digital symbol timing recovery

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Analysis and performance of coded symbol recovery loop using oversampling

Analysis and performance of coded symbol recovery loop using oversampling

hardware is a closed loop made of a phase detector, a voltage pump, a low-pass filter, a VCO, and finally a fre- quency divider by 2. In particular, the phase detector gains a binary data for both the pilot sequence and the RX side clock, sampling these waveforms at clock 1/8T, by using eight different clocks , CLK1, CLK2, ..., CLK8. Moreover, the digital phase detector measures the leading one of the two 8-bit registers at the CLK8-positive edge: P[7:0] (linked to the pilot sequence) and C[7:0] (linked to the RX oscillation), starting from the most significant bit (MSB) to the least significant bit (LSB) deriving two numbers CP and CC respectively. When CC < CP, the positive edge of the RX clock anticipates the positive edge of the pilot sequence so the pump receives an impulse to increase the voltage at the loop filter input. When CC > CP, the pump receives the command to decrease the output value. Finally, when CP = CC the two waveforms are aligned in phase, the pump clears the output value, and the VCO runs with the final offset, acquiring the timing recovery. We simulate with voltage step of 1.0 V for the analog pump, a loop filter with pole at 100 Mhz and a VCO with sensitivity K 0 such that K F · K 0 = 0.052. This sub-system
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A Novel and Efficient Mixed Signal VLSI Circuit for Multimode Demodulator

A Novel and Efficient Mixed Signal VLSI Circuit for Multimode Demodulator

587 The Gardner loop method is developed for BPSK and QPSK symbol synchronization. It basically detects the zero crossing point of the symbols, and corrects the gradient using neighboring sample values. The recursion process is performed to reduce the error for timing recovery, and a timing tone is recovered though convergence. To avoid the interpolation operation needed to estimate the correct sampling instance, a 4-bit digital timing-error signal is converted to analog domain using a 5-bit high-speed current-steering DAC. Then, the timing-error signal is filtered by a passive loop filter at a loop bandwidth of 2 MHz. This error signal controls the phase of the baseband VCO. The digital timing-error detector block is capable of handling high data rate at low power consumption; it does not require any digital multiplier and utilizes 657 gates (2163 m ) to perform a 6-bit input error calculation.
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Symbol Synchronization Techniques in Digital Communications

Symbol Synchronization Techniques in Digital Communications

In digital receivers, the timing recovery leads to obtain symbol synchronization. Floyd                         Gardner [1] states that timing adjustment can be achieved by interpolation if the sampling is not                                 synchronized to the data symbols. Some of proposed solutions are to use synchronous Double                             Side Band systems. Costas [4] shows that Double Side Band has power advantage over Single                               Side Band when all factors, such as system complexity and susceptibility to jamming, are taken                               into account. Franks [5] illustrates that Maximum­likelihood estimation theory is another solution                         for the timing recovery which depends on root mean square jitter of the timing parameters as an                                   approach   to   the   evaluation   of   timing   recovery   circuit   performance. 
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Robust impulsive noise suppression 
		technique for iterative timing recovery

Robust impulsive noise suppression technique for iterative timing recovery

In [8], the authors proposed a framework called “matched myriad filtering” (MMyF) framework, in order to suppress the presence of outliers at the receiver. It consists of TED, TA and a turbo equalizer where each module operates orderly and independently. Their results demonstrated bit error rate (BER) performance gains over impulsive noise channels for various impulsive indices and convergence performances of timing recovery. However, as mentioned earlier, the separation in timing recovery unit from ECCs results in the timing recovery does not benefit from the soft-information generated by the iterative decoder. Hence, the separated design does not benefit the timing recovery at the low SNR region.
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ZAMAGE DIGITAL ART IMAGING, INC. (Symbol: ZMGD: PK) Quarterly Report

ZAMAGE DIGITAL ART IMAGING, INC. (Symbol: ZMGD: PK) Quarterly Report

Over the quarter, Zamage Digital Art Imaging, Inc. (ZMGD) completed a merger with its current subsidiary, EverdowCRM Inc. Long pegged as a promising merger candidate by ZMGD, EverdowCRM Inc. was officially declared a merger candidate on May 4, and after carrying out due diligence and completing what were termed “smooth negotiations,” ZMGD announced the completed merger on May 10. The stock’s price per share

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Digital methods of timing recovery

Digital methods of timing recovery

For example, a tank is a resonant circuit which is used to filter some timing wave recovered from the transmitted data stream.. The center frequency of a tank circuit will vary over the [r]

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Digital and Cloud Forensics

Digital and Cloud Forensics

• Authenticity - refers to the ability to confirm the integrity of information; for example that the imaged media matches the original evidence. The ease with which digital media can be modified means that documenting the chain of custody from the crime scene, through analysis and, ultimately, to the court, is important to establish the authenticity of evidence.

