Intelligent Reflecting Surface-Aided LEO Satellite Communication: Cooperative Passive Beamforming and Distributed Channel Estimation

Zheng, Beixiong; Lin, Shaoe; Zhang, Rui

doi:10.1109/jsac.2022.3196119

Cited by 29 publications

(13 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As A follows a Gaussian distribution, SNR is non-central chi-square distributed with one degree of freedom. To evaluate the bit error probability (BEP), the moment generating function (MGF) of a noncentral chi-square distribution [33] is utilized as given in (19). By utilizing the symbol error probability (SEP) expression for M -PSK signals given in [34], the error probability for binary phase shift keying (BPSK) is obtained as in (20).…”

Section: B Single Ris-assisted Wireless Channel and Associated Perfor...mentioning

confidence: 99%

“…RISs are expected to be a key enabler for THz waves in small satellites of the future [16] due to the energy efficiency [17] and low hardware complexity [18] provided by RISs. In [19], an architecture for RIS-assisted LEO satellite communications with RISs deployed at satellite and ground nodes and cooperative passive beamforming are proposed. The authors jointly optimize both beamforming at satellite and ground nodes to maximize the channel gain between satellite and ground nodes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Reconfigurable Intelligent Surfaces Empowered THz Communication in LEO Satellite Networks

Tekbıyık¹,

Kurt

Ekti

et al. 2022

IEEE Access

View full text Add to dashboard Cite

Massive swarms of low Earth orbit (LEO) satellites are poising to serve for high-speed and low-latency ubiquitous connectivity with almost global coverage. Broadband inter-satellite communication is one of the key elements of satellite communication systems that orchestrate massive satellite swarms in cooperation. Thanks to technological advancements in microelectronics and micro-systems, the terahertz (THz) band has emerged as a strong candidate for inter-satellite links (ISLs) due to its promise of wideband communication. Especially, multi-antenna systems can improve the system performance along with the wideband supported by the THz band. However, multi-antenna systems should be reconsidered due to their size, weight, and price/power (SWaP) constraints. On the other hand, as a state-of-art multi-antenna technology, reconfigurable intelligent surface (RIS) is able to relax SWaP constraints because of its passive component-based structures. However, as similar reflection characteristic throughout wideband is difficult to meet, it is possible to observe beam misalignment. In this work, we first provide an assessment of the use of the THz band for ISLs and quantify the impact of misalignment fading on error performance. Then, in order to compensate for the high path loss associated with high carrier frequencies, and to further improve the signal-to-noise ratio (SNR), we propose the use of RISs mounted on neighboring satellites to enable signal propagation. Based on a mathematical analysis of the problem, we present the error rate expressions for RIS-assisted ISLs with misalignment fading. Also, numerical results show that RIS can leverage the error rate performance and achievable capacity of THz ISLs.INDEX TERMS Inter-satellite links (ISLs), low Earth orbit (LEO) satellite networks, terahertz (THz) band, reconfigurable intelligent surfaces (RISs).

show abstract

Section: B Single Ris-assisted Wireless Channel and Associated Perfor...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Reconfigurable Intelligent Surfaces Empowered THz Communication in LEO Satellite Networks

Tekbıyık¹,

Kurt

Ekti

et al. 2022

IEEE Access

View full text Add to dashboard Cite

show abstract

“…Moreover, Khan et al [34] have proposed a sustainable framework for maximizing the spectral efficiency of RIS-assisted GEO satellite networks by jointly optimizing the transmit power of the satellite and phase shift at RIS. The work in [35] has designed a new architecture to enhance the overall channel gain in RIS-assisted LEO satellite networks by jointly optimising the transmit and receive beamforming. Further, Tekbiyik et al [36] have investigated bit error rate and achievable rate for RISassisted terahertz communication in LEO satellite networks.…”

Section: A Recent Literature On Leo Satellite Networkmentioning

confidence: 99%

When RIS Meets GEO Satellite Communications: A New Sustainable Optimization Framework in 6G

