ORCID Profile
0000-0002-5861-2873
Current Organisation
Monash University
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Data Format | Coding and Information Theory | Wireless Communications | Communications Technologies |
Mobile Data Networks and Services | Network Infrastructure Equipment | Expanding Knowledge in the Information and Computing Sciences | Electronic Information Storage and Retrieval Services | Mobile Telephone Networks and Services | Communication Networks and Services not elsewhere classified | Management of Greenhouse Gas Emissions from Information and Communication Services
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-06-2023
DOI: 10.36227/TECHRXIV.22011110.V2
Abstract: The design and development of sub-Terahertz (THz) communication systems entail the need for new channel models that can precisely predict channel characteristics at such frequencies ( GHz) in outdoor and dynamic environments. This work proposes a novel hybrid-stochastic ultra-wideband channel model for sub-THz bands, developed within the framework of a class of spatio-temporal stochastic processes called ambit-process. The proposed model is capable of supporting bandwidths of upto 10 GHz. The spatio-temporal evolution of the ambit framework allows for a reasonably accurate and tractable characterization of the fading statistics and multipath propagation of a cellular channel with good spatial consistency. We leverage a recently proposed low-complexity ambit-process based channel simulation algorithm with necessary modifications to study key features of the outdoor sub-THz channel like associated diffused scattering, molecular absorption, spatio-temporal correlations, and consistency between the time-evolving delay and Doppler of the multipaths. Simulation results on path loss, delay spread, and channel correlation indicate that the ambit model accurately captures the typicalities of an urban microcellular sub-THz channel and agrees well with the measurement results reported in the literature.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-02-2023
DOI: 10.36227/TECHRXIV.22011110.V1
Abstract: The design and development of sub-Terahertz (THz) communication systems entail the need for new channel models that can precisely predict channel characteristics at such frequencies ( GHz) in outdoor and dynamic environments. This work proposes a novel hybrid-stochastic ultra-wideband channel model for sub-THz bands, developed within the framework of a class of spatio-temporal stochastic processes called ambit-process. The proposed model is capable of supporting bandwidths of upto 10 GHz. The spatio-temporal evolution of the ambit framework allows for a reasonably accurate and tractable characterization of the fading statistics and multipath propagation of a cellular channel with good spatial consistency. We leverage a recently proposed low-complexity ambit-process based channel simulation algorithm with necessary modifications to study key features of the outdoor sub-THz channel like associated diffused scattering, molecular absorption, spatio-temporal correlations, and consistency between the time-evolving delay and Doppler of the multipaths. Simulation results on path loss, delay spread, and channel correlation indicate that the ambit model accurately captures the typicalities of an urban microcellular sub-THz channel and agrees well with the measurement results reported in the literature.
Publisher: IEEE
Date: 08-2014
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2015
Publisher: IEEE
Date: 02-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-1998
DOI: 10.1109/18.681321
Publisher: IEEE
Date: 04-2008
Publisher: Now Publishers
Date: 2004
DOI: 10.1561/0100000003
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-1998
DOI: 10.1109/18.681327
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2009
Publisher: IEEE
Date: 04-2018
Publisher: IEEE
Date: 11-2018
Publisher: IEEE
Date: 06-2007
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2004
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2014
Publisher: IEEE
Date: 11-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2012
Publisher: IEEE
Date: 04-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 28-01-2022
DOI: 10.36227/TECHRXIV.18865082
Abstract: This paper presents unitary-precoded single-carrier (USC) modulation as a family of waveforms based on multiplexing the information symbols on time domain unitary basis functions. The common property of these basis functions is that they span the entire time and frequency plane. / The recently proposed orthogonal time frequency space (OTFS) and orthogonal time sequency multiplexing (OTSM) based on discrete Fourier transform (DFT) and Walsh Hadamard transform (WHT), respectively, fall in the general framework of USC waveforms. In this work, we present channel estimation and detection methods that work for any USC waveform and numerically show that any choice of unitary precoding results in the same error performance. Lastly, we implement some USC systems and compare their performance with OFDM in a real-time indoor setting using an SDR platform. /
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2008
Publisher: IEEE
Date: 07-2014
Publisher: Springer Science and Business Media LLC
Date: 29-04-2008
DOI: 10.1155/2008/548741
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-1999
DOI: 10.1109/18.771234
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2016
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2000
DOI: 10.1109/18.868475
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2013
Publisher: IEEE
Date: 29-03-2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1996
DOI: 10.1109/18.481786
