Mobile communication systems: Architecture, technologies, performance analysis, and future trends

Mobile communication systems have become an indispensable component of modern society, enabling ubiquitous connectivity, real-time information exchange, and seamless access to multimedia services. The evolution from first- generation (1G) analog systems to advanced fifth-generation (5G) and emerging sixth-generation (6G) networks reflects continuous innovation driven by the demand for higher data rates, lower latency, massive connectivity, and improved reliability. This review presents a comprehensive, and in-depth study of mobile communication systems, focusing on their fundamental principles, network architectures, multiple access techniques, propagation characteristics, performance metrics, and real-world applications. Detailed discussions on cellular concepts, handoff mechanisms, channel modeling, modulation and coding schemes, and modern technologies such as LTE, 5G New Radio, and mobile edge computing are included. Furthermore, challenges and limitations of existing systems are analyzed, followed by future research directions emphasizing artificial intelligence-driven networks, ultra-reliable low-latency communications, and sustainable mobile communication infrastructures.