Khan

Lagunas

Mahmood

et al. 2022

2022 IEEE 95th Vehicular Technology Conference: (VTC2022-Spring)

View full text Add to dashboard Cite

Low Earth Orbit (LEO) satellite networks are expected to play a crucial role in providing high-speed internet access and low-latency communication worldwide. However, some challenges can affect the performance of LEO satellite networks. For example, they can face energy and spectral efficiency challenges, such as high power consumption and spectral congestion, due to the increasing number of satellites. Furthermore, mobile ground users tend to operate with low directive antennas, which pose significant challenges in closing the LEO-toground communication link, especially when operating at a highfrequency range. To overcome these challenges, energy-efficient technologies like reconfigurable intelligent surfaces (RIS) and advanced spectrum management techniques like non-orthogonal multiple access (NOMA) can be employed. RIS can improve signal quality and reduce power consumption, while NOMA can enhance spectral efficiency by sharing the same resources among multiple users. This paper proposes an energy-efficient RIS-assisted downlink NOMA communication for LEO satellite networks. The proposed framework simultaneously optimizes the transmit power of ground terminals of the LEO satellite and the passive beamforming of RIS while ensuring the quality of services. Due to the nature of the considered system and optimization variables, the energy efficiency maximization problem is non-convex. In practice, obtaining the optimal solution for such problems is very challenging. Therefore, we adopt alternating optimization methods to handle the joint optimization in two steps. In step 1, for any given phase shift vector, we calculate satellite transmit power towards each ground terminal using the Lagrangian dual method. Then, in step 2, given the transmit power, we design passive beamforming for RIS by solving the semi-definite programming. We also compare our solution with a benchmark framework having a fixed phase shift design and a conventional NOMA framework without involving RIS. Numerical results show that the proposed optimization framework achieves 21.47% and 54.9% higher energy efficiency compared to the benchmark and conventional frameworks.

show abstract

“…Recently, RIS has become a research hot-spot and has drawn much attention. As far as we know, RIS has been widely researched in different novel communication applications, such as secure communication [9]- [11], covert communication [12], satellite communication [13], [14], simultaneous wireless information and power transfer (SWIPT) [15], vehicle networks [16] and spatial modulation [17], [18]. A RIS-aided multiple input multiple output secure network was proposed in [9], where the transmit beamforming and RIS phase shift matrix were jointly optimized by an alternate optimization (AO) algorithm for maximum sum secrecy rate.…”

Section: Introductionmentioning

confidence: 99%

“…A RIS-aided multiple input multiple output secure network was proposed in [9], where the transmit beamforming and RIS phase shift matrix were jointly optimized by an alternate optimization (AO) algorithm for maximum sum secrecy rate. In [13], a RIS-assisted low-earth orbit satellite system was considered. A flexible beamforming can be achieved by controlling phase shifts of RIS in a programable way, so that the time-varying channel can be costeffectively handled.…”

Section: Introductionmentioning

confidence: 99%

Beamforming Design for RIS-Aided AF Relay Networks

Wang¹,

Feng²,

Chen³

et al. 2023

Preprint

View full text Add to dashboard Cite

Since reconfigurable intelligent surface (RIS) is considered to be a passive reflector for rate performance enhancement, a RIS-aided amplify-and-forward (AF) relay network is presented. By jointly optimizing the beamforming matrix at AF relay and the phase shifts matrices at RIS, two schemes are put forward to address a maximizing signal-to-noise ratio (SNR) problem. Firstly, aiming at achieving a high rate, a highperformance alternating optimization (AO) method based on Charnes-Cooper transformation and semidefinite programming (CCT-SDP) is proposed, where the optimization problem is decomposed to three subproblems solved by CCT-SDP and rankone solutions can be recovered by Gaussian randomization. While the optimization variables in CCT-SDP method are matrices, which leads to extremely high complexity. In order to reduce the complexity, a low-complexity AO scheme based on Dinkelbachs transformation and successive convex approximation (DT-SCA) is put forward, where matrices variables are transformed to vector variables and three decoupled subproblems are solved by DT-SCA. Simulation results verify that compared to two benchmarks (i.e. a RIS-assisted AF relay network with random phase and a AF relay network without RIS), the proposed CCT-SDP and DT-SCA schemes can harvest better rate performance. Furthermore, it is revealed that the rate of the low-complexity DT-SCA method is close to that of CCT-SDP method.

show abstract

Intelligent Reflecting Surface-Aided LEO Satellite Communication: Cooperative Passive Beamforming and Distributed Channel Estimation

Cited by 29 publications

References 54 publications

Reconfigurable Intelligent Surfaces Empowered THz Communication in LEO Satellite Networks

Reconfigurable Intelligent Surfaces Empowered THz Communication in LEO Satellite Networks

When RIS Meets GEO Satellite Communications: A New Sustainable Optimization Framework in 6G

Beamforming Design for RIS-Aided AF Relay Networks

Contact Info

Product

Resources

About