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Efficient inner receiver design for OFDM based WLAN systems: Algorithm and architecture

Efficient inner receiver design for OFDM based WLAN systems: Algorithm and architecture

the SNR increases. Nevertheless, since saturation is easily detectable at the ADC, the previous effect can be highly mitigated by setting to zero all those saturated samples before being delivered to the frame detector. The obtained standard deviation for the normalized frequency offset estimator shows no dependency on the AGC and has a minimum bound of 0.01, i.e. 1% of the sub-carrier spacing. This value helps in determining the number of bits necessary to represent the frequency offset in the arctangent calculator used in the synchronizer. Finally, Fig. 6(b) depicts the Timing Error Probability (TEP) derived from the crosscorrelator. Symbol timing is provided by the position of the first significant peak coming out from the crosscorrelator. The ideal position of the peak, i.e. m 1 in Fig. 2, is known beforehand and a timing error occurs when the estimated position of the peak differs in more than ±2 samples from the ideal position. Nevertheless this definition of the timing error only makes sense if the CP of the symbol being received immediately after the preamble symbols is considered to be 14 samples long instead of 16 in order to compensate positive timing errors. Four possible versions of the crosscorrelator have been tested depending on the length of the reference signal c REF (m), either 32 or 64
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Packet Format Design and Decision Directed Tracking Methods for Filter Bank Multicarrier Systems

Packet Format Design and Decision Directed Tracking Methods for Filter Bank Multicarrier Systems

In the past, a number of authors have looked into the problem of carrier and timing synchronization in FBMC communication systems, [34–43]. However, the approaches taken in these studies are different from the work presented in this paper. While we use pilot symbols (preambles) for carrier and timing acquisitions, most of the past works operate based on the statistical properties of the FBMC signals, that is, they are blind methods. B¨olsckei was the first to propose a blind carrier offset and timing estimation method for the Saltzberg’s FBMC method [34]. It relies on the second-order statistics and cyclostationarity of the modulated signals. Also, [34] acknowledges that when all subcarrier channels carry the same amount of power, the (unconjugate) correlation function of multicarrier signals vanishes to zero and thus proposes unequal subcarrier powers (subcarrier weighting) to enable the proposed syn- chronization methods. Noting this, Ciblat and Serpedin have developed a carrier acquisition/tracking method using the conjugate correlation function of FBMC signals which they found exhibits conjugate cyclic frequencies at twice the CFO [35]. Fusco and Tanda [36] have taken advantage of both the conjugate and unconjugate cyclostationarity of Saltzberg’s multicarrier signals to derive a maximum likelihood CFO estimator. Other related works can be found in [37–45]. An exception to the above works is [46] where the authors propose a synchronization method that uses a known periodic pilot signal, similar to the short preamble in IEEE 802.11a and g, and IEEE 802.16e, [28, 29]. Also, more recently, Fusco et al. [47] have proposed a pilot signal similar to the long preamble proposed in this paper. Fusco et al. [47] use this pilot signal for timing recovery and carrier phase estimation, based on a cost function which is different from the one proposed in this paper. Simulation results that compare the accuracy of the timing recovery method of [47] with the one proposed in this paper are presented in Section 9. To the best of our knowledge there is no report of any synchronization method for the Chang’s multicarrier technique.
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A Method of Symbol Rate Estimation Based on Wavelet Transform for Digital Modulation Signals

A Method of Symbol Rate Estimation Based on Wavelet Transform for Digital Modulation Signals

To use the wavelet function in wavelet analysis with ( )  t diversity, there are Haar wavelet, Daubechies wavelet (dbN), Mexican Hat wavelet, Morlet wavelet and Meyer wavelet commonly used [4] (Figure 1). Each wavelet function has different application fields, using different wavelet functions for dealing with same problem can produce different results. The choosen of wavelet function is related to the accuracy and convenience of the symbol rate estimation, so the selection of the best wavelet function is a very important problem.

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3 4 13h Hybrid Simulation of a Temperature Rate Flight Control System for Re Entry Vehicles 1965 pdf

3 4 13h Hybrid Simulation of a Temperature Rate Flight Control System for Re Entry Vehicles 1965 pdf

General Description of Digital Program In addition to solving the translational, temperature, and guidance equations, the digital program must accept mode control and timing commands fro[r]

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Not Just a Symbol But a Status Symbol

Not Just a Symbol But a Status Symbol

! My time in graduate school has truly been a continuous growth process. Three years ago I couldn’t have imagined that my work would have evolved as much as it has. Every step along the way served a stepping-stone getting me to the next stage and I feel I am getting to place where I can trust the artistic decisions that I make. My series “Not Just a Symbol but a Status Symbol” is a result of me fully realizing an idea and pushing past it to achieve the next step. This work allowed me to break free of my self- confining way of working and opened me up to the freedom of just making. I’m not sure what my next step for this work will be but I still see a lot of potential in working this way. What I do know is, when it is time to grow past this and create something new,
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Tampered Digital Image Recovery

