M Sheeba Kumari

Bio: M Sheeba Kumari is an academic researcher from Visvesvaraya Technological University. The author has contributed to research in topics: Telecommunications link & Path loss. The author has an hindex of 1, co-authored 2 publications receiving 1 citations.

Performance of Downlink SISO NR System using MMSE-IRC Receiver

Abstract: In this work, we investigated the performance of single input single output (SISO) downlink channel considering 5G new radio (NR). A number of parameters such as different modulation schemes, channel coding with varying code rates, scalable numerology μ and 3GPP channel models have been considered for evaluation. In addition, the minimum mean square error-interference rejection combining (MMSE-IRC) technique for interference mitigation and bit error rate (BER) performance is analyzed and presented. We also compared the sum-rate performance of LTE and 5G NR. It is observed that MMSE-IRC receiver successfully mitigates the interferences compared to only MMSE based receiver. Simulation results also show performance improvement over various parameters like sum-rate, interference mitigation and BER compared to prior technologies i.e. 4G-LTE, WiMAX, etc.

Performance of mmWave Ray Tracing Outdoor Channel Model Exploiting Antenna Directionality

Abstract: The millimeter (mmWave) 5G new radio (NR) aims to provide orders of magnitude greater capacity through increased bandwidth and beamforming assisted narrow beam transmissions. The assumption of directional antennas with narrow radiating beams will reduce the number of contributing multipaths causing the channel to be sparser and simpler than the omnidirectional microwave channel. In this paper, we used a custom ray tracing model to study the behavior of directional mmWave urban micro (UMi) street canyon (SC) links. The proposed channel model harnesses the higher attenuation in high frequency mmWaves and the spatial filtering of directional antennas to reduce ray tracing complexity. The potential of this low complexity model has been evaluated through comprehensive simulation for both line of sight and non-line of sight mmWave communications at ranges up to 200m with different transmitter and receiver geometries. The impact of crossroad gaps on channel performance in a real urban SC 5G outdoor network design is also formulated. Several interesting insights have been derived. The strength of the proposed model constitutes path loss predictions at varying positions, frequency, and street orientation with/ without sidewall discontinuities.

Fixed-Point MIMO Detector for 5G New Radio

Abstract: Fixed-point simulation of multiple-input and multiple-output (MIMO) with ordered successive interference cancellation (OSIC) detector for 5G new radio (NR) is presented. 5G NR is in demand to provide high data rate (in Gbps) and the massive multiple devices connectivity. The above requirements are fulfilled with the incorporation of multiple antenna based transceiver in 5G NR. The spatial multiplexed MIMO system resulted from aforesaid incorporation effectively increases the data rate using MIMO detectors. The performance of various optimal and sub-optimal MIMO detectors used for MIMO channel matrix inversion is limited to the singularity of the channel matrix. While triangularization and orthogonalization are prerequisites for solving the singularity of the channel matrix in MIMO systems, QR decomposition using Gram-Schmidt (GS) method is one of the stable technique. Also, using the QROSIC detection, the system succeeds to achieve near maximum likelihood (ML) performance. In this work, we investigated the fixed-point implementation of QR-OSIC MIMO detector over 5G NR. The simulation results also validate the proposed fixed-point detector succeed to achieve near ML performance while maintaining the word precision low compared to floating-point implementation.

Link-Level Assessment of NOMA Aided Multi-hop DECT-2020 New Radio for mMTC Applications

Abstract: Digital enhanced cordless telecommunication-2020 new radio (DECT-2020 NR) is an essential part of the fifth generation (5G) standards proposed by the international telecommunication union (ITU). With an achievable density of approximately one million connections per square km, it is a potential candidate which promises to fill in the actual gap in the wireless internet of things (IoT) market for the massive machine-type communications (mMTC). In this paper, we explore a non-orthogonal multiple access (NOMA) assisted cooperative multi-hop (MH) relaying system for DECT-2020 NR system for mMTC applications. The use of cooperative multi-hop (MH) relaying system allows a reliable long-haul communication system and further the use of NOMA scheme helps in achieving a better spectral efficiency and massive connectivity. The link level evaluation of the proposed system is carried out for the proposed NOMA aided MH DECT-2020 NR system and further error rate analysis is presented in terms of outage probability and the bit error rate (BER). Monte-Carlo simulations further corroborate the correctness of the analytical findings.

Link-Level Assessment of NOMA Aided Multi-hop DECT-2020 New Radio for mMTC Applications

Abstract: Digital enhanced cordless telecommunication-2020 new radio (DECT-2020 NR) is an essential part of the fifth generation (5G) standards proposed by the international telecommunication union (ITU). With an achievable density of approximately one million connections per square km, it is a potential candidate which promises to fill in the actual gap in the wireless internet of things (IoT) market for the massive machine-type communications (mMTC). In this paper, we explore a non-orthogonal multiple access (NOMA) assisted cooperative multi-hop (MH) relaying system for DECT-2020 NR system for mMTC applications. The use of cooperative multi-hop (MH) relaying system allows a reliable long-haul communication system and further the use of NOMA scheme helps in achieving a better spectral efficiency and massive connectivity. The link level evaluation of the proposed system is carried out for the proposed NOMA aided MH DECT-2020 NR system and further error rate analysis is presented in terms of outage probability and the bit error rate (BER). Monte-Carlo simulations further corroborate the correctness of the analytical findings.