Terrestrial Stations Research Articles

Joint Cache Placement, Flight Trajectory, and Transmission Power Optimization for Multi-UAV Assisted Wireless Networks

It is well known that unmanned aerial vehicles (UAVs) can help terrestrial base stations (BSs) offload data traffic from crowded areas to improve coverage and boost throughput. However, the limited backhaul capacity cannot cope with the ever-increasing data demands, for which caching is introduced to relieve the backhaul bottleneck. In this paper, we focus on a multi-UAV assisted wireless network, and target to fully utilize the benefits of wireless caching and UAV mobility for multiuser content delivery. By taking into account the limited storage, our goal is to maximize the minimum throughput among UAV-served users by jointly optimizing cache placement, UAV trajectory, and transmission power in a finite period. The resultant problem is a mixed-integer non-convex optimization problem. To facilitate solving this problem, an alternating iterative algorithm is proposed by adopting the block alternating descent and successive convex approximation methods. Specifically, this problem is split into three subproblems, namely cache placement optimization, trajectory optimization, and power allocation optimization. Then these subproblems are solved alternately in an iterative manner. We show that the proposed algorithm can converge to the set of stationary solutions of this problem. Besides, we further analyze the computational complexity of this algorithm. Numerical results show that great throughput enhancement is achieved by applying our proposed joint design in comparison with other benchmarks without trajectory design and power control.

Improvement of the Global Connectivity Using Integrated Satellite-Airborne-Terrestrial Networks With Resource Optimization

In this paper, we propose a novel wireless scheme that integrates satellite, airborne, and terrestrial networks aiming to support ground users. More specifically, we study the enhancement of the achievable users’ throughput assisted with terrestrial base stations, high-altitude platforms (HAPs), and satellite stations. The goal is to optimize the resource allocations and the HAPs’ locations in order to maximize the users’ throughput. In this context, we formulate and solve an optimization problem in two stages: a short-term stage and a long-term stage. In the short-term stage, we start by proposing an approximated solution and a low complexity solution to solve the associations and power allocations. In the approximated solution, we formulate and solve a binary linear optimization problem to find the best associations and then we use the Taylor expansion approximation to optimally determine the power allocations. In the latter solution, we propose a low complexity approach based on a frequency partitioning technique to solve the associations and power allocations. On the other hand, in the long-term stage, we optimize the locations of the HAPs by proposing an efficient algorithm based on a recursive shrink-and-realign process. Finally, selected numerical results underline the advantages provided by our proposed optimization scheme.

The Meshing of the Sky: Delivering Ubiquitous Connectivity to Ground Internet of Things

Nowadays, unmanned aerial vehicles (UAVs) are being used in several novel applications, especially in the telecommunication domain. However, ensuring UAV communication and networking for the purpose of a specific application is still challenging. Indeed, due to the mobility of a UAV in a vast area, permanent connectivity over the backhaul is very sporadic and might be lost. In this article, we consider an aerial mesh network where each UAV can serve as a flying base station to boost terrestrial base station in case of damaged infrastructure case for example, or/and provide connectivity for uncovered or poorly covered nodes, and behaves as a relay to establish communication between two components owing to a lack of reliable direct communication link between them. We then detail a case study where a UAV-fleet is used to collect data from the ground Internet-of-Things (IoT) devices and forward it to the cloud for further processing passing by a remote gateway. We aim here to build a queueing framework, including network layer, MAC layer, and physical layer, and investigate both uplink and downlink communication links. Next, we derive some closed forms allowing us to predict the network performance in terms of traffic intensity at every UAV of the aerial mesh network, end-to-end (E2E) throughput, and E2E delay of ongoing streams. Next, we conduct extensive simulations to illustrate the benefit of our framework. Results discussion and numerous insights on parameter setting, target quality of service, and design consideration are also drawn.

