![]() Querol Borras, Jorge ![]() in Remote Sensing (2019), 11(24), 3042 Radio frequency interference (RFI) is a well-known problem in microwave radiometry (MWR). Any undesired signal overlapping the MWR protected frequency bands introduces a bias in the measurements, which ... [more ▼] Radio frequency interference (RFI) is a well-known problem in microwave radiometry (MWR). Any undesired signal overlapping the MWR protected frequency bands introduces a bias in the measurements, which can corrupt the retrieved geophysical parameters. This paper presents a literature review of RFI detection and mitigation techniques for microwave radiometry from space. The reviewed techniques are divided between real aperture and aperture synthesis. A discussion and assessment of the application of RFI mitigation techniques is presented for each type of radiometer. [less ▲] Detailed reference viewed: 59 (6 UL)![]() Merlano Duncan, Juan Carlos ![]() ![]() ![]() in Proceedings of the 37th International Communications Satellite Systems Conference (2019, November 01) In this paper, we present a new hardware test-bed to demonstrate closed-loop precoded communications for interference mitigation in multi-beam ultra high throughput satellite systems under realistic ... [more ▼] In this paper, we present a new hardware test-bed to demonstrate closed-loop precoded communications for interference mitigation in multi-beam ultra high throughput satellite systems under realistic payload and channel impairments. We build the test-bed to demonstrate a real-time channel aided precoded transmission under realistic conditions such as the power constraints and satellite-payload non-linearities. We develop a scalable architecture of an SDR platform with the DVB-S2X piloting. The SDR platform consists of two parts: analog-to-digital (ADC) and digital-to-analog (DAC) converters preceded by radio frequency (RF) front-end and Field-Programmable Gate Array (FPGA) backend. The former introduces realistic impairments in the transmission chain such as carrier frequency and phase misalignments, quantization noise of multichannel ADC and DAC and non-linearities of RF components. It allows evaluating the performance of the precoded transmission in a more realistic environment rather than using only numerical simulations. We benchmark the performance of the communication standard in realistic channel scenarios, evaluate received signal SNR, and measure the actual channel throughput using LDPC codes. [less ▲] Detailed reference viewed: 180 (49 UL)![]() Querol Borras, Jorge ![]() Scientific Conference (2019, September 26) The number of applications based on Global Navigation Satellite Systems (GNSS) has been increasing in the last years. With its proliferation, Radio-Frequency Interference (RFI) has become one of the most ... [more ▼] The number of applications based on Global Navigation Satellite Systems (GNSS) has been increasing in the last years. With its proliferation, Radio-Frequency Interference (RFI) has become one of the most concerning topics on GNSS-based devices for navigation, positioning and timing, but also for Earth Observation purposes such as GNSS-Reflectometry (GNSS-R) and GNSS-Radio Occultations (GNSS-RO) due to the corruption of the received signal and the corresponding geophysical measurements. The Front-End GNSS Interference eXcisor (FENIX) mitigates the problem of RFI by providing a plug-and-play solution which, placed between the antenna and the receiver, excises virtually any kind of interference signal, as its mitigation algorithm is agnostic on the particular type of RFI. The new version of FENIX is also capable of operating with large signal bandwidths ($\sim$50 MHz) and dual-band applications (e.g. L1 + L2 or L1/E1 + L5/E5). This paper shows the performance of the system for commercial GNSS receivers and GNSS-R applications. The use of FENIX in Microwave Radiometers is also possible, but it is out of the scope of this paper. [less ▲] Detailed reference viewed: 99 (6 UL)![]() Merlano Duncan, Juan Carlos ![]() ![]() in 2019 IEEE International Geoscience and Remote Sensing Symposium (IGARSS) (2019, August 31) Phase, frequency and time synchronization is a crucial requirement for many applications as such as multi-static remote sensing and distributed beamforming for communications. The literature on the field ... [more ▼] Phase, frequency and time synchronization is a crucial requirement for many applications as such as multi-static remote sensing and distributed beamforming for communications. The literature on the field is very wide, and in some cases, the requirements of the proposed synchronization solution may surpass the ones set by the application itself. Moreover, the synchronization solution becomes even more challenging when the nodes are flying or hovering on aerial or space platforms. In this work, we compare and classify the synchronization technologies available in the literature according to a common proposed framework, and we discuss the considerations of an implementation for distributed remote sensing applications. The general framework considered is based on a distributed collection of autonomous nodes that try to synchronize their clocks with a common reference. Moreover, they can be classified in non-overlapping, adjacent and overlapping frequency band scenarios [less ▲] Detailed reference viewed: 139 (16 UL)![]() Maturo, Nicola ![]() ![]() ![]() in 2019 8th International Workshop on Tracking, Telemetry and Command Systems for Space Applications (TTC) (2019) Detailed reference viewed: 102 (20 UL) |
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