Satellite-terrestrial Cooperative Network Research Articles

Joint computing and communication resource allocation for edge computing towards Huge LEO networks

The satellite-terrestrial cooperative network is considered an emerging network architecture, which can adapt to various services and applications in the future communication network. In recent years, the combination of satellite communication and Mobile Edge Computing (MEC) has become an emerging research hotspot. Satellite edge computing can provide users with full coverage on-orbit computing services by deploying MEC servers on satellites. This paper studies the task offloading of multi-user and multi-edge computing satellites and proposes a novel algorithm that joint task offloading and communication computing resource optimization (JTO-CCRO). The JTO-CCRO is decoupled into task offloading and resource allocation sub-problems. After the mutual iteration of the two sub-problems, the system utility function can be further reduced. For the task offloading sub-problem, it is first confirmed that the offloading problem is a game problem. The offloading strategy can be obtained from the Nash equilibrium solution. We confirm resource optimization sub-problem is a convex optimization problem that can be solved by the Lagrange multiplier method. Simulation shows that the JTO-CCRO algorithm can converge quickly and effectively reduce the system utility function.

Performance on Multiple Pilot-Based Grouping Methods in Satellite-Terrestrial Cooperative Wireless Networks

The grouping method is an efficient transmitting strategy in a spatial diversity system. In this paper, relay-based grouping methods in satellite terrestrial cooperative wireless networks are proposed. The proposed methods focus on finding out the best two signals received from relay stations in a user’s neighborhood and use the advantage of space diversity to overcome the effect of channel fading. A grouping method, called the pilot-based grouping method was proposed in our previous work. In order to improve the grouping success rate and the channel capacity, a modified grouping method is proposed. In addition, for a single relay the modified grouping method can achieve better results than the pilot-based grouping method. In the end, several analysis strategies of the grouping method for multimedia broadcast and multicast services in satellite terrestrial cooperative networks are proposed. The simulation results show the performance improvement and the system evaluation for different quality of services in the demanded relay-based cooperative networks. The proposed modified grouping methods can be widespread in any relay-based cooperative networks.

Performance Analysis of Hybrid Satellite-Terrestrial Cooperative Networks With Relay Selection

This paper conducts the performance analysis of a hybrid satellite-terrestrial cooperative network (HSTCN) having multi-antenna terrestrial relays. By assuming the availability of the direct link between the satellite and the destination, and considering the effects of hardware impairments (HIs) and interference on both relays and destination, we first propose a relay selection scheme to enhance the quality of the downlink transmission of the considered HSTCN. Then, we derive analytical expressions for the outage probability (OP) and throughput of the system using the proposed relay selection scheme. Furthermore, the asymptotic behavior of the HSTCN at high signal-to-noise-ratio (SNR) is also investigated to reveal the diversity order and array gain of the system. Finally, computer simulation results are provided to show the effectiveness of the relay selection scheme. The analysis shows that the system performance is significantly affected by the HIs and interference.

On the Performance of Hybrid Satellite-Terrestrial Cooperative Networks with Different Combining Schemes

On the Performance of Hybrid Satellite-Terrestrial Cooperative Networks with Different Combining Schemes

Average symbol error rate for integrated satellite-terrestrial cooperative transmission with interference

As an indispensable method of constructing ubiquitous communication network, satellite communication technology has received significant attention in both industrial and academic areas recently. In this paper we investigate the performance of an integrated satellite-terrestrial cooperative network in the presence of co-channel interference, which consists of a satellite source having a single antenna, a terrestrial relay equipped with multiple antennas to assist satellite signal transmission, and a single-antenna user corrupted by multiple co-channel interference. On the assumption that the user receives the signals from direct link and relaying link with decode-and-forward protocol, the output signal-to-interference-plus-noise ratio of the user with the maximal ratio combining scheme is firstly obtained. Then, according to the Meijer-G function, we derive the moment generating function of the destination and the relay, where the satellite links are assumed to experience Shadowing-Rician fading while the terrestrial links undergo Rayleigh fading, and the analytical average symbol error rate expression for the considered system is obtained. Finally, the simulation results demonstrate the effectiveness of the theoretical analysis and reveal theinfluences of antenna number, interference number, and modulation schemes on the system performance. Therefore, our work provides useful guidelines for the engineers in designing the integrated satellite-terrestrial cooperative networks for future satellite mobile communication.

Performance evaluation for underlay cognitive satellite-terrestrial cooperative networks

With the continuously increasing demand for broadband applications and services, underlay cognitive satellite-terrestrial networks, enabling to accommodate better wireless services within the scarce spectrum, have attracted tremendous attentions recently. In this network, satellite communications are allowed to operate in the frequency bands allocated to terrestrial networks under the interference constraints imposed by terrestrial network, which may lead to a performance degradation of the satellite network. To guarantee the performance of the primary terrestrial network as well as the secondary satellite network, we introduce the cooperation into cognitive satellite-terrestrial networks and investigate the performance of the new framework, i.e., cognitive satellite-terrestrial cooperative network (CSTCN). Specifically, by restricting the transmit power of satellite communications with interference power constraints imposed by terrestrial communications, we firstly obtain the received signal-to-interference-plus-noise ratio (SINR) of the considered network. Moreover, by employing themoment generating function (MGF) approach, closed-form expressions for symbol error rate (SER) and outage probability (OP) of the considered cognitive network are derived. The analytical results obtained in this paper can provide theoretical support for optimizing the performance of satellite-terrestrial networks.

