Showing 1-25 of 34,109 resultsfor "Index Terms":Orthogonal Frequency Division Multiplexing Signal
"Index Terms":Orthogonal Frequency Division Multiplexing Signal
- Sort
Get notified when new research is published matching your search criteria.
Sort By
Results
A novel minimum output variance estimator for carrier frequency offset in OFDM systems
Tsinghua Science and Technology
Cited by: Papers (2)
In orthogonal frequency-division multiplexing (OFDM) systems, the carrier frequency offset (CFO) destroys the orthogonality among subcarriers which degrades system performance. Various CFO estimation methods have been developed to compensate for the CFO at the receiver. This paper describes a novel minimum output variance method for OFDM systems with CFO in additive white Gaussian noise channels. ...Show More
In this letter, we analyze the transmitter design for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) employing predistortion. Digital clipping and digital predistortion processes are introduced to the radio frequency OFDM transmitter to compensate the nonlinearity effect introduced by the optical in-phase/quadrature modulator. We first provide a detailed description of signa...Show More
Improving the Nonlinear Tolerance of Polarization-Division-Multiplexed CO-OFDM in Long-Haul Fiber Transmission
We present digital signal processing techniques and algorithms for improving the tolerance of polarization-division multiplexed (PDM) coherent optical orthogonal frequency-division multiplexing (CO-OFDM) to fiber nonlinear effects, in both single-channel and wavelength-division multiplexed (WDM) transmission. For single-channel transmission, we discuss a self-phase modulation (SPM) compensation me...Show More
An Experimental Proof of Concept for OFDM-based ISAC System Utilizing Stepped-Carrier and TDM MIMO scheme
2024 IEEE 25th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)
Year: 2024 | Conference Paper |
The problem with orthogonal frequency-division multiplexing (OFDM)-based integrated sensing and communication (ISAC) system is that the bandwidth required for high range resolution cannot be obtained. This problem can be overcome by using a stepped-carrier method, where the carrier frequency of each OFDM signal increases linearly to achieve wide overall RF bandwidth. In this article, for the first...Show More
A New Blind Joint Timing and Frequency Offset Estimator for OFDM Systems Over Multipath Fading Channels
A blind joint timing and frequency synchronization algorithm is derived for orthogonal frequency-division multiplexing (OFDM) signals transmitting over multipath fading channels. The proposed estimator requires neither the knowledge of the signal-to-noise ratio (SNR) nor the power delay profile of the fading channels, except that the maximum delay spread L should be known and should be shorter tha...Show More
Interference Cancellation Between OFDM Radars Using Pre-Assigned Pilot Signal and Strong Target Elimination
2024 21st European Radar Conference (EuRAD)
Year: 2024 | Conference Paper |
This paper proposes a simple approach to cancel mutual interference between orthogonal frequency-division multiplexing (OFDM) radars, which is implemented by inserting pre-assigned pilot signals into OFDM radar waveforms. This enables a victim radar to estimate the modulated data as well as the time and frequency offsets of the interfering signal from an aggressor radar. This allows also the recei...Show More
Transmission of Wavelength-Division-Multiplexed Channels With Coherent Optical OFDM
IEEE Photonics Technology Letters
Cited by: Papers (6)
Transmission performance for wavelength-division-multiplexed (WDM) systems with coherent optical orthogonal frequency-division multiplexing is simulated including the fiber nonlinearity effect. The simulation shows that the system Q of the WDM channels at 10 Gb/s is over 13.0 dB for a transmission up to 4800 km of standard single-mode fiber without dispersion compensationShow More
The Effects of Narrowband Interference on OCDM
2020 IEEE 21st International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)
Year: 2020 | Conference Paper |
Cited by: Papers (12)
Orthogonal chirp division multiplexing (OCDM) is a fairly new multi-carrier modulation scheme that has been proposed for optical fiber communications. It spreads data over an entire band using a set of linear chirps that are mutually orthogonal thus achieving the maximum spectral efficiency. This paper analyzes the performance of OCDM in wireless multi-path channels with narrow band interference (...Show More
