Noncoherent Wireless Systems for 5G and Beyond

Advancing into the 5th Generation (5G) and beyond, wireless communications unfolds with three primary use cases, namely, enhanced mobile broadband services, ultrareliable and low-latency communications, and massive machine-type communications. The applications targeting these use cases aim to achieve high peak data rates, ultralow latency, and extensive device connectivity. These attractive features are achieved by the utilization of various technologies, of which noncoherent communications and technologies addressing Line-of-Sight (LoS) communications in an ultra-dense network have piqued interest amongst researchers over recent years. Inspired by the research gaps in these areas, this chapter studies the performance of noncoherent wireless communication systems for 5G applications, considering the presence of a prominent LoS component in the multipath of the fading channel affecting the transmitted signal. This chapter delves into the design of a receive diversity noncoherent wireless communication system, focusing on designing receivers that are both energy-efficient and hardware-efficient. In this system, the transmitter utilizes multi-level one-sided and two-sided Amplitude-Shift Keying (ASK) schemes to transmit data over Rician fading channels. At the receiver end, an optimal noncoherent maximum likelihood detector is employed to efficiently decode the transmitted signals. The performance of the proposed system is evaluated by deriving both series-form and asymptotic closed-form expressions for the union bound on SEPs (Symbol Error Probabilities). These expressions are based on pairwise error probabilities and the proposed detection rule, ensuring accurate system analysis. Moreover, a comprehensive framework is introduced to obtain the optimal multi-level ASK constellations that minimize SEPs while adhering to an average transmit energy constraint. Through numerical analysis, the system's effectiveness is demonstrated, showcasing its improved performance with optimal ASK constellations in comparison to traditional equally-spaced ASK constellations. This highlights the potential of the proposed approach in enhancing the efficiency of noncoherent wireless communication systems.