NASA Near Earth Network (NEN) DVB-S2 Demonstration Testing for Enhancing Higher Data Rates for CubeSat/Small Satellite Missions at X-band and Ka-band

National Aeronautics and Space Administration (NASA) CubeSat/SmallSat missions are moving to higher data rates. Digital Video Broadcast, Satellite Second Generation (DVB-S2) is a communications standard that uses power and bandwidth efficient modulation and coding techniques to deliver performance approaching radio frequency (RF) channel theoretical limits. The Near Earth Network (NEN) will test DVB-S2’s ability to provide higher data rates for CubeSat/SmallSat missions at X-band and Ka-band at Wallops Flight Facility (WFF). The goal is to upgrade the NEN with DVB-S2 to increase science data return for missions and enable support for more CubeSat/SmallSat missions. This paper describes NEN DVB-S2 X-band and Ka-band demonstration objectives, scope, and performance measures as well as NEN channel test configuration. The NEN has planned 2020 tests to demonstrate all modulation and coding schemes in the Consultative Committee for Space Data Systems (CCSDS) DVB-S2 standard over X-band and Ka-band. A link analysis study for the trade-offs among achievable data rates, modulations, codes, spacecraft antenna sizes and power amplifiers (PA) is provided. This paper identifies Commercial off-the-shelf (COTS) CubeSat/SmallSat X-band and Ka-band communication systems and discusses low cost DVB-S2 X-band software defined radio (SDR) transmitter development concepts and implementation with a practical system for CubeSats/SmallSats

Landsat Data Continuity Mission (LDCM) - Optimizing X-Band Usage

The NASA version of the low-density parity check (LDPC) 7/8-rate code, shortened to the dimensions of (8160, 7136), has been implemented as the forward error correction (FEC) schema for the Landsat Data Continuity Mission (LDCM). This is the first flight application of this code. In order to place a 440 Msps link within the 375 MHz wide X band we found it necessary to heavily bandpass filter the satellite transmitter output . Despite the significant amplitude and phase distortions that accompanied the spectral truncation, the mission required BER is maintained at < 10(exp -12) with less than 2 dB of implementation loss. We utilized a band-pass filter designed ostensibly to replicate the link distortions to demonstrate link design viability. The same filter was then used to optimize the adaptive equalizer in the receiver employed at the terminus of the downlink. The excellent results we obtained could be directly attributed to the implementation of the LDPC code and the amplitude and phase compensation provided in the receiver. Similar results were obtained with receivers from several vendors

Architecture and DSP Implementation of a DVB-S2 Baseband Demodulator

This paper presents the design and implementation of a baseband demodulator for DVB-S2 satellite receivers. In order to meet the requirements of different complex and multi-domain signal processing stages of the DVB-S2 baseband signal-flow, the presented architecture is based on efficient fixed-point implementation of the various demodulation algorithms and on the use of a dynamic time-sharing scheduler for the various DSP software tasks. The prototyping of the demodulator and its verification in the design of a complete digital DVB-S2 satellite receiver using a versatile testbed is also presented

Low cost passive radar through software defined radio

Passive radars utilise existing terrestrial radio signals, such as those produced by radio or television stations, to track objects within their range. This project aims to determine the suitability of low cost USB TV tuners as hardware receivers for a Software Defined Radio (SDR) based passive radar receiver. Subsequently determining its effectiveness in producing inverse synthetic aperture radar images using data collected from Digital Television signals. Since the initial identification of passive radar, Militaries the world over have been using it as a part of electronic warfare. The evolution of SDR has enabled greater access to the technologies required to implement passive radar, with the greatest limitation being the cost of the required hardware. The availability of low cost hardware was therefore investigated to determine its suitability and subsequently the availability of passive radar to a wider audience. Research was conducted into the available SDR receivers, and comparison of specifications was made against the low cost receiver used in the project. A functional hardware platform based around the Realtek RTL2832U chipset has been developed to determine its suitability as a low cost receiver verifying its ability to coherently receive radio signals for target identification. A complex ambiguity function was implemented to interpret sampled data windows, with the output of these windows to be compared to the requirements for an inverse synthetic aperture radar input, thus determining the suitability of the device. Interpretation of the received data has identified that although the hardware is capable, a real time implementation of data processing is not yet possible, impeding the ability to determine the suitability of the receiver as an inverse synthetic aperture receiver. The results of testing show that the hardware is capable of receiving and producing radar images, however due to the bandwidth of DVB-T signals , and the bandwidth limitations inherent in RTL-SDR dongles, they have proven not to be suitable for DVB-T based inverse synthetic aperture radar receivers

