Kang An

Performance Analysis of Multi-Antenna Hybrid Satellite-Terrestrial Relay Networks in the Presence of Interference

The integration of cooperative transmission into satellite networks is regarded as an effective strategy to increase the energy efficiency as well as the coverage of satellite communications. This paper investigates the performance of an amplify-and-forward (AF) hybrid satellite-terrestrial relay network (HSTRN), where the links of the two hops undergo Shadowed-Rician and Rayleigh fading distributions, respectively. By assuming that a single antenna relay is used to assist the signal transmission between the multi-antenna satellite and multi-antenna mobile terminal, and multiple interferers corrupt both the relay and destination, we first obtain the equivalent end-to-end signal-to-interference-plus-noise ratio (SINR) of the system. Then, an approximate yet very accurate closed-form expression for the ergodic capacity of the HSTRN is derived. The analytical lower bound expressions are also obtained to efficiently evaluate the outage probability (OP) and average symbol error rate (ASER) of the system. Furthermore, the asymptotic OP and ASER expressions are developed at high signal-to-noise ratio (SNR) to reveal the achievable diversity order and array gain of the considered HSTRN. Finally, simulation results are provided to validate of the analytical results, and show the impact of various parameters on the system performance.

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.

On the Performance of Multiuser Hybrid Satellite-Terrestrial Relay Networks With Opportunistic Scheduling

In this letter, we investigate the performance of a multiuser amplify-and-forward (AF) hybrid satellite-terrestrial relay network (HSTRN) with opportunistic scheduling. Specifically, we derive the analytical approximated expression as well as the tight upper and lower bound for the ergodic capacity of the system. Moreover, we present the analytical and asymptotic formulas of the outage probability (OP), which provide practical insights on the diversity order and code gain. Finally, simulation results are given to validate the theoretical results, and show the impact of key parameters such as user numbers and shadowing severity on the performance of the considered network.

Outage Performance of Cognitive Hybrid Satellite–Terrestrial Networks With Interference Constraint

This paper investigates the performance of a cognitive hybrid satellite-terrestrial network, where the primary satellite communication network and the secondary terrestrial mobile network coexist, provided that the interference temperature constraint is satisfied. By using the Meijer-G functions, the exact closed-form expression of the outage probability (OP) for the secondary network is first derived. Then, the asymptotic result in a high-signal-to-noise-ratio (SNR) regime is presented to reveal the diversity order and coding gain of the considered system. Finally, computer simulations are carried out to confirm the theoretical results and reveal that a more loose interference constraint or heavier shadowing severity of a satellite interference link leads to a reduced OP, whereas stronger satellite interference power poses a detrimental effect on the outage performance.

Secure Transmission in Cognitive Satellite Terrestrial Networks

This paper investigates the physical layer security of a satellite network, whose downlink spectral resource is shared with a terrestrial cellular network. We propose to employ a multi-antenna base station (BS) as a source of green interference to enhance secure transmission in the satellite network. By taking the mutual interference between these two networks into account, we first formulate a constrained optimization problem to maximize the instantaneous rate of the terrestrial user while satisfying the interference probability constraint of the satellite user. Then, with the assumption that imperfect channel state information (CSI) and statistical CSI of the link between the BS and satellite user are available at the BS, we present two beamforming (BF) schemes, namely, hybrid zero-forcing and partial zero-forcing to solve the optimization problem and obtain the BF weight vectors in a closed form. Moreover, we analyze the secrecy performance of primary satellite network by considering two practical scenarios, namely: Scenario I, the eavesdroppers CSI is unknown at the satellite and Scenario II, the eavesdroppers CSI is known at the satellite. Specifically, we derive the analytical expressions for the secrecy outage probability for Scenario I and the average secrecy rate for Scenario II. Finally, numerical results are provided to confirm the superiority of the proposed BF schemes and the validity of the performance analysis, as well as demonstrate the impacts of various parameters on the secrecy performance of the satellite network.

