In this work, we propose a novel approach to estimate the parameters of the multipath channel to improve the performance of the wireless communication system using the OFDM modulation. The pilot pulse is inserted with...
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ISBN:
(纸本)9781728131573
In this work, we propose a novel approach to estimate the parameters of the multipath channel to improve the performance of the wireless communication system using the OFDM modulation. The pilot pulse is inserted within the 0'th subcarrier of every OFDM symbol. A simple and efficient fft algorithm is used to estimate the channel parameters from the frequency spectrum of the matched filter output of the pilot signal. The computer simulations show the capability of this approach to estimate the channel parameters even when the received signal is contaminated with the additive white Gaussian noise (AWGN). An important feature of the proposed algorithm is that the number of the channel paths need not be known.
To design a simple voltage signal analysis system and realize waveform measurement and spectrum analysis on voltage signals inputted, adopt STC12C5A60S2 single-chip microcomputer (SCM) as core processor and, in combin...
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ISBN:
(纸本)9781538653746
To design a simple voltage signal analysis system and realize waveform measurement and spectrum analysis on voltage signals inputted, adopt STC12C5A60S2 single-chip microcomputer (SCM) as core processor and, in combination with waveform shaping circuit, realize the function of period measurement on voltage signals measured, and then have the measured voltage signals transformed into digital signals using the 10-digit high-speed analog-digital converter provided within the single-chip microcomputer itself, followed by the storage of digital signals, thus finally realizing the functions of oscilloscope in combination with the function of period measurement. Realize the function of spectrum analysis on the measured voltage signals by fft algorithm, and realize the function of display using LCD (liquid crystal display). The test reveals that for the oscilloscope, its frequency measurement scope is 1Hz ~ 5KHz, amplitude measurement scope is 0V~5V, the largest periodic error and amplitude error are respectively 12us and 19mV, and what shown in the frequency analysis chart of sine wave and square wave is basically consistent with corresponding theory.
TMS320F2808 DSP chip as the core, combined with signal conditioning and keyboard scan peripheral circuits, made up the hardware circuit of the measuring system. As for software,DSP as the main controller, realized the...
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TMS320F2808 DSP chip as the core, combined with signal conditioning and keyboard scan peripheral circuits, made up the hardware circuit of the measuring system. As for software,DSP as the main controller, realized the data display,controlment and management about the whole system Using the DSP internal integrated ADC module to achieve the data collection, while using its internal resources to complete the fft algorithm and optimization. The field test results show that this measuring system of digital signal distortion realizes the amplitude and frequency display in time domain and frequency domain when the setting signal passed the test system, and the measuring error is less than 0.8dB.
In this paper,research for the cell search of the LTE TDD system and the initialization of carrier frequency offset estimation algorithm,theoretical derivation is given from Timing Synchronization and sector ID detect...
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In this paper,research for the cell search of the LTE TDD system and the initialization of carrier frequency offset estimation algorithm,theoretical derivation is given from Timing Synchronization and sector ID detection *** this work,simulated and researched the performance of cell search algorithm in the spread of multi-path *** the method of analyze the complex and quantitative for symbol timing estimation and sector ID detection algorithm,a simplified algorithm for fft is proposed to reduce the algorithm complexity and verified the correctness of algorithm by the *** results show that the fast algorithm using fft and none fft fast algorithm for the use of the cell ID error detection probability have the same *** of observations from five semi-frame frames was reduced to three semi-frames,the error detection probability has a very small performance degradation.
The article addresses estimating of the polynomial phase coefficients of a quadratic FM signal. A new algorithm is proposed that uses fast Fourier transform algorithms to find estimates. Each polynomial coefficient is...
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ISBN:
(数字)9781728149448
ISBN:
(纸本)9781728149455
The article addresses estimating of the polynomial phase coefficients of a quadratic FM signal. A new algorithm is proposed that uses fast Fourier transform algorithms to find estimates. Each polynomial coefficient is estimated based on a unified procedure consisting of three similar steps. The synthesized algorithm yields more accurate estimates compared to the "cubic phase function" algorithm (CPF-algorithm) for signal-to-noise ratios (SNR) more than 3 dB. For SNR less than 3 dB, the quality of the estimates deteriorates due to anomalous errors caused by the loss of unambiguity of the estimation.
The paper issues a improvement about BLAST algorithm which is a local parallel algorithm about DNA sequence alignment. In order to test science character and applicability of the algorithm, we compare with a kind of i...
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The paper issues a improvement about BLAST algorithm which is a local parallel algorithm about DNA sequence alignment. In order to test science character and applicability of the algorithm, we compare with a kind of improving fft algorithm which implements in the Super Computer, and analyze their results.
We propose a new scheme to physically realize the short time Fourier transform of chirped optical pulses using time lens array that enables us to get time-frequency distribution without using fft algorithm. The idea o...
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ISBN:
(纸本)9781467365451
We propose a new scheme to physically realize the short time Fourier transform of chirped optical pulses using time lens array that enables us to get time-frequency distribution without using fft algorithm. The idea of Short-time Fourier transform (STFT) is physically realized in our scheme. The Fourier processor based upon a four-wave mixing time lens is used to perform the process of Fourier transformation. The ultra-short optical input signal is divided to multiple duplicates that is delayed in turn, and different short period of time of multiple duplicates are separately transformed into the frequency domain by multiple time lens. Pump pulse is both worked as the provider who has the quadratic phase and the window function of STFT. Simulations have been done to investigate performance of the time-frequency scheme compared with STFT using fft algorithm.
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