Validation of the EGSIEM-REPRO GNSS Orbits and Satellite Clock Corrections

In the framework of the European Gravity Service for Improved Emergency Management (EGSIEM) project, consistent sets of state-of-the-art reprocessed Global Navigation Satellite System (GNSS) orbits and satellite clock corrections have been generated. The reprocessing campaign includes data starting in 1994 and follows the Center for Orbit Determination in Europe (CODE) processing strategy, in particular exploiting the extended version of the empirical CODE Orbit Model (ECOM). Satellite orbits are provided for Global Positioning System (GPS) satellites since 1994 and for Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS) since 2002. In addition, a consistent set of GPS satellite clock corrections with 30 s sampling has been generated from 2000 and with 5 s sampling from 2003 onwards. For the first time in a reprocessing scheme, GLONASS satellite clock corrections with 30 s sampling from 2008 and 5 s from 2010 onwards were also generated. The benefit with respect to earlier reprocessing series is demonstrated in terms of polar motion coordinates. GNSS satellite clock corrections are validated in terms of completeness, Allan deviation, and precise point positioning (PPP) using terrestrial stations. In addition, the products herein were validated with Gravity Recovery and Climate Experiment (GRACE) precise orbit determination (POD) and Satellite Laser Ranging (SLR). The dataset is publicly available.

Intelligent learning diversity mechanism for unmanned aerial vehicles applications

The increased use of drones and aerial vehicles in applications poses challenges of airspace safety for aviation organizations. It is important to ensure the safety of the airspace when a significant number of unmanned aerial vehicles are deployed by civilian users. A solution that meets this requirement is important to promote innovation in the commercialization of air space for civilian users deploying unmanned aerial vehicle. The discussion in this paper proposes a mechanism that uses artificial intelligence to address this challenge. The proposed mechanism utilizes a low altitude platform (LAP) and entities in terrestrial wireless networks. The low altitude platform (LAP) observes, develops insights and training data (with human aid). The training data is used to develop learning mechanisms which determine the suitable unmanned aerial vehicles flight parameters in different scenarios. The use of the LAP reduces the burden of communicating with terrestrial base stations. The unmanned aerial vehicles have a reduced altitude between the LAPs in comparison to terrestrial base stations. This reduces the free space path loss and rain-induced attenuation. The performance benefit of the proposed mechanism in comparison to existing solution is examined via MATLAB simulations. Evaluation shows that the proposed mechanism reduces the network access costs by up to 90% on average. The proposed mechanism also increases available flight power and improves airspace safety by 37.3% and up to 53.2% on average respectively.
 Keywords: Autonomous unmanned aerial vehicles, Intelligence Paradigm; Aviation Safety, Capital Constrained Aviation Organizations.

UAV Placement and Power Allocation in Uplink and Downlink Operations of Cellular Network

The wireless communication field is approaching the realization of the integrated unmanned aerial vehicle (UAV) and cellular network for further improved communication performance. In this paper, we consider a cellular network with a UAV-mounted aerial base station (ABS) coexisting with multiple terrestrial base stations (TBSs), where each base station (BS) is serving multiple users. Under the probabilistic channel based environment, we design the three-dimensional (3D) positioning for the ABS and the transmit power allocation for all the nodes in the uplink (UL), downlink (DL), and combined UL and DL operations. Considering the ABS user (AU) and the TBS user (TU) as contending parties, our objective is to maximize the weighted sum of the minimum data rate of the AUs and the minimum data rate of the TUs. The whole optimization problem is non-convex and difficult to be directly solved, for which we employ the block coordinate descent (BCD), the successive convex approximation (SCA), the particle swarm optimization (PSO), and the discrete search algorithm (DSA) methods. Numerical results shed some light on interesting observations regarding the comparison between our solution and benchmark schemes, as well as the optimal 3D position of the ABS in UL, DL, and combined UL and DL operations.

Intelligent Optimization of Availability and Communication Cost in Satellite-UAV Mobile Edge Caching System With Fault-Tolerant Codes

Mobile computing provides storage and computation resources of proximal devices to satisfy the real-time and low-energy communication demands of the Internet of Things (IoT). However, in the areas without terrestrial base station infrastructures, the IoT sensors have trouble implementing reliable and stable connections, which results in the difficulties of data gathering and data caching. In this paper, we consider a space-air-ground integrated mobile edge caching IoT system composed of satellite and unmanned aerial vehicles (UAVs), where LEO satellite broadcasts data, and UAVs collect the data from decentralized ground sensors. Since the sensors’ low-power property leads data loss, fault-tolerant codes are employed for availability protection. We first derive the exact expressions of system availability and communication cost for data repair and collection. Then, to address the problems of the lower availability, we exploit an intelligent optimization to determine the erasure coding parameters. Lastly, we further optimize the system parameters, i.e., communication ranges and unit power costs of UAV and decentralized sensors, to minimize the total communication cost. Simulation results show that, compared to MDS codes and regenerating codes, adaptive minimum storage regenerating (AMSR) codes with optimized parameters can significantly reduce total communication cost and maintain availability of the system.

