| 1. |
- Abu-Shaban, Zohair, et al.
(author)
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Reduced complexity satellite broadcast receiver with interference mitigation in correlated noise
- 2018
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In: International Journal of Satellite Communications And Networking. - : Edward Elgar Publishing. - 1542-0973 .- 1542-0981. ; 36:5, s. 402-415
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Journal article (peer-reviewed)abstract
- The recent commercial trends towards using smaller dish antennas for satellite receivers and the growing density of broadcasting satellites necessitate the application of robust adjacent satellite interference cancellation schemes. This orbital density growth along with the wider beamwidth of a smaller dish have imposed an overloaded scenario at the satellite receiver, where the number of transmitting satellites exceeds the number of receiving elements at the dish antenna. To ensure successful operation in this practical scenario, we propose a satellite receiver that enhances signal detection from the desired satellite by mitigating the interference from neighboring satellites. Towards this objective, we propose an enhanced list-based group-wise search detection (E-LGSD) receiver under the assumption of spatially correlated additive noise. To further enhance detection performance, the proposed satellite receiver utilizes a newly designed whitening filter to remove the spatial correlation among the noise parameters, while also applying a preprocessor that maximizes the signal-to-interference-plus-noise ratio. We exploit the structure of this filter and propose a reduced complexity LGSD (RC-LGSD) receiver. Extensive simulations under practical scenarios show that the proposed receiver enhances the performance of satellite broadcast systems in the presence of adjacent satellite interference compared with existing methods. Also, under pointing error, RC-LGSD exhibits similar behavior to that of the optimum receiver
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| 2. |
- Browne Mwakyanjala, Moses, et al.
(author)
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Concurrent development and verification of an all‐software baseband for satellite ground operations
- 2020
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In: International Journal of Satellite Communications And Networking. - : John Wiley & Sons. - 1542-0973 .- 1542-0981. ; 38:2, s. 209-227
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Journal article (peer-reviewed)abstract
- Communication systems are adopting all‐software architectures, because of their scalability, extensibility, flexibility, and cost‐effectiveness. This paper introduces a concurrent approach to the development and verification of baseband systems for satellite ground operations based on the behaviour‐driven development methodology. The open‐source GNU Radio development kit is used for developing the software‐defined radio baseband signal processing, as well as simulating the satellite and realistic channel impairments. The system performance at the end shows deviations of less than 1 dB with respect to the ideal performance and the Green Book standards specified by the Consultative Committee for Space Data Systems.
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| 3. |
- Browne Mwakyanjala, Moses, et al.
(author)
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Feasibility of using a software-defined baseband for multiple space per aperture (MSPA) ground operations
- 2022
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In: International Journal of Satellite Communications And Networking. - : John Wiley & Sons. - 1542-0973 .- 1542-0981. ; 40:2, s. 133-147
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Journal article (peer-reviewed)abstract
- This paper presents the feasibility of performing multiple spacecraft per aperture (MSPA) ground operations by using a low-cost software-defined baseband (SDB). The SDB is a Consultative Committee for Space Data Systems (CCSDS)-compliant baseband that employs a personal computer for signal processing and a low-cost commercial-off-the-shelf RF front end for RF signal sampling. The SDB is customized to offer traditional telemetry, tracking, and command (TT&C) services for near-Earth missions operating in S band. The study starts by reviewing MSPA methods already studied by space agencies such as NASA and ESA before going to MSPA methods proposed in the latest CCSDS blue book on RF and modulation systems. The feasibility of operating the CCSDS-proposed multiple uplink carrier MSPA method using the SDB is assessed after evaluating in-band interference and out-of-band emissions from the uplink signals radiated by the low-cost RF front end employed by the SDB. Furthermore, we present a case study where the SDB is used in MSPA operations on a typical solid-state amplifier (SSPA) amplifier typically used in near-Earth missions.
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| 4. |
- Browne Mwakyanjala, Moses, et al.
