Abstract: A receiver includes a gain adjusting circuit and a timing control circuit. The gain adjusting circuit adjusts the strength of an input signal according to a gain value to generate an adjusted input signal. The timing control circuit generates a control signal according to the input signal or the adjusted input signal to determine a time point at which the gain adjusting circuit changes the gain value.

Abstract: A method for detecting a notch band is applied to a multicarrier communication system that operates in a wideband. The method includes: receiving a received signal, and generating a plurality of frequency-domain signals according to the received signal; performing a magnitude operation on the frequency-domain signals to obtain a plurality of magnitude values; determining a plurality of ratios of a first magnitude set among the magnitude values to a second magnitude set among the magnitude value to determine whether the received signal contains a notch band.

Abstract: 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 mth weighting of M weightings to an mth delayed signal of the M delayed signals to generate an mth weighted 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)}n,p=[en,p,1 . . . en,p,M], where the symbol en,p,j is defined as en,p,j=?k(z[k]*z[k?Dp,j]*), the symbol n is an iteration index, k is a sample index, z[k] is a kth sample of the equalized signal, j is an integer index between 1 and M, and Dp,j represents a time delay amount corresponding to a jth delayed signal of the M delayed signals.

Abstract: 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 mth weighting of M weightings to an mth delayed signal of the M delayed signals to generate an mth weighted 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 n,p=[en,p,1 . . . en,p,M], where the symbol en,p,j is defined as en,p,j=?k(z[k]*z[k?Dp,j]*) the symbol n is an iteration index, k is a sample index, z[k] is a kth sample of the equalized signal, j is an integer index between 1 and M, and Dp,j represents a time delay amount corresponding to a jth delayed signal of the M delayed signals.

Abstract: A signal processing device of a television receiving end is provided. The television receiving end includes a tuner, which receives a television signal including a preamble signal. The signal processing device includes: an analog-to-digital converter, converting the television signal from an analog format to a digital format; an FFT circuit, transforming the television signal in the digital format to a frequency domain; a preamble data detecting circuit, detecting the preamble signal in the frequency-domain television signal to generate a preamble data detection result; a frequency notch detecting circuit, detecting a frequency notch of the preamble signal in the frequency-domain television signal according to the preamble data detection result to generate a frequency notch detection result; and a decoder, decoding the frequency-domain television signal to generate decoded data. The frequency notch detection result is for the tuner to accordingly determine whether to change the receiving frequency band.

Abstract: A method for detecting a notch band is applied to a multicarrier communication system that operates in a wideband. The method includes: receiving a received signal, and generating a plurality of frequency-domain signals according to the received signal; performing a magnitude operation on the frequency-domain signals to obtain a plurality of magnitude values; determining a plurality of ratios of a first magnitude set among the magnitude values to a second magnitude set among the magnitude value to determine whether the received signal contains a notch band.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A time-varying channel discriminating device capable of determining whether a wireless communication channel is time-varying is provided. The time-varying channel discriminating device includes: a channel response estimating circuit, estimating a channel response of a baseband signal at a plurality of time points to generate a plurality of estimated channel responses; a transforming unit, transforming the estimated channel responses to generate a plurality of estimated channel frequency responses; a calculating unit, calculating a plurality of calculated values according to the estimated channel frequency responses; and a determining module, determining a channel state corresponding to the baseband signal according to the calculated values.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.