Video conferencing is becoming an increasingly desirable alternative to face-to-face meetings. Ma... more Video conferencing is becoming an increasingly desirable alternative to face-to-face meetings. Many companies and organizations have multiple locations, and their employees' communication options are typically limited to audio-only conference calls. These are often ineffective because of the limited level of interaction between the participants. Video conferencing is seen as a promising alternative to increase efficiency and reduce carbon emissions by mitigating the need for travel. However, current video conferencing solutions are either too expensive, require dedicated equipment and infrastructure, or are too cumbersome to implement on an individual location basis for widespread use. Low cost solutions usually provide neither the desired level of interaction nor the consistent quality needed for corporate communications. In this paper, we propose a novel hybrid video conferencing architecture that incorporates peer-to-peer communication functions for media distribution. In addition, new concepts, such as novel video cameras, cordless camera adaptors, a two-sided display, and a device that provides bidirectional remote presence are presented to enhance the experience for the remote participants. The proposed solution aims to significantly improve collaboration across sites, thus enhancing remote workplace effectiveness through low cost video conferencing, reducing the need for travel, and serving as an important enabler for eco-sustainability.
Post-equalization bit-errors from ISI-impaired 50G PON transmission experiments are modeled using... more Post-equalization bit-errors from ISI-impaired 50G PON transmission experiments are modeled using Fritchman’s Markov chain. LDPC FEC evaluation with this error model reveals a 0.3-0.6 dB optical power penalty for equalizing ISI including 83 ps/nm dispersion.
Journal of Optical Communications and Networking, Dec 4, 2020
Channel measurements for a 50G passive optical network (PON) show a significant amount of intersy... more Channel measurements for a 50G passive optical network (PON) show a significant amount of intersymbol interference (ISI) due to chromatic dispersion (CD) and the use of low-cost, bandwidth-limited 25 Gbaud class components. The channel characteristics at the input of the forward error correction (FEC) decoder are measured for several receiver equalization schemes, and the error correlation at the output of each equalizer is characterized using a sub-class of a Fritchman’s Markov model. This model is used to generate error sequences that match the observed correlation statistics, and these sequences are then used to evaluate the performance of a candidate low-density parity-check (LDPC) code with lifting factor 256 and hard-input decoding. It is shown that for a bandwidth-limited 50G PON system with 83 ps/nm dispersion, the optical power sensitivity penalty (OPSP) due to a reduction in error correction performance caused by correlated errors is 0.3–0.6 dB. Precoding, i.e., differential encoding of the input data and differential decoding, helps to reduce the OPSP for some equalizers, but the penalty increases for other equalizers. The use of a 256-bit segment-interleaver only marginally improves the decoding performance, whereas bit-interleaving across four codewords reduces the penalty to within 0.05 dB relative to the binary symmetric channel.
2021 29th European Signal Processing Conference (EUSIPCO), 2021
Speech enhancement aims to improve the intelligibility and quality of speech that is affected by ... more Speech enhancement aims to improve the intelligibility and quality of speech that is affected by noise. In this paper, we propose a novel speaker-aware speech enhancement (SASE) method that extracts speaker information using long short-term memory (LSTM) layers, and then uses a convolutional recurrent neural network (CRN) to embed the extracted speaker information. It is shown in a series of comprehensive experiments that only a few seconds of reference audio suffice for the proposed SASE method to perform better than LSTM and CRN baseline systems. The addition of a self-attention mechanism can further boost relevant speech-quality metrics.
DIMACS Series in Discrete Mathematics and Theoretical Computer Science, 2008
Page 1. DIMACS Series in Discrete Mathematics and Theoretical Computer Science I Advances in Info... more Page 1. DIMACS Series in Discrete Mathematics and Theoretical Computer Science I Advances in Information Recording Paul H. Siegel Emina Soljanin Adriaan J. van Wijngaarden Bane Vasic Editors American Mathematical Society Page 2. Page 3. ...