Implementação em FPGA do transceiver FMCOMMS3 para o protocolo de comunicação DVBS2X

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Faculdade UnB Gama, Engenharia Eletrônica, 2020.Esse trabalho apresenta um estudo detalhado da implementação em FPGAs (Field Programmable Gate Arrays) de um sistema operacional embarcado via PetaLinux desenvolvido para ser o front-end de um sistema de recepção para o protocolo de comunicação DVB-S2X integrado com o transceiver FMCOMMS3 em comparação com um DDC (Digital Down Converter) totalmente desenvolvido no hardware programável do FPGA. É também desenvolvido nesse documento a integração do DDC com o CFC (Cource Frequency Correction) conforme normatizado no padrão DVB-S2X. Por fim são feitas ponderações do desempenho entre o sistema front-end em SDR (Software Defined Radio) implementado através do PetaLinux e o circuito do DDC implementado em hardware e descrito em VHDL. Um dos componentes inerentes a qualquer padrão é o módulo de recepção do sinal, especificamente o DDC, para qual existem várias soluções implementadas tanto em hardware quanto para aplicações em SDR. A proposta central deste trabalho é desenvolver um sistema de recepção para a placa ZCU104 da empresa Xilinx integrada fisicamente com o transceiver FMCOMMS3 da empresa Analog Devices por meio do PetaLinux, em paralelo a um Digital Down converter em hardware integrado com o CFC. No caso do PetaLinux visa-se desenvolver um sistema operacional ainda não disponibilizado oficialmente pela empresa Analog Devices para o kit de desenvolvimento ZCU104. Observa-se que a empresa, até o presente momento, disponibiliza oficialmente o PetaLinux para a placa ZCU102, contudo, essa segunda é uma placa com um custo maior que a ZCU104 que possui entradas FMC que permitiria a mesma implementação a um custo menor. Em relação ao DDC visa-se explorar de forma intrínseca as especificidades do padrão DVBS2X, como largura de banda, Roll-off, taxa de bits e entre outras métricas se refletindo em um baixo custo de implementação explorando a quantidade de coeficientes dos filtros, formas de ondas esperadas e resolução do oscilador acarretando em uma redução efetiva do processamento ao longo de toda cadeia da down conversão sem perda de generalidade. A generalidade irá se manter pois todos os coeficientes, largura de banda, excursão de frequência são configurados diretamente na descrição do hardware ou usando scripts desenvolvidos como modelos de referência em software que geram os trechos da descrição em hardware. Adicionalmente todos os circuitos foram sintetizados e implementados no FPGA para uma taxa de amostragem de 100 MSPS e caracterizados em termos de precisão, recursos de hardware, latência, throughput e consumo de energia e então comparados com as soluções existentes. Os resultados experimentais mostram que o circuito projetado e integrado com o CFC é viável e eficiente para a recepção e sincronização do sinal conforme a norma DVB-S2X, além de consumir menos recursos e tempo de execução do que os encontrados na literatura.This paper presents a detailed study of the implementation in FPGAs ( textit Field Programmable Gate Arrays) of an embedded operating system via PetaLinux developed to be the textit front-end of a reception system for the communication protocol DVB- S2X integrated with the FMCOMMS3 transceiver compared to a DDC textit (Digital Down Converter) fully developed on the FPGA’s programmable hardware. It is also developed in this document the integration of the DDC with the CFC ( textit Cource Frequency Correction) as standardized in the DVB-S2X standard. Finally, performance considerations are made between the textit front-end system in SDR textit (Software Defined Radio) implemented through PetaLinux and the DDC circuit implemented in hardware and described in VHDL. One of the components inherent to any standard is the signal reception module, specifically the DDC, for which there are several solutions implemented both in hardware and for SDR applications. The main proposal of this work is to develop a reception system for the ZCU104 board from the company Xilinx physically integrated with the FMCOMMS3 transceiver from the company Analog devices through PetaLinux, in parallel a Digital Down converter in hardware integrated with the CFC. In the case of PetaLinux, the aim is to develop an operating system not yet officially made available by the company Analog devices for the ZCU104 development kit. It is observed that the company, until now, officially makes PetaLinux available for the ZCU102 board, however, this second one is a board with a higher cost than the ZCU104 that has FMC inputs that would allow the same implementation at a lower cost. Regarding DDC, the aim is to explore intrinsically the specifics of the DVB-S2X standard, such as bandwidth, textit Roll-off, bit rate and other metrics, reflecting a low cost of implementation exploring the amount filter taps, expected waveforms and oscillator resolution resulting in an effective reduction in processing along the entire down conversion chain without loss of generality. The generality will remain as all the coefficients, bandwidth, frequency excursion are configured directly in the hardware description or using scripts developed as reference models in software that generate the parts of the hardware description. Additionally, all circuits were synthesized and implemented in the FPGA for a sampling rate of 100 MSPS and characterized in terms of precision, hardware resources, latency, textit throughput and energy consumption and then compared with existing solutions. The experimental results show that the circuit designed and integrated with the CFC is feasible and efficient for the reception and synchronization of the signal according to the DVB-S2X standard, in addition to consuming less resources and execution time than those found in the literature

