High Data Rate Wireless Transmission Research Articles

Automatic Gbps Receiver for Mobile Device in Beam-Steered Infrared Light Communication System

This work presents a beam-steered infrared light communication (BS-ILC) system that enables high data rate wireless optical transmission to individual mobile users. The BS-ILC system comprises arrayed waveguide grating router-based optical antennas, camera-based user localization, and optical receivers (each integrated with an infrared tag). A high-speed photodetector has typically a small active area to minimize its junction capacitance, but this small size will result in a very limited field of view (FoV), which is detrimental to an optical wireless system aimed to provide some degree of mobility to users. Thus, the desired BS-ILC system requires precise and automatic alignment to establish a high-performance optical link between users and optical antennas. In this work, we propose an optical wireless receiver that can automatically align its orientation with respect to the optical antenna to ensure the light angle of incidence within the receiver’s FoV. The automatic receiver consists of a motorized actuator and an optimization control algorithm. The actuator controls the orientation of the receiver, and the optimization algorithm is developed to accelerate the searching process of the actuator. In an indoor laboratory system setup, the amount of less than 200 ms has been demonstrated to establish gigabit-per-second optical link, and seamless transmission has also been realized for the mobile receiver while on the move with the FoV of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm 0.6^{\circ }$</tex-math></inline-formula> .

On the Secrecy Capacity of Hybrid FSO-mmWave Wiretap Channels

Hybrid Free-Space Optical (FSO) and millimeter Wave (mmWave) systems have emerged as a promising candidate for high data rate wireless transmissions due to the unique complementary properties against the different channel and environment conditions. Consequently, in this study, we investigate the hybrid FSO-mmWave systems from a physical-layer security point of view in the presence of different types of eavesdroppers, where the communication between two legitimate peers takes place over both FSO and RF links simultaneously. In particular, exponential atmospheric turbulence and Weibull fading channels are considered for FSO and mmWave links, respectively. We examine practical scenarios to eavesdrop the legitimate communication, and discuss the effects of random radio power of mmWave link and optical irradiance of FSO link on the probability of achieving a secure transmission. The impact of the fundamental physical layer parameters on the secrecy performance of the hybrid system is analyzed by obtaining analytical derivations of the probability of strictly positive secrecy capacity (SPSC) for different types of eavesdroppers, namely RF-, FSO- and Hybrid-Eve. In the light of results, we show that the analytical expressions are in exact agreement with the Monte-Carlo simulations.

On the secrecy capacity of hybrid FSO-mmWave links with correlated wiretap channels

Hybrid Free-Space Optical (FSO) and millimeter Wave (mmWave) systems have emerged as a promising candidate for high data rate wireless transmissions due to the unique complementary properties against the different channel and environment conditions. Consequently, in this study, for the first time, we investigate the hybrid FSO-mmWave systems from a physical-layer security point of view in the presence correlated wiretap channel for different types of eavesdroppers, where the communication between two legitimate peers takes place over both FSO and mmWave links simultaneously. In particular, gamma–gamma turbulence and Nakagami-m fading channels are considered for FSO and mmWave links, respectively. We examine practical scenarios to eavesdrop the legitimate communication and discuss the effects of random radio power of mmWave link and optical irradiance of FSO link on the probability of achieving a secure transmission. The impact of the fundamental physical layer parameters on the secrecy performance of the hybrid system is analyzed by obtaining analytical expressions of the probability of strictly positive secrecy capacity (SPSC) for correlated wiretap channels. In the light of results, we show that the analytical expressions are in perfect agreement with the Monte-Carlo simulations.