We show the first experiment of bit and power loading for coherent optical orthogonal frequency-division-multiplexing (CO-OFDM) systems. The data rate of CO-OFDM systems can be dynamically adjusted according to the channel condition. The system performance can be further improved through optimal power loading into each modulation band.Show More
Experimental Demonstration and Numerical Simulation of 107-Gb/s High Spectral Efficiency Coherent Optical OFDM
Orthogonal frequency-division multiplexing (OFDM) is a multicarrier modulation format in which the data are transmitted with a set of orthogonal subcarriers. Recently, this modulation format has been actively explored in the field of optical communications to take advantages of its high spectral efficiency and resilience to chromatic and polarization dispersion. However, to realize the optical OFD...Show More
Blind symbol-timing and frequency-offset estimation in OFDM systems with real data symbols
In this letter, the problem of blind symbol-timing and frequency-offset estimation in orthogonal frequency-division multiplexing (OFDM) systems with real data symbols is considered. Maximum-likelihood (ML) estimators for the parameters of interest have been derived by modeling the OFDM signal as a proper complex Gaussian random process. However, when data symbols belong to a real constellation, th...Show More
Robust Channel Estimation for Coherent Optical Orthogonal Chirp-Division Multiplexing With Pulse Compression and Noise Rejection
Journal of Lightwave Technology
Cited by: Papers (30)
Orthogonal chirp-division multiplexing (OCDM) was recently proposed as a promising modulation technique for high-speed fiber-optic communications due to its resilience to transmission impairments. By exploiting the pulse-compression property of the chirped waveforms, in this paper we propose a channel estimation algorithm compatible with the coherent optical (CO) OCDM system. In the proposed algor...Show More
Carrier Frequency Offset Estimation for OFDM Systems Over Mobile Radio Channels
In this paper, a new technique is proposed for blind estimation of carrier frequency offset (CFO) in wireless orthogonal frequency-division multiplexing (OFDM) systems with constant-modulus constellations. The proposed scheme is based on the assumption that the channel slowly changes in the time domain with respect to the OFDM symbol duration. As a consequence, the channel effect on a given subcar...Show More
Comments on "Semi-Blind Channel Estimation and Equalization for MIMO Space - Time Coded OFDM
For original paper see ibid., vol.53, no.2, p.363-374, Feb. 2006. A semiblind channel estimation scheme of the multiple-input-multiple-output space-time coded orthogonal frequency-division multiplexing system was proposed in the aforementioned paper for either real or complex with symmetric signals. We point out that this scheme cannot work correctly for complex signal scenario.Show More
Optimal training signals for MIMO OFDM channel estimation in the presence of frequency offset and phase noise
We develop robust mean-square error (MSE)-optimal training signal designs for multiple-input multiple-output orthogonal frequency-division multiplexing channel estimation with frequency offset and phase noise (PN), and present analytical and simulation results for the frequency-offset and PN effects on channel estimation. The proposed designs are more advantageous for moderate-to-high values of si...Show More
Noniterative Joint Frequency Offset and Channel Estimation for MIMO OFDM Systems Using Cascaded Orthogonal Pilots
In this paper, we reconsider the issues of frequency offset and channel estimation in multiple-input-multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. We first design “cascaded orthogonal” pilot symbols and adopt the properties of Fourier transform and Hadamard product to deliver a closed-form estimate of frequency offset; meanwhile, another closed-form estimate of ch...Show More
An EM-Based Semiblind Joint Channel and Frequency Offset Estimator for OFDM Systems Over Frequency-Selective Fading Channels
We propose an estimator that will jointly estimate the channel and the carrier frequency offset (CFO) for orthogonal frequency-division multiplexing (OFDM) systems based on the maximum-likelihood criterion. The proposed estimator uses only one received OFDM symbol to perform estimation and does not require the knowledge of power delay profile, except that the number of delay paths should be known....Show More
Transmission performance of adaptively modulated optical OFDM signals in multimode fiber links