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2020
Publisher: IEEE
Date: 05-2008
Publisher: IEEE
Date: 04-2015
Publisher: IEEE
Date: 05-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2021
Publisher: IEEE
Date: 05-2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2011
Publisher: The Optical Society
Date: 11-01-2012
DOI: 10.1364/OE.20.001635
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 21-01-2021
DOI: 10.36227/TECHRXIV.13246931.V2
Abstract: This paper presents a linear complexity iterative rake detector for the recently proposed orthogonal time frequency space (OTFS) modulation scheme. The basic idea is to extract and coherently combine the received multipath components of the transmitted symbols in the delay-Doppler grid using maximal ratio combining (MRC) to improve the SNR of the combined signal. We reformulate the OTFS input-output relation in simple vector form by placing guard null symbols or zero padding (ZP) in the delay-Doppler grid and exploiting the resulting circulant property of the blocks of the channel matrix. Using this vector input-output relation we propose a low complexity iterative decision feedback equalizer (DFE) based on MRC. The performance and complexity of the proposed detector favorably compares with the state of the art message passing detector. An alternative time domain MRC based detector is also proposed for even faster detection. We further propose a Gauss-Seidel based over-relaxation parameter in the rake detector to improve the performance and the convergence speed of the iterative detection. We also show how the MRC detector can be combined with outer error-correcting codes to operate as a turbo DFE scheme to further improve the error performance. / All results are compared with a baseline orthogonal frequency ision multiplexing (OFDM) scheme employing a single tap minimum mean square error (MMSE) equalizer. /
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 19-11-2020
DOI: 10.36227/TECHRXIV.13246931.V1
Abstract: This paper presents a linear complexity iterative rake detector for the recently proposed orthogonal time frequency space (OTFS) modulation scheme. The basic idea is to extract and coherently combine the received multipath components of the transmitted symbols in the delay-Doppler grid using maximal ratio combining (MRC) to improve the SNR of the combined signal. We reformulate the OTFS input-output relation in simple vector form by placing guard null symbols or zero padding (ZP) in the delay-Doppler grid and exploiting the resulting circulant property of the blocks of the channel matrix. Using this vector input-output relation we propose a low complexity iterative decision feedback equalizer (DFE) based on MRC. The performance and complexity of the proposed detector favorably compares with the state of the art message passing detector. An alternative time domain MRC based detector is also proposed for even faster detection. We further propose a Gauss-Seidel based over-relaxation parameter in the rake detector to improve the performance and the convergence speed of the iterative detection. We also show how the MRC detector can be combined with outer error-correcting codes to operate as a turbo DFE scheme to further improve the error performance. / All results are compared with a baseline orthogonal frequency ision multiplexing (OFDM) scheme employing a single tap minimum mean square error (MMSE) equalizer. /
Publisher: IEEE
Date: 07-2019
Publisher: Institution of Engineering and Technology (IET)
Date: 03-2019
DOI: 10.1049/EL.2018.6940
Publisher: The Optical Society
Date: 23-10-2014
DOI: 10.1364/OE.22.027026
Publisher: IEEE
Date: 06-2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2020
Publisher: IEEE
Date: 06-2010
Publisher: IEEE
Date: 11-2014
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2004
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1999
DOI: 10.1109/18.782126
Publisher: IEEE
Date: 05-2017
Publisher: IEEE
Date: 1999
Publisher: IEEE
Date: 06-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2006
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 15-01-2021
DOI: 10.36227/TECHRXIV.12619706
Abstract: Polarization-adjusted convolutional (PAC) codes are special concatenated codes in which we employ a one-to-one convolutional transform as a pre-coding step before the polar transform. In this scheme, the polar transform (as a mapper) and the successive cancellation process (as a demapper) present a synthetic vector channel to the convolutional transformation. The numerical results show that this concatenation improves the Hamming distance properties of polar codes. / In this work, we implement the parallel list Viterbi algorithm (LVA) and show how the error correction performance moves from the poor performance of the Viterbi algorithm (VA) to the superior performance of list decoding by changing the constraint length, list size, and the sorting strategy (local sorting and global sorting) in the LVA. Also, we analyze the latency of the local sorting of the paths in LVA relative to the global sorting in the list decoding and the trade-off between the sorting latency and the error correction performance. /
Publisher: IEEE
Date: 06-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-02-2023
DOI: 10.36227/TECHRXIV.21993275
