Overview

Localization (2022-Present)

UAV-aided indoor localization for emergency applications such as locating first responders
- Cramer Rao lower bound (CRLB) based analysis by considering various system parameters.
- Created a simulation framework to assess the positioning performance.
- Developing algorithms to meet CRLB.
NTN-based 6G localization
- Identified prospective study items for NTN-based accurate positioning in 6G.
- Created a 3GPP-compliant simulation framework to evaluate positioning performance based on CRLB analysis.

Analysis of Performance Differences in ORAN ULPI Proposed Architectures

Developed an uplink multi-user MIMO link level simulator (LLS) leveraging 5G toolbox in MATLAB.
Investigated proposed uplink performance improvement (ULPI) architectures compliant to ORAN 7-2x.
LLS Features: Channel estimation, equalization with modular granularity, MU-MIMO, hybrid ARQ, antenna array, CDL channel model, and evaluation metrics (sum throughput and post-processing SINR).

Developed a system framework to enable real-time RIC functionality.

Developed scheduling algorithms and enabled the wireless system (srsRAN) to support simultaneous connections from multiple users.
Facilitated the collection of scheduling weights from the RIC and efficient resource allocation for the connected users.

Developed a 3GPP-compliant downlink and uplink SLS for design validation of massive MIMO beamforming and scheduling solutions.

SLS Features: FD-MIMO Channel Model, Antenna Array, Different Numerologies, Flexible Slot Formats, CSI Feedback, Traffic Modeling, Proportional Fair Scheduler, SU/MU-MIMO Multiplexing, MU-MIMO User Pairing, Precoding, Hybrid ARQ, Outer Loop Rate Control, and Uplink Power Control.
Conducted channel model and throughput calibration aligned with 3GPP.
Devised an innovative scheduler capable of efficiently managing hundreds of users, supporting both SU-MIMO and MU-MIMO.
Developed novel user pairing algorithms to spatially multiplex users for downlink MU-MIMO transmission.
Designed and validated beamforming algorithms to enhance downlink control channel capacity in 4G systems.
Designed receiver beamforming algorithms for the uplink to reduce computational complexity and hardware cost for receivers.
Proposed uplink coverage enhancements for extremely large cells in 5G NR.
Proposed port signaling for reference signals as a means to mitigate inter-cell interference.
Self-Organizing Networks (SON):
- Implemented SON functionality to monitor and control RAN parameters.
- SON Features: Configuring cell-specific parameters such as transmit power, antenna pattern, boresight, downtilt, etc., flexible eNB locations, multiple eNBs, intra-inter frequency handover, and collecting key metrics (RSRP, SINR, CQI, etc.).