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Zepernick, Hans-Juergen
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Publications (10 of 241) Show all publications
Fiedler, M., Zepernick, H.-J. & Kelkkanen, V. (2019). Network-induced temporal disturbances in virtual reality applications. In: 2019 11th International Conference on Quality of Multimedia Experience, QoMEX 2019: . Paper presented at 11th International Conference on Quality of Multimedia Experience, QoMEX, Berlin, 5 June 2019 through 7 June 2019. Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Network-induced temporal disturbances in virtual reality applications
2019 (English)In: 2019 11th International Conference on Quality of Multimedia Experience, QoMEX 2019, Institute of Electrical and Electronics Engineers Inc. , 2019Conference paper, Published paper (Refereed)
Abstract [en]

Virtual Reality (VR) applications put high demands on software and hardware in order to enable an immersive experience for the user and avoid causing simulator sickness. As soon as networks become part of the Motion-To-Photon (MTP) path between rendering and display, there is a risk for extraordinary delays that may impair Quality of Experience (QoE). This short paper provides an overview of latency measurements and models that are applicable to the MTP path, complemented by demands on user and network levels. It specifically reports on freeze duration measurements using a commercial TPCAST wireless VR solution, and identifies a corresponding stochastic model of the freeze length distribution, which may serve as disturbance model for VR QoE studies. © 2019 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2019
Keywords
Application programs, Multimedia systems, Quality of service, Stochastic systems, Virtual reality, Disturbance modeling, High demand, Latency measurements, Length distributions, Network level, Quality of experience (QoE), Simulator sickness, Software and hardwares, Stochastic models
National Category
Communication Systems Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-18605 (URN)10.1109/QoMEX.2019.8743304 (DOI)000482562000056 ()2-s2.0-85068679022 (Scopus ID)9781538682128 (ISBN)
Conference
11th International Conference on Quality of Multimedia Experience, QoMEX, Berlin, 5 June 2019 through 7 June 2019
Funder
Knowledge Foundation, 20170056
Available from: 2019-09-10 Created: 2019-09-10 Last updated: 2019-09-13Bibliographically approved
Chu, T. M., Zepernick, H.-J. & Sundstedt, V. (2018). Analysis of Variance of Opinion Scores for MPEG-4 Scalable and Advanced Video Coding. In: Wysocki, TA Wysocki, BJ (Ed.), 2018 12TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS): . Paper presented at 12th International Conference on Signal Processing and Communication Systems (ICSPCS), Cairns,DEC 17-19. IEEE
Open this publication in new window or tab >>Analysis of Variance of Opinion Scores for MPEG-4 Scalable and Advanced Video Coding
2018 (English)In: 2018 12TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) / [ed] Wysocki, TA Wysocki, BJ, IEEE , 2018Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we conduct an analysis of variance (ANOVA) on opinion scores for MPEG-4 scalable video coding (SVC) and advanced video coding (AVC) standards. This work resorts on a publicly available database providing opinion scores from subjective experiments for several scenarios such as different bit rates and resolutions. In particular, ANOVA is used for statistical hypothesis testing to compare two or more sets of opinion scores instead of being constrained to pairs of sets of opinion scores as would be the case for t-tests. As the ANOVA tests of the different scenarios are performed for mean opinion scores (MOS), box plots are also provided in order to assess the distribution of the opinion scores around the median. It is shown that the opinion scores given to the reference videos in SVC and AVC for different resolutions are statistically significantly similar regardless of the content. Further, for the opinion scores of the considered database, the ANOVA tests support the hypothesis that AVC generally outperforms SVC although the performance difference may be less pronounced for higher bit rates. This work also shows that additional insights on the results of subjective experiments can be obtained by extending the analysis of opinion scores beyond MOS to ANOVA tests and box plots.

