106 research outputs found
Dual-Polarization OFDM-OQAM Wireless Communication System
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
PAPR Analysis for Dual-Polarization FBMC
In a recent work we proposed a new radio access technique based on filter
bank multi-carrier (FBMC) modulation using two orthogonal polarizations:
dual-polarization FBMC (DP-FBMC). We showed that with good cross-polarization
discrimination (XPD), DP-FBMC solves the intrinsic imaginary interference
shortcoming of FBMC without extra processing. DP-FBMC also has other
interesting advantages over cyclic prefix orthogonal frequency-division
multiplexing (CP-OFDM) and FBMC such as more robustness in dispersive channels,
and it is also more robust to receiver carrier frequency offset (CFO) and
timing offset (TO). In this paper we analyze the peak to average power ratio
(PAPR) of DP-FBMC and compare PAPR simulation results with that of conventional
FBMC, for different prototype filters and overlapping factors. According to the
analysis and results, with a proper choice of prototype filter, DP-FBMC has
comparable PAPR to FBMC.Comment: This paper has been published in IEEE MILCOM Conference 2018. Some
results has been changed from first versio
Hyper-Spectral Communications, Networking and ATM as Foundation for Safe and Efficient Future Flight: Transcending Aviation Operational Limitations with Diverse and Secure Multi-Band, Multi-Mode, and mmWave Wireless Links: Project Overview, Aviation Communications and New Signaling
NASA's Aeronautics Research Mission Directorate (ARMD) has recently solicited proposals and awarded funds for research and development to achieve and exceed the goals envisioned in the ARMD Strategic Implementation Plan (SIP). The Hyper-Spectral Communications and Networking for Air Traffic Management (ATM) (HSCNA) project is the only University Leadership Initiative (ULI) program to address communications and networking (and to a degree, navigation and surveillance). This paper will provide an overview of the HSCNA project, and specifically describe two of the project's technical challenges: comprehensive aviation communications and networking assessment, and proposed multi-band and multimode communications and networking. The primary goals will be described, as will be research and development aimed to achieve and exceed these goals. Some example initial results are also provided
Chirp Spread Spectrum Signaling for Future Air-Ground Communications
In this paper, we investigate the use of chirp spread spectrum signaling over
air-ground channels. This includes evaluation of not only the traditional
linear chirp, but also of a new chirp signal format we have devised for
multiple access applications. This new format is more practical than prior
multi-user chirp systems in the literature, because we allow for imperfect
synchronism. Specifically we evaluate multi-user chirp signaling over
air-ground channels in a quasi-synchronous condition. The air-ground channels
we employ are models based upon an extensive NASA measurement campaign. We show
that our new signaling scheme outperforms the classic linear chirp in these
air-ground settings.Comment: This paper published in IEEE Milcom conference November 2019. arXiv
admin note: text overlap with arXiv:1909.0988
AG Channel Measurement and Modeling Results for Over-Water and Hilly Terrain Conditions
This report describes work completed over the past year on our project, entitled "Unmanned Aircraft Systems (UAS) Research: The AG Channel, Robust Waveforms, and Aeronautical Network Simulations." This project is funded under the NASA project "Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS)." In this report we provide the following: an update on project progress; a description of the over-freshwater and hilly terrain initial results on path loss, delay spread, small-scale fading, and correlations; complete path loss models for the over-water AG channels; analysis for obtaining parameter statistics required for development of accurate wideband AG channel models; and analysis of an atypical AG channel in which the aircraft flies out of the ground site antenna main beam. We have modeled the small-scale fading of these channels with Ricean statistics, and have quantified the behavior of the Ricean K-factor. We also provide some results for correlations of signal components, both intra-band and inter-band. An updated literature review, and a summary that also describes future work, are also included
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