Performance Analysis of Amplify-and-Forward Hybrid Satellite-Terrestrial Networks With Cochannel Interference

In this paper, we consider an amplify-and-forward hybrid satellite-terrestrial co-operative network in the presence of cochannel interference (CCI). More specifically, we assume that both the satellite-destination and the satellite-relay links undergo the shadowed-Rician fading and the relay-destination link follows the Nakagami- m fading. By applying the amplify-and-forward (AF) protocol at the terrestrial relay, both the relay and the destination are corrupted by cochannel interference from the terrestrial network. Based on this setup, we first derive the approximate statistical distributions signal-to-interference-plus noise ratio (SINR) and then analyze the system performance. To obtain more insights into the system performance, some asymptotical bit-error rate (BER) results are provided. Moreover, we extend our analysis to a multiple-relay network and analyze the asymptotic performance. Finally, some numerical results are provided to verify our analysis.

Beamforming schemes for hybrid satellite-terrestrial cooperative networks

This paper studies the relay beamforming (BF) schemes for a hybrid satellite-terrestrial cooperative network (HSTCN), where a cognitive base station (CBS) with multi-antenna is used not only as a relay to assist the signal transmission between a satellite and a terrestrial primary user (PU), but also as a base station to transmit signals to multiple secondary users (SUs). Our goal is to minimize the total transmit power, while guaranteeing the quality-of-service (QoS) of all users. Specifically, by supposing that the channel state information (CSI) of both the uplink and downlink are perfectly known at the relay, we first present a non-robust BF method. Then, note that downlink CSI often contains errors, we propose two approaches based on worst-case criterion, namely, lowest bound robust BF scheme (LB-RBF) and tight bound robust BF scheme (TB-RBF), each of which relaxes the constraints and converts the complex problem to a convex optimization problem so that it can be solved by using standard numerical optimization packages. Finally, computer simulations are provided to demonstrate the performance of the three BF algorithms.

Symbol Error Analysis of Hybrid Satellite–Terrestrial Cooperative Networks With Cochannel Interference

This letter investigates the effect of cochannel interference (CCI) on a hybrid satellite-terrestrial cooperative relay network (HSTCN), where both the satellite-destination and satellite-relay links undergo the shadowed Rician fading, whereas the relay-destination link follows the Rayleigh fading. By assuming that decode-and-forward (DF) protocol is adopted at the terrestrial relay, and the destination is corrupted by multiple CCI, we first derive the analytical expression for the moment generating function (MGF) of the output signal-to-interference-plus-noise ratio (SINR). Then, based on the Meijer-G functions, we present an approximated yet accurate method to evaluate the average symbol error rate (ASER) of the cooperative network. Moreover, the asymptotic ASER at high signal-to-noise ratio (SNR) with respect to diversity order and array gain are also given to gain further insights. Finally, numerical results are provided to demonstrate the validity of the performance analysis as well as the impact of CCI on the HSTCN.

Performance Analysis of AF Based Hybrid Satellite-Terrestrial Cooperative Network over Generalized Fading Channels

In this paper, the transmission of signals in a hybrid satellite-terrestrial link is considered. In particular, we address the problem of amplify-and-forward (AF) relaying in a hybrid satellite-terrestrial link, where a masked destination node receives the relayed transmission from a terrestrial link and direct transmission from the satellite link. The satellite-relay and satellite-destination links are assumed to follow the Shadowed-Rician fading; and the channel of the terrestrial link between the relay and destination is assumed to follow the Nakagami-m fading. The average symbol error rate of the considered AF cooperative scheme for M-ary phase shift keying constellation is derived for these generalized fading channels. Moreover, analytical diversity order of the hybrid system is also obtained.

Exact Symbol Error Probability of Hybrid/Integrated Satellite-Terrestrial Cooperative Network

In this paper, we study the Symbol Error Probability (SEP) performance of a hybrid/integrated satellite-terrestrial cooperative network. In particular, we focus on the case of mobile relays that forward the satellite signal to a masked mobile destination node. The Selective Decode-and-Forward (SDF) transmission scheme is implemented and only the relay nodes which can successfully decode the satellite message are selected to retransmit the signal. The destination node exploits the spatial diversity advantages by implementing a typical Maximum Ratio Combining (MRC) technique. The closed-form expressions for the exact average SEP of the arbitrary M-ary phase shift keying and M-ary quadrature amplitude modulation signaling with MRC diversity reception over independent but not necessarily identically distributed fading channels are derived using a Moment Generating Function (MGF) approach. These closed-form expressions are represented in terms of a finite sum of Lauricella hypergeometric functions. The analytical expressions show excellent agreement with the simulation results. Numerical results show that for a system using QPSK under the frequent heavy shadowed fading condition, the diversity gain of approximately 7 dB can be obtained at the SEP of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> with respect to the direct transmission, when only one relay is used. It increases to around 12 dB in the case of 3 relays.

A Hybrid Satellite-Terrestrial Cooperative Network over Non Identically Distributed Fading Channels

This paper investigates a hybrid satellite-terrestrial cooperative relaying communications network (HSTCN) under independent and non-identical shadowed Rician and Nakagami-m fading channels. It evaluates the performance of such a network using amplify-and-forward (AF) cooperative relaying protocol. The maximal ratio combining (MRC) technique is used at the destination to combine the signals received from the source and cooperating relay nodes. An analytical approach is derived to evaluate the performance of the system in terms of outage probability and symbol error rate (SER). The closed form expressions for the probability density function (PDF), cumulative distribution function (CDF) and moment generating function (MGF) of the end-to-end signal to noise ratio (SNR) are also derived. The derived analytical expressions are applied to the general operating conditions with the help of satellite channel data available from the literature. The analytical results are compared with Monte Carlo simulations. The results show the improvement in the performance of the HSTCN under challenging fading conditions with the help of fixed multiple terrestrial relay nodes.