Place, publisher, year, edition, pages
IEEE, 2018
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-17694 (URN)000458665600006 ()
Conference
12th International Conference on Signal Processing and Communication Systems (ICSPCS), Cairns,DEC 17-19
Funder
Knowledge Foundation, 20170056
Available from: 2019-03-07 Created: 2019-03-07 Last updated: 2019-04-05Bibliographically approved
Chu, T. M. & Zepernick, H.-J. (2018). Downlink outage analysis for cognitive cooperative radio networks employing non-orthogonal multiple access. In: 2018 IEEE 7th International Conference on Communications and Electronics, ICCE 2018: . Paper presented at 7th IEEE International Conference on Communications and Electronics, ICCE 2018,Saigon Morin HotelHue; Viet Nam, 18 July 2018 through 20 July 2018 (pp. 27-32). Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Downlink outage analysis for cognitive cooperative radio networks employing non-orthogonal multiple access
2018 (English)In: 2018 IEEE 7th International Conference on Communications and Electronics, ICCE 2018, Institute of Electrical and Electronics Engineers Inc. , 2018, p. 27-32Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we employ power-domain non-orthogonal multiple access (NOMA) to simultaneously transmit signals to both a primary user (PU) and a secondary user (SU) of a cognitive cooperative radio network (CCRN). Higher priority is given to the PU over the SU by keeping the power allocation coefficients at the base station (BS) and relay (R) above a certain threshold. In this way, similar as the interference power limit imposed by the PU in a conventional underlay CCRN, the power allocation coefficients at the BS and R of the CCRN can be controlled to maintain a given outage performance. Analytical expressions of the cumulative distribution function of the end-to-end signal-to-interference-plus-noise ratios at the PU and SU are derived and then used to assess the outage probabilities of both users. Numerical results are presented to study the impact of system parameters on outage performance of the CCRN with power-domain NOMA. In addition, it is illustrated that increased downlink performance can be obtained by combining power-domain NOMA with CCRNs. © 2018 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Cognitive radio, Distribution functions, Mobile telecommunication systems, Probability distributions, Signal to noise ratio, Analytical expressions, Cognitive cooperative radio networks, Cumulative distribution function, Downlink performance, Interference power, Non orthogonal multiple accesses (NOMA), Non-orthogonal multiple access, Signal to interference plus noise ratio, Outages
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-17426 (URN)10.1109/CCE.2018.8465755 (DOI)2-s2.0-85057577602 (Scopus ID)9781538636787 (ISBN)
Conference
7th IEEE International Conference on Communications and Electronics, ICCE 2018,Saigon Morin HotelHue; Viet Nam, 18 July 2018 through 20 July 2018
Available from: 2018-12-13 Created: 2018-12-13 Last updated: 2018-12-13Bibliographically approved
Chu, T. M. & Zepernick, H.-J. (2018). Non-orthogonal multiple access for DF cognitive cooperative radio networks. In: IEEE International Conference on Communications Workshops: . Paper presented at IEEE International Conference on Communications Workshops, ICC Workshops 2018; Kansas City (pp. 1-6). Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Non-orthogonal multiple access for DF cognitive cooperative radio networks
2018 (English)In: IEEE International Conference on Communications Workshops, Institute of Electrical and Electronics Engineers Inc. , 2018, p. 1-6Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we study a power domain non-orthogonal multiple access (NOMA) scheme for cognitive cooperative radio networks (CCRNs). In the proposed scheme, a secondary transmitter communicates with two secondary users (SUs) by allocating transmit powers inversely proportional to the channel power gains on the links to the respective SUs. A decode-and-forward (DF) secondary relay is deployed which decodes the superimposed signals associated with the two SUs. Then, power domain NOMA is used to forward the signals from the relay to the two SUs based on the channel power gains on the corresponding two links. Mathematical expressions for the outage probability and ergodic capacity of each SU and the overall power domain NOMA CCRN are derived. Numerical results are provided to reveal the impact of the power allocation coefficients at the secondary transmitter and secondary relay, the interference power threshold at the primary receiver, and the normalized distances of the SUs on the outage probability and ergodic capacity of each SU and the whole NOMA system. © 2018 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Series
IEEE International Conference on Communications Workshops, ISSN 2164-7038
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-16905 (URN)10.1109/ICCW.2018.8403614 (DOI)000445022200128 ()2-s2.0-85050303770 (Scopus ID)9781538643280 (ISBN)
Conference
IEEE International Conference on Communications Workshops, ICC Workshops 2018; Kansas City
Available from: 2018-08-20 Created: 2018-08-20 Last updated: 2018-10-18Bibliographically approved
Tran, D. N., Zepernick, H.-J. & Chu, T. M. (2018). On Moderately Significant Bit Data Hiding Techniques for High-Definition Images. In: International Conference on Advanced Technologies for Communications: . Paper presented at 11th International Conference on Advanced Technologies for Communications, ATC 2018, Ho Chi Minh City, 18 October 2018 through 20 October 2018 (pp. 47-52). IEEE Computer Society
Open this publication in new window or tab >>On Moderately Significant Bit Data Hiding Techniques for High-Definition Images
2018 (English)In: International Conference on Advanced Technologies for Communications, IEEE Computer Society , 2018, p. 47-52Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we study moderately significant bit data hiding techniques for high-definition (HD) images. In contrast to least significant bit data hiding, we explore the potential of HD images to engage higher order bits for increasing the capacity of hiding secret images. In particular, the number of secret images embedded in moderately significant bits of a given cover image is successively increased to study the impact of this data hiding approach on image fidelity and image quality in the context of HD images. A comprehensive performance assessment is conducted on the stego-image carrying the secret images in terms of peak-signal-to-noise ratio (PSNR) and structural similarity (SSIM) index. It is shown that HD images indeed offer the potential of hiding several images within certain image fidelity and objective perceptual image quality constraints of the resulting stego-HD images. © 2018 IEEE.

