300 research outputs found
DVB-T signal detection for indoor environments in low-SNR regime
The problem of coexistence between the primary
(licensed) and secondary (non-licensed) users can be solved
in various ways. One of them assumes the application of the
detailed Radio Environment Maps being a kind of database,
where some crucial information about the licensed
transmission can be stored. In this paper we propose the
new methods for signal detection in low signal-to-noise
regime and compare it through hardware experiment with
other known techniques used for spectrum sensing.Peer ReviewedPostprint (authorâs final draft
Laboratory measurement campaign of DVB-T signal with transmit delay diversity
The requirements for future DVB-T/H networks demand that broadcasters design and deploy networks that provide ubiquitous reception in challenging indoors and other obstructed situations. It is essential that such networks are designed cost-effectively and with minimized environmental impact. The EC funded project PLUTO has since its start in 2006 explored the use of diversity to improve coverage in these difficult situations. The purpose of this paper is to investigate the performance of Transmit Delay Diversity (DD) with two antennas to improve the reception of DVB-T/H systems operating in different realistic propagation conditions through a series of tests using a SPIRENT SR5500 dual channel emulator. The relationship between correlation coefficient between channels, receiver velocity and diversity gain is nvestigated. It is shown that transmit delay diversity significantly improves the quality of reception particularly in simulated fast fading mobile broadcasting applications. This paper documents research conducted by Brunel University and Broadreach Systems
Design and Validation of a Software Defined Radio Testbed for DVB-T Transmission
This paper describes the design and validation of a Software Defined Radio (SDR) testbed, which can be used for Digital Television transmission using the Digital Video Broadcasting - Terrestrial (DVB-T) standard. In order to generate a DVB-T-compliant signal with low computational complexity, we design an SDR architecture that uses the C/C++ language and exploits multithreading and vectorized instructions. Then, we transmit the generated DVB-T signal in real time, using a common PC equipped with multicore central processing units (CPUs) and a commercially available SDR modem board. The proposed SDR architecture has been validated using fixed TV sets, and portable receivers. Our results show that the proposed SDR architecture for DVB-T transmission is a low-cost low-complexity solution that, in the worst case, only requires less than 22% of CPU load and less than 170 MB of memory usage, on a 3.0 GHz Core i7 processor. In addition, using the same SDR modem board, we design an off-line software receiver that also performs time synchronization and carrier frequency offset estimation and compensation
Sensing of DVB-T signals for white space cognitive radio systems
In cognitive radio networks, systems operating in digital television white spaces are particularly interesting for practical applications. In this paper, we consider single- antenna and multi-antenna spectrum sensing of real DVB-T signals under different channel conditions. Some of the most important algorithms are considered and compared, including energy detection, eigenvalue based techniques and methods exploiting OFDM signal knowledge. The obtained results show the algorithm performance and hierarchy in terms of ROC and detection probability under fixed false alarm rate, for different channel profiles in case of true DVB-T signal
DVB-T channels power measurements in indoor/outdoor cases
In this paper the analysis of the spectrum
occupancy in the TV band is provided based on the indoor and
outdoor measurements campaigns carried out in Poznan, Poland,
and Barcelona, Spain, in 2013. The goal of this work is to discuss
the stability and other important features of the observed
spectrum occupancy in the context of indoor/outdoor Radio
Environment Maps database deployment. Reliable deployment of
these databases seems to be one of the critical points in practical
utilization of the TV White Spaces for cognitive purposes inside
buildings and in densely populated cities.Postprint (published version
Dual-band directional antenna for receiving DVB-T signal
CĂlem tĂ©to prĂĄce je navrhnout dvoupĂĄsmovou antĂ©nu pro pĆĂjem DVB-T signĂĄlu v oblasti mÄsta Brna. AntĂ©na bude navrhnuta a pĆizpĆŻsobena pro pĆĂjem multiplexu 1 a 3, tedy pro frekvence 538 a 778 MHz. AntĂ©na bude odzkouĆĄena v programech 4nec2 a CST Microwave Studio.The main goal of the masters project is to design a dual band antenna for receiving DVB-T signal in the area of the city of Brno. The antenna will be designed and detaily adjusted for receiving multiplex 1 and 3, exactly for frequencies of 538 MHz and 778 MHz. The designed antenna will be deeply tested in 4nec2 and CST Microwave Studio programs.
Assessment of rfi measurements for lofar
In the North-Western part of Europe, ASTRON is building the world-largest largest low-frequency radio telescope. The telescope is based on phased array principles and is known as the LOw Frequency ARray (LOFAR). LOFAR is optimized for detecting astronomical signals in the 30-80 MHz and 120-240 MHz frequency windows. Since this part of the spectrum is in extensive use by others, special care must be taken in the selection of possible out-station sites for LOFAR. RFI measurements were made to be sure that the radio spectrum at the potential out-station locations is suitable for LOFAR operations. An assessment procedure is presented here and specific issues are discussed, such as the impact of Digital Video Broadcast, and wind turbines. The results of\ud
the RFI observations has generated a list of specifications for (international) LOFAR out-stations
Spectrum Sensing of DVB-T2 Signals in Multipath Channels for Cognitive Radio Networks
© 2018 VDE VERLAG GMBHIn this paper, spectrum sensing of digital video broadcasting-second generation terrestrial (DVB-T2) signals in different fading environments with energy detection (ED) is considered. ED is known to achieve an increased performance among low computational complexity detectors, but it is susceptible to noise uncertainty. By taking into consideration the edge pilot and scattered pilot periodicity in DVB-T2 signals, a low computational complex noise power estimator is proposed. It is shown analytically that the choice of detector depends on the environment, the detector requirements, the available prior knowledge and with the noise power estimator. Simulation confirm that with the noise power estimator, ED significantly outperforms the pilot correlation-based detectors. Simulation also show that the proposed scheme enables ED to obtain increased detection performance in fading channels
Spectrum Sensing of DVB-T2 Signals using a Low Computational Noise Power Estimation
© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted ncomponent of this work in other works.Cognitive radio is a promising technology that answers the spectrum scarcity problem arising from the proliferation of wireless networks and mobile services. In this paper, spectrum sensing of digital video broadcasting-second generation terrestrial (DVB-T2) signals in AWGN, WRAN and COST207 multipath fading environment are considered. ED is known to achieve an increased performance among low computational complexity detectors, but it is susceptible to noise uncertainty. Taking into consideration the edge pilot and scattered pilot periodicity in DVB-T2 signals, a low computational noise power estimator is proposed. Analytical forms for the detector are derived. Simulation results show that with the noise power estimator, ED significantly outperforms the pilot correlation-based detectors. Simulation also show that the proposed scheme enables ED to obtain increased detection performance in multi-path fading environments. Moreover, based on this algorithm a practical sensing scheme for cognitive radio networks is proposed.Peer reviewedFinal Accepted Versio
R-DVB: Software Defined Radio implementation of DVB-T signal detection functions for digital terrestrial television
This thesis describes the implementation steps of ETSI DVB-T compliant software defined radio bench receiver, using the GNU Radio framework.
It also analyzes its performances and suggest futures optimization tasks in order to achieve the real-time goal
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