Performance analysis of index modulation based link-selection mechanism for hybrid FSO-mmWave systems

Hybrid free-space optical (FSO) and millimeter wave (mmWave) systems have emerged as promising candidates for high data rate wireless transmissions due to their unique complementary properties with respect to different channel and environment conditions. A main issue in hybrid FSO-mmWave systems is the mechanism followed to activate one of the links. Most of the proposed selection mechanisms suffer from high overhead and required side information at the transmitter. In this study, a novel selection mechanism is proposed for hybrid FSO-mmWave systems without the need for any feedback or channel state information at the transmitter side. The activation of each link, either FSO or mmWave, is determined by the use of the Index Modulation (IM) concept. The proposed IM-based link selection mechanism is analyzed in terms of spectral efficiency, average bit error rate (BER), outage probability and ergodic capacity. Moreover, it is compared to conventional switching mechanisms under various scenarios including different modulation orders, link distances, and weather conditions. In light of the numerical and simulation results, it is shown that the proposed system significantly improves the overall system performance in terms of spectral efficiency and average BER.

PERFORMANCE COMPARISON OF MIMO-OFDM USING WEINER HAMMERSTEIN AND CNN EQUALIZERS

To use multiple antennas on both sides, which is transmitting and receiving side, will satisfy the necessity for a strong-performance 4 G wireless service. The capabilities for high-rate internet and multimedia services can be accomplished by the use of several antenna technologies, and also the capacity and accuracy of communication systems can be improved. For a very high data rate wireless transmission over multipath fading the orthogonal frequency-division multiplexing (OFDM) approach is used. In this work we describe an OFDM wireless communication device with multiple inputs, with compact technique i.e. Equalizer on CNN. By this, the findings provided in this paper clearly show increased power, coverage, and accuracy of the message systems. Thus, BER plot simulation outputs illustrate the utility of our proposed functional image transmission method. By using CNN technique the rate of bit error that occurred due to interference and fading effect was reduced. This approach provides better quality and BER performance.

Intelligent Offloading Strategy Design for Relaying Mobile Edge Computing Networks

To support the application of IoT and smart city, high data-rate wireless transmission is required. To meet the demand of high data-rate, the techniques of multiple antennas and mobile edge computing (MEC) networks have been proposed in order to enhance the data transmission rate significantly. However, there still exist lots of challenges array signal processing assisted MEC networks. In this paper, we propose an intelligent framework of offloading strategy for MEC networks assisted by array signal processing, where one user with multiple antennas has some computational tasks. These tasks can be computed by the user itself which however has limited computational capability, or computed by the near-by computational access points (CAPs) which has a powerful computational capability at the cost of wireless transmission. We consider the system cost by jointly taking into account the computational price, the energy consumption and the latency. By minimizing the system cost, we propose an intelligent offloading strategy based on ant colony optimization (ACO) algorithm, where the ants randomly visit the CAPs in order to obtain the final results. To further enhance the MEC network performance, the array signal processing is utilized at the user, where either the maximum ratio transmission (MRT) or selection combining (SC) is used to assist the data transmission from the user to CAPs. Simulation results with MRT and SC are finally demonstrated to verify the effectiveness of the proposed ACO-based offloading strategy and array signal processing schemes.

Generic Deep Learning-Based Linear Detectors for MIMO Systems Over Correlated Noise Environments

To support the and development and application of the fifth-generation (5G) communication and internet of things (IoT) networks, high data-rate wireless transmission is required. To meet the demand of high data-rate, multiple antennas are equipped at the transmitter and receiver, forming multiple-input multiple-output (MIMO) systems. A big challenge of MIMO is the detector design in correlated noise environments, which should achieve a fine performance with moderate computational complexity. To this end, we employ an iterative framework of a deep convolutional neural network (DCNN) and a linear detector for MIMO systems over correlated noise environments. In this framework, the linear detector can be zero-forcing (ZF), minimum mean square error (MMSE), ZF with successive interference cancellation (ZF-SIC), or MMSE-SIC, which produces an initial estimate of transmitted signals. The DCNN is used to capture the local correlation among noise, and it can produce a more accurate estimate of transmitted signals. Simulation results are finally provided to show that the proposed detector can outperform the conventional linear detectors substantially through capturing the local correlation characteristics among noise.

Tricolor visible-light laser diodes based visible light communication operated at 40.665 Gbit/s and 2 m free-space transmission.