Place, publisher, year, edition, pages
IEEE Computer Society, 2018
Keywords
Image quality, Signal to noise ratio, Steganography, Comprehensive performance assessments, High definition, Image fidelity, Least significant bits, Peak signal to noise ratio, Perceptual image quality, Secret images, Structural similarity indices (SSIM), Digital television
National Category
Communication Systems
Identifiers
urn:nbn:se:bth-17622 (URN)10.1109/ATC.2018.8587484 (DOI)000458771800010 ()2-s2.0-85060813550 (Scopus ID)9781538661130 (ISBN)
Conference
11th International Conference on Advanced Technologies for Communications, ATC 2018, Ho Chi Minh City, 18 October 2018 through 20 October 2018
Available from: 2019-02-21 Created: 2019-02-21 Last updated: 2019-03-08Bibliographically approved
Tran, D. N., Zepernick, H.-J. & Chu, T. M. (2018). On the Positioning of Moderately Significant Bit Data Hiding in High-Definition Images. In: Wysocki, TA Wysocki, BJ (Ed.), 2018 12TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS): . Paper presented at 12th International Conference on Signal Processing and Communication Systems (ICSPCS, Cairns, DEC 17-19. IEEE
Open this publication in new window or tab >>On the Positioning of Moderately Significant Bit Data Hiding in High-Definition Images
2018 (English)In: 2018 12TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) / [ed] Wysocki, TA Wysocki, BJ, IEEE , 2018Conference paper, Published paper (Refereed)
Abstract [en]

Mobile services have seen a shift from voice services toward visual stimuli-based services ranging from mobile imaging over mobile gaming to upcoming mobile extended reality applications. In this paper, given the increased resolutions of the related mobile multimedia formats, we propose and examine positioning strategies for light-weight data hiding of secret images in moderately significant bits of high-definition (HD) cover images. Apart from linear and random positioning, visual attention mechanisms of the human visual system are addressed by separately utilizing either the background or center of the HD cover image for data hiding. A performance assessment of these positioning strategies is conducted in terms of the peak-signal-to-noise ratio (PSNR), structural similarity (SSIM) index, and visual information fidelity (VIF). It is shown that HD cover images indeed can carry more than a single secret image until noticeable quality loss is observed. Further, it is revealed that linear positioning of secret images in the whole, background, or center of HD cover images outperforms random positioning. As for the utilized performance metrics, it has been observed that PSNR cannot differentiate among the positioning strategies as it measures pixel-by-pixel differences and hence removes the impact of the position of the hidden data. As for the two quality metrics, compared to the SSIM index, VIF is found to stronger differentiate among the performance of the considered positioning strategies.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
LSB SUBSTITUTION; QUALITY; PSNR
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-17693 (URN)000458665600008 ()978-1-5386-5602-0 (ISBN)
Conference
12th International Conference on Signal Processing and Communication Systems (ICSPCS, Cairns, DEC 17-19
Available from: 2019-03-07 Created: 2019-03-07 Last updated: 2019-04-05Bibliographically approved
Chu, T. M. & Zepernick, H.-J. (2018). Optimal Power Allocation for Hybrid Cognitive Cooperative Radio Networks with Imperfect Spectrum Sensing. IEEE Access, 6, 10365-10380
Open this publication in new window or tab >>Optimal Power Allocation for Hybrid Cognitive Cooperative Radio Networks with Imperfect Spectrum Sensing
2018 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 10365-10380Article in journal (Refereed) Published
Abstract [en]

