This paper proposes a novel joint source coding and modulation scheme. The modulation constellation points are selected according to their prior symbol probabilities for better bandwidth as well as better bit error ra...
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This paper proposes a novel joint source coding and modulation scheme. The modulation constellation points are selected according to their prior symbol probabilities for better bandwidth as well as better bit error rate performance. Both the analysis and simulation results are presented to verify that the proposed scheme can achieve better performance than the conventional disjoint source coding and modulation schemes if the modulation and source coding are designed jointly and efficiently.
With Unequal Error Protection (UEP), more important symbols are given greater protection against channel errors than are less important symbols. The protection can be accomplished by various methods, including joint s...
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With Unequal Error Protection (UEP), more important symbols are given greater protection against channel errors than are less important symbols. The protection can be accomplished by various methods, including joint source-channel coding (JSCC) and hierarchical modulation. In this paper, a robust progressive source transmission system using forward error correction (FEC) and a bits-to-symbol assignment methodology that provides UEP is proposed. UEP is not only provided by hierarchical modulation but also by the packetization methodology combined with channel coding. It is demonstrated by simulation that our system improves performance compared to an Equal Error Protection (EEP) technique and to a baseline JSCC-only mechanism.
In conventional wireless systems with layered architectures, the physical layer treats all data streams from upper layers equally and apply the same modulation and coding schemes. Newer systems such as Digital Video B...
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ISBN:
(纸本)9781424458387
In conventional wireless systems with layered architectures, the physical layer treats all data streams from upper layers equally and apply the same modulation and coding schemes. Newer systems such as Digital Video Broadcast start to introduce hierarchical modulation schemes with SuperPosition precoding (SPC) and support data streams of different priorities. However, SPC requires specialized hardware and has high complexity beyond most existing handheld devices. We thus propose scalable modulation (s-mod) by reusing the current mainstream modulation schemes with software-based bit-remapping. In this paper, we study how to optimize the configuration of the PHY layer s-mod and coding schemes to maximize the utility of videos with Scalable Video coding (SVC). Simulation results demonstrate significant performance gains using s-mod and the cross-layer optimization, indicating s-mod and SVC is a good combination for wireless video multicast.
Physical-layer network coding (PNC) is a new electromagnetic-wave based network coding scheme proposed recently to enhance network capacity, which deals with two nodes exchanging information through a relay node. In t...
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ISBN:
(纸本)9781424463275
Physical-layer network coding (PNC) is a new electromagnetic-wave based network coding scheme proposed recently to enhance network capacity, which deals with two nodes exchanging information through a relay node. In this article, based on Turbo code and M-ary phase-shift keying (MPSK), an improved PNC method is proposed. More specifically, the transmitting information of each node is encoded by Turbo codes and modulated to an MPSK signal, and the sum-signal of any two MPSK signals corresponds to a unique exclusive OR (XOR) value of the two transmitting information bits, which can be modulated to a unique MPSK signal. Considering the noise existing in wireless relay channels, Turbo code is adopted to ensure the correctness of signals. Moreover, we analyze the transmission energy consumption of the proposed scheme. It is shown by simulation that the enhanced PNC method can reduce half transmission energy in the relay node over the original PNC.
An example of how circuit related techniques can help solving optimisatin problems originating from completely different domains is provided. It is shown that a specific class of Unconstrained Binary Quadratic Program...
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An example of how circuit related techniques can help solving optimisatin problems originating from completely different domains is provided. It is shown that a specific class of Unconstrained Binary Quadratic Programming (UBQP) problems, including those arising in the optimisation of flutter control via blade mistiming, can be solved by means of ΔΣ modulators. This is done in steps, first restating the UBQP problem as a specific signal processing problem, and then attacking the latter via the design of a ΔΣ modulator with a suitably derived Noise Transfer Function. A (heuristically) optimal solution for the original problem is finally obtained from the modulator output stream. The method is validated by two numerical examples arising in the design of turbo-machines.
In-Band on-Channel (IBOC) broadcasts digital audio signals simultaneously with analog Amplitude modulation (AM) programs in the AM band. The transmit capacity has reached its limitations for the bandwidth, thus, enhan...
