A novel scheme‘user assisted cooperative relaying in beamspace massive multiple input multiple output(M-MIMO)non-orthogonal multiple access(NOMA)system’has been proposed to improve coverage area,spectrum and energy ...A novel scheme‘user assisted cooperative relaying in beamspace massive multiple input multiple output(M-MIMO)non-orthogonal multiple access(NOMA)system’has been proposed to improve coverage area,spectrum and energy efficiency for millimeter wave(mmWave)communications.A downlink system for M users,where base station(BS)is equipped with beamforming lens antenna structure having NRF radio frequency(RF)chains,has been considered.A dynamic cluster of users is formed within a beam and the intermediate users(in that cluster)between beam source and destination(user)act as relaying stations.By the use of successive interference cancellation(SIC)technique of NOMA within a cluster,the relaying stations relay the symbols with improved power to the destination.For maximizing achievable sum rate,transmit precoding and dynamic power allocation for both intra and inter beam power optimization are implemented.Simulations for performance evaluation are carried out to validate that the proposed system outperforms the conventional beamspace M-MIMO NOMA system for mmWave communications in terms of spectrum and energy efficiency.展开更多
OFDM (Optical Orthogonal Frequency Division Multiplexing) in the optical domain is a promising technology which provides solutions to problems of today’s optical networks. In the present research an optical OFDM syst...OFDM (Optical Orthogonal Frequency Division Multiplexing) in the optical domain is a promising technology which provides solutions to problems of today’s optical networks. In the present research an optical OFDM system is designed using different modulation techniques QPSK (quadrature phase shift keying), QAM (quadrature amplitude Modulation). Various signal conditioning parameters, like OSNR (optical signal to noise ratio), BER (bit error rate), chromatic dispersion and electrical SNR (signal to noise ratio) have been reported in present research. These parameters could be used for identifying the fault. On the basis of conclusion drawn for values of these parameters, the system may dynamically adapt and reconfigure itself for better transmission. In present research OPTSIM and MATLAB has been used as Simulation tools.展开更多
文摘A novel scheme‘user assisted cooperative relaying in beamspace massive multiple input multiple output(M-MIMO)non-orthogonal multiple access(NOMA)system’has been proposed to improve coverage area,spectrum and energy efficiency for millimeter wave(mmWave)communications.A downlink system for M users,where base station(BS)is equipped with beamforming lens antenna structure having NRF radio frequency(RF)chains,has been considered.A dynamic cluster of users is formed within a beam and the intermediate users(in that cluster)between beam source and destination(user)act as relaying stations.By the use of successive interference cancellation(SIC)technique of NOMA within a cluster,the relaying stations relay the symbols with improved power to the destination.For maximizing achievable sum rate,transmit precoding and dynamic power allocation for both intra and inter beam power optimization are implemented.Simulations for performance evaluation are carried out to validate that the proposed system outperforms the conventional beamspace M-MIMO NOMA system for mmWave communications in terms of spectrum and energy efficiency.
文摘OFDM (Optical Orthogonal Frequency Division Multiplexing) in the optical domain is a promising technology which provides solutions to problems of today’s optical networks. In the present research an optical OFDM system is designed using different modulation techniques QPSK (quadrature phase shift keying), QAM (quadrature amplitude Modulation). Various signal conditioning parameters, like OSNR (optical signal to noise ratio), BER (bit error rate), chromatic dispersion and electrical SNR (signal to noise ratio) have been reported in present research. These parameters could be used for identifying the fault. On the basis of conclusion drawn for values of these parameters, the system may dynamically adapt and reconfigure itself for better transmission. In present research OPTSIM and MATLAB has been used as Simulation tools.