Tampered Digital Image Recovery

A digital watermark is a kind of marker covertly embedded in a noise-tolerant signal such as an audio, video or image data. It is typically used to identify ownership of the copyright of such signal. Watermarking is the process of hiding digital information in a carrier signal; the hidden information should, but does not need to, contain a relation to the carrier signal. Digital watermarks may be used to verify the authenticity or integrity of the carrier signal or to show the identity of its owners. It is prominently used for tracing copyright infringements and for bank note authentication. We apply the wavelet transform and set partitioning in hierarchical transforms (SPIHT) source encoding method to efficiently compress the original image. Tampered area can be detected by using watermarking algorithm.
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Symbol Recovery Circuit design for deep-space MARS receiver using SOI technology

Symbol Recovery Circuit design for deep-space MARS receiver using SOI technology

Unlike the other PLLs discussed the ADPLL is made up completely of digital parts. Not only are the blocks digital, even the signals involved in the ADPLL are digital. The ADPLL doesn’t suffer from the issues of analog circuit design, like mismatch, non-linearity and effect of parasitics. It also consumes considerably lower power than a conventional LPLL. However, the ADPLL often needs a clock which is at a much higher rate than the inputs of the ADPLL and can only be used in situations where such high-rates are available. Since all parts of the ADPLL are digital, it can be built on-chip and the cost is much lower when compared to the other PLLs. The mathematical treatment of ADPLLs is usually more complicated than the others as they are non-linear systems and the dynamics of LPLL can often not be applied. The main components of the ADPLL are the same as the LPLL, namely, phase detector, loop filter and voltage-controlled oscillator. However, there is a large variety of designs in each sub-block depending on applications.
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Simple Timing Signal Analysis Device XY Mode Displays the Multichannel Shift Waveform

Simple Timing Signal Analysis Device XY Mode Displays the Multichannel Shift Waveform

In order to accurately display the multi-channel digital timing signals on the oscilloscope display screen, the basic requirements such as standard test signal acquisition and manual trigger condition setting must be met first. In this process, the two-channel D/A conversion circuit is precisely controlled, and two channels of analog signals are output to the x-y channel of the oscilloscope, and the oscilloscope screen is scanned quickly and orderly, and the multi-channel signals are displayed by using the afterglow effect of the ratio. Therefore, reasonable function module setting and control become the key [2] .
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Timing of Locomotor Recovery from Anoxia Modulated by the white Gene in Drosophila

Timing of Locomotor Recovery from Anoxia Modulated by the white Gene in Drosophila

system (Anaka et al. 2008). Levels of dopamine and serotonin, important modulators of synaptic transmission, are reduced in the heads of w mutants relative to the wild type according to some but not all reports (Borycz et al. 2008; Sitaraman et al. 2008; Simon et al. 2009). Mutations at the w locus, including complete lack of transcription in null mutants, altered amounts of transcript, and mislocation to neighboring heterochromatin, are associated with impaired pigment transport and deposition in the compound eyes (Nolte 1950; Pirrotta and Bröckl 1984). In addition to eye pigmentation, extraretinal functions of w have been observed (Zhang and Odenwald 1995; Campbell and Nash 2001). In the context of locomotor recovery from an- oxia, such a w + transport system could have critical house-
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N S chart honours project report : a Nassi Scneiderman cartographer

N S chart honours project report : a Nassi Scneiderman cartographer

Symbol caption text style Length of top part of symbol Total length of symbols "inside" this symbol Length of bottom part of symbol Total length of whole symbol Width of the symbol Posit[r]

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Creating Volatility Support for FreeBSD

Creating Volatility Support for FreeBSD

Once the profile has been parsed, Volatility needs the DTB, the kernel’s cr3 value for Intel architectures. The DTB is the directory table base, or the address of the operating system’s page directory. Volatility needs this value to translate kernel virtual addresses to physical addresses properly. The address for the page table mapping in FreeBSD is stored in the symbol kernel_pmap_store located in our system.map file. The offset for the cr3 value itself is then a member of the kernel_pmap_store symbol, called pm_cr3. Adding the cr3 offset to the page mapping address gives us the approximate address of the cr3 value. However, we still need to account for the 64-bit architecture, so we subtract a preset shift of 0xffffffff80000000. We can then unpack this result to retrieve the exact address of the kernel’s cr3 value. See the related code in Figure 4.
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EE290C - Spring 2004 Advanced Topics in Circuit Design High-Speed Electrical Interfaces

EE290C - Spring 2004 Advanced Topics in Circuit Design High-Speed Electrical Interfaces

UTP FFE Combined DFE/TCM decoder + Timing recovery DPLL 25M 125M Physical C ont rol Sublayer (P C S) Analog Digital T&H A/D 125M FIFO Analog Front- end D/A Hy brid 0.25+0.75z -1 3 N[r]

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Alan R. Martello and Steven P. Levitan. University of Pittsburgh. Pittsburgh, PA 15261

Alan R. Martello and Steven P. Levitan. University of Pittsburgh. Pittsburgh, PA 15261

The second kind of statement expresses the constraints that a device puts on the rest of the environment in order for it to operate correctly. This is a requirement on the temporal relationships of signals to ensure correct operation of the device. During verication, a requirement is checked by comparing the temporal relationship between its two events and determining if the required timing is violated. There are two types of requirements in the system: positive requirements and negative requirements. The positive requirement of \ e

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