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In-Band on-Channel (IBOC) broadcasts digital audio signals simultaneously with analog Amplitude modulation (AM) programs in the AM band. The transmit capacity has reached its limitations for the bandwidth, thus, enhancing digital transmission becomes a key technology in IBOC system. Bit-interleaved coded modulation (BICM) can provide spatial diversity without occupying high bandwidth. Meanwhile, space-time block code (STBC) , the technique of temporal diversity, is applied to raise transmission reliability. Based on spatial and temporal diversity, a scheme that STBC is embedded in MIMO-BICM, can add the reliability and effectivity of transmission over Rayleigh fading channels. In this paper, BICM-STBC instead of the conventional in IBOC would result coding gains and implicative transmit capacity progressively without increasing the bandwidth. The simulation results show when BER is below 10 -4 , the improved channel coding scheme can achieve more than 2 dB coding gains.
This paper presents in the first part a short overview of the Global Positioning System (shortly GPS), used to explain the software approach described in the paper's body. This software approach makes possible to ...
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This paper presents in the first part a short overview of the Global Positioning System (shortly GPS), used to explain the software approach described in the paper's body. This software approach makes possible to emphasize the main aspects of signal processing blocks in GPS receiver, illustrating the entire process involved in coordinates calculation. The software model is implemented and tested in Matlab, but most components are proven to be functional in Octave. The paper describes the most important blocks and present results of simulation.
The achievable performance of a jointly optimised iterative source and channel decoding (ISCD) arrangement invoking the Adaptive MultiRate Wideband (AMR-WB) speech codec is characterized, which exploits the intentiona...
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ISBN:
(纸本)9781424425181;9781424425198
The achievable performance of a jointly optimised iterative source and channel decoding (ISCD) arrangement invoking the Adaptive MultiRate Wideband (AMR-WB) speech codec is characterized, which exploits the intentional redundancy imposed by the proposed Over-Complete source-Mapping (OCM) scheme. The resultant OCM-aided AMR-WB bitstream is protected by a Recursive Systematic Convolutional (RSC) code and mapped to a Differential Space-Time Spreading (DSTS) arrangement using Sphere Packing (SP) modulation for transmission over narrowband temporally correlated Rayleigh fading channels. The effect of appropriately apportioning the total amount of redundancy between the source and channel codecs on the attainable system performance is demonstrated, while keeping the overall coding rate constant. The decoding convergence of the proposed scheme is studied with the aid of Extrinsic Information Transfer (EXIT) charts. Explicitly, our experimental results show that the specific scheme using a 2/3-rate channel encoder and a 3/4-rate OCM scheme exhibits an E b /N 0 gain of 0.7 dB at the SegSNR degradation point of 1 dB, when compared to the system that assigns all the redundancy to the OCM scheme. By contrast, the scheme using a 3/4-rate channel encoder and a 8/9-rate OCM results in an E b /N 0 gain of 1.0 dB.
This paper presents two options of the Inner Symbol interleaving in channel coding of digital television DVB-T and DVB-H standards. Comparison and differences of both the Native and In-depth interleaving are outlined....
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This paper presents two options of the Inner Symbol interleaving in channel coding of digital television DVB-T and DVB-H standards. Comparison and differences of both the Native and In-depth interleaving are outlined. There is also described MATLAB model of the transmission channel and simulation results of the DVB-H system working in an impulse noise conditions are presented. Comparison between the 2k, 4k and 8k transmission modes and different Symbol Interleaving choices are discussed considering specific mode application in DVB-T/H digital television systems.
A novel scheme using single phase modulator for simultaneous generating and decoding of time domain spectral phase encoded signal and DPSK data modulation is proposed and experimentally demonstrated for five 16-chip, ...
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ISBN:
(纸本)9781557528896
A novel scheme using single phase modulator for simultaneous generating and decoding of time domain spectral phase encoded signal and DPSK data modulation is proposed and experimentally demonstrated for five 16-chip, 40GHz/chip optical code patterns.
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