Outage Analysis of Multi-Antenna Cognitive Hybrid Satellite-Terrestrial Relay Networks With Beamforming

This letter investigates the outage performance of a multi-antenna cognitive decode-and-forward (DF) hybrid satellite-terrestrial relay network (HSTRN) with beamforming (BF), where the secondary source and relay can coexist with the primary user (PU) as long as their interference imposed to PU is below a predefined threshold. Specifically, the novel closed-form expression for the outage probability (OP) of the cognitive network are derived. Furthermore, the asymptotic OP expression at high SNR is developed to reveal the diversity order and code gain of the considered network. Finally, simulation results are provided to demonstrate the validity of the theoretical results, and show the effect of antenna number and interfering satellite link on the performance of the cognitive network.

EFFECT OF BEAMFORMING ON MULTI-ANTENNA TWO HOP ASYMMETRIC FADING CHANNELS WITH FIXED GAIN RELAYS

In this paper, we investigate the impact of beamforming (BF) on a multi-antenna two hop amplify-and-forward (AF) flxed gain relay network over Rician-Rayleigh and Rayleigh-Rician asymmetric fading channels, respectively. The network consists of a relay with single antenna used to assist the signal transmission from the source to the destination, both of which are equipped with multiple antennas. By using the channel state information (CSI), the maximal output signal-to-noise ratio (SNR) with optimal beamforming is flrst obtained. Then, the novel analytical expressions for the outage probability (OP), probability density function (PDF) and generalized moments of the maximal output SNR are derived. Moreover, the theoretical formulas of the Ergodic capacity and average symbol error rates (ASERs) with various modulation formats are also developed. To gain further insights, the asymptotic ASERs at high SNR are presented to reveal the diversity order and array gain of the multi-antenna relay network. Finally, computer simulations conflrm the validity of the theoretical analysis and indicate the in∞uence of antenna number and Rican factor on the system performance.

Optimal Power Control for Real-Time Applications in Cognitive Satellite Terrestrial Networks

Cognitive satellite terrestrial networks have received considerable attention as a promising candidate to address the spectrum scarcity problem in future wireless communications. When satellite networks act as cognitive users in the networks, power control is a significant research challenge in the uplink case, especially for real-time applications. We propose two optimal power control schemes for maximizing the delay-limited capacity and outage capacity, respectively, which are useful performance indicators for real-time applications. From the long-term and short-term aspects, average and peak power constraints are adopted, respectively, at the satellite user to limit the harmful interference caused to the terrestrial base station. Extensive numerical results demonstrate the impact of interference constraints and channel condition parameters on the performance limits of satellite users.

Secure transmission in multi-antenna hybrid satellite-terrestrial relay networks in the presence of eavesdropper

This paper investigates the secrecy capacity of a multi-antenna amplify-and-forward (AF) hybrid satellite-terrestrial relay netwrok (HSTRN), which consists of a satellite, a relay, a terrestrial destination and a terrestrial eavesdropper. Specifically, by employing a two-stage beamforming (BF) scheme, where the relay first adopts the maximal ratio combining (MRC) to receive the signal from satellite and then performs zero-forcing (ZF) to completely null the eavesdroppers signal, the achievable secrecy capacity of the considered hybrid network is derived in closed-from. Eventually, simulation results are provided to demonstrate the superiority of the proposed BF scheme as well as the validity of the theoretical results, and show the effect of various channel parameters on the system performance.

Effect of feedback delay on dual-hop fixed gain relay networks over mixed fading channels

In this paper, we investigate the effect of feedback delay on a dual-hop fixed gain amplify-and-forward relay network over Rayleigh-Rician mixed fading channels, where the source and destination are all equipped with multiple antennas, while the relay has a single antenna. By using the model of beamforming with feedback delay, the equivalent output signal-to-noise ratio SNR of the amplify-and-forward relay network is first obtained. Then, based on the infinite series representation, the analytical expressions for the outage probability and the probability density function of the output SNR are derived. Furthermore, the analytical formulas of the ergodic capacity and the average symbol error rate formulas with various modulation formats are developed. To reveal the diversity order and array gain of the multi-antenna relay network, the asymptotic average symbol error rates at high SNR are also presented. Finally, computer simulations are provided to validate the theoretical analysis and to indicate the effect of antenna number, feedback delay and channel parameters on the system performance. Copyright