Mstar Semiconductor, Inc.

Yi-Ying Liao

Tai-Lai Tung

Kai-Wen Cheng

Ko-Yin Lai

Tung-Sheng Lin

Chu-Hsin Chang

Chen-Yi Liu

Fong-Shih Wei

Chun-Chieh Wang

Yu-Che Su

Yu-Hsien Ku

Kuan-Chou Lee

Ting-Nan Cho

Yu-Shen Chou

Jen-Hsing Wang

Kun-Yu Wang

Chien-Jen Hung

Wei-Hung Liu

Fong Shih Wei

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.

Method and device for detecting notch band

A carrier frequency offset (CFO) tracking circuit includes: a CFO estimation circuit, generating an estimated CFO signal; a loop filter, coupled to the CFO estimation circuit, performing a loop filter operation on the estimated CFO signal according to an initial value to generate a loop filtered result; and an averaging circuit, coupled to the CFO estimation circuit and the loop filter, performing an average operation on the estimated CFO signal to generate the initial value as an average of the estimated CFO signal.

Carrier frequency offset tracking circuit and method

A decoding apparatus includes an input power estimating circuit, an error correction decoder and a controller. The input power estimating circuit generates multiple estimated input powers for multiple sets of data included in a packet that needs to be corrected, and calculates respective power differences between the multiple estimated input powers and a reference power. The controller determines one or multiple candidate error positions according to one of the multiple power differences that is higher than a predetermined threshold. The error correction decoder performs a decoding process on the packet according to the one or multiple candidate error positions.

Decoding apparatus and decoding method including error correction process based on power differences

A receiving circuit capable of estimating frequency offset includes a front circuit and a calculation circuit. The front circuit receives a remote signal to generate a received signal. The calculation circuit includes: an exponentiation module, calculating an exponent of a power to generate a high-order signal; a frequency-domain transform module, performing frequency-domain transform on the high-order signal to generate a spectrum; a peak searching module, searching for a peak of the amplitude of the spectrum to generate a peak coordinate value reflecting a frequency where the peak occurs; an offset estimating module, adding the peak coordinate value with a compensation value to generate a sum, dividing the sum by a first divisor to generate a remainder, subtracting the compensation value from the remainder to generate a difference, and dividing the difference by a second divisor to generate an offset estimation value reflecting the frequency offset.

Receiving circuit for estimating frequency offset and associated method

A decoding apparatus includes a differential decoder, an error correction decoder and a controller. The differential decoder performs differential decoding according to a differential encoding dependency to generate a differential decoding result. The error correction decoder performs a decoding process on multiple packets that need to be corrected according to the differential decoding result to accordingly generate respective error correction records, wherein the packets are generated according to the differential decoding results, and the packets include a first packet and a second packet. When the error correction record of the first packet indicates that the decoding process of the first packet is unsuccessful, the controller generates a set of error position information according to the error correction record of the second packet, and requests the error correction decoder to perform another decoding process on the first packet according to the error position information.

Decoding apparatus and decoding method including error correction process

A time-domain equalizer for eliminating an echo signal from a received signal is provided. The received signal includes an original signal and the echo signal. The time-domain equalizer includes a time delay estimator, an amplitude amplifying ratio estimator and a phase shift estimator. The time delay estimator determines a delay amount maximizing a cost function to serve as an estimated delay amount of the echo signal relative to the original signal. The amplitude amplifying ratio estimator determines an estimated amplitude amplifying ratio of the echo signal relative to the original signal. The phase shift estimator determines an estimated phase shift of the echo signal relative to the original signal according to the estimated delay amount. The estimated delay amount, the estimated amplitude amplifying ratio and the estimated phase shift are used to set a filtering condition to be applied to the received signal.

Time-domain equalizer and control method thereof

A sequence estimation device includes a grouping unit, a sequence estimation unit and a combination unit. The grouping unit groups a first plurality of equalized signals into a plurality of equalized signal groups according to a grouping rule. The sequence estimation unit, coupled to the grouping unit, processes the plurality of equalized signal groups according to a sequence estimation rule to obtain a plurality of estimated signal groups, respectively. The combination unit, coupled to the sequence estimation unit, permutes the plurality of estimated signal groups to a plurality of estimated signals according to the grouping rule.

Sequence estimation device and method

A communication apparatus for correcting a situation of a spectrum inverted signal includes a channel estimation module and an equalization module. The channel estimation module determines a channel estimation parameter, and receives at least one frame signal to generate a convolution restored frame signal corresponding to the frame signal. The equalization module includes a first computation circuit and a second computation circuit. The first computation circuit receives the channel estimation parameter and the convolution restored frame signal to generate a transformation channel estimation parameter and a transformed convolution restored frame signal. The second computation circuit receives the transformed channel estimation parameter and the transformed convolution restored frame signal to generate an original frame signal corresponding to the frame signal. The first computation circuit further feeds back a transient original frame signal to the channