The discrete Fourier transform (DFT) is used for error detection and correction. An iterative decoder is proposed for erasure and impulsive noise which also works with moderate amount of additive random noise. The ite...
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The discrete Fourier transform (DFT) is used for error detection and correction. An iterative decoder is proposed for erasure and impulsive noise which also works with moderate amount of additive random noise. The iterative method is very simple and efficient consisting of modules of fast Fourier transforms (FFT) and inverse FFTs. This iterative decoder can be implemented in a feedback configuration. The authors are working on a DSP implementation of this technique.< >
Reports the performance evaluation of transmitted basic line diagram graphic images, such as street maps and building plans, over a digital mobile radio channel at data rates of 2400 bits/s and 4800 bits/s. A low bit-...
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Reports the performance evaluation of transmitted basic line diagram graphic images, such as street maps and building plans, over a digital mobile radio channel at data rates of 2400 bits/s and 4800 bits/s. A low bit-rate source code is used to represent line diagram images. The characteristics and error analysis of the fading channel have been evaluated by computer simulation. Subjective tests have been carried out to assess the quality and the usefulness of the received images for various mobile channel parameters. The subjective results were acceptable under normal mobile channel conditions. However, the results were seen to degrade under certain conditions. To improve performance, two types of channel error control schemes were considered; forward errorcorrection codes with bit interleaving and ARQ schemes. A substantial improvement in performance was observed using certain channel error control codes.< >
The authors outline the development of an experimental codec for HDTV signals aimed at terrestrial transmission on around 25 Mbit/s fitting into 8 MHz channel space using advanced digital modulation. The codec uses an...
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The authors outline the development of an experimental codec for HDTV signals aimed at terrestrial transmission on around 25 Mbit/s fitting into 8 MHz channel space using advanced digital modulation. The codec uses an extension of the basic motion compensated hybrid-DCT coding algorithm adopted in CCITT (H261), ISO/MPEG and CCIR/ETSI. These extensions include advanced motion estimation/compensation and compression of the motion vector field by the use of intra/inter-DCT coding. The system is based on 1250 lines, 50 Hz 2:1 interlaced pictures using 54 MHz sampling for luminance and 13.5 MHz for chrominance. The system consists of a coder and a decoder with an interface to a COFDM modem for 27 Mbit/s transmission including forward errorcorrection (FEC) suitable for 8 MHz terrestrial channels.< >
The data terminal (HF-Maxi terminal) is an outcome of the research and development done by CRC. The first generation of the HF message terminal developed by CRC (HF-Mini terminal) used a simple selective ARQ protocol ...
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The data terminal (HF-Maxi terminal) is an outcome of the research and development done by CRC. The first generation of the HF message terminal developed by CRC (HF-Mini terminal) used a simple selective ARQ protocol for data transmission reference. Alternate techniques were investigated to improve the ARQ protocol for the second generation of a HF packet radio system by utilizing the soft decision information received in a block with errors in subsequent receptions to improve throughput of the system. The HF-Maxi terminal system was designed built and extensively tested over sky wave paths to prove the viability of transmitting large data files at high speeds through HF radio channels. The system has facilities to input text, data and facsimile images for transmission.< >
This paper is concerned with an assessment of a range of (forward error control) FEC options appropriate to submarine transmission systems. Both established and novel coding arrangements are considered and promising a...
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This paper is concerned with an assessment of a range of (forward error control) FEC options appropriate to submarine transmission systems. Both established and novel coding arrangements are considered and promising avenues for further investigation are identified. We first briefly review the currently proposed RS tributary coding arrangement. We then present alternative coding schemes which offer comparable error performance at the critical region of system operation but with considerably reduced complexity. Implementation aspects, such as tributary versus line rate coding and hard decision versus soft decision decoding, are then discussed. Finally, convolutional codes are revisited and the implications of recently discovered high rate punctured convolutional codes for this application are discussed.< >
Integration of biometrics is considered as an attractive solution for the issues associated with password based human authentication as well as for secure storage and release of cryptographic keys which is one of the ...
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ISBN:
(纸本)9781479951499
Integration of biometrics is considered as an attractive solution for the issues associated with password based human authentication as well as for secure storage and release of cryptographic keys which is one of the critical issues associated with modern ***,the widespread popularity of bio-cryptographic solutions are somewhat restricted by the fuzziness associated with biometric ***,error control mechanisms must be adopted to make sure that fuzziness of biometric inputs can be sufficiently *** this paper,we have outlined such existing techniques used in bio-cryptography while explaining how they are deployed in different types of ***,we have elaborated on the important facts to be considered when choosing appropriate errorcorrection mechanisms for a particular biometric based solution.
A family of (PC) codes of rate v/N is presented, where N is constant and even and v can be varied between N/2 and (N-1). These PC codes are called rate selective punctured convolutional codes of equal code length (RSP...
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A family of (PC) codes of rate v/N is presented, where N is constant and even and v can be varied between N/2 and (N-1). These PC codes are called rate selective punctured convolutional codes of equal code length (RSPC codes). From best known rate 1/2 codes, a set of good RSPC codes of rates 7/12 to 11/12 having memory 2<=M<=6 have been derived, and the maximum free distance d/sub f/ and minimum information weight C(d/sub f/) of these RSPC codes are provided. The RSPC coding/Viterbi decoding scheme with soft decision has been simulated. The obtained bit error rate (BER) performances with rates 7/12 to 11/12 for a Gaussian channel are provided.< >
Signal integrity analysis is a critical part in highspeed interconnect *** common practices to account for noise effect like placement,routing,impedance matching and shielding are usually complex and *** data rate inc...
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Signal integrity analysis is a critical part in highspeed interconnect *** common practices to account for noise effect like placement,routing,impedance matching and shielding are usually complex and *** data rate increases and layout size reduces,there are huge challenges in high-speed interconnect *** paper discusses a new method to overcome the restriction from the perspective of tolerance to *** looking into the noise feature of the interconnect system from transient simulation,the relationship between design parameters and noise effect is *** on the noise model obtained above,the Low Density Parity Check(LDPC)code is *** the calculation of prior information when decoding is modified to make coding more applicable for the interconnection *** bit error rate(BER)of transmission using this optimized LDPC coding is compared with the conventional one by *** the result shows that the case with this new coding has excellent BER performance,demonstrating the feasibility of performance enhancement realized by this new method.
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