Research in cooperative transmissions for Mobile Ad Hoc Networks (MANETs) focuses on enhancing communication reliability, energy efficiency, and throughput through node collaboration during data forwarding. Recent works explore adaptive relay selection, power control, and beamforming techniques to optimize cooperative communication under dynamic topology and mobility conditions. Machine learning and game-theoretic models are being applied to improve relay coordination, interference management, and link stability. Additionally, secure and energy-aware cooperative transmission protocols are proposed to defend against malicious relays and ensure data integrity. These advancements significantly improve network resilience, spectral efficiency, and overall performance in decentralized MANET environments.