Visible light communication (VLC) can provide a dedicated, secure, and high data rate wireless transmission link. It has gained considerable attentions recently, and is considered as one of the promising technologies for beyond 5G mobile and wireless communications. In this work, we demonstrate a VLC system with a recorded data rate of 40.665 Gbit/s using tricolor red, green and blue (RGB) laser diodes (LDs) and polarization multiplexing. 2 m free-space transmission distance is achieved. The implementation of bit-loading, power-loading, and polarization multiplexing are discussed. Experimental bit-error-ratio (BER) results show that each of the 6 polarization and wavelength de-multiplexed channels can achieve the forward-error-correction (FEC) requirement.

PAPR Reduction in MIMO-OFDM Using Modified PTS Scheme With Hybride ABC-FF Algorithem

Orthogonal Frequency Division Multiplexing (OFDM) is an admired method for high data rate wireless transmission. OFDM can be clubbed with antenna arrays at the transmitter and receiver to increase diversity gain to enhance the system capacity on time variant and frequency selective channels, resulting in (Multi input and Multi output)MIMO. One main flaw of MIMO-OFDM is that the signals transmitted on different antennas might exhibit a prohibitively large Peak-to-Average Power Ratio (PAPR). There are two techniques mainly used to mitigate the effect of PAPR namely Partial Transmit Sequence (PTS) and Selective Mapping (SLM). In this paper a new optimized Partial Transmit Sequence (PTS) scheme and SLM for PAPR reduction in MIMO-OFDM have been proposed. Both the techniques are connected in series to get efficient throughput. Hybrid of ABC–FF algorithm has been intended for optimal phase factor. The proposed technique has achieved better results than existing techniques. This intended technique has been implemented on the working platform of MATLAB.

Multiplexing Antenna System in the Non-Far Region Exploiting Two-dimensional Beam Mode Orthogonality in the Rectangular Coordinate System

A multiplexing antenna system is proposed for high data rate wireless transmission applications in the non-far region. The system is composed of two identical flat rectangular antennas directed toward each other and separated by a distance. Each antenna radiates four beam modes with 2-D orthogonality in the rectangular coordinate system by means of a passive and low-loss beam forming network. Thanks to the orthogonality relation among the modes up to four independent channels in the same direction with the same frequency and polarization can be carried and the signal demultiplexing is facilitated in the reception side. To validate the proposed concepts, the antennas have been designed and fabricated in the E-band around 78.5 GHz. Based on that, the multiplexing system has been experimentally tested. Good agreement between simulations and measurements has been obtained.

Selective Spanning With Fast Enumeration Algorithm for MIMO

Multiple input multiple output system have been emerged technology to increase channel capacity and a technical breakthrough for high data rate wireless transmission. The main objective of MIMO system is to obtain low Symbol Error Rate (SER) and acceptable computational complexity. The MIMO system cannot be implemented due to complexity problem. The complexity of MIMO system can be reduced by using different detector algorithms. In this paper, the performance of MIMO system over AWGN (Additive White Gaussian Noise) with ZF, MMSE, SD, K best algorithm and SSFE are analyzed using different antenna configuration. The Bit Error Rate performance of all detectors are studied for 16QAM modulation technique using AWGN channel for the analysis purpose and their effect on BER (Bit Error Rate) have been presented.

Uplink Spectral Efficiency Analysis of In-Building Distributed Antenna Systems

Providing high data rate wireless transmissions has been difficult in indoor environments, particularly in multi-floor buildings. One way to achieve high data rate wireless transmissions is to reduce the radio transmission distance between the transmitter and the receiver by using distributed antenna systems (DASs) and employing frequency reuse. However, due to the reuse of the limited available spectrum, co-channel interference can severely degrade system capacity. In this paper, the uplink spectral efficiency of an in-building DAS with frequency reuse is studied, where remote antenna units (RAUs) deployed on each floor throughout the building are connected to a central unit (CU) where received signals are processed. The impact of co-channel interference on system performance is investigated by using a propagation channel model derived from multi-floor, in-building measurement results. The proposed scheme exploits the penetration loss of the signal through the floors, resulting in frequency reuse in spatially separated floors, which increases system spectral efficiency and also reduces co-channel interference. A comparative analysis with conventional co-located antenna deployment at the floor center is provided. Location based RAU selection and deployment options are investigated. System performance is evaluated in terms of location-specific spectral efficiency for a range of potential mobile terminal (MT) locations and various in-building propagation characteristics.

