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Component crosstalk causes severe system performance degradation in an optical network. In this paper the influence of the component crosstalk originated from signal-crosstalk beat noise, on the performance of a preamplified WDM receiver is investigated assuming both Gaussian and non-Gaussian model. From the analysis it is evident that for the finite interfering channels the results obtained using...
Orthogonal Frequency Division Multiplexing (OFDM) system is used for the reducing almost every kind of interference in any communication system. For designing OFDM system need to use FFT and IDFT phenomena of signal processing, in this work mainly concern to improve peak to average power ratio for this system because this system is multicarrier system, and in the multiple carriers are nearly having...
This paper addresses the performance of the Multiple-Input-Multiple-Output(MIMO)-Orthogonal Fre-quency Division Multiplexing (OFDM), MIMO-OFDM communication system in environments where the interfering noise exhibits non-Gaussian behavior due to impulsive phenomena. It presents the design and simulation of an adaptive receiver technique that aims to minimize the effect of impulsive noise on the performance...
We describe the implementation of radio-over-fiber (ROF) techniques with a combination of spectral-amplitude-coding optical code-division-multiple-access (SAC-OCDMA). The architecture of proposed fiber-radio network is presented in details where the radio frequency (RF) modulated signal is up-converted to the spectrum-coded optical carriers. System evaluation is analyzed by deriving the average bit...
Hybrid fibre and optical wireless systems are a potential route to flexible access networks. When combined with code division multiple access (CDMA), there is the possibility of using a power combiner to extend the network to multiple users in a wider coverage area or different rooms and such a scheme is proposed and analyzed here. Moment generating function (MGF) techniques are used to account for...
A direct-conversion receiver (DCR) reduces the power consumption and cost. However, DCR in Orthogonal frequency division multiplex (OFDM) systems suffer from IQ imbalance. Until this time, many algorithms are proposed to compensate IQ imbalance in OFDM. However, the complexity is still considerable work. On the other hand, time-frequency interferometry-OFDM (TFI-OFDM) system has been proposed to achieve...
Multiuser multiple-input multiple-output (MU-MIMO) wireless systems that employ single-carrier frequency-domain equalization (SC-FDE) for uplink transmissions can provide high data rates with increased spectral efficiency under severe channel conditions. However, the availability of accurate channel estimates at the base station (BS) receiver is crucial for achieving peak performance. In this paper,...
This paper presents an optical wireless identification (OWID) scheme utilizing high-energy harvesting thinfilm embedded onto the corner cube retroreflector (CCR). We apply optical wireless communication (OWC) for transmitting information. The thinfilm is used as a rechargeable battery that absorbs the power when the incident light beam goes through the CCR and reflects On-Off-Keying (OOK) modulated...
We propose the use of a divided spectrum balanced detection (DSBD) to reduce the intensity noise in spectral amplitude coding (SAC) OCDMA systems. Simulation results show several order of magnitude improvements in bit error rate (BER) compared to the conventional balanced detection.
Sampling frequency offset (SFO) that occurs due to a sampling frequency mismatch between the transmitter and receiver oscillators is one of the main problem in the orthogonal frequency division multiplexing (OFDM) based digital terrestrial television (DTTV) system. The SFO can cause an intersymbol interference and an intercarrier interference that may degrade the performance of an OFDM system and...
One of the most serious disturbances in Power Line Communications (PLC) is produced by the presence of impulsive noise sources in the transmission line. This paper analyses how impulsive noise affects the PLC communication's performance from a theoretical and simulation point of view and proposes a signal processing method to enhance its robustness. Authors focus on a popular narrowband PLC solution...
Clipping and filtering can be used to effectively reduce the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals at the cost of introducing distortion. So far, various clipping and filtering techniques have been proposed in the literature, which have different performance in terms of PAPR reduction and signal distortion. However, the minimum signal distortion...
Free space optical communication (FSO) links have gained huge popularity in last couple of decades. In this paper FSO link performance has been studied by calculating the DSNR and link margin for wavelengths of mid and far infrared regions, so as to find out the validity of popular myth that performance of FSO systems improves with selection of longer wavelengths. Although most of the FSO systems...
In this paper, we propose a new physical layer network coding (PNC) scheme based on rateless coding for two-way relay systems which consist of two end nodes and one relay. The two-way relay channel is studied from a new perspective of end-to-end channel equivalence, and a novel end-to-end demodulator is proposed based on the resultant end-to-end equivalent channel. Unlike the conventional demodulator...
Recently, there has been considerable interest to utilize the power line infrastructure for broadband communications. Power Line Communications (PLC) operate in the frequency range between 1.8MHz to 30MHz defined by the IEEE 1901 standard. Within this frequency range, a number of organizations and users occupy their own specific spectrum. As a result, spectrum notching and interference avoidance need...
Recently, a hybrid single carrier(SC) and multi-carrier (MC) system based on the 4-weighted fractional Fourier transform (4-WFRFT) was proposed. As this hybrid carrier (HC) system contains MC component, it inherits the problem of high peak to average power ratio (PAPR). In this paper, we investigate the clipping technique for PAPR reduction in HC system. By analysis and simulation, we show that clipping...
Employing the low bitwidth, e.g. 1 bit or 2 bit analog-to-digital converter (ADC) can remarkably reduce the high power dissipation of ADC in the orthogonal frequency division multiplexing (OFDM) communications. However, the biterror-rate (BER) performance will be considerably undermined. In the paper, through deliberately reserving the subcarrier at the transmitter, the quantization distortion can...
Controller area network is a shared serial bus communication that is widely used in automotive and industrial networks. The CAN bus is considerably affected by the conducted electromagnetic interference, which is generated from many disturbances such as load dumb and ignition system noise. The EMI reduces the bus efficiency by introducing bit errors in the data frame. In this paper, the effect of...
Embedded memory is a major design element in microprocessors and system-on-chips. Typically embedded memories are constituted of SRAM circuits. SRAM cell stability is a major determinant of Vmin for ultra-low power mobile computing. At low voltages, thermal noise plays a role in SRAM cell stability. In this work, we present an analysis of random thermal noise on stability of SRAM bit cells. Of specific...
For a DS/FFH spectrum spread system, DAGC(Digital AGC) diversity combining is investigated. The performance of DAGC is evaluated under the case of partial-band jamming plus AWGN. Performances of several widely-used methods of diversity combining are compared with DAGC. The coherent DS/FFH system with DAGC has been implemented in a FPGA circuit, tested and verified to be effective for practical realizations.
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