A Survey of Smart Antenna Technology: Architectural Evolution, Performance Comparison, and Future Challenges

Smart antenna technology, a critical innovation in wireless communications, significantly enhances system performance through dynamic beamforming and spatial filtering. It effectively addresses limitations of traditional antennas in anti-interference capability, spectrum utilization efficiency, and coverage flexibility, making it a fundamental component of fifth-generation (5G) and future mobile communication systems. This paper systematically reviews the primary technical approaches in smart antenna research, focusing on three mainstream implementations: switched-beam, adaptive beamforming, and hybrid architectures. A comprehensive analysis and comparison of their technical principles, performance characteristics, and application scenarios are provided. Based on the examination and synthesis of existing work, potential future research directions for smart antenna technology are also proposed.