Constellation Design for Future Communication Systems: A Comprehensive Survey

Abstract

The choice of modulation schemes is a fundamental building block of wireless communication systems. As a key component of physical layer design, they critically impact the expected communication capacity and wireless signal robustness. Their design is also critical for the successful rollout of wireless standards that require a compromise between performance, efficiency, latency, and hardware requirements. This paper presents a survey of constellation design strategies and associated outcomes for wireless communication systems. The survey discusses their performance and complexity to address the need for some desirable properties, including consistency, channel capacity, system performance, required demapping architecture, flexibility, and independence. Existing approaches for constellation designs are investigated using appropriate metrics and categorized based on their theoretical algorithm design. Next, their application to different communication standards is analyzed in context, aiming at distilling general guidelines applicable to the wireless building block design. Finally, the survey provides a discussion on design directions for future communication system standardization processes.INDEX TERMS Bandwidth, communication waveforms, mobile communications, spectral efficiency, wireless communications.

Study on MPPT Algorithm Based on an Efficient Hybrid Conjugate Gradient Method in a Photovoltaic System

“…Here, the authors chose the linear CG As for the nonlinear type ( just like the parameter 𝛾 z ), scientists have widely researched it and successfully taken it to practice [36]. These cases illustrate that using the nonlinear type can solve a problem of the large-scale stationary point through a common nonlinear function 𝑓.There are some famous parameters 𝛾 z for the nonlinear conjugate algorithm, including HS (Hestenes & Stiefel) [37], DY ( Dai& Yuan) [38], PRP (Polak, Ribiere & Polyak) [39], and FR(Fletcher & Reeves) [40]. Their definitions are as the following formulas:…”

“…Although there are many MPPT algorithms and comparisons of MPPT methods, most of the literature took aims for only one goal [38]. Although there are many MPPT algorithms and comparisons of MPPT methods, most of the literature took aims for only one goal [39]. Overall, it is hard to simultaneously consider the dynamic performance, steady-state performance, and implementation cost of the MPPT [40].…”

Challenges in meeting QoS requirements toward 6G wireless networks: A state of the art survey

“…Also, constellation designs using joint geometric and probabilistic shaping techniques (GS and PS), use of pattern coding for transmission of constellation points and use of machine learning techniques for construction of smart de-mapping processes which can act according to the received mapped data can be considered. 57 Such GS-PS joint approach may address the issue related to the use of large number of IoT sensors with equal and unequal bit probability distribution. In MEC based 6G network, the holistic delay characteristics model on the basis of the determination of computational and communication resource allocation, which is studied in Reference 65, can be examined in multiple user scenario.…”

“…As a result, a challenge for future 6G networks to achieve such stringent latency requirements is to design high order constellations/demappers that not only support very high spectral efficiencies, but are also low in complexity in order to avoid increasing the system latency. 57 In addition, the studies in References 80,81,82 show that present cellular technology cannot support data exchange feature from battery-powered equipment in wide area coverage network. The narrow-band IoT (NB-IoT) does not provide expected performance because of over-computational process, which may introduce delay, and varying QoS requirements.…”

“…In order to achieve this, each element in the communication chain must have latencies that are a few orders of magnitude below this latency. As a result, a challenge for future 6G networks to achieve such stringent latency requirements is to design high order constellations/demappers that not only support very high spectral efficiencies, but are also low in complexity in order to avoid increasing the system latency 57 …”