Abstract: The design and development of sub-Terahertz (sub-THz) cellular systems entail the need for new channel models that can precisely predict channel characteristics beyond 100 GHz in outdoor and dynamic environments. This work proposes a novel multiple-input and multiple-output (MIMO) channel model for cellular communication, developed within the framework of a class of spatio temporal stochastic processes called ambit-process. The modeling methodology effectively captures the typicalities of sub-THz propagation like molecular absorption and scattering of the evolving multipaths while accounting for the propagation delay of electromagnetic waves across large array apertures deployed at the transmitter and the receiver. This allows for an accurate characterization of the spatial-wideband effect along with other relevant spatio-temporal attributes of the channel. Numerical simulations indicate a good level of agreement between the spectral efficiency and spatio-temporal correlation of the proposed model against a state-of-the-art stochastic Terahertz (THz) channel model and measurements reported in literature.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2016
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2012
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2020
Publisher: IEEE
Date: 04-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2001
DOI: 10.1109/49.914497
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2019
Publisher: IEEE
Date: 2013
Publisher: IEEE
Date: 06-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 19-01-2021
DOI: 10.36227/TECHRXIV.13580678.V1
Abstract: In the Shannon lecture at the 2019 International Symposium on Information Theory (ISIT), Arıkan proposed to employ a one-to-one convolutional transform as a pre-coding step before the polar transform. The resulting codes of this concatenation are called polarization-adjusted convolutional (PAC) codes. In this scheme, a pair of polar mapper and demapper as pre- and postprocessing devices are deployed around a memoryless channel, which provides polarized information to an outer decoder leading to improved error correction performance of the outer code. In this paper, the list decoding and sequential decoding (including Fano decoding and stack decoding) are first adapted for use to decode PAC codes. Then, to reduce the complexity of sequential decoding of PAC olar codes, we propose (i) an adaptive heuristic metric, (ii) tree search constraints for backtracking to avoid exploration of unlikely sub-paths, and (iii) tree search strategies consistent with the pattern of error occurrence in polar codes. These contribute to the reduction of the average decoding time complexity from 50% to 80%, trading with 0.05 to 0.3 dB degradation in error correction performance within FER=10^-3 range, respectively, relative to not applying the corresponding search strategies. Additionally, as an important ingredient in Fano decoding of PAC olar codes, an efficient computation method for the intermediate LLRs and partial sums is provided. This method is effective in backtracking and avoids storing the intermediate information or restarting the decoding process. Eventually, all three decoding algorithms are compared in terms of performance, complexity, and resource requirements.
Publisher: Elsevier
Date: 2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-07-2020
DOI: 10.36227/TECHRXIV.12628718.V1
Abstract: In this paper, we present a novel method to expand a graph over a finite field into a larger one over one of / the original field’s subfields. This allows a number of different graph expansions for any given graph. / These expansions can be used in various applications, and we focus specifically on the case of decoding / NB-LDPC codes. Using the novel expanded graphs, it is possible to reduce decoding complexity of NB- / LDPC codes significantly with minimal performance losses. /
Publisher: IEEE
Date: 2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 28-01-2022
DOI: 10.36227/TECHRXIV.18865082.V1
Abstract: This paper presents unitary-precoded single-carrier (USC) modulation as a family of waveforms based on multiplexing the information symbols on time domain unitary basis functions. The common property of these basis functions is that they span the entire time and frequency plane. / The recently proposed orthogonal time frequency space (OTFS) and orthogonal time sequency multiplexing (OTSM) based on discrete Fourier transform (DFT) and Walsh Hadamard transform (WHT), respectively, fall in the general framework of USC waveforms. In this work, we present channel estimation and detection methods that work for any USC waveform and numerically show that any choice of unitary precoding results in the same error performance. Lastly, we implement some USC systems and compare their performance with OFDM in a real-time indoor setting using an SDR platform. /
Publisher: IEEE
Date: 1995
Publisher: IEEE
Date: 05-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2013
Publisher: IEEE
Date: 07-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 14-06-2021
DOI: 10.36227/TECHRXIV.14404460
Abstract: This paper proposes orthogonal time sequency multiplexing (OTSM), a novel single carrier modulation scheme that places information symbols in the delay-sequency domain followed by a cascade of time- ision multiplexing (TDM) and Walsh-Hadamard sequence multiplexing. Thanks to the Walsh Hadamard transform (WHT), the modulation and demodulation do not require complex domain multiplications. For the proposed OTSM, we first derive the input-output relation in the delay-sequency domain and present a low complexity detection method taking advantage of zero-padding. We demonstrate via simulations that OTSM offers high performance gains over orthogonal frequency ision multiplexing (OFDM) and similar performance to orthogonal time frequency space (OTFS), but at lower complexity owing to WHT. Then we propose a low complexity time-domain channel estimation method. Finally, we show how to include an outer error control code and a turbo decoder to improve error performance of the coded system.
