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The multiple input multiple output (MIMO) technology combined with orthogonal frequency division multiplexing (OFDM) is a dominant air interface technology for 4G and 5G wireless communication technologies. In this paper we proposed a new threshold based soft partial parallel interference canceller for MIMO-OFDM system. The MIMO detector based on the hybrid use of soft minimum mean square error (MMSE)...
In this paper, we consider simultaneous transmission of information and energy in a wireless network with channels undergoing frequency-selective fading. The receivers are capable of decoding the information as well as harvesting energy from the same received signal. The network employs orthogonal frequency division multiplexing (OFDM) for signal transmission. In this context, we address two different...
This work proposes a transceiver architecture for the OFDM PHY of IEEE802.15.4g standard targeting Smart Metering Utility Networks. It also details the main components implemented for preliminary hardware prototyping. The OFDM transceiver is part of a project that is under development and aims to implement in ASIC the three PHYs defined by the IEEE802.15.4g standard, i.e. MR-FSK, MR-OQPSK and MR-OFDM...
The recently developed orthogonal frequency-division multiplexing relying on index modulation (OFDM-IM) is adopted to the in-vehicle power line communications (PLCs) in order to combat the deleterious effects of frequency-selective fading and impulsive noise, whilst improving the energy efficiency of data communications. Furthermore, the low density parity check (LDPC) coding is invoked to further...
The space-time trellis coded orthogonal frequency division multiplexing (STTC-OFDM) has been implemented with the conventional maximum-likelihood decoder for multiple antenna transmission since the STTC-OFDM was initially proposed. In this paper, a modified maximum-likelihood decoding method with the utilization of a multiplexer at the transmitter and a demultiplexer at the receiver to isolate each...
Physical-layer network coding (PNC) can potentially boost the throughput of a two-way relay network by 100% compared with conventional packet forwarding schemes. However, the complexity of PNC channel decoders can be considerably higher than the complexity of channel decoders for point-to-point communication systems. Although many PNC channel decoders proposed to date have good decoding performance,...
In wideband communication systems, Multi-Input Multi-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) has been proposed as an efficient technique to enhance the link reliability and the spectral efficiency. However, the high Peak to Average Power Ratio (PAPR) of the output signals degrades the advantage of the MIMO-OFDM systems. In order to overcome this issue, several methods requiring...
In this paper, we propose a joint soft iterative detection scheme utilizing expectation maximization (EM) and low density parity check (LDPC) codes for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. A soft iterative MIMO detector is introduced, by exploiting soft-input soft-output in the detection and decoding, the tractable extrinsic information efficiently...
To improve the power-spectral efficiency trade-off of intensity-modulated direct-detection (IM/DD) optical transmissions, enhanced unipolar orthogonal frequency-division multiplexing (eU-OFDM) was recently introduced. Uncoded eU-OFDM systems have been presented in literature but coding techniques to further improve the reliability of transmissions over such systems have not yet been explored. Applying...
This paper depicts a results of field test for an implemented digital video broadcasting for cable system (DVB-C2) transceiver, which has been implemented using field programmable gate arrays (FPGAs). The test results show the physical channel status and performance of the DVB-C2 transceiver, which includes the sampling clock offset (SCO), the frequency offset (FO), the frequency response of the hybrid...
In recent years, there has been enormous interest in millimeter (mm) wave communication systems such as IEEE 802.11ad and IEEE 802.15.3c operating in higher and unused frequency bands. To make system more resilient in time varying, multipath fading channels, a modulation scheme called π/2-quadrature phase shift keying (QPSK) along with a forward error control (FEC) scheme has been proposed in these...
In this paper, we study the physical layer abstracting model for MIMO OFDM systems with iterative MMSE receiver. Unlike the abstracting model studied in the literature, we propose to use median variance transfer function to describe the decoder behaviour, where we introduced a new method to compute the symbol variance. The proposed physical layer abstraction model, requires only 2 variance transfer...
In this paper, we study the design of low density signature-orthogonal frequency division multiple access (LDS-OFDM). Compare to the conventional OFDMA system, LDS system has some desirable properties that allows system operating at overloaded conditions. LDS-OFDM system has been shown that outperforms the corresponding OFDMA system. In this paper, we focus on the design of the LDS degrees distribution,...
In order to achieve array gain and spatial diversity or multiplexing gain simultaneously, a novel joint beamforming based on MIMO and array antenna techniques, referred to as J-BF, is proposed for the LTE and Wifi downlink. Array gain is achieved from array antenna based beamforming, referred to as AA-BF. Spatial diversity and multiplexing gains are achieved from MIMO based beamforming, referred to...
Narrowband cyclostationary interference severely limits the performance of power line communications (PLC) on low-voltage in the [3–500] kHz frequency band. For the IEEE 1901.2 narrowband PLC standard system parameters, this interference is not sparse in the time or the frequency domains making recently-proposed sparse interference mitigation techniques ineffective. In this paper, we investigate other...
This paper presents Powerline Physical-layer Network Coding (Powerline-PNC), a powerline communication architecture that employs physical-layer network coding (PNC). As the first work that applies PNC in powerline communication, we show that Powerline-PNC improves the throughput of bidirectional information interchange in the powerline network by 100% at the SNR cost of 3dB. Specifically, we design...
In this paper we consider the cognitive radio system based on spectrum sensing, and propose an error correction technique for its performance improvement. We analyze secondary user link based on Orthogonal Frequency-Division Multiplexing (OFDM), realized by using Universal Software Radio Peripheral N210 platforms. Parameters of low density parity check codes and interleaver that provide significant...
Spectrum sculpting (SS) is a precoding scheme for sidelobe suppression of orthogonal frequency division multiplexing (OFDM) signals and can shape a spectrum with deep notches at chosen frequencies. However, the SS method will degrade the error rate as the number of notched frequencies increases. Orthogonal precoding of the SS has both a notched spectrum and an ideal error rate, but the computational...
WLAN IEEE 802.11n is recent wireless data communication technology which provides high throughput and high performance. These features are definitely determined by the strength of MIMO decoder. The existing MIMO decoder of WLAN 802.11n is based on linear method, i.e Zero Forcing (ZF) and Minimum Mean Square Error (MMSE). Both of them are low in complexity but poor in performance. In the other hand...
This paper presents a low-complexity detection scheme, which consists of a lattice sphere decoder (LSD), for Orthogonal Frequency Division Multiplexing (OFDM) systems. The inter-carrier interference (ICI) resulting from selective fading channel destroys the orthogonality of the OFDM signal and poses a significant limitation on wireless OFDM systems. The aim of this paper is to propose an efficient...
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