Mstar Semiconductor, Inc.

Fong-Shih Wei

Tai-Lai Tung

Ko-Yin Lai

Jen-Hsing Wang

Yi-Ying Liao

Chih-Cheng Kuo

Chen-Yi Liu

Yu-Shen Chou

Cheng-Han Wu

Chien-Chih Yu

Yu-Peng Wu

A time-domain equalizer includes a delay circuit, a weighting circuit, a controller and a summation circuit. The delay circuit receives an equalized signal and accordingly generates M delayed signals for an equalized signal. The weighting circuit applies an mweighting of M weightings to an mdelayed signal of the M delayed signals to generate an mweighted signal. The summation circuit sums up the M weighted signals, according to which the equalized signal is updated. The controller iteratively updates the M weightings according to a vector {right arrow over (e)}=[e. . . e], where the symbol eis defined as e=&#x3a3;(z[k]*z[k&#x2212;D]*), the symbol n is an iteration index, k is a sample index, z[k] is a ksample of the equalized signal, j is an integer index between 1 and M, and Drepresents a time delay amount corresponding to a jdelayed signal of the M delayed signals.

Time-domain equalizer and signal processing method thereof

A method for processing a multiple carrier signal provided with subcarriers distributed in a band. The method includes calculating a subcarrier noise of an edge of the band, calculating a subcarrier noise of a center of the band, calculating a ratio of the subcarrier noise of the edge of the band to the subcarrier noise of the center of the band, determining whether the ratio is greater than a threshold, and acknowledging that the edge of the band suffers from interference when the ratio is greater than the threshold.

Method and apparatus for processing a multiple-carrier signal provided with subcarriers distributed in a band

A wireless receiving device includes: a time-domain channel estimation circuit, generating channel information in the time domain according to a part of a received signal; a fast Fourier transform (FFT) circuit, coupled to the time-domain channel estimation circuit, transforming another part of the received signal and the channel information to the frequency domain to generate a plurality of sets of received data; an equalizer, coupled to the FFT circuit, adjusting the received data to generate a plurality of sets of complex equalized data; an adjusting unit, coupled to the equalizer, adjusting the sets of complex equalized data such that the sets of adjusted equalized data is closer to the origin of a complex plane; and a decision circuit, generating a plurality of sets of binary data according to the sets of adjusted equalized data.

Wireless receiving device and signal processing method thereof

An echo discriminating method capable of discriminating whether an echo occurs in a communication channel is provided. The echo discriminating device includes: a channel estimation unit, that receives a baseband signal and generates a plurality of estimated channel responses according to a plurality of subcarriers of the baseband signal; a transforming unit, that transforms the estimated channel responses to generate a plurality of estimated channel frequency responses; a calculating unit, that calculates a representative value of each of the subcarriers to generate a plurality of representative values; a characteristic value generating unit, that generates a characteristic value according to the representative values; and a determining module, that determines whether the echo occurs according to the characteristic value and the representative values to obtain a determination result.

Echo discriminating device and method thereof

A communication device includes: a detecting unit, performing a mobility detection in a time interval to generate a detection result; a selecting unit, selecting a channel estimation method from a plurality of channel estimation methods according to the detection result; and a channel estimating unit, coupled to the selecting unit, performing a channel estimation on a channel for receiving a signal according to the selected channel estimation method.

Device and method for handling channel estimation

A method for determining impulsive interference applicable to an orthogonal frequency division multiple access (OFDMA) signal receiver is provided. The receiving method includes calculating a subcarrier noise of a first symbol, calculating a subcarrier noise of a second symbol, calculating a first ratio of the subcarrier noise of the first symbol to the subcarrier noise of the second symbol, determining whether the ratio is greater than a first threshold, and recognizing that the first symbol suffers from impulsive interference when the first ratio is greater than the first threshold.

Method for determining impulsive interference applicable to orthogonal frequency division multiple access signal receiver and receiver thereof

A television signal receiving device and a method for determining whether a target channel includes a television program signal are provided. The television signal receiving device, including a tuner to receive a radio-frequency (RF) signal, to select the target channel from a plurality of channels in the RF signal, and to down-convert the target channel, includes: an analog-to-digital converter (ADC), configured to convert an analog signal carried in the down-converted target channel to a digital signal; an operation circuit, configured to perform an operation on the digital signal to obtain a correlation comparing result; and a control circuit, configured to determine whether the target channel includes the television program signal according to the correlation comparing result.

Television signal receiving device and method for determining whether channel includes television program signal

A signal processing method includes: converting an analog signal to a digital signal; converting the digital signal from a time domain to a frequency domain, the frequency-domain digital signal including a plurality of sets of data exhibiting a predetermined order associated with frequencies respectively corresponding to the data; performing a correlation operation according to the data and the predetermined order to generate a forward correlation result; performing the correlation operation according to the data and a reverse order of the predetermined order to generate a reverse correlation result; selectively generating a control signal according to the forward and reverse correlation results; and processing the digital signal in the time domain according to the control signal so that the data generated in the subsequent step of converting the digital signal from the time domain to the frequency domain exhibit the predetermined order or the reverse order.

Signal processing method and associated device, and method for determining whether spectrum of multicarrier signal is reversed

A frequency offset estimation method for a multi-carrier communication system is provided. The method includes: transforming a representation of a reception signal from a time domain to a frequency domain, and generating a plurality of symbols; calculating a correlation of two symbols among the symbols, and obtaining a plurality of correlating complex numbers corresponding to a plurality of subcarriers; generating M number of candidate subcarrier position sets according to a subcarrier position set of a specific signal and M number of candidate frequency offsets; calculating M number of calculated values according to the correlating complex numbers corresponding to the M number of candidate subcarrier position sets; and determining a frequency offset according to the maximum calculated value among the M number of calculated values.

Frequency offset estimation method and associated apparatus applied to multi-carrier communication system

A wireless reception system includes a reception module, a preliminary estimation module, an equalization module and a selection module. The reception module receives a reference signal and at least one input signal transmitted via a multipath environment. The reference signal is associated with a known signal unaffected by the multipath environment. The preliminary estimation module generates a plurality of candidate channel effects according to the at least one input signal. The equalization module performs equalization on the reference signal according to the candidate channel effects to generate a plurality of equalization results. From the equalization results, the selection module selects an optimal equalization result that is most similar to the known signal, and selects the candidate channel effect corresponding to the optimal equalization result to represent the multipath environment.

Wireless reception system and method for estimating channel effect thereof

An offset estimation apparatus for a multi-carrier communication system is provided. The offset estimation apparatus includes an FFT unit configured to transform a reception signal and to generate multiple symbols, a conjugate multiplier configured to receive and conjugate multiply two consecutive symbols corresponding to predetermined subcarrier indices to generate multiple correlating complex numbers, a powering unit configured to raise the correlating complex numbers by a received exponent to generate multiple powered correlating complex numbers, and a calculation unit configured to estimate a frequency offset according to the powered correlating complex numbers.

Carrier and sampling frequency offsets estimation method and associated apparatus applied to multi-carrier communication system

A method of communication parameter detection for detecting a temporal length of a guard interval of cyclic messages in a communication is provided. The method includes: searching peaks of an autocorrelation signal in the communication signal, and providing a peak for each cyclic message; sorting a time difference between two consecutive peaks to one of bins of a histogram, and determining the temporal length of the guard interval according to a result of the histogram; while a peak is found, providing a signal average according to an average of the autocorrelation signal over an average calculating period, comparing whether a ratio of the peak to the signal average is greater than a threshold, and accordingly detecting whether the communication signal carries valid information.

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Taipei, Taiwan

Fong-Shih Wei