The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper explores new multicarrier signals and systems for 5G; spectrally efficient frequency division multiplexing (SEFDM), in which higher spectral efficiency (SE) compared to conventional orthogonal frequency division multiplexing (OFDM) is achieved by violating the orthogonality of its subcarriers. This work proposes new system and receiver models and then investigates the employment of various...
Growth in telecommunication world leads to an increase in the importance of efficient usage of frequency spectrum. Increasing number of subscribers and their demands force network operators to use the frequency bands as efficiently as possible. It is necessary to detect and prevent the interference of secondary or unauthorized frequency band occupations. Cyclostationary signal analysis is widely used...
A new method of applying EMD (empirical mode decomposition) algorithm to realize the CFO (carrier frequency offset) estimation of single channel OFDM (orthogonal frequency division multiplexing) system is proposed in this paper. Firstly, the observation signal is extracted by using correlation detection technology to process the received OFDM signal. Then the data with CFO information is obtained...
This paper deals with simple and effective residual carrier frequency offsets (CFO) estimation approaches for interleaved orthogonal frequency division multiple access (OFDMA) uplink systems. It has been shown that the propagator method (PM) has low computational load and is efficient in noise free environments. However, the PM is not robust to noise. With the forward-backward (FB) correlation matrix...
With the rapid deployment of the high speed railway (HSR), the wireless communication in HSR has been one of the indispensable scenarios in the fifth generation (5G) communications. In order to improve the performance of the orthogonal frequency division multiplexing (OFDM) system in the HSR scenarios, we propose an enhanced linear minimum mean square error channel estimation scheme based on multi-path...
In the scenario of multiple access communication, the spectral sidelobes and peak-to-average power radio (PAPR) problems of orthogonal frequency division multiplexing (OFDM) must not be ignored. This paper proposes a novel precoding scheme that ahead of inverse discrete Fourier transformation (IDFT) is presented to jointly suppress the in-band-out-of-subband (IBOSB) radiation and high PAPR in orthogonal...
The estimation of the noise power is a core issue in wireless communication systems. In broadcasting, every OFDM frame starts with a preamble symbol, which facilitates the noise power estimation. However, the performance of preamble-based noise estimation schemes worsens in fast-changing environments and cannot efficiently track the noise variation well. In order to track the noise variation symbol...
Efficient and accurate spectrum sensing is a necessary part in cognitive radio networks. A simple and efficient spectrum sensing technique is proposed to solve the bad performance of spectrum sensing in non synchronous OFDM signals with low SNR regimes. Through the decomposition of the traditional OFDM signal spectrum sensing technology based on cyclostationarity, the real part and the imaginary part...
We propose computationally efficient carrier frequency offset estimators for multicarrier underwater acoustic communication using identical pilot tones equi-spaced in the frequency domain. The first estimator uses the phase of the maximal eigenvector of a channel-dependent correlation matrix. Next, the phase of the minimal eigenvector of a channel-independent correlation matrix is combined with the...
This paper presents time-variant channel characteristics at the 20-GHz band for line of sight (LoS) scenarios in an urban street canyon environment. A measurement campaign is conducted using a channel sounder for the 20-GHz band with a 50-MHz-bandwidth orthogonal frequency-division multiplexing signal. A uniform planar array (UPA) in a 16-by-16 matrix is used on the receiver side to measure time-variant...
This work investigates the antenna mutual coupling effect on multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems with oscillator phase noises. Since the antenna correlation when taking the mutual coupling effect into account is smaller than that when the mutual coupling effect is omitted, it is shown that, at small antenna separations, the error rate performance...
Selection of a subset of receiver antennas for a multiple-input-multiple-output (MIMO) wireless link has been studied by many as a way to reduce cost and complexity in a spatial multiplexing MIMO system, while providing diversity gain. However, most of these studies have been over simulated channels. In this paper, we use measured indoor channels. We compare three selection criteria to be implemented...
This paper proposes a downlink MU-MIMO-OFDM transmission using simple receive antenna selection. In the proposal, base station transmits to users with selected receive antenna per subcarrier to obtain diversity gain. The proposal also decreases computational complexity by narrowing down the number of antenna combination in accordance with correlation value between receive antennas at each user. From...
This paper proposes an inter-symbol interference (ISI) suppression scheme employing periodic signals for network MIMO-OFDM systems. Network MIMO-OFDM suffers from the ISI due to long time difference of arrival (TDOA) among the users especially in large cells. In the proposed scheme, the periodic signals generated by only the even-numbered sub-carriers is adopted for suppressing the ISI and the appropriate...
In order to improve the channel estimation performance of OFDM based on compressive sensing, the pilot design criterion is studied. The Euclidean distance between the measurement matrix and the identity matrix is used as the definition of mutual coherence of measurement matrix. Then a new pilot design criterion based on the definition above is gotten. Simulation results demonstrate that compared to...
The need for high data rate is growing since the multimedia applications are gaining popularity which needs high data rate and quality of service. Multiple Input Multiple Output (MIMO) transmission system is one of the most promising approach of the Smart Antenna Technology which uses multiple antennas in the transmitter and the receiver side and is currently followed for high-rate wireless communication[1]...
In this paper, we propose a cyclostationary noise model for multi-input multi-output (MIMO) narrowband power line communication (NB-PLC) based on frequency-shift (FRESH) filtering. The MIMO FRESH filters are designed to shape a multi-input white noise spectrum to a muti-output cyclic spectrum extracted from experimental noise measurements of three-phase low-voltage power lines. The noise modeling...
A large part of unoccupied licensed spectrum can be vital for many applications and can be accessed opportunistically by Cognitive Radio. Cognitive Radio serves to be a framework for forthcoming 5G communication systems and therefore, extensive research is being carried out in its different domains. The task of sensing spectrum should be efficient and reliable to avoid interference between licensed...
In this paper, a novel impulsive noise (IN) cancel- lation scheme based on structured compressed sensing (SCS) for multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) power line communication systems is proposed. The SCS theory is introduced to IN recovery for the first time in this paper to the best of the authors' knowledge, and the gap of lack of research on the...
Sparse channel estimation (SCE) in orthogonal frequency division multiplexing (OFDM) systems with large number of virtual sub-carriers and regularly spaced pilots is studied in this paper. Such OFDM systems are present in wireless standards like long term evolution (LTE). We numerically evaluate the performance of popular compressive sensing (CS) algorithms and shows that low complexity CS algorithms...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.