The performance of auto control system becomes higher in nuclear power plant (NPP), and the requirement of operation support system changes more advanced. So the inspecting parameters will become more and more, the sa...
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ISBN:
(纸本)9781509000760
The performance of auto control system becomes higher in nuclear power plant (NPP), and the requirement of operation support system changes more advanced. So the inspecting parameters will become more and more, the sampling frequency will change higher and higher, the transmitting data will be produced more and more, the saving space will be demanded bigger and bigger. As auto control system in NPP is a real time system, the saving time of running-data without compression will be increased, and the transmitting data will be walled up or produce error extremely. In this study, we research the statistic character of the running-data by using the experiment data, and then compare the performance between common lossless compression coding methods. The results produced by using experimental data can show that: the lossless compression method basing on statistic characters is not fit for running data in NPP. Run-length coding and differential coding method has the best performance for less changing data. This conclusion can be applied for lossless compression in control system of NPP.
In this paper, we propose a novel differential faster-than-Nyquist (DFTN) signaling scheme, which allows us to dispense with any channel estimation at the receiver while benefiting from the rate boost of faster-than-N...
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ISBN:
(纸本)9781538646595
In this paper, we propose a novel differential faster-than-Nyquist (DFTN) signaling scheme, which allows us to dispense with any channel estimation at the receiver while benefiting from the rate boost of faster-than-Nyquist (FTN) signaling. At the transmitter, differentially modulated binary phase-shift keying (DBPSK) symbols are transmitted with the symbol interval that is smaller than that defined by the Nyquist criterion. The receiver noncoherently estimates the DBPSK symbols, suffering from the effects of FTN-specific inter-symbol interference (ISI), based on frequency-domain equalization. This is enabled, because FTN-specific lSI is deterministic, by assuming that the FTN's symbol packing ratio and the roll-off factor of a shaping filter are known in advance at the receiver.
This paper presents a novel solution for external memory bandwidth reduction in video coding systems. The approach is based on reference frame compression, using a differential coding and a hardware-aware adaptation o...
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ISBN:
(纸本)9781479957521
This paper presents a novel solution for external memory bandwidth reduction in video coding systems. The approach is based on reference frame compression, using a differential coding and a hardware-aware adaptation of the traditional Huffman algorithm, besides, it is a lossless solution fully compliant to state-of-art video coding standards, as H.264/AVC and HEVC. This solution is called DRFVLC (differential Reference Frame Variable-Length Coder) and it uses differential coding to concentrate the samples values distribution. With the samples concentrated, an efficient static Huffman coding is applied to represent them in fewer bits. The DRFVLC reaches an average compression rate higher than 60% for the evaluated HD 1080p video sequences. This compression rate also indicates the external memory bandwidth reduction achieved with our technique. This solution can be easily implemented in hardware demanding one differentiator and a simple variable-length coder.
Ambient backscatter is a new communication technology that utilizes ambient radio frequency signals to enable battery-free devices to communicate with each other. In this paper, we study the problem of signal detectio...
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ISBN:
(纸本)9781479959532
Ambient backscatter is a new communication technology that utilizes ambient radio frequency signals to enable battery-free devices to communicate with each other. In this paper, we study the problem of signal detection and bit error rate (BER) performance for this new communication system where the differential encoding is adopted to eliminate the necessity of channel estimation. We formulate a new transmission model, design the data detection approach, and derive the optimal/approximate closed-form detection thresholds. In addition, the performance at high signal-to-noise region (SNR) is also analyzed, where the lower and the upper bounds of BERs are found. Simulation results are then provided to corroborate our theoretical studies.
Noncoherent multi-user detection schemes are attractive in massive MIMO uplink systems. In particular, sorted decision-feedback differential detection (DFDD) in combination with noncoherent decision-feedback equalizat...
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Noncoherent multi-user detection schemes are attractive in massive MIMO uplink systems. In particular, sorted decision-feedback differential detection (DFDD) in combination with noncoherent decision-feedback equalization (nDFE) over the users has been shown to perform well, avoiding the need for channel estimation. So far, integrating channel coding in massive MIMO systems requires knowledge of the channel, where reliability information for the bits is calculated after combining a large number of symbol observations at the receiver. In this paper, we address one method to calculate reliability information by augmenting the sorted decision-feedback differential detection process. To this end, an equivalent trellis-encoder representation of bit-to-symbol mapping and differential encoding is established. Based on this, log-likelihood ratios for the differential symbols can be calculated. The performance of soft-decision decoding in noncoherent massive MIMO systems is assessed by means of numerical simulations and compared to that of a coherent scheme using channel estimation.
A peak-to-average power ratio (PAPR) reduction technique that exploits the principle of differential encoding of subcarriers is proposed and investigated. The absolute maximum sample of the time-domain OFDM symbol is ...
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ISBN:
(纸本)9781479931026
A peak-to-average power ratio (PAPR) reduction technique that exploits the principle of differential encoding of subcarriers is proposed and investigated. The absolute maximum sample of the time-domain OFDM symbol is chosen as the reference to carry out the differential encoding process at the transmitter. A real multiplier (δ) is applied to this reference to achieve appropriate PAPR level. Information about the proposed reference, however, is required to be communicated to the receiver, which performs the reverse effect to obtain back the original sequence of samples. The effectiveness of the proposed technique is evaluated through extensive computer simulations and complementary cumulative distribution function (CCDF) are obtained as a function of number of subcarriers and modulations. Numerical results confirm that significant reduction in PAPR can be achieved. For example, the proposed technique reduces the 0.1 percent PAPR to 1.5 dB for a 1024 subcarrier OFDM system, resulting in 10.3 dB reduction. Moreover, error performances of the OFDM system before and after applying the proposed technique are investigated using Monte Carlo simulations. Numerical results show that the average bit error rate performance of the proposed system does not degrade relative to the un-encoded system. An investigation of the complexity of the proposed technique with other techniques show that it is quite low complex.
Camera communications is the use of an image sensor to receive LED modulated *** paper shows how frequency shift ON-OFF keying-at frequencies that avoid flicker-can be used to encode bits while at the same time being ...
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ISBN:
(纸本)9781467356985
Camera communications is the use of an image sensor to receive LED modulated *** paper shows how frequency shift ON-OFF keying-at frequencies that avoid flicker-can be used to encode bits while at the same time being successfully decoded by a low frame rate camera using *** is done by selecting mark and space frequencies that are harmonics of the camera frame rate and then processing the subsampled aliased frequencies to decode bit data.
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