How Effective Are Radio Messages Aimed at Reducing Teen Births Among Latinas? A Randomized Controlled Trial

This study uses a randomized controlled trial (RCT) to evaluate the effectiveness of a mass media campaign designed to reduce pregnancy among Latina teenagers. We aired public service announcements (PSAs) on terrestrial radio stations in California. The sample includes 28 radio stations and over 11,000 births to Latina teenagers in 2016. The PSA, narrated by a young Latina, stressed the opportunity costs to teenage mothers of having a baby, e.g., missed opportunities for fun, socializing with friends, or attending school. Although this message expresses themes articulated by Latina teens and young mothers whom we interviewed, geocoded birth records suggest the PSAs had little effect. With data on all births in the state obtained from the California Department of Public Health, we can reject the hypothesis that the PSAs reduced births to Latina teenagers by 9% or more based on the 90% confidence interval of the estimated average treatment effect. In addition to shedding light on this particular radio campaign, this study provides a template for the design and analysis of mass media campaigns to improve other public health outcomes.

The feasibility of using TRMM satellite data for missing terrestrial stations in Iraq for mapping the rainfall contour lines

Rainfall data are considered an important and critical element of many environmental and hydrological studies such as drought, desertification, climate change and other strategic studies. These studies are mainly based on the rainfall data archive for previous years. During the last two decades, a large number of meteorological stations have been destroyed as a result of wars and internal conflicts, reducing the stations to 16 after the number was more than 30 stations, resulting in a significant lack of meteorological data archive. In addition to the spatial distribution of these stations does not adequately cover Iraq. The research aim to evaluate the feasibility of the TRMM satellite data (3B42 V7 product) to complete the rainfall data archive of the missing terrestrial stations. Several rainfall contour maps of the season 2017-2018 were drawn from data of 16 terrestrial stations, 16 and 30 stations derived from TRMM satellite data, and a hybrid map derived from the TRMM satellite data and available terrestrial stations, afterwards there were compared with the general rainfall contour map. The correlation was made between the satellite data and terrestrial stations data, and the results showed a positive correlation with a strong correlation coefficient reach to 0.91. The results showed that TRMM data could be used as a good alternative to terrestrial station data for its accuracy, wide coverage and ease of availability.

Geological model and development of the Cenozoic Wiang Pa Pao Basin, Chiang Rai Province, Northern Thailand, based on gravity data modelling and surface structural interpretation

3-D Inverse gravity modelling, constrained by surface geological data across the Neogene Wiang Pa Pao Basin (WPB), Northern Thailand, provides new subsurface models of the basin geometry and its structural development. The intermontaine WPB is seismically active and exhibits many geothermal sites; both are indicative of active fault zones. Six hundred thirty-six terrestrial gravity stations with ~500 m spacing were acquired. The residual Complete Bouguer Anomaly map (CBA) reveals an N–S elongate basin characterized by gravity lows bounded by gravity highs on the eastern margin of the basin (metasedimentary basement), and moderate gravity anomalies on the western margin (granitic basement). Structural edge detection revealed N–S trending faults along the eastern and western margins linked by NE–SW and NW–SE trending lineaments. The 3-D gravity model indicates an asymmetric graben; with a maximum depocenter depth of ~1300 m. Surface structure and seismicity confirm the gravity interpretation that the WPB is a dextral transtensional basin characterized by WSW–ENE trending R'-shears and NNE–SSW R-shears distributed in duplex-like geometries along the N–S trending principal displacement zone. The WPB displays unusually well-developed R’-shears, where Palaeozoic metasedimentary rocks in the basement and Cenozoic basin sediments are present, these faults disappear to the south, where the main N–S fault resides entirely within the granite. The WPB is associated with Cenozoic multi-phase rifting: in the Late Oligocene–Miocene, major rift basins formed under W–E extension, strongly influenced by WSW–ENE to NE–SW and NW–SE pre-existing trends. In the Latest Miocene–Recent, the younger basins, including the WPB, underwent dextral strike-slip along new and existing N–S dextral fault trends.

