9,372 research outputs found

    Dual-Polarization OFDM-OQAM Wireless Communication System

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    In this paper we describe the overall idea and results of a recently proposed radio access technique based on filter bank multicarrier (FBMC) communication system using two orthogonal polarizations: dual-polarization FBMC (DP-FBMC). Using this system we can alleviate the intrinsic interference problem in FBMC systems. This enables use of all the multicarrier techniques used in cyclic-prefix orthogonal frequency-division multiplexing (CP-OFDM) systems for channel equalization, multiple-input/multiple-output (MIMO) processing, etc., without using the extra processing required for conventional FBMC. DP-FBMC also provides other interesting advantages over CP-OFDM and FBMC such as more robustness in multipath fading channels, and more robustness to receiver carrier frequency offset (CFO) and timing offset (TO). For DP-FBMC we propose three different structures based on different multiplexing techniques in time, frequency, and polarization. We will show that one of these structures has exactly the same system complexity and equipment as conventional FBMC. In our simulation results DP-FBMC has better bit error ratio (BER) performance in dispersive channels. Based on these results, DP-FBMC has potential as a promising candidate for future wireless communication systems.Comment: 1.This paper is accepted to be published in IEEE Vehicular Technology Conference (VTC) FALL 2018. 2.In this new submitted version authors have revised the paper based on the VTC FALL reviewers comments. Therefore some typos have fixed and some results have change

    System Performance Analysis for 4G Mobile Wireless Communication System

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    [[sponsorship]]IEEE[[conferencetype]]國際[[conferencedate]]20150606~20150608[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]台灣/台北 國立臺灣科技大

    Hardware-Conscious Wireless Communication System Design

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    The work at hand is a selection of topics in efficient wireless communication system design, with topics logically divided into two groups.One group can be described as hardware designs conscious of their possibilities and limitations. In other words, it is about hardware that chooses its configuration and properties depending on the performance that needs to be delivered and the influence of external factors, with the goal of keeping the energy consumption as low as possible. Design parameters that trade off power with complexity are identified for analog, mixed signal and digital circuits, and implications of these tradeoffs are analyzed in detail. An analog front end and an LDPC channel decoder that adapt their parameters to the environment (e.g. fluctuating power level due to fading) are proposed, and it is analyzed how much power/energy these environment-adaptive structures save compared to non-adaptive designs made for the worst-case scenario. Additionally, the impact of ADC bit resolution on the energy efficiency of a massive MIMO system is examined in detail, with the goal of finding bit resolutions that maximize the energy efficiency under various system setups.In another group of themes, one can recognize systems where the system architect was conscious of fundamental limitations stemming from hardware.Put in another way, in these designs there is no attempt of tweaking or tuning the hardware. On the contrary, system design is performed so as to work around an existing and unchangeable hardware limitation. As a workaround for the problematic centralized topology, a massive MIMO base station based on the daisy chain topology is proposed and a method for signal processing tailored to the daisy chain setup is designed. In another example, a large group of cooperating relays is split into several smaller groups, each cooperatively performing relaying independently of the others. As cooperation consumes resources (such as bandwidth), splitting the system into smaller, independent cooperative parts helps save resources and is again an example of a workaround for an inherent limitation.From the analyses performed in this thesis, promising observations about hardware consciousness can be made. Adapting the structure of a hardware block to the environment can bring massive savings in energy, and simple workarounds prove to perform almost as good as the inherently limited designs, but with the limitation being successfully bypassed. As a general observation, it can be concluded that hardware consciousness pays off

    Kernel-based nonlinear beamforming construction using orthogonal forward selection with Fisher ratio class separability measure

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    This letter shows that the wireless communication system capacity is greatly enhanced by employing nonlinear beamforming and the optimal Bayesian beamformer outperforms the standard linear beamformer significantly in terms of a reduced bit error rate, at a cost of increased complexity. Block-data adaptive implementation of the Bayesian beamformer is realized based on an orthogonal forward selection procedure with Fisher ratio for class separability measure

    Multi-user indoor optical wireless communication system channel control using a genetic algorithm

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    A genetic algorithm controlled multispot transmitter is demonstrated that is capable of optimising the received power distribution for randomly aligned single element receivers in multiple fully diffuse optical wireless communications systems with multiple mobile users. Using a genetic algorithm to control the intensity of individual diffusion spots, system deployment environment changes, user movement and user alignment can be compensating for, with negligible impact on the bandwidth and root mean square delay spread. It is shown that the dynamic range, referenced against the peak received power, can be reduced up to 27% for empty environments and up to 26% when the users are moving. Furthermore, the effect of user movement, that can perturb the channel up to 8%, can be reduced to within 5% of the optimised case. Compared to alternative bespoke designs that are capable of mitigating optical wireless channel drawbacks, this method provides the possibility of cost-effectiveness for mass-produced receivers in applications where end-user friendliness and mobility are paramount

    GFDM FOR NEXT GENERATION WIRELESS COMMUNICATION SYSTEM

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    In modern scenarios, there are several applications of OFDM, but it also has some demerits like sensitive to Carrier Frequency Offset (CFO), high Peak to Average Power Ratio (PAPR), and timing offset large. Out Of Band (OOB) and low spectral efficiency due to cyclic prefix per symbol insertion. To diminish and discard above problems, new multiplexing technique is required for next generation wireless communication i.e. GFDM. GFDM is becoming popular day by day due to flexibility in pulse shape as well as single cyclic prefix in a multipath channel and which makes it eligible for the 5th generation technology. This paper deals with an overview of a GFDM and presents a comparative study between OFDM and GFDM

    General Purpose Wireless Communication System Using Data Acquisition

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    A sensor-enabled and RFID-integrated, Wireless Data Acquisition System (WDAS) that has similar functionality as multiple input multiple output (MIMO) systems for health-care applications has been developed, simulated and imple-mented. The system can accept various measurements via sensors placed on patients or elders and transmit information wirelessly to base station at a remote location. A microcontroller is used to control and process the signals submitted from sensor-enabled RFID devices using sequential logic. Processed signals are then sent to single receiver and trans-mitter pair instead of conventional MIMO antenna systems. This reduces the cost significantly in comparison to existing systems. It has been shown that the data transmitted from measurement locations can be acquired at the base station located 20 mile away. Data acquisition system (DAQ) is used to determine the measured value, apply the required sta-tistics and display information to health-care professional at the base station. The system developed can be used for health-care applications including nursing homes in rural areas where access is difficult
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