A survey of digital television broadcast transmission techniques

This paper is a survey of the transmission techniques used in digital television (TV) standards worldwide. With the increase in the demand for High-Definition (HD) TV, video-on-demand and mobile TV services, there was a real need for more bandwidth-efficient, flawless and crisp video quality, which motivated the migration from analogue to digital broadcasting. In this paper we present a brief history of the development of TV and then we survey the transmission technology used in different digital terrestrial, satellite, cable and mobile TV standards in different parts of the world. First, we present the Digital Video Broadcasting standards developed in Europe for terrestrial (DVB-T/T2), for satellite (DVB-S/S2), for cable (DVB-C) and for hand-held transmission (DVB-H). We then describe the Advanced Television System Committee standards developed in the USA both for terrestrial (ATSC) and for hand-held transmission (ATSC-M/H). We continue by describing the Integrated Services Digital Broadcasting standards developed in Japan for Terrestrial (ISDB-T) and Satellite (ISDB-S) transmission and then present the International System for Digital Television (ISDTV), which was developed in Brazil by adopteding the ISDB-T physical layer architecture. Following the ISDTV, we describe the Digital Terrestrial television Multimedia Broadcast (DTMB) standard developed in China. Finally, as a design example, we highlight the physical layer implementation of the DVB-T2 standar

Economically sustainable public security and emergency network exploiting a broadband communications satellite

The research contributes to work in Rapid Deployment of a National Public Security and Emergency Communications Network using Communication Satellite Broadband. Although studies in Public Security Communication networks have examined the use of communications satellite as an integral part of the Communication Infrastructure, there has not been an in-depth design analysis of an optimized regional broadband-based communication satellite in relation to the envisaged service coverage area, with little or no terrestrial last-mile telecommunications infrastructure for delivery of satellite solutions, applications and services. As such, the research provides a case study of a Nigerian Public Safety Security Communications Pilot project deployed in regions of the African continent with inadequate terrestrial last mile infrastructure and thus requiring a robust regional Communications Satellite complemented with variants of terrestrial wireless technologies to bridge the digital hiatus as a short and medium term measure apart from other strategic needs. The research not only addresses the pivotal role of a secured integrated communications Public safety network for security agencies and emergency service organizations with its potential to foster efficient information symmetry amongst their operations including during emergency and crisis management in a timely manner but demonstrates a working model of how analogue spectrum meant for Push-to-Talk (PTT) services can be re-farmed and digitalized as a “dedicated” broadband-based public communications system. The network’s sustainability can be secured by using excess capacity for the strategic commercial telecommunication needs of the state and its citizens. Utilization of scarce spectrum has been deployed for Nigeria’s Cashless policy pilot project for financial and digital inclusion. This effectively drives the universal access goals, without exclusivity, in a continent, which still remains the least wired in the world