The Impact of Atmospheric Correction on Brazilian Earth Tide Models

Terrestrial gravity stations have been in operation for several years throughout Brazil. Minimizing geophysical effects on gravimetric observations is a major challenge in the generation of solid Earth tide models. The objective of this work was to conduct an analysis of barometric information and the impact of four barometric correction methodologies on gravimetric data for two stations located in the state of Sao Paulo: Presidente Prudente and Cananeia. The proposed approach involves three steps: (1) the processing of gravimetric data in order to obtain preliminary Earth tide models, (2) the application of four methodologies for atmospheric loading correction, and (3) the analysis of the impact on each wave constituent. The results show that the observed Earth tide models have a standard deviation (SD) of 0.001 and 0.01° for gravimetric factors and phases, respectively. The impact on the application of different methodologies for minimizing the air mass overload was less than 1.5 nm/s2 for the observation residuals. In addition, for both stations, the residuals in Earth tide constituents showed greater sensitivity to different atmospheric corrections for P1 and S2, which is related to the higher intensity of diurnal and semidiurnal solar constituents.

Orbit Angular Momentum MIMO with Mode Selection for UAV-Assisted A2G Networks.

As an emerging solution for line-of-sight (LOS) wireless communications, in air-to-ground (A2G) channels, the unmanned aerial vehicle (UAV), and allowing the dynamic and flexible network deployments enables the supplement or/and replacement of the terrestrial base stations (BSs). However, in conventional multiple-input-multiple-output (MIMO) systems, high-speed communications are significantly limited by channel crosstalks and spectrum scarcities. An orbit angular momentum (OAM) wireless network, allowing co-existence of multiple physical channels within the same frequency band, offers new degrees of freedom to address this dilemma. In this paper, we investigate the UAV-based A2G radio vortex wireless networks and study its channel model. Then we propose a branch and bound search-based mode selection (BBS-MS) scheme, which uses the spatial distribution characteristics of vortex beams to optimize the spectrum efficiency (SE). Theoretical derivations and numerical results demonstrate that our developed BBS-MS scheme can obtain the optimal performance, which outperforms conventional OAM-based MIMO systems. Also, it possesses a lower complexity compared with exhaustive searches.

HCP: Heterogeneous Computing Platform for Federated Learning Based Collaborative Content Caching Towards 6G Networks

A heterogeneous computing architecture is essential to facilitate intelligent network traffic control for a joint computation, communication, and collaborative caching optimization in 6G networks to provide stringent Quality of Experience (QoE) guarantees. In this paper, we consider a 6G integrated aerial-terrestrial network model where Unmanned Aerial Vehicles (UAVs) and terrestrial Remote Radio Heads (RRHs) jointly serve as heterogeneous Base Stations (hgNBs) of a Cloud Radio Access Network (HCRAN) serving different mobile user (UE) types. We propose a distributed heterogeneous computing platform (HCP) across the UAVs and terrestrial Base Stations (BSs) by utilizing their caching and cooperative communication capabilities. In order to preserve the privacy of the content of the UEs, we propose a 2-stage federated learning algorithm among the UEs, UAVs/BSs, and HCP to collaboratively predict the content caching placement by jointly considering traffic distribution, UE mobility and localized content popularity. An asynchronous weight updating method is adopted to avoid redundant learning transfer in the federated learning. Once the global model is learnt by the HCP, it transfers the learned model to the UEs to facilitate the much desired edge intelligence in the considered 6G tiny cell. The effectiveness of the proposal is evaluated by extensive numerical analysis.

Secure Energy Efficiency Maximization in Cognitive Satellite-Terrestrial Networks

This article investigates the secure energy efficiency (EE) optimization problem in a cognitive satellite-terrestrial network with a capable eavesdropper. The objective is to maximize the secure EE for the primary satellite network while satisfying the allowable signal-to-interference-plus-noise ratio requirements of the secondary and primary users along within the transmit power limitation of both satellite and the terrestrial base station. Owing to the nonconvexity and intractability of the original optimization problem, a beamforming scheme and associated transformation algorithms are proposed by jointly applying the Taylor approximation, fraction programming, and alternating search to cope with the implementation difficulty. The key is to convert the original optimization problem into a simple convex framework and obtain the optimal solution step by step. Finally, numerical simulations are given to verify the feasibility and practicability of the proposed optimization algorithms.