IEEE Journal on Selected Areas in Communications, 2010
ABSTRACT The sequence replacement technique converts an input sequence into a constrained sequenc... more ABSTRACT The sequence replacement technique converts an input sequence into a constrained sequence in which a prescribed subsequence is forbidden to occur. Several coding algorithms are presented that use this technique for the construction of maximum run-length limited sequences. The proposed algorithms show how all forbidden subsequences can be successively or iteratively removed to obtain a constrained sequence and how special subsequences can be inserted at predefined positions in the constrained sequence to represent the indices of the positions where the forbidden subsequences were removed. Several modifications are presented to reduce the impact of transmission errors on the decoding operation, and schemes to provide error control are discussed as well. The proposed algorithms can be implemented efficiently, and the rates of the constructed codes are close to their theoretical maximum. As such, the proposed algorithms are of interest for storage systems and data networks.
Part I. Information theory for sources: Source coding and parallel routing by A. Faridi, K. Sayra... more Part I. Information theory for sources: Source coding and parallel routing by A. Faridi, K. Sayrafian-Pour, M. Alasti, and A. Ephremides Compressing a representation of events in a concurrent system by S. A. Savari Sum rate of a class of multiterminal Gaussian source coding problems by P. Viswanath Coding theorems for reversible embedding by F. M. J. Willems and T. Kalker Part II. Information theory for channels: Unbounded loss in writing on dirty paper is possible by A. S. Cohen and R. Zamir A game-theoretic look at the Gaussian multiaccess channel by R. J. La and V. Anatharam Bounds on the sum timing capacity of single-server queues with multiple input and output terminals by X. Liu and R. Srikant Job scheduling and multiple access by S. Raj, E. Telatar, and D. Tse Fading Gaussian broadcast channels with state information at the receivers by D. Tuninetti and S. Shamai (Shitz) Wireless network information theory by L.-L. Xie and P. R. Kumar The structure of least-favorable noise in...
Video conferencing is becoming an increasingly desirable alternative to face-to-face meetings. Ma... more Video conferencing is becoming an increasingly desirable alternative to face-to-face meetings. Many companies and organizations have multiple locations, and their employees' communication options are typically limited to audio-only conference calls. These are often ineffective because of the limited level of interaction between the participants. Video conferencing is seen as a promising alternative to increase efficiency and reduce carbon emissions by mitigating the need for travel. However, current video conferencing solutions are either too expensive, require dedicated equipment and infrastructure, or are too cumbersome to implement on an individual location basis for widespread use. Low cost solutions usually provide neither the desired level of interaction nor the consistent quality needed for corporate communications. In this paper, we propose a novel hybrid video conferencing architecture that incorporates peer-to-peer communication functions for media distribution. In addition, new concepts, such as novel video cameras, cordless camera adaptors, a two-sided display, and a device that provides bidirectional remote presence are presented to enhance the experience for the remote participants. The proposed solution aims to significantly improve collaboration across sites, thus enhancing remote workplace effectiveness through low cost video conferencing, reducing the need for travel, and serving as an important enabler for eco-sustainability.
Post-equalization bit-errors from ISI-impaired 50G PON transmission experiments are modeled using... more Post-equalization bit-errors from ISI-impaired 50G PON transmission experiments are modeled using Fritchman’s Markov chain. LDPC FEC evaluation with this error model reveals a 0.3-0.6 dB optical power penalty for equalizing ISI including 83 ps/nm dispersion.