In this paper, two optimal power allocation strategies for hybrid interweave-underlay cognitive cooperative radio networks (CCRNs) are proposed to maximize channel capacity and minimize outage probability. The proposed power allocation strategies are derived for the case of Rayleigh fading taking into account the impact of imperfect spectrum sensing on the performance of the hybrid CCRN. Based on the optimal power allocation strategies, the transmit powers of the secondary transmitter and secondary relay are adapted according to the fading conditions, the interference power constraint imposed by the primary network (PN), the interference from the PN to the hybrid CCRN, and the total transmit power limit of the hybrid CCRN. Numerical results are provided to illustrate the effect of the interference power constraint of the PN, arrival rate of the PN, imperfect spectrum sensing, and the transmit power constraint of the hybrid CCRN on channel capacity and outage probability. Finally, comparisons of the channel capacity and outage probability of underlay, overlay, and hybrid interweaveunderlay CCRNs are presented to show the advantages of the hybrid spectrum access. OAPA

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
amplify-and-forward relaying, Channel capacity, Cognitive radio, hybrid interweave-underlay scheme, Hybrid power systems, imperfect spectrum sensing, Interference, outage probability, power allocation, Power system reliability, Probability, Resource management, Sensors, Cognitive systems, Fading (radio), Rayleigh fading, Wave interference, Power allocations, Outages
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-15892 (URN)10.1109/ACCESS.2018.2792063 (DOI)000428148400001 ()2-s2.0-85041174409 (Scopus ID)
Available from: 2018-02-15 Created: 2018-02-15 Last updated: 2018-04-12Bibliographically approved
Chu, T. M. & Zepernick, H.-J. (2018). Performance of a Non-orthogonal Multiple Access System with Full-Duplex Relaying. IEEE Communications Letters, 22(10), 2084-2087
Open this publication in new window or tab >>Performance of a Non-orthogonal Multiple Access System with Full-Duplex Relaying
2018 (English)In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 22, no 10, p. 2084-2087Article in journal (Refereed) Published
Abstract [en]

In this paper, we study a power-domain nonorthogonal multiple access (NOMA) system in which a base station (BS) superimposes the transmit signals to the users. To enhance spectral efficiency and link reliability for the far-distance user, a full-duplex (FD) relay assists the BS while the neardistance user is reached over the direct link. For this setting, we analyze outage probability and sum rate of the NOMA system over Nakagami-m fading with integer fading severity parameter m. Numerical results are provided for outage probability and sum rate to show the effect of system parameters on the performance of the FD NOMA system over Nakagami-m fading. IEEE

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
full-duplex, NOMA, outage, sum rate, Finite difference method, Full-duplex relaying, Non orthogonal multiple accesses (NOMA), Non-orthogonal multiple access, Outage probability, Spectral efficiencies, Sum-rate, Outages
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-16887 (URN)10.1109/LCOMM.2018.2852308 (DOI)000447079300030 ()2-s2.0-85049336586 (Scopus ID)
Available from: 2018-08-20 Created: 2018-08-20 Last updated: 2018-10-30Bibliographically approved
Chu, T. M. & Zepernick, H.-J. (2018). Performance Optimization for Hybrid Two-Way Cognitive Cooperative Radio Networks with Imperfect Spectrum Sensing. IEEE Access, 6, 70582-70596
Open this publication in new window or tab >>Performance Optimization for Hybrid Two-Way Cognitive Cooperative Radio Networks with Imperfect Spectrum Sensing
2018 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 70582-70596Article in journal (Refereed) Published
Abstract [en]

