Felix Academic Publications International Journal of Innovative Trends in Engineering Science and Technology 3139-6887 1 1 2026 08 01 Optimization and Performance Evaluation of RIS-Integrated Hybrid Precoding in Millimeter Wave Massive MIMO 8 12 eng CheekatlaSwapna Priya Associate Professor,Department of CSE, Vignans Institute of Information Technology (A), Visakhapatnam, India S Naga Mallik Raj Associate Professor, Department of CSE, Vignans Institute of Information Technology (A), Visakhapatnam, India Gulshan Sri Babu Thorlapati Student, Department of CIVIL, Vignans Institute of Information Technology (A), Visakhapatnam, India G. Madhavi Assistant Professor, Department of BS&H, Vignans Institute of Information Technology (A), Visakhapatnam, India IJITEST-2026-002 2026 03 29 2026 08 01 The evolution toward sixth-generation (6G) wireless systems requires extremely high data rates, massive device connectivity, very low latency, and improved energy efficiency. Millimeter-wave (mmWave) communication is considered a key enabler due to its large available bandwidth and ability to support multi-gigabit transmission. Nevertheless, mmWave signals experience high path loss, vulnerability to blockage, and increased implementation complexity caused by large antenna arrays and multiple RF chains.To overcome these limitations, this thesis explores the integration of Reconfigurable Intelligent Surfaces (RIS) with hybrid analogdigital precoding in mmWave Massive MIMO systems. RIS enables intelligent control of signal propagation by adjusting the phase of reflected waves, while hybrid precoding reduces hardware cost and power consumption without significantly degrading performance. A detailed system model, mathematical analysis, and optimization strategies for precoders and RIS phase shifts are presented. Performance evaluation based on spectral efficiency, energy efficiency, and hardware complexity demonstrates that RIS- assisted hybrid architectures provide notable improvements in coverage, achievable rate, and power utilization.