Papers by SHATRUGHNA PRASAD YADAV
Spectral Efficiency Improvement with Filtered OFDM for IoT Applications in 5G/6G
European Journal of Theoretical and Applied Sciences
Future generation mobile communication system requires asynchronous transmission of data, reduced... more Future generation mobile communication system requires asynchronous transmission of data, reduced out-of-band power emission, low peak-to-average power ratio, low latency, high data transmission rate, better spectrum, energy, and power efficiency, etc. Investigations on suitable waveform candidates for future-generation mobile communication have been reported in this paper. Filtered Orthogonal Frequency Division Multiplexing (F- OFDM), F- OFDM with Selective Mapping Method (SLM), and F- OFDM with Partial Transmit Sequence (PTS) technique, have been investigated. Its performances have been evaluated in terms of peak-to-average power ratio (PAPR), bit error rate (BER), and out-of-band power emissions. F–OFDM is a suitable candidate for future-generation mobile communication systems that can be used with single-rate or multirate filters. It can also be used in combination with other PAPR reduction techniques. F-OFDM with PTS technique requires a smaller number of IFFT operations than F...
International journal of electrical and computer engineering systems
Next generation communication systems require better performance to support high - bandwidth, pea... more Next generation communication systems require better performance to support high - bandwidth, peak data rate, spectral efficiency, mobility, connection density, positioning accuracy, etc. Investigation on efficient modulation technique for next generation has become very important so as to meet its expectations. In this paper performance optimization of universal filtered multicarrier (UFMC) technique for next generation communication systems have been investigated. Dolph-Chebyshev (DC) and Kaiser-Bessel- derived (KBD) filters have been used to optimize power spectral density, channel equalization, bit error rate, and peak to average power ratio (PAPR). It has been observed that KBD filter response is comparatively better than DC filter. Effect of filter length also influences the system performance, filter with bigger length improves performance at the cost of computational complexity. Performance of UFMC has been compared with that of orthogonal frequency division multiplexing (OF...
Orthogonal Versus Novel Orthogonal Pulse Shaped Waveforms for Future Generation Wireless Communication Systems
2022 IEEE 10th Region 10 Humanitarian Technology Conference (R10-HTC)
European Journal of Electrical Engineering and Computer Science
Future mobile communication systems are mainly focused on flexibility, reliability, scalability, ... more Future mobile communication systems are mainly focused on flexibility, reliability, scalability, spectral efficiency, and robustness. A higher data rate, increased capacity, higher mobility, lower latency, and improved quality are prime objectives that need to be improved in future communication systems. This paper investigates generalized frequency division multiplexing (GFDM), a suitable waveform candidate for future communication systems. It has low complexity compared to FBMC and is highly suitable for burst signal transmission. Due to the use of non-rectangular pulse shaping, out-of-band leakage is also less. This technique is more flexible in terms of frequency localization, scalability, and integration with MIMO. Its performance in terms of BER has been computed considering the number of subcarriers, number of sub-symbols, input power back-off, and roll-off factor as variable parameters. It has been observed that change in the BER is low when the number of sub-carriers is cha...
European Journal of Electrical Engineering and Computer Science, 2022
Higher data rates, higher mobility, lower latency, and better quality of service are the prime re... more Higher data rates, higher mobility, lower latency, and better quality of service are the prime requirements for future communication systems. It is expected to provide connectivity to the Internet of everything, time-sensitive/time-engineered application, and service to high-fidelity holographic society. Its performance in terms of data rate, latency, synchronization, security, and reliability will be much better compared to 4G and 5G mobile communication systems. This paper investigates the performance of the pulse shaping-based filter bank multicarrier (FBMC) modulation technique used in 5G mobile communication systems. Simulation results show that the FBMC system has a better performance compared to the conventional orthogonal frequency division multiplexing (OFDM) system in terms of many parameters such as achievable channel capacity, signal to noise ratio, time, and frequency response, out of band leakage, etc.
European Journal of Electrical Engineering and Computer Science, 2022
Recently healthcare sector has attracted service robots to prevent the spread of infection. Durin... more Recently healthcare sector has attracted service robots to prevent the spread of infection. During COVID-19 pandemic, service robots have been able to reduce direct contact of front-line healthcare workers by separating them from direct exposure to infection. Robots have been used for delivery systems, disinfection of the exposed area, remote monitoring of patients, etc. In the present work, we have designed a disinfection robot that radiates ultraviolet C rays for UV sterilization of hospitals that kills 95.0% of bacteria within 20 second of exposure from a distance of 0.5 meter. UVC disinfection is more effective than disinfection by hydrogen peroxide, and with other chemical-based disinfectants like chlorine, chloramine, etc. Our designed robot can also be used as a dispenser in hospital delivery system for transporting medicine, laboratory samples, etc. Its use will not only increase logistics efficiency but will also avoid spread of Hospital Acquired Infections (HAIs), healthca...
