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28 articles for “multiplexing”
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2D Interpolation technique for Channel Estimation in OFDM Systems
Abstract: The use of interpolation technique with low estimation error is imperative for estimating the channel impulse response at data subcarriers for pilot assisted channel estimation techniques in the Orthogonal Frequency Division Multiplexing (OFDM) systems. In this paper, a novel interpolation technique based on 2 d interpolation is presented. The proposed interpolation technique is based on minimizing the interpolation error and channel noise inherent in Least Square (LS) estimation. A comparative …
Published in International Journal of Digital Communication and Analog Signals · Vol. 3, Issue 1, 2017 · pp. 27–34 Read article
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Low Density Parity Check (LDPC) Coded MIMO-Constant Envelop Modulation System With IF Sampled 1-Bit ADC
Abstract: MIMO-constant envelop modulation (CEM) is a very power and complexity efficient system, which is introduced as alternative candidate to the currently used MIMO-Orthogonal Frequency Division Multiplexing (OFDM). CEM system enables to use high efficient nonlinear power amplifier on the transmitter side and 1 bit (low resolution) analog to digital converter (ADC) on the receiver side. Due to adopting the low resolution at the receiver side a great reduction in hardware …
Published in International Journal of Digital Communication and Analog Signals · Vol. 4, Issue 1, 2018 · pp. 1–6 Read article
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BER Analysis of Digital Modulation Schemes for OFDM System
Abstract: The growth in the field of communication and the requirement of high-speed and secured data transmission are increasing day by day. Orthogonal frequency-division multiplexing modulation technique is a new technique which supports high-speed data transmission. It is a method of signal modulation that divides a high data rate modulating stream into several slowly modulated narrowband close-spaced subcarriers, and in this way, it is less sensitive to frequency-selective fading. The present …
Published in International Journal of Digital Communication and Analog Signals · Vol. 4, Issue 1, 2018 · pp. 15–23 Read article
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OFDM Systems with Reduced PAPR
Abstract: To reduce peak to average power radio (PAPR) of orthogonal frequency division multiplexing (OFDM) system, flexible and distortion less methods like SLM (Selected mapping) and PTS (Partial transmit sequences) are very useful. The variation of OFDM signal amplitudes is very wide with high PAPR. Huge PAPR necessitates a DAC with sufficient dynamic range to handle the OFDM signals' large peaks. PAPR reduction has been demonstrated to save considerable amounts of …
Published in International Journal of Microwave Engineering and Technology · Vol. 7, Issue 1, 2021 · pp. 22–28 Read article
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Model Simulation & Resource Allocation in Cognitive Radio System
Abstract: Cognitive radio is the technique where different sorts of wireless communication devices work dynamically and change frequencies and other parameters over time. The idea of cognitive radio (CR) is to find means to use these “gaps” or “holes” in the frequency spectra and do something useful of the frequencies floating around unused and the goal of cognitive radios is to utilize under used spectrum as spectral resources are becoming sparts. …
Published in International Journal of Telecommunications & Emerging Technologies · Vol. 2, Issue 1, 2016 · pp. 14–17 Read article
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Power Theft Identification Using Embedded System
Abstract: Today, power theft plays the key role in transmission losses of electricity from the generating station to the consumer end. About 30% of power produced is being theft. Though the electricity boards know that there is power theft in the area under their vigilance, they are not able to locate the area or location of theft. So, to identify the power theft and to communicate to the EB there needs …
Published in International Journal of Telecommunications & Emerging Technologies · Vol. 2, Issue 1, 2016 · pp. 18–23 Read article
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Implementation of OFDM Using MATLAB and VHDL
Abstract: Orthogonal Frequency Division Multiplexing (OFDM) could be a digital transmission technique developed to fulfil the growing demand for higher information rates transmission of voice and video signals, which might be utilized in each wired and wireless environments. During a basic communication system, the information is modulated onto one carrier frequency. The obtainable information measure is then completely occupied by every symbol. This sort of system will result in inter-symbol-interference (ISI) …
Published in International Journal of Telecommunications & Emerging Technologies · Vol. 2, Issue 2, 2016 · pp. 6–16 Read article
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Performance Enhancement of Mobile WiMAX using TimeFrequency Training OFDM Scheme
Abstract: ABSTRACT Mobile WiMAX, IEEE 802.16 m is a Wireless Metropolitan Area Network offering a mobile broadband internet service. It uses cyclic prefix OFDMA (CP-OFDMA) as a multiple access scheme. CP-OFDMA embeds a large number of pilot subcarriers in OFDMA symbol for channel estimation purpose, reducing the data rate and spectral efficiency of mobile WiMAX system. This paper suggests the application of time-frequency training OFDM (TFT –OFDM) as a modulation and …
Published in International Journal of Telecommunications & Emerging Technologies · Vol. 6, Issue 1, 2020 · pp. 20–31 Read article