Publisher: IEEE
Date: 05-2019
Publisher: IEEE
Date: 09-2019
Publisher: IEEE
Date: 03-2008
Publisher: IEEE
Date: 03-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-06-2023
DOI: 10.36227/TECHRXIV.22011110
Abstract: The design and development of sub-Terahertz (THz) communication systems entail the need for new channel models that can precisely predict channel characteristics at such frequencies ( GHz) in outdoor and dynamic environments. This work proposes a novel hybrid-stochastic ultra-wideband channel model for sub-THz bands, developed within the framework of a class of spatio-temporal stochastic processes called ambit-process. The proposed model is capable of supporting bandwidths of upto 10 GHz. The spatio-temporal evolution of the ambit framework allows for a reasonably accurate and tractable characterization of the fading statistics and multipath propagation of a cellular channel with good spatial consistency. We leverage a recently proposed low-complexity ambit-process based channel simulation algorithm with necessary modifications to study key features of the outdoor sub-THz channel like associated diffused scattering, molecular absorption, spatio-temporal correlations, and consistency between the time-evolving delay and Doppler of the multipaths. Simulation results on path loss, delay spread, and channel correlation indicate that the ambit model accurately captures the typicalities of an urban microcellular sub-THz channel and agrees well with the measurement results reported in the literature.
Publisher: IEEE
Date: 07-2012
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: IEEE
Date: 2013
Publisher: IEEE
Date: 2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 14-04-2021
DOI: 10.36227/TECHRXIV.14404460.V1
Abstract: This paper proposes orthogonal time sequency multiplexing (OTSM), a novel single carrier modulation scheme that places information symbols in the delay-sequency domain followed by a cascade of time- ision multiplexing (TDM) and Walsh-Hadamard sequence multiplexing. Thanks to the Walsh Hadamard transform (WHT), the modulation and demodulation do not require complex domain multiplications. For the proposed OTSM, we first derive the input-output relation in the delay-sequency domain and present a low complexity detection method taking advantage of zero-padding. We demonstrate via simulations that OTSM offers high performance gains over orthogonal frequency ision multiplexing (OFDM) and similar performance to orthogonal time frequency space (OTFS), but at lower complexity owing to WHT. Then we propose a low complexity time-domain channel estimation method. Finally, we show how to include an outer error control code and a turbo decoder to improve error performance of the coded system.
Publisher: IEEE
Date: 07-2019
Publisher: IEEE
Date: 05-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 14-06-2021
DOI: 10.36227/TECHRXIV.14404460.V2
Abstract: This paper proposes orthogonal time sequency multiplexing (OTSM), a novel single carrier modulation scheme that places information symbols in the delay-sequency domain followed by a cascade of time- ision multiplexing (TDM) and Walsh-Hadamard sequence multiplexing. Thanks to the Walsh Hadamard transform (WHT), the modulation and demodulation do not require complex domain multiplications. For the proposed OTSM, we first derive the input-output relation in the delay-sequency domain and present a low complexity detection method taking advantage of zero-padding. We demonstrate via simulations that OTSM offers high performance gains over orthogonal frequency ision multiplexing (OFDM) and similar performance to orthogonal time frequency space (OTFS), but at lower complexity owing to WHT. Then we propose a low complexity time-domain channel estimation method. Finally, we show how to include an outer error control code and a turbo decoder to improve error performance of the coded system.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2015
Publisher: IEEE
Date: 06-2015
Publisher: IEEE
Date: 07-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-07-2020
DOI: 10.36227/TECHRXIV.12628718
Abstract: In this paper, we present a novel method to expand a graph over a finite field into a larger one over one of / the original field’s subfields. This allows a number of different graph expansions for any given graph. / These expansions can be used in various applications, and we focus specifically on the case of decoding / NB-LDPC codes. Using the novel expanded graphs, it is possible to reduce decoding complexity of NB- / LDPC codes significantly with minimal performance losses. /
Publisher: IEEE
Date: 08-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2019