Journal of Optical Communications and Networking, Dec 4, 2020
Channel measurements for a 50G passive optical network (PON) show a significant amount of intersy... more Channel measurements for a 50G passive optical network (PON) show a significant amount of intersymbol interference (ISI) due to chromatic dispersion (CD) and the use of low-cost, bandwidth-limited 25 Gbaud class components. The channel characteristics at the input of the forward error correction (FEC) decoder are measured for several receiver equalization schemes, and the error correlation at the output of each equalizer is characterized using a sub-class of a Fritchman’s Markov model. This model is used to generate error sequences that match the observed correlation statistics, and these sequences are then used to evaluate the performance of a candidate low-density parity-check (LDPC) code with lifting factor 256 and hard-input decoding. It is shown that for a bandwidth-limited 50G PON system with 83 ps/nm dispersion, the optical power sensitivity penalty (OPSP) due to a reduction in error correction performance caused by correlated errors is 0.3–0.6 dB. Precoding, i.e., differential encoding of the input data and differential decoding, helps to reduce the OPSP for some equalizers, but the penalty increases for other equalizers. The use of a 256-bit segment-interleaver only marginally improves the decoding performance, whereas bit-interleaving across four codewords reduces the penalty to within 0.05 dB relative to the binary symmetric channel.
2021 29th European Signal Processing Conference (EUSIPCO), 2021
Speech enhancement aims to improve the intelligibility and quality of speech that is affected by ... more Speech enhancement aims to improve the intelligibility and quality of speech that is affected by noise. In this paper, we propose a novel speaker-aware speech enhancement (SASE) method that extracts speaker information using long short-term memory (LSTM) layers, and then uses a convolutional recurrent neural network (CRN) to embed the extracted speaker information. It is shown in a series of comprehensive experiments that only a few seconds of reference audio suffice for the proposed SASE method to perform better than LSTM and CRN baseline systems. The addition of a self-attention mechanism can further boost relevant speech-quality metrics.
DIMACS Series in Discrete Mathematics and Theoretical Computer Science, 2008
Page 1. DIMACS Series in Discrete Mathematics and Theoretical Computer Science I Advances in Info... more Page 1. DIMACS Series in Discrete Mathematics and Theoretical Computer Science I Advances in Information Recording Paul H. Siegel Emina Soljanin Adriaan J. van Wijngaarden Bane Vasic Editors American Mathematical Society Page 2. Page 3. ...
IEEE Journal on Selected Areas in Communications, 2010
ABSTRACT The sequence replacement technique converts an input sequence into a constrained sequenc... more ABSTRACT The sequence replacement technique converts an input sequence into a constrained sequence in which a prescribed subsequence is forbidden to occur. Several coding algorithms are presented that use this technique for the construction of maximum run-length limited sequences. The proposed algorithms show how all forbidden subsequences can be successively or iteratively removed to obtain a constrained sequence and how special subsequences can be inserted at predefined positions in the constrained sequence to represent the indices of the positions where the forbidden subsequences were removed. Several modifications are presented to reduce the impact of transmission errors on the decoding operation, and schemes to provide error control are discussed as well. The proposed algorithms can be implemented efficiently, and the rates of the constructed codes are close to their theoretical maximum. As such, the proposed algorithms are of interest for storage systems and data networks.
Part I. Information theory for sources: Source coding and parallel routing by A. Faridi, K. Sayra... more Part I. Information theory for sources: Source coding and parallel routing by A. Faridi, K. Sayrafian-Pour, M. Alasti, and A. Ephremides Compressing a representation of events in a concurrent system by S. A. Savari Sum rate of a class of multiterminal Gaussian source coding problems by P. Viswanath Coding theorems for reversible embedding by F. M. J. Willems and T. Kalker Part II. Information theory for channels: Unbounded loss in writing on dirty paper is possible by A. S. Cohen and R. Zamir A game-theoretic look at the Gaussian multiaccess channel by R. J. La and V. Anatharam Bounds on the sum timing capacity of single-server queues with multiple input and output terminals by X. Liu and R. Srikant Job scheduling and multiple access by S. Raj, E. Telatar, and D. Tse Fading Gaussian broadcast channels with state information at the receivers by D. Tuninetti and S. Shamai (Shitz) Wireless network information theory by L.-L. Xie and P. R. Kumar The structure of least-favorable noise in...
Uploads
Papers