Investigations on PAPR Reduction using PTS Technique for OFDM Communication Systems
Orthogonal Frequency Division Multiplexing (OFDM) is a spectral efficient technique for high data... more Orthogonal Frequency Division Multiplexing (OFDM) is a spectral efficient technique for high data rate communication systems. It also provides robustness to multipath frequency selective fading but suffers from high peak-to-average power ratio (PAPR) and causes high power amplifiers to operate in the nonlinear region. In this paper partial transmit sequence (PTS) as PAPR reduction technique has been investigated. Mathematical modelling and Matlab simulation have been carried out to analyse its performances. At 0.01 percent of CCDF, PAPR values for OFDM signal without applying any reduction technique are 11.5, 11.8, 12.0, 12.2 and 12.5 dB for 64, 128, 256, 512 and 1024 number of subcarriers respectively. Whereas with PTS technique with 16 number of sub blocks, the corresponding values are 6.4, 7.0, 7.6, 8.1, 8.4 and dB respectively. PTS method reduces the PAPR value by 4.1 dB than that of the OFDM signal with 1024 number of sub carriers.Orthogonal frequency division multiplexing (OFD...
PAPR Reduction using DFT Spread Technique for Nonlinear Communication Systems
178 Abstract—Discrete Fourier Transform (DFT) spread is a modified form of orthogonal frequency d... more 178 Abstract—Discrete Fourier Transform (DFT) spread is a modified form of orthogonal frequency division multiplexing (OFDM) system. It promises high data rate for uplink communications with lower peak to average power ratio (PAPR) than the conventional OFDM system. It has similar throughput performance and structural complexity as OFDM. In the present work PAPR performance analysis has been done for its different subcarrier mapping approaches. Among the localized FDMA (LFDMA), distributed FDMA (DFDMA) and interleaved FDMA (IFDMA) the PAPR performance of IFDMA has been found to be better than that of DFDMA and LFDMA. When the DFD spreaded signals are passed through a raised cosine pulse shaping filer IFDMA system shows sharp reduction in PAPR with increase in roll-off factor from 0 to 1. The response of LFDMA is not that much affected by the pulse shaping network. The PAPR performance of DFT spread also depends on the number of subcarriers allocated to each user. The PAPR of LFDMA d...
Hardware implementation of SLM technique for OFDM communication systems
Requirement of high data rate by the modern mobile communication system requires a linear power a... more Requirement of high data rate by the modern mobile communication system requires a linear power amplifier with extremely low power consumption and long battery life. Orthogonal frequency division multiplexing (OFDM) modulation technique promises to deliver high data rate with simple receiver structure. It is more spectral efficient and has been recommended to be used by many standards. But it has one major disadvantage of having high peak to average power ratio (PAPR). High PAPR drives the power amplifier in saturation region and causes it to operate in nonlinear region with reduced efficiency. There are several techniques to reduce PAPR of OFDM system. In this paper we have done FPGA implementation of selective mapping method (SLM) for PAPR reduction for 4 QAM baseband signal for 64, 128, 256, 512 and 1024 number of subcarriers. The result obtained have been compared with PAPR values obtained through mathematical analysis and Matlab simulations and also with original signal. For 10...
Modeling and simulation of solid state power amplifier for mobile communication
2017 International Conference on Recent Innovations in Signal processing and Embedded Systems (RISE), 2017
Power amplifier exhibit nonlinearity behavior at microwave frequencies. The effect of nonlinearit... more Power amplifier exhibit nonlinearity behavior at microwave frequencies. The effect of nonlinearity appears in the form of adjacent channel interference, gain compression, harmonic distortion, phase distortion, inter-modulation distortion, etc. In this paper, mathematical modeling and simulation with AWR software have carried out on solid state class B power amplifier for feedback, feed forward and digital predistortion techniques. From the result obtained, it is evident that the performance of digital predistortion technique is better in terms of efficiency compared to other techniques as there is no degradation in amplitude with 20 dB reduction in ACPR and 3dB bandwidth of 10 MHz.
FPGA Implementation of SLM Technique for OFDM Communication Systems
Indian Journal of Science and Technology, Dec 29, 2016
FPGA Implementation of SLM Technique for OFDM Communication Systems
Indian Journal of Science and Technology
International Journal of Electrical and Computer Engineering (IJECE)
Highly linear power amplifiers are required for transferring large amount of data for future comm... more Highly linear power amplifiers are required for transferring large amount of data for future communication. Orthogonal frequency division multiplexing (OFDM) provides high data rate transmission capability with robustness to radio channel impairments. It has been widely accepted for future communication for different services. But, it suffers from high value of peakto-average power ratio (PAPR). High value of PAPR drives high power amplifiers in saturation and causes it to operate in the nonlinear region. In this paper, comparative study of four different PAPR reduction techniques: clipping and filtering (CF), selective mapping method (SLM), partial transmit sequence (PTS) and DFT-spread technique have been done. Mathematical modeling and Matlab simulations have been performed to arrive at the results with 4 QAM modulation format and 1024 number of sub carriers. At 0.01 % of complementary cumulative distribution function (CCDF) significant reduction of 11.3, 3.5, 3.4 and 1.0 dB have been obtained with DFT-spread, SLM, PTS and CF techniques respectively.
