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In the recent years, power line communication technology has seen a rapid development. However, due to the unsteadiness of the power line channels, there are still some problems of obstruction and attenuation in this field which decrease the prospect and scope of this technology. This paper which is based on previous basic studies about spread spectrum communication and OFDM (orthogonal frequency-division...
Owning to the advantage of an increase in spectral efficiency by reducing the transmitted pilot tones, compressed sensing has been widely applied to pilot-aided sparse channel estimation in OFDM systems. In this paper, we focus on increasing the accuracy of channel estimation and propose a novel sparse channel estimation method that takes the effect of the additive noise into consideration. In the...
We demonstrate a simple method to experimentally evaluate nonlinear transmission performance of high order modulation formats using a low number of channels and channel-like ASE. We verify it's behaviour is consistent with the AWGN model of transmission.
A cost-optimized 40nm CMOS integrated powerline communications SoC is presented. This SoC includes all the analog and digital components required for the HomePlugAV standard. Circuit techniques for the RXPGA and TX line driver are described. The powerline SoC can achieve full HPAV 200Mbps PHY rate and operates with a 96dB channel dynamic range with low external component cost.
This paper introduces filter bank multicarrier (FBMC) as a potential candidate in the application of massive MIMO communication. It also points out the advantages of FBMC over OFDM (orthogonal frequency division multiplexing) in the application of massive MIMO. The absence of cyclic prefix in FBMC increases the bandwidth efficiency. In addition, FBMC allows carrier aggregation straightforwardly. Self-equalization,...
Impulsive noise is a major source of degradation in industrial communications. Orthogonal frequency-division multiplexing (OFDM) is an extended technique used in many industrial communications, however the performance of OFDM systems is reduced under an impulsive noise source. To increase the system performance, impulsive noise detection and suppression techniques can be designed in the communication...
In this paper, we propose a time-domain oversampled receiver for orthogonal frequency division multiplexing (OFDM) in underwater acoustic communication. Without changing the structure of the transmitter, significant gains are acquired by time- domain oversampling at the receiver. Using time- domain oversampling, the energy of transmitted symbols is concentrated on the first N subcarriers, while additive...
In this paper we consider the use of single carrier modulations combined with frequency-domain equalization schemes (SC-FDE) for underwater acoustic (UWA) communications. The propagation channel is doubly selective, with both time dispersion effects inherent to multipath propagation and phase drifts associated to Doppler effects. We propose a joint equalization and phase drift estimation and compensation...
The design of efficient receivers for orthogonal frequency division multiplexing I space division multiple access (OFDM/SDMA) channels remain a challenging task especially when the number of mobile stations (MSs) transmitting exceed base station (BS) antennas. The benchmark performance is achieved by Maximum Likelihood (ML) detector at the cost of computational complexity that exponentially increases...
PMD incurs nonlinear noise in Stokes vector direct detection systems. We propose a novel algorithm to mitigate the PMD-induced nonlinear noise. DGD tolerance is improved from 4 to 10 ps for a 93-Gb/s signal.
This paper analyzes the performance of the OS-CDMA system using OFDM technique to enhance the channel data rate, to save power and increase the number of user of OSCDMA systems. This system compared with previous hybrid subcarrier multiplexing/optical spectrum code division multiple-access (SCM/OSCDMA) system. The average received SNR with the nonlinearity of subcarriers is derived. The theoretical...
Recent changes in user employment of Internet based services, new deployment technologies for mobile networks as well as an ongoing realisation of fixed and mobile converged networks e.g. the EU FP7 project COMBO, are significant examples of enablers for increasing demands on DSL links. Investigating cross-layer dependencies between all layers in the OSI reference model becomes increasingly important...
This paper addresses two majors problems in today's wireless network using MIMO-OFDM. In fact, the performances of such a network depend on the interference management and on the equalization. These two problems are closely linked to channel estimation algorithms. In this paper, we propose a resource sharing scenario combined with a blind channel estimation algorithm based on fourth order statistics...
The influence of a nonlinear power amplifier on the performance of OFDM-MRT is investigated. It is shown that the ratio between the useful signal and the nonlinear distortions is proportional to the number of TX antennas, i.e., the influence of the nonlinear distortions decreases as the number of TX antennas increases. The Distortion Reduction Factor (DRF) is proposed as a performance metric for multi-antenna...
This paper proposes a non-linear distortion noise power control method which uses clipping and in-band and out-of-band filtering methods for multi-band OFDM transmission. The proposed method selects appropriate clipping levels and filtering methods according to transmission power and required noise power conditions on own and the other system bands in a transmitter. The evaluation results show that...
Non-Gaussian impulsive interference mitigation is of great interest in robust and reliable communication over wired and wireless channels. One of the most popular impulsive noise cancellation methods used along with the orthogonal frequency division multiplexing (OFDM) is blanking nonlinearity. Although its simplicity and efficiency, the blanking method suffers from inter-carrier interference (ICI)...
Inter-cell interference in LTE-Advanced can be mitigated using coordinated multi-point (CoMP) techniques with joint transmission of user data. However, this requires tight coordination of the eNodeBs, using the X2 interface. In this paper we use discrete-event simulation to evaluate the latency requirements for the X2 interface and investigate the consequences of a constrained backhaul. Our simulation...
Relaxed synchronization is considered essential for future generations of wireless networks in order to reduce signaling overhead. Filterbank Multicarrier (FBMC) modulation receivers may be implemented in the frequency domain as synchronization and equalization may be performed jointly. Furthermore it is demonstrated that FBMC exhibits better capacity than OFDM when frequency division multiple access...
In the LTE, OFDM is the multicarrier technology used for the downlink data transmission of the multicarrier signal. OFDM (orthogonal frequency division multiplexing) the main well known drawback is peak average power ratio (PAPR). Due to the increase in the PAPR the power amplifier of the transmission must be operated in high back-off region in order to be in the linear region. The system efficiency...
In cognitive positioning systems, spectrum sensing methods play an important role to understand the surrounding spectrum. Due to their good performance under noisy environments, cyclostationary methods are commonly used to characterise the received signals. These methods require a higher computational cost and high sampling rates [1]. With that in mind, this paper uses real measurement data, acquired...
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