Publisher: IEEE
Date: 11-2014
Publisher: IEEE
Date: 04-2015
Publisher: IEEE
Date: 07-2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2008
Publisher: IEEE
Date: 04-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1999
DOI: 10.1109/18.782174
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2005
Publisher: IEEE
Date: 2007
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2018
Publisher: IEEE
Date: 07-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2022
Publisher: IEEE
Date: 11-2014
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-1996
DOI: 10.1109/18.485720
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2017
Publisher: IEEE
Date: 07-2006
Publisher: American Institute of Mathematical Sciences (AIMS)
Date: 11-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2018
Publisher: IEEE
Date: 03-2008
Publisher: IEEE
Date: 09-2008
Publisher: IEEE
Date: 06-2017
Publisher: IEEE
Date: 2012
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2013
Publisher: Kluwer Academic Publishers
Date: 2006
Publisher: Institution of Engineering and Technology (IET)
Date: 1999
DOI: 10.1049/EL:19991190
Publisher: IEEE
Date: 2006
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 19-01-2021
DOI: 10.36227/TECHRXIV.13580678
Abstract: In the Shannon lecture at the 2019 International Symposium on Information Theory (ISIT), Arıkan proposed to employ a one-to-one convolutional transform as a pre-coding step before the polar transform. The resulting codes of this concatenation are called polarization-adjusted convolutional (PAC) codes. In this scheme, a pair of polar mapper and demapper as pre- and postprocessing devices are deployed around a memoryless channel, which provides polarized information to an outer decoder leading to improved error correction performance of the outer code. In this paper, the list decoding and sequential decoding (including Fano decoding and stack decoding) are first adapted for use to decode PAC codes. Then, to reduce the complexity of sequential decoding of PAC olar codes, we propose (i) an adaptive heuristic metric, (ii) tree search constraints for backtracking to avoid exploration of unlikely sub-paths, and (iii) tree search strategies consistent with the pattern of error occurrence in polar codes. These contribute to the reduction of the average decoding time complexity from 50% to 80%, trading with 0.05 to 0.3 dB degradation in error correction performance within FER=10^-3 range, respectively, relative to not applying the corresponding search strategies. Additionally, as an important ingredient in Fano decoding of PAC olar codes, an efficient computation method for the intermediate LLRs and partial sums is provided. This method is effective in backtracking and avoids storing the intermediate information or restarting the decoding process. Eventually, all three decoding algorithms are compared in terms of performance, complexity, and resource requirements.
Publisher: IEEE
Date: 06-2015
Publisher: IEEE
Date: 11-2014
Publisher: IEEE
Date: 1995
Publisher: IEEE
Date: 2003
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1994
DOI: 10.1109/20.334299
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2009
Publisher: Springer Science and Business Media LLC
Date: 23-06-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2007
Publisher: IEEE
Date: 12-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1998
DOI: 10.1109/4234.658610
Publisher: IEEE
Date: 08-2019
Publisher: Hindawi Limited
Date: 24-03-2008
DOI: 10.1155/2008/351962
Abstract: Multi-input multi-output (MIMO) systems combined with orthogonal frequency- ision multiplexing (OFDM) gained a wide popularity in wireless applications due to the potential of providing increased channel capacity and robustness against multipath fading channels. However these advantages come at the cost of a very high processing complexity and the efficient implementation of MIMO-OFDM receivers is today a major research topic. In this paper, efficient architectures are proposed for the hardware implementation of the main building blocks of a MIMO-OFDM receiver. A sphere decoder architecture flexible to different modulation without any loss in BER performance is presented while the proposed matrix factorization implementation allows to achieve the highest throughput specified in the IEEE 802.11n standard. Finally a novel sphere decoder approach is presented, which allows for the realization of new golden space time trellis coded modulation (GST-TCM) scheme. Implementation cost and offered throughput are provided for the proposed architectures synthesized on a 0.13 CMOS standard cell technology or on advanced FPGA devices.