Linearity improvement of microwave power amplifiers
2016 IEEE Annual India Conference (INDICON), 2016
International Journal of Engineering and Technology, 2016
Orthogonal frequency division multiplexing (OFDM) is preferred for mobile communications applicat... more Orthogonal frequency division multiplexing (OFDM) is preferred for mobile communications applications due to its increased data transmission capability. At one hand, it has advantages of being robust to multipath fading and possessing high data rate transmission capability, on the other hand it suffers from high peak to average power ratio (PAPR). In this paper FPGA implementation of clipping and filtering method have been implemented on Xilinx Spartan 3 Protoboard XC 3S 400 board for 4 QAM OFDM signals. The results obtained have been compared with National Instrument's (NI) AWR visual system simulator and Matlab software simulations. FPGA implementation of pre-filtering and post clipping technique results with 2.2 dB PAPR, whereas, PAPR values obtained in the case of pre-clipping and post filtering method, are 10.6, 10.7 and 10.9 dB with NI's AWR simulation, Matlab simulation and FPGA implementation respectively. When compared with original OFDM signal having 12.5 dB PAPR, FPGA implementation of pre-filtering and post-clipping reduces PAPR by 10.3 dB, whereas for the case of pre-clipping and post-filtering technique the reductions in PAPR are 1.6, 1.8 and 1.9 dB with FPGA implementation, Matlab and NI's AWR software simulations respectively. Keyword-FPGA, OFDM, PAPR, BER, Clipping and filtering I. INTRODUCTION In the modern mobile communication systems, one of the major concerns is the nonlinearity of RF amplifiers. The nonlinear power amplifiers degrades quality of the transmitted signal, causing increase in the bit error rate (BER), increase in adjacent channel interference, causing harmonic and phase distortions, gain compression, intermodulation distortions etc. Different techniques are available to analyse linear circuits [1]. But OFDM is required to be used in modern mobile communications systems in order to reduce the power consumption requirement, enhance battery life, reduce weight and size of battery and increased data transmission capability. Apart from that it has additional advantage of high spectrum efficiency and immunity to multi-path fading. OFDM systems are widely used for other applications like, digital high definition tele vision (HDTV) broadcasting, digital subscriber line (DSL), digital video broadcasting (DVB), and digital audio broadcasting (DAB), etc. But one of the major disadvantage of OFDM system is that it exhibits high peak to average power ratio (PAPR). The effect of power amplifier nonlinearity is further gets increased with use of orthogonal frequency division multiplexing (OFDM) owing to its high PAPR. The problem of power amplifier linearity can be reduced at three different levels. First in the transmitter itself by introducing power amplifier linearity techniques. One of the simplest method is to operate power amplifiers in power back-off mode. It is one of the simplest technique to reduce the effect of nonlinearity in power amplifiers. But it results in lower efficiency, oversized amplifier and unsuitable for most of the practical applications [2-3]. This also causes not only to in-band signal distortion but also to out-of-band spectral regrowth, which are strictly regulated as a service provider cannot pollute the band of its competitor [4]. In order to improve linearity along with efficiency there are different power amplifier linearization techniques, such as feedback, feed forward and pre-distortion. Feedback technique is simple to implement but results in lowest efficiency. Feedforward technique is used for wide bandwidths applications in multicarrier systems where feedback technique is impractical. It gives improvements in distortion from 20 to 40 dB with 10-15% lower efficiency. This technique also costs more due to use of couplers, delay lines, error power amplifier, etc. The digital predistortion technique does not use these RF components and improves linearity with approximately 1dB degradation in efficiency[5]. In modern communication systems digital predistortion technique is mostly used owing to many advantages associated with it when compared with other available techniques.Second method of reducing power amplifier linearity is to reduce the effect of PAPR of OFDM systems in the transmitter itself by incorporating different PAPR reduction techniques[6-8]. There are different PAPR reduction techniques such as, clipping and filtering, selective mapping method, partial transmit sequence,
PAPR analysis of single carrier FDMA system for uplink wireless transmission
2015 10th International Conference on Information, Communications and Signal Processing (ICICS), 2015
Single carrier FDMA technique for wireless communication system
2015 Annual IEEE India Conference (INDICON), 2015
Nonlinearity effect of high power amplifiers in communication systems
2014 International Conference on Advances in Communication and Computing Technologies (ICACACT 2014), 2014
ABSTRACT This paper presents Nonlinearity Effect of high Power Amplifiers in communication Systems
Nonlinearity Effect of high Power Amplifiers in communication Systems
This paper presents Nonlinearity Effect of high Power Amplifiers in communication Systems
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Papers by SHATRUGHNA PRASAD YADAV