchronism, while keeping low latency and reduced transceiver implementation complexity. In the last decade, many waveforms have been proposed in order...
This paper focuses on performance evaluation of waveforms in the fifth generation, i.e. universal-filtered multi-carrier technique (UFMC), resource block filtered orthogonal frequency-division multiplexing (RB-F-OFDM), filtered-OFDM (F-OFDM), and filter-bank multi-carrier (FBMC) in high speed scenarios. The block error rates (BLERs) of the channel model of tapped-delay-line-D (TDL-D) defined in 3GPP...
This paper proposes a two-dimension encryption orthogonal frequency division multiplexing passive optical network (OFDM-PON) based on dynamic chaos-iteration. The correlation monitoring method is adopted to achieve dynamic key distribution between OLT and ONUs. It is shown that key space can be larger than 1086, which would be against exhaustive attack effectively. We experimentally demonstrate a...
Recent developments in wireless communications have led to numerous applications that require accurate positioning. Further, people are becoming more dependent on location based services. Many of these services are located indoors. Because of the complexity of indoor channels, traditional algorithms cannot accurately estimate the signal attenuation, which degrades positioning accuracy. To overcome...
The cognitive radio (CR) have been proposed to improve spectral efficiency and to meet growing demands for higher data rates in mobile communications and satellite communications. In this paper, we propose a blind estimation algorithm for a secondary user to estimate transmission parameters of the primary signal in an OFDM overlay system, using only the available fast Fourier transform (FFT) component...
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