Publisher: Informa UK Limited
Date: 07-1998
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2018
Publisher: IGI Global
Date: 2012
DOI: 10.4018/978-1-4666-1616-5.CH011
Abstract: This chapter presents a different perspective on the chipless RFID system where the chipless RFID detection problem is viewed in terms of a digital communication point of view. A novel mathematical model is presented, and a novel approach to detection is formulated based on the model. The chipless RFID tag frequency signatures are visualized as points in a signal space. Although data bits are stored in the tags using unconventional techniques, the proposed model enables the detection of these data bits through conventional robust detection methods. Through simulations it is shown that the proposed detection method has better performance compared to contemporary detection approaches.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 21-01-2021
DOI: 10.36227/TECHRXIV.13580201
Abstract: This paper proposes i orthogonal time sequency multiplexing /i (OTSM), a novel single carrier modulation scheme based on the well known Walsh-Hadamard transform (WHT) combined with row-column interleaving, and zero padding (ZP) between blocks in the time-domain. The information symbols in OTSM are multiplexed in the delay and sequency domain using a cascade of time- ision and Walsh-Hadamard (sequency) multiplexing. By using the WHT for transmission and reception, the modulation and demodulation steps do not require any complex multiplications. We then propose two low-complexity detectors: (i) a simpler non-iterative detector based on a single tap minimum mean square time-frequency domain equalizer and (ii) an iterative time-domain detector. We demonstrate, via numerical simulations, that the proposed modulation scheme offers high performance gains over orthogonal frequency ision multiplexing (OFDM) and exhibits the same performance of orthogonal time frequency space (OTFS) modulation, but with lower complexity. In proposing OTSM, along with simple detection schemes, we offer the lowest complexity solution to achieving reliable communication in high mobility wireless channels, as compared to the available schemes published so far in the literature.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1999
DOI: 10.1109/18.796396
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2022
Publisher: IEEE
Date: 07-2016
Publisher: IEEE
Date: 12-2006
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2018
Publisher: IEEE
Date: 10-2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2022
Publisher: IEEE
Date: 08-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2021
Publisher: Informa UK Limited
Date: 07-1990
Publisher: IEEE
Date: 04-2007
Publisher: IEEE
Date: 2005
Publisher: IEEE
Date: 06-2014
Publisher: IEEE
Date: 10-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 21-01-2021
DOI: 10.36227/TECHRXIV.13580201.V2
Abstract: This paper proposes i orthogonal time sequency multiplexing /i (OTSM), a novel single carrier modulation scheme based on the well known Walsh-Hadamard transform (WHT) combined with row-column interleaving, and zero padding (ZP) between blocks in the time-domain. The information symbols in OTSM are multiplexed in the delay and sequency domain using a cascade of time- ision and Walsh-Hadamard (sequency) multiplexing. By using the WHT for transmission and reception, the modulation and demodulation steps do not require any complex multiplications. We then propose two low-complexity detectors: (i) a simpler non-iterative detector based on a single tap minimum mean square time-frequency domain equalizer and (ii) an iterative time-domain detector. We demonstrate, via numerical simulations, that the proposed modulation scheme offers high performance gains over orthogonal frequency ision multiplexing (OFDM) and exhibits the same performance of orthogonal time frequency space (OTFS) modulation, but with lower complexity. In proposing OTSM, along with simple detection schemes, we offer the lowest complexity solution to achieving reliable communication in high mobility wireless channels, as compared to the available schemes published so far in the literature.