Efficient Technique for Sidelobe Suppression and PAPR Reduction in OFDM-Based Cognitive Radios

Orthogonal Frequency Division Multiplexing (OFDM) is a transceiver technology able to achieve spectrally efficient and high data rate wireless transmissions. It is also able to transmit in a non-contiguous (NC) fashion by utilizing several separate spectral whitespaces. Cognitive radio (CR) is an efficient solution for solving the spectrum scarcity problem, while OFDM based CR system, i.e. NC OFDM system is used as modulation scheme. NC-OFDM has two significant problems, high peak to average power ratio (PAPR) and high sidelobe power, which cause out of band radiation and interference with primary users (PU). Many solutions were proposed for solving either of these problems while in this paper, an efficient technique for reducing both PAPR and sidelobe power is proposed. This technique is based on using the Advanced Cancelation Carriers combined with signal set expansion and gives an efficient reduction for both PAPR and sidelobe power. A modified version is also proposed which reduces the transmitted power and decreases the complexity but gives a little reduction for PAPR. Simulation results cover the PAPR and sidelobe reduction for both the proposed technique and its modified version for comparison purposes.

VLSI Design and Investigation of an Area Efficient and Low Power MOD-R2MDC FFT for MOMO-OFDM

In this paper, an area-efficient low power fast Fourier transform processor is proposed for multi input multi output-orthogonal frequency division multiplexing (MIMO-OFDM) in wireless communication system. It consists of a modified architecture of radix-2 (R2) algorithm which is described as modified R2 multipath delay commutation (MOD-R2MDC). OFDM is a popular method for high data rate wireless transmission. This paper describes the very large scale integration design of an area efficient MOD-R2MDC FFT for MIMO-OFDM system targeted to future wireless communication systems. The very high speed integrated hardware description language simulation results have been tested practically by implementing in the Altera development and education-2 field programmed gate array (FPGA) development board. Also the existing OFDM system has been tested with these FFT algorithms and their performances were analyzed with respect to occupation of area in FPGA and power consumption. A low-power and area efficient architecture enables the real-time operations of MIMO-OFDM system.

Achievable Rate Evaluation of In-Building Distributed Antenna Systems

Over the last few years high data rate wireless transmission has gained considerable attention in hot spot areas, including high buildings. It has been demonstrated that distributed antenna systems (DASs) improve the performance of the indoor environment by covering dead spots. In this paper, the achievable rate is investigated for indoor high data rate wireless transmission in high buildings when DASs are employed. In the system, radio transmission/reception within one or several neighbouring floors is controlled by one central unit (CU) exploiting the entire system bandwidth. In order to efficiently use the spectrum, the same frequency channels are reused among floors controlled by different CUs. The radio signals in high buildings can propagate vertically and reach the neighbouring floors. Therefore, the performance of the system is limited by cochannel interference. Direct propagation inside the building and reflection from nearby buildings are considered in the channel model. The achievable rate of the system is evaluated through analysis and simulation. The impact of representative system parameters on the achievable rate, including the number of remote antenna units (RAUs), the frequency reuse factor, the floor penetration loss, the path loss exponent, and the Nakagami fading parameter, is discussed.

60 GHz Ultrawideband Polarimetric MIMO Sensing for Wireless Multi-Gigabit and Radar

Polarimetric radio wave processing becomes of increasing interest for very high-data rate wireless transmission and for short-range radar at millimeter-waves (mm-W). This goes along with the huge bandwidth of 7 to 9 GHz, which is available worldwide in the 60 GHz unlicensed band. In this paper, we propose a 60 GHz ultra-wideband (UWB) polarimetric multiple-input-multiple-output (MIMO) sensing system architecture and polarimetric signal processing for short-range communications and radar. Demonstration measurements were made by using an UWB radar interface. By measurements in multipath rich environments it is demonstrated that tap-wise polarimetric filtering in delay domain can enhance the 60 GHz link budget by filtering some paths and then reducing shadowing due to human activity. Additionally, optimum MIMO polarimetric filtering is proposed to reduce heavy clutter for mm-W radar, increasing by about 30 dB the signal-to-clutter-plus-noise-ratio.