A novel optical signal modulation concept of adaptively modulated optical orthogonal frequency-division multiplexing (AMOOFDM) is proposed and numerical simulations of the transmission performance of AMOOFDM signals are undertaken in unamplified multimode fiber (MMF)-based links using directly modulated distributed feedback lasers (DMLs). It is shown that 28 Gb/s intensity modulation and direct-de...Show More
Random Multiplexing for an MIMO-OFDM Radar With Compressed Sensing-Based Reconstruction
Christina Knill;Fabian Roos;Benedikt Schweizer;Daniel Schindler;Christian Waldschmidt
In many applications, the direction of arrival information of the radar signal plays a decisive role in target localization. A multiple-input multiple-output (MIMO) radar allows to obtain the position of an object in space within one measurement frame. Recent research and publications verify the high potential of digital radar principles such as orthogonal frequency-division multiplexing (OFDM). I...Show More
Signal clipping and μ-law companding have been suggested as simple and effective peak-to- average power ratio (PAPR) reduction schemes for orthogonal frequency-division multiplexing (OFDM). This paper, addresses the problem of PAPR and the relation between it and the number of subcarriers, and analyzes clipped and companded M-ary phase-shift keying (M-PSK) OFDM signals. Their performance in AWGN c...Show More
A novel non-data-aided symbol timing recovery technique for OFDM systems
A new highly efficient non-data-aided technique to recover symbol timing of orthogonal frequency-division multiplexing systems is proposed. The algorithm in the proposed work exploits the interference that results due to the loss of orthogonality between subcarriers, where the second-order statistics of the resulting interference is proportional to the offset from the optimum sampling point. The p...Show More
PONIARD: A Programmable Optical Networking Infrastructure for Advanced Research and Development of Future Internet
Wei Wei;Junqiang Hu;Dayou Qian;Philip N. Ji;Ting Wang;Xin Liu;Chunming Qiao
Journal of Lightwave Technology
Cited by: Papers (38)
Motivated by the design goals of Global Environment for Network Innovation (GENI), we consider how to support the slicing of link bandwidth resources as well as the virtualization of optical access networks and optical backbone mesh networks. Specifically, in this paper, we study a novel programmable mechanism called optical orthogonal frequency division multiplexing (OFDM)/orthogonal frequency di...Show More
Maximum-Likelihood-Based Performance Enhancement of Clipped and Filtered OFDM Systems With Clipping Noise Cancellation
Clipping and filtering (CAF) technique is known as a simple and effective approach that reduces the peak-to-average power ratio (PAPR) of orthogonal frequency-division multiplexing (OFDM) signals at the cost of increasing in-band distortion. Clipping noise cancelation (CNC) can compensate for the performance degradation due to the in-band distortion caused by CAF, especially when the number of sub...Show More
Analysis of RF-Pilot-Based Phase Noise Compensation for Coherent Optical OFDM Systems
In coherent optical long-haul transmission systems, orthogonal frequency-division multiplexing represents a promising modulation format. However, due to long symbol length, laser phase noise can be a major impairment. In this manuscript, the RF-pilot-based phase noise compensation scheme is analyzed and compared to conventional common-phase error compensation. It has been shown that the RF-pilot-b...Show More
Eigenvalue-Decomposition-Precoded Ultra-Dense Non-Orthogonal Frequency-Division Multiplexing
This paper proposes a novel ultra-dense non-orthogonal frequency-division multiplexing (NOFDM) transmission, where subcarrier spacing is set significantly lower than that of orthogonal frequency-division multiplexing (OFDM). In order to eliminate the detrimental effects of NOFDM-specific inter-carrier interference and correlated additive noises, eigenvalue-decomposition-aided precoding is conceive...Show More
IEEE Account
Purchase Details
Profile Information
Need Help?
- US & Canada: +1 800 678 4333
- Worldwide: +1 732 981 0060
- Contact & Support
- About IEEE Xplore
- Contact Us
- Help
- Accessibility
- Terms of Use
- Nondiscrimination Policy
- Sitemap
- Privacy & Opting Out of Cookies
A not-for-profit organization, IEEE is the world's largest technical professional organization dedicated to advancing technology for the benefit of humanity.
© Copyright 2025 IEEE - All rights reserved. Use of this web site signifies your agreement to the terms and conditions.