Co-operative RF-UWOC link performance over hyperbolic tangent log-normal distribution channel with pointing errors

In this paper, we have proposed an analytic model and determined the outage probability and average bit error rate (BER) performance of a co-operative radio frequency − underwater wireless optical communication (RF−UWOC) system. In recent years, UWOC has attracted attention as a useful enabler of underwater activities such as climate and ocean monitoring, surveillance, ocean exploration, underwater wireless optical sensor networks (UWOSN) and internet of underwater things (IoUT) because of its high speed, ease of deployability and wide bandwidth availability which is free of licensing fees. The proposed co-operative RF–UWOC system is designed to establish a connection between an underwater vehicle inside the ocean to a terrestrial ground station using decode−forward and amplify−forward relays. The RF link between the terrestrial ground station to relay is modeled as a Rayleigh distributed channel. The UWOC link between the relay to the underwater vehicle is modeled as being perturbed by the hyperbolic tangent log-normal (HTLN) distribution. To the best of our knowledge, it is for the first time that the perturbations due to weak oceanic turbulence have been modeled using HTLN distribution. This distribution is a member of the class of log-normal distributions derived from hyperbolic tangent distribution. Novel closed-form expressions have been derived for the outage probability and average BER for various modulation techniques that can be employed in this system. The analytical results are evaluated and validated with Monte-Carlo simulations in the presence and absence of pointing errors. The results show that the impact of pointing errors in the RF-UWOC system is to impose an additional SNR penalty of at-least 10 dB to obtain a BER of 10−6 when compared with the system operating without pointing errors.

Assessing swells in La Réunion Island from terrestrial seismic observations, oceanographic records and offshore wave models

SUMMARY La Réunion Island in the southwest Indian Ocean is seasonally affected by austral swells among which some extreme events may have strong impacts on coastal infrastructures. The very limited number of sensors available on and around the island and in the whole SW Indian Ocean impedes any direct monitoring of the swell activity. In this study, we analyse direct observations of the ocean swell by combining terrestrial measurements of the microseismic noise with in situ oceanographic observations issued from two pressure gauges and an Acoustic Doppler Current Profiler (ADCP), together with swell numerical modelling. The reliability of the terrestrial seismic station to characterize the ocean activity in both the primary and secondary microseisms peaks (PM and SM, respectively), and also in the long period secondary microseismic peak (LPSM) for the case of La Réunion Island is presented and discussed here. By computing the hourly RMS of the PM and LP(SM) amplitudes, we establish a transfer function between the PM and (LP)SM amplitude and the maximum wave height, which appears to be valid for any PM and LPSM amplitudes >0.15 μm and >1.0 μm, respectively. The correlation coefficient between the PM amplitude and the wave height is >0.92. It suggests that the PM amplitude can be used as a robust proxy for the swell height and may help calibrating the wave heights from other independent observable. For some swell events, we observe LPSM that correlate well (>0.91) with the local wave height suggesting a generation by coastal swell reflection. From polarization and spectral analyses, directions and periods of swells are also well retrieved from seismic data. Finally, continuous measure of the SM amplitude shows that it can be used as precursor information for distant swells that may hit La Réunion Island a few days after their generation in the southern Indian Ocean.

Propagation curves and coverage areas of digital terrestrial television base stations in the tropical zone

This study investigated the propagation curves and coverage areas of some Digital Terrestrial Television Broadcast Stations (DTTBS) over four climatic zones of coastal (Lagos), tropical rain forest (Akure), Sudan Savannah (Kaduna) and Sahel Savannah (Katsina) cities of Nigeria. Measurement of the Received Signal Strength (RSS) was carried out along different routes with each of the DTTBS as reference points. Measurements of RSS were carried out using two specified antenna receiver heights of 1.5 and 3.0 m for each data point. The GPS receiver was used to measure the geographic coordinates, elevation and Line of Sight (LOS) of data points along the routes in a drive test. Measurement was done during dry and wet season months at 1 km interval up to about 20 km in each of the selected routes covering a period of three years (2016–2018). Mean data were obtained and used to generate the propagation curves and the coverage areas over the study locations. Generally, results revealed that RSS undulates with LOS separation distance from DTTBS in all routes irrespective of seasons and routes. Particularly, RSS reduces to about half of its base station's value at about 8 and 12 km LOS from the DTTBS in Akure and Katsina respectively while, it reduces to about half of its base station's value at about 6 km from the DTTBS in Lagos and Kaduna. The implication of this is that higher coverage areas were obtained in suburban compared to urban cities. In addition, radial maps showing coverage areas and their grades useful for networking purposes were generated. Television White Spaces (TVWS) for secondary users were also proposed. For networking purposes and spatial arrangements of DTTBS that will ensure optimum coverage over the study locations, DTTBS can be sited at 8.0 and 13.5 km (LOS) interval from each other in urban and sub urban cities respectively. The overall results will enable system engineers to know the appropriate distance(s) and locations to site additional DTTBS for networking purposes and prepare power budget for optimum coverage area and good quality of services for terrestrial digital channels.