Publisher: MDPI AG
Date: 29-08-2022
DOI: 10.3390/E24091210
Abstract: In the successive cancellation (SC) list decoding, the tree pruning operation retains the L best paths with respect to a metric at every decoding step. However, the correct path might be among the L worst paths due to the imposed penalties. In this case, the correct path is pruned and the decoding process fails. shifted pruning (SP) scheme can recover the correct path by additional decoding attempts when decoding fails, in which the pruning window is shifted by κ≤L paths over certain bit positions. A special case of the shifted pruning scheme where κ=L is known as SCL-flip decoding, which was independently proposed in 2019. In this work, a new metric that performs better in particular for medium and long codes is proposed, and nested shift-pruning schemes are suggested for improving the average complexity.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 19-01-2021
DOI: 10.36227/TECHRXIV.13580201.V1
Abstract: This paper proposes i orthogonal time sequency multiplexing /i (OTSM), a novel single carrier modulation scheme based on the well known Walsh-Hadamard transform (WHT) combined with row-column interleaving, and zero padding (ZP) between blocks in the time-domain. The information symbols in OTSM are multiplexed in the delay and sequency domain using a cascade of time- ision and Walsh-Hadamard (sequency) multiplexing. By using the WHT for transmission and reception, the modulation and demodulation steps do not require any complex multiplications. We then propose two low-complexity detectors: (i) a simpler non-iterative detector based on a single tap minimum mean square time-frequency domain equalizer and (ii) an iterative time-domain detector. We demonstrate, via numerical simulations, that the proposed modulation scheme offers high performance gains over orthogonal frequency ision multiplexing (OFDM) and exhibits the same performance of orthogonal time frequency space (OTFS) modulation, but with lower complexity. In proposing OTSM, along with simple detection schemes, we offer the lowest complexity solution to achieving reliable communication in high mobility wireless channels, as compared to the available schemes published so far in the literature.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: IEEE
Date: 05-2010
Publisher: IEEE
Date: 2008
DOI: 10.1109/ICC.2008.56
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2014
Publisher: IEEE
Date: 07-2006
Publisher: IEEE
Date: 04-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2001
DOI: 10.1109/4234.929603
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2020
Publisher: IEEE
Date: 03-2017
Publisher: IEEE
Date: 2003
Publisher: ACM Press
Date: 2007
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2016
Publisher: IEEE
Date: 09-2008
Publisher: IEEE
Date: 06-2013
Publisher: Association for Computing Machinery (ACM)
Date: 02-2010
Abstract: A wireless sensor network with randomly deployed nodes can be used to provide an irregular s ling of a physical field of interest. We assume that a sink node collects the data gathered by the sensors and uses a linear filter for the reconstruction of a bandlimited scalar field defined over a d -dimensional domain. Sensors' locations are assumed to be known at the sink node, up to a certain position error. We then take the mean square error (MSE) of the reconstructed field as performance metric, and evaluate the effect of both uniform and quasi-equally spaced sensor layouts on the quality of the reconstructed field. We define a parameter that provides a measure of the regularity of the sensors deployment, and, through asymptotic analysis, we derive the MSE in the case of different sensor spatial distributions. For two of them, an approximate closed form expression is obtained. We validate our analysis through numerical results, and we show that an excellent match exists between analysis and simulation even for a small number of sensors.
Publisher: IEEE
Date: 1999
Publisher: IEEE
Date: 09-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 21-01-2021
DOI: 10.36227/TECHRXIV.13246931
Abstract: This paper presents a linear complexity iterative rake detector for the recently proposed orthogonal time frequency space (OTFS) modulation scheme. The basic idea is to extract and coherently combine the received multipath components of the transmitted symbols in the delay-Doppler grid using maximal ratio combining (MRC) to improve the SNR of the combined signal. We reformulate the OTFS input-output relation in simple vector form by placing guard null symbols or zero padding (ZP) in the delay-Doppler grid and exploiting the resulting circulant property of the blocks of the channel matrix. Using this vector input-output relation we propose a low complexity iterative decision feedback equalizer (DFE) based on MRC. The performance and complexity of the proposed detector favorably compares with the state of the art message passing detector. An alternative time domain MRC based detector is also proposed for even faster detection. We further propose a Gauss-Seidel based over-relaxation parameter in the rake detector to improve the performance and the convergence speed of the iterative detection. We also show how the MRC detector can be combined with outer error-correcting codes to operate as a turbo DFE scheme to further improve the error performance. / All results are compared with a baseline orthogonal frequency ision multiplexing (OFDM) scheme employing a single tap minimum mean square error (MMSE) equalizer. /
Publisher: IEEE
Date: 10-2011
Publisher: IEEE
Date: 11-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2020
Publisher: ETH Zurich
Date: 2014
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2003
Publisher: IEEE
Date: 06-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2008
Publisher: IEEE
Date: 11-2014
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2015
Publisher: IEEE
Date: 08-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2022
