O-RAN Architecture, Massive MIMO Beamforming and NOMA-Assisted Multi-User Scheduling for 5G NR Network Densification in Indian Urban Corridors

India's 5G rollout, initiated with spectrum auctions in August 2022 and commercial launch by Reliance Jio and Bharti Airtel in October 2022, has expanded to cover over 640 cities and towns by March 2024 — yet average 5G downlink throughput of 312 Mbps, while far exceeding 4G's 48 Mbps, remains substantially below the theoretical peak of 20 Gbps promised by IMT-2020 specifications. The gap reflects network densification deficits — insufficient small cell deployments in dense urban environments where macro-cell signal penetration into indoor environments is limited — and scheduling algorithm inefficiencies that do not exploit the spatial multiplexing and multi-user diversity gains available from massive MIMO antenna arrays already deployed in the Jio and Airtel 5G infrastructure. This paper presents an integrated radio access network design study combining three complementary technologies: Open Radio Access Network (O-RAN) architecture for disaggregated multi-vendor network deployment, Massive MIMO beamforming with 64-antenna ULA arrays for spatial coverage enhancement, and Non-Orthogonal Multiple Access (NOMA) with successive interference cancellation (SIC) for improved spectral efficiency under high user density. System-level simulations using an IIT Madras-developed 5G NR link-level simulator calibrated to Jio's Chennai deployment are validated against drive test measurements. The proposed NOMA-Massive MIMO scheduling achieves 15% sum spectral efficiency improvement over standard OMA at 10 simultaneous users and reduces P95 latency from 38ms (LTE baseline) to 2.1ms (O-RAN 5G) — meeting the URLLC 5ms target for 94.7% of the simulated network area.