Modelling and performance analysis of FFR‐aided two layer aerial‐terrestrial network

Exploiting aerial base stations (A-BSs) in conjunction with terrestrial base stations (T-BSs) is an effective solution to provide uniform coverage everywhere, and anytime. However, the addition of A-BSs in an existing terrestrial network would intensify the inter-cell interference to user equipment, leads to a degraded signal-to-interference-ratio. There is a need to exploit inter-cell-interference-coordination (ICIC) scheme in such aerial-terrestrial network. Further, the aerial-terrestrial network requires a multi-layer environment to be modelled in many scenarios. In this study, the authors propose fractional frequency reuse (FFR) scheme as an ICIC scheme for two-layer aerial-terrestrial network. The analytical expression of coverage probability and average rate are derived for the proposed scheme, and compare it with the scheme, where no ICIC is considered in aerial-terrestrial network, and conventional scheme, where only T-BSs are considered. It is shown that the proposed scheme outperforms the no ICIC scheme and conventional scheme. Simulation results are shown to support their analytical results.

Joint Access and Backhaul Resource Management in Satellite-Drone Networks: A Competitive Market Approach

In this paper, the problem of user association and resource allocation is studied for an integrated satellite-drone network (ISDN). In the considered model, drone base stations (DBSs) provide downlink connectivity, supplementally, to ground users whose demand cannot be satisfied by terrestrial small cell base stations (SBSs). Meanwhile, a satellite system and a set of terrestrial macrocell base stations (MBSs) are used to provide resources for backhaul connectivity for both DBSs and SBSs. For this scenario, one must jointly consider resource management over satellite-DBS/SBS backhaul links, MBS-DBS/SBS terrestrial backhaul links, and DBS/SBS-user radio access links as well as user association with DBSs and SBSs. This joint user association and resource allocation problem is modeled using a competitive market setting in which the transmission data is considered as a good that is being exchanged between users, DBSs, and SBSs that act as "buyers", and DBSs, SBSs, MBSs, and the satellite that act as "sellers". In this market, the quality-of-service (QoS) is used to capture the quality of the data transmission (defined as good), while the energy consumption the buyers use for data transmission is the cost of exchanging a good. According to the quality of goods, sellers in the market propose quotations to the buyers to sell their goods, while the buyers purchase the goods based on the quotation. The buyers profit from the difference between the earned QoS and the charged price, while the sellers profit from the difference between earned price and the energy spent for data transmission. The buyers and sellers in the market seek to reach a Walrasian equilibrium, at which all the goods are sold, and each of the devices' profit is maximized. A heavy ball based iterative algorithm is proposed to compute the Walrasian equilibrium of the formulated market.

Analysis of heterogeneous satellite networks with multi‐user detectors

SummaryIn this work, a heterogeneous network, where both terrestrial‐ and multiple spot beam‐based geosynchronous satellite networks use the same sub‐channel, is investigated. Moreover, the satellite uses same sub‐channel to serve users across all spot beams. Apart from inter spot beam interference, satellite users also receive strong interfering signal from the terrestrial base station. The satellite receivers manage the inter system interference (ie, interference from terrestrial network) while the inter spot beam interference is mitigated through precoding at the gateway. To be specific, the following interference‐aware detectors are used to mitigate the inter system interference: successive interference canceller (SIC) and joint decoder (JD). The proposed decoders are shown to achieve better data rate and bit error rate (BER) than the interference ignorant decoder at moderate to strong interference levels. Although JD and SIC achieve same sum rate at moderate and strong interference levels, JD is shown to allow the terrestrial user achieve higher data rate than SIC.