Joint Optimization of Microstrip Patch Antennas Using Particle Swarm Optimization for UWB Systems

Ultra wideband (UWB) systems are the most appropriate for high data rate wireless transmission with low power consumption. However, the antenna design for UWB has been a challenging task. Moreover, it is always desirable to have more freedom by designing different shape antennas with identical characteristics so that they can be used in either transmitter or receiver depending on other physical constraints such as area. To tackle these issues, in this paper, we have investigated a joint optimization of three different shape-printed monopole antennas, namely, printed square monopole antenna, printed circular monopole antenna and printed hexagonal monopole antenna, for UWB applications. More specifically, we have obtained the optimized geometrical parameters of these antennas by minimizing the mean-square-error for desired lower band edge frequency, quality factor, and bandwidth. The objective of joint optimization is to have identical frequency characteristics for the aforementioned three types of PMA which will give a freedom to interchangeably use them at either side, transmitting or receiving. Moreover, we employ particle swarm optimization (PSO) algorithm for our problem as it is well known in the literature that PSO performs well in electromagnetic and antenna applications. Simulation results are presented to show the performance of the proposed design.

High-Speed $W$-Band Integrated Photonic Transmitter for Radio-Over-Fiber Applications

A high-speed <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">W</i> -band integrated photonic transmitter is demonstrated. The presented integrated photonic transmitter is essentially developed with a near-ballistic uni-traveling-carrier photodiode integrated with a broadband front end through the flip-chip assembling technique. Technically, compared to our previous design, a <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">W</i> -band bandpass filter is exploited to significantly increase the transmitter IF modulation bandwidth. The demonstrated integrated photonic transmitter has a flat broad IF modulation response, as well as a broad optical-to-electrical (O-E) bandwidth. Specifically, the variation of the normalized IF modulation response, ranging from dc to around 13 GHz, is within 3 dB, and the normalized 3-dB O-E bandwidth is about 24 GHz. On the other hand, an up to 20-Gb/s high data-rate wireless transmission realized with the presented transmitter is demonstrated. The integrated photonic transmitter is expected to find applications in high-speed radio-over-fiber communications.

High-speed multicarrier transmission scheme for implantable medical devices

A high data rate wireless transmission scheme, utilizing the Medical Implant Communications Service (MICS) band for implantable medical devices (IMD) is proposed. An orthogonal frequency division multiplexing (OFDM)-based multicarrier scheme is used to overcome the data rate limitation caused by the narrow bandwidth. By optimizing subcarrier allocation, inverse fast Fourier transform (IFFT) architecture and sidelobe suppression techniques, the proposed scheme utilizes multiple MICS channels simultaneously, satisfying the MICS mask specification. Simulation results show that this scheme can support a maximum data rate of 4.86Mbps, which is more than ten times faster than the existing system.

Study and Survey about Mixed Radix FFT Processor in MIMO OFDM

The design of a highly configurable continuous flow mixed-radix (CFMR) Fast Fourier Transform (FFT) processor is presented in Multi-Input Multi-Output (MIMO) Orthogonal frequency division multiplexing (OFDM). Multi-Input Multi-Output (MIMO) system has drawn much attention in 4G wireless technologies. Orthogonal frequency division multiplexing (OFDM) is a popular method for high data rate wireless transmission. OFDM may be combined with antenna arrays at the transmitter and receiver to increase the diversity gain and enhance the system capacity on time variant and frequency selective channels, resulting in Multi-Input Multi-Output (MIMO) configuration. This paper represent as Mixed radix FFT in MIMO-OFDM system design including channel modeling, space time block code techniques, channel estimation and signal processing algorithms used for performing time and frequency synchronization in MIMO-OFDM system.