Future technologies for very high throughput satellite systems

Jia

Wei

et al. 2020

J Wireless Com Network

Adopting full frequency reuse in high throughput satellite (HTS) systems is expected to cope with huge communication demands and large user populations. Moreover, a kind of multicast transmission, which embeds the data of several users in each frame, can be employed to increase the efficiency of HTS systems. Multicast precoding is usually utilized in such systems to mitigate the co-frequency interference between beams and improve the efficiency of transmission. In this context, considering that the number of users may exceed the number of available communication resources in the system, we investigate user scheduling for the multicast transmission in HTS systems with full frequency reuse and multicast precoding. We perform user scheduling according to the user channel state information and decouple the scheduling problem into two phases: intra-beam and inter-beam scheduling. Intra-beam scheduling determines the users involved in the transmission of each frame with the purpose of reducing the influence of the multicast fashion. For intra-beam scheduling, we put forth a fixed-size user grouping algorithm. In contrast to previous studies, this algorithm takes the interference among beams into consideration during the scheduling. In inter-beam scheduling, user groups belonging to different beams are scheduled to improve the performance of the multiplexed transmission. An inter-beam scheduling algorithm is proposed to improve the fairness among users. The simulation results verify the superiority of the proposed algorithms in terms of fairness and spectral efficiency.

“…where C k is the average spectral efficiency per beam for G k and is calculated with (10). The constraints that should be satisfied during the scheduling are:…”

Section: Problem Statementmentioning

confidence: 99%

“…The average spectral efficiency is calculated with (10). Figure 3 depicts the average spectral efficiency verse R under different scheduling schemes with M = 90, 120.…”

Section: Average Spectral Efficiencymentioning

confidence: 99%

See 1 more Smart Citation

User scheduling for multicast transmission in high throughput satellite systems

Jia

Wei

et al. 2020

J Wireless Com Network

“…Recent studies focus on aggressive frequency reuse, even full-frequency reuse, to augment the available bandwidth in each beam and meet the future communication demands. [3][4][5] As an indispensable part of the future communication system, HTSs play an important role in offloading the terrestrial traffic and supporting high-quality services for large user populations. 3 Multicast services raise serious challenges to communication systems in terms of occupying numerous resources in serving separate users distributed in broad areas.…”

Section: Introductionmentioning

confidence: 99%

“…[3][4][5] As an indispensable part of the future communication system, HTSs play an important role in offloading the terrestrial traffic and supporting high-quality services for large user populations. 3 Multicast services raise serious challenges to communication systems in terms of occupying numerous resources in serving separate users distributed in broad areas. Moreover, the ever-increasing traffic demands of multicast services, such as online games, video meetings, and especially bandwidth-hungry video content delivery, further burden the system.…”

Section: Introductionmentioning

confidence: 99%

Subgrouping‐based multicast transmission over high‐throughput satellite systems with beam cooperation

Yang

Wei

et al. 2020

Satell Commun Network

This paper investigates the multicast transmission for multicast services in high-throughput satellite (HTS) systems. Considering the multibeam multicast feature of HTSs, cooperative transmission among beams is involved in to improve the efficiency of the multicast transmission. Since the multicast transmission rate depends on the worst user channel state, all the users experience an unreasonably low rate. In this situation, subgrouping techniques are employed to increase transmission rates of users. A subgrouping-based multicast transmission problem aiming at maximizing the lowest transmission rate of the users is studied to guarantee fairness among users. We formulate the problem as a max-min optimization problem and propose two low-complex subgrouping algorithms for this problem. Additionally, we also consider multicasting in a single beam and devise a two-layer transmission scheme for it. In the performance evaluation part, besides the impact of parameters on subgrouping performance, we analyze the performance and the computational complexity of the proposed algorithms. The results indicate that the two subgrouping algorithms can achieve favorable performance with low complexity.

Low‐complexity detection method based on channel matrix periodic N‐diagonal equivalence for uplink MU‐MIMO of multi‐beam satellite communication systems

Zhu

et al. 2021

Satell Commun Network

Summary In this paper, a low‐complexity detection method for uplink Multi‐User Multiple‐Input Multiple‐Output (MU‐MIMO) of multi‐beam satellite communication systems is studied. Firstly, we derive the uplink receiving system model and give the beam‐domain channel expression. Utilizing the characteristics of energy concentration of uplink channel in beam domain, we propose that the channel matrix can be equivalent to periodic N‐diagonal matrix, which can reduce the number of channel estimations and reduce the computational complexity of detection. Then, based on the beam‐domain channel matrix equivalent model, two low‐complexity minimum mean square error (MMSE) detection methods are proposed to reduce the computational complexity of traditional MMSE detection from O()K2 to O(K). Simulation results show that the proposed methods have limited performance loss compared with the traditional methods.