Publisher: IEEE
Date: 10-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2022
Publisher: IEEE
Date: 2002
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2020
Publisher: Institution of Engineering and Technology (IET)
Date: 1996
DOI: 10.1049/EL:19960816
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2013
Publisher: IEEE
Date: 02-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2009
Publisher: IEEE
Date: 07-2019
Publisher: Institution of Engineering and Technology (IET)
Date: 1992
DOI: 10.1049/EL:19921295
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2006
Publisher: IEEE
Date: 2016
Publisher: IEEE
Date: 12-2011
Publisher: IEEE
Date: 08-2008
Publisher: IEEE
Date: 02-2014
Publisher: IEEE
Date: 05-2020
Publisher: IEEE
Date: 07-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2009
Publisher: IEEE
Date: 2007
Publisher: Wiley
Date: 07-09-2016
DOI: 10.1002/ETT.2984
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-07-2020
DOI: 10.36227/TECHRXIV.12619706.V1
Abstract: Polarization-adjusted convolutional (PAC) codes are special concatenated codes in which we employ a one-to-one convolutional transform as a pre-coding step before the polar transform. In this scheme, the polar transform (as a mapper) and the successive cancellation process (as a demapper) present a synthetic vector channel to the convolutional transformation. The numerical results show that this concatenation improves the Hamming distance properties of polar codes. / In this work, we implement the parallel list Viterbi algorithm (LVA) and show how the error correction performance moves from the poor performance of the Viterbi algorithm (VA) to the superior performance of list decoding by changing the constraint length, list size, and the sorting strategy (local sorting and global sorting) in the LVA. Also, we analyze the latency of the local sorting of the paths in LVA relative to the global sorting in the list decoding and the trade-off between the sorting latency and the error correction performance. /
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 15-01-2021
DOI: 10.36227/TECHRXIV.12619706.V2
Abstract: Polarization-adjusted convolutional (PAC) codes are special concatenated codes in which we employ a one-to-one convolutional transform as a pre-coding step before the polar transform. In this scheme, the polar transform (as a mapper) and the successive cancellation process (as a demapper) present a synthetic vector channel to the convolutional transformation. The numerical results show that this concatenation improves the Hamming distance properties of polar codes. / In this work, we implement the parallel list Viterbi algorithm (LVA) and show how the error correction performance moves from the poor performance of the Viterbi algorithm (VA) to the superior performance of list decoding by changing the constraint length, list size, and the sorting strategy (local sorting and global sorting) in the LVA. Also, we analyze the latency of the local sorting of the paths in LVA relative to the global sorting in the list decoding and the trade-off between the sorting latency and the error correction performance. /
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2012
Publisher: IEEE
Date: 2000
Publisher: IEEE
Date: 04-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2016
Publisher: IEEE
Date: 02-2014
Publisher: IEEE
Date: 04-2015
Publisher: Wiley
Date: 15-04-2003
DOI: 10.1002/0471219282.EOT378
Abstract: Permutation codes are special spherical codes designed for the bandlimited Gaussian channel. A Variant I permutation code is the set of codewords obtained by taking all permutations of an initial vector in the n ‐dimensional Euclidean space. A Variant II permutation code is the set of codewords obtained by taking all permutations and sign changes of the components of an initial vector in the n ‐dimensional Euclidean space. These codes may be attractive because of their simple maximum likelihood decoding algorithm.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Publisher: IEEE
Date: 05-2009
Publisher: IEEE
Date: 02-2014
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-02-2023
DOI: 10.36227/TECHRXIV.21993275.V1
Abstract: The design and development of sub-Terahertz (sub-THz) cellular systems entail the need for new channel models that can precisely predict channel characteristics beyond 100 GHz in outdoor and dynamic environments. This work proposes a novel multiple-input and multiple-output (MIMO) channel model for cellular communication, developed within the framework of a class of spatio temporal stochastic processes called ambit-process. The modeling methodology effectively captures the typicalities of sub-THz propagation like molecular absorption and scattering of the evolving multipaths while accounting for the propagation delay of electromagnetic waves across large array apertures deployed at the transmitter and the receiver. This allows for an accurate characterization of the spatial-wideband effect along with other relevant spatio-temporal attributes of the channel. Numerical simulations indicate a good level of agreement between the spectral efficiency and spatio-temporal correlation of the proposed model against a state-of-the-art stochastic Terahertz (THz) channel model and measurements reported in literature.
Publisher: IEEE
Date: 05-2020
Start Date: 12-2020
End Date: 06-2024
Amount: $420,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 03-2017
Amount: $330,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 10-2016
Amount: $270,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 11-2016
End Date: 12-2018
Amount: $345,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2016
End Date: 12-2019
Amount: $310,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2020
End Date: 06-2024
Amount: $487,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2016
End Date: 12-2019
Amount: $335,000.00
Funder: Australian Research Council
View Funded Activity