(author)
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Validation of a software-defined baseband system for satellite telemetry and telecommand
- 2021
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In: International Journal of Satellite Communications And Networking. - : John Wiley & Sons. - 1542-0973 .- 1542-0981. ; 39:6, s. 605-625
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Journal article (peer-reviewed)abstract
- This paper presents the validation of a software-defined baseband (SDB) system for satellite telemetry and telecommand (TM/TC). The baseband system was developed using the open-source GNU Radio development kit. It runs on a personal computer connected to a commercial-off-the-shelf (CoTS) RF frontend. The validation process was performed by the use of a mission-qualified satellite emulator, a state-of-the-art baseband unit, and orbiting satellites. The baseband is designed to offer multimission support. Hence, it includes a suite of modulation schemes, line codes, matched filters, and Consultative Committee for Space Data Systems (CCSDS) forward error correction codes (convolutional, Reed–Solomon, concatenated, and low-density parity-check [LDPC]) typically employed in TM/TC missions. The figures of merit used for the validation of the TM receiver are bit error rate (BER) and frame error rate (FER). For the TC transmitter, the validated features are modulation index, power spectrum, and the physical layer operations procedures (PLOP).
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| 5. |
- Danilo, Spano, et al.
(author)
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Per-antenna power minimization in symbol-level precoding for the multibeam satellite downlink
- 2018
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In: International Journal of Satellite Communications And Networking. - : Wiley. - 1542-0973 .- 1542-0981. ; 37:1, s. 15-30
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Journal article (peer-reviewed)abstract
- This paper addresses the problem of multiuser interference in the forward downlink channel of a multibeam satellite system. A symbol-level precoding scheme is considered, to exploit the multiuser interference and transform it into useful power at the receiver side, through a joint utilization of the data information and the channel state information. In this context, a per-antenna power minimization scheme is proposed, under quality-of-service constraints, for multilevel modulation schemes. The consideration of the power limitations individually for each transmitting radio frequency chain is a central aspect of this work, and it allows to deal with systems using separate per-antenna amplifiers. Moreover, this feature is also particularly relevant for systems suffering nonlinear effects of the channel. This is the case of satellite systems, where the nonlinear amplifiers should be properly driven to reduce the detrimental saturation effect. In the proposed scheme, the transmitted signals are designed to reduce the power peaks, while guaranteeing some specific target signal-to-noise ratios at the receivers. Numerical results are presented to show the effectiveness of the proposed scheme, which is compared both with the state of the art in symbol-level precoding and with the conventional minimum mean square error precoding approach.
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| 6. |
- Pourmoghadas, A., et al.
(author)
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On the spectral coexistence of GSO and NGSO FSS systems : power control mechanisms and a methodology for inter-site distance determination
- 2016
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In: International Journal of Satellite Communications And Networking. - : John Wiley & Sons. - 1542-0973 .- 1542-0981. ; 35, s. 443-459
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Journal article (peer-reviewed)abstract
- The coexistence of geostationary satellite orbit (GSO) and non-GSO (NGSO) fixed satellite service systems withinthe same spectrum to enhance the spectrum efficiency in Ka band has attracted many interests lately. However,the coexistence of GSO-NGSO satellite systems with limited shared spectrum can cause in-line interference froma satellite to other satellite’s earth terminals. In this context, this contribution investigates three possible powercontrol approaches to mitigate the in-line interference caused by an NGSO satellite to the GSO earth terminal,while the NGSO satellite is crossing the GSO satellite’s illumination zone. Moreover, three types of interferencemitigation techniques, namely, range-based, traffic-aware, and cognitive power control techniques are investigated.Furthermore, to increase the spectrum efficiency of the GSO-NGSO fixed satellite service terrestrial network, weformulate and solve an optimization problem with the objective of minimizing the inter-site distance between earthuser-terminals. More specifically, we find the minimum distance from a GSO earth terminal, where an NGSOearth terminal can be implemented subject to minimizing received interference level at the victim system. Finally,our comparative results show that the cognitive power control technique performs the best in protecting the victimreceiver from the in-line interference.
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| 7. |
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