In this paper, we consider a two-way cognitive cooperative radio network (TW-CCRN) with hybrid interweaveunderlay spectrum access in the presence of imperfect spectrum sensing. Power allocation strategies are proposed that maximize the sum-rate and minimize the outage probability of the hybrid TW-CCRN. Specifically, based on the state of the primary network (PN), fading conditions, and system parameters, suitable power allocation strategies subject to the interference power constraint of the PN are derived for each transmission scenario of the hybrid TW-CCRN. Given the proposed power allocation strategies, we analyze the sum-rate and outage probability of the hybrid TW-CCRN over Rayleigh fading taking imperfect spectrum sensing into account. Numerical results are presented to illustrate the effect of the arrival rate, interference power threshold, transmit power of the PN, imperfect spectrum sensing, and maximum total transmit power on the sum-rate and outage probability of the hybrid TW-CCRN. OAPA

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Cognitive cooperative radio network, hybrid interweave-underlay spectrum access, Hybrid power systems, Interference, outage probability, power allocation, Power system reliability, Probability, Relays, Resource management, Sensors, sum-rate, two-way communications, Cognitive radio, Cognitive systems, Cooperative communication, Rayleigh fading, Spectroscopy, Wave interference, Cognitive cooperative radio networks, Power allocations, Spectrum access, Two way communications, Outages
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-17349 (URN)10.1109/ACCESS.2018.2879901 (DOI)000453265500001 ()2-s2.0-85056331705 (Scopus ID)
Available from: 2018-11-29 Created: 2018-11-29 Last updated: 2019-01-09Bibliographically approved
Chu, T. M. & Zepernick, H.-J. (2018). Symbol error rate and achievable rate of cognitive cooperative radio networks utilizing non-orthogonal multiple access. In: 2018 IEEE 7th International Conference on Communications and Electronics, ICCE 2018: . Paper presented at 7th IEEE International Conference on Communications and Electronics, ICCE 2018, Saigon Morin HotelHue; Viet Nam, 18 July 2018 through 20 July 2018 (pp. 33-38). Institute of Electrical and Electronics Engineers Inc., Code 141951
Open this publication in new window or tab >>Symbol error rate and achievable rate of cognitive cooperative radio networks utilizing non-orthogonal multiple access
2018 (English)In: 2018 IEEE 7th International Conference on Communications and Electronics, ICCE 2018, Institute of Electrical and Electronics Engineers Inc. , 2018, Vol. Code 141951, p. 33-38Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we study the employment of power-domain non-orthogonal multiple access (NOMA) concepts for a cooperative cognitive relay network (CCRN) downlink system in order to allow a base station (BS) to simultaneously transmit signals to a primary user (PU) and a secondary user (SU). As such, the considered system falls into the field of cognitive radio inspired power-domain NOMA. In this scheme, the interference power constraint of the PU imposed to SUs in conventional underlay CCRNs is replaced by controlling the power allocation coefficients at the BS and relay. Specifically, expressions for the symbol error rates at the PU and SU for different modulation schemes as well as expressions for the achievable rates are derived. On this basis, the effect of system parameters such as total transmit power and power allocation coefficients on the performance of the CCRN with power-domain NOMA is numerically studied. These numerical results provide insights into selecting favorable operation modes of the CCRN employing power-domain NOMA. © 2018 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
Electronics engineering, Electronics industry, Cognitive cooperative radio networks, Cognitive relay networks, Interference power constraints, Modulation schemes, Non orthogonal multiple accesses (NOMA), Non-orthogonal multiple access, Symbol error rate (SER), Total transmit power, Cognitive radio
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-17427 (URN)10.1109/CCE.2018.8465739 (DOI)2-s2.0-85057619071 (Scopus ID)9781538636787 (ISBN)
Conference
7th IEEE International Conference on Communications and Electronics, ICCE 2018, Saigon Morin HotelHue; Viet Nam, 18 July 2018 through 20 July 2018
Available from: 2018-12-13 Created: 2018-12-13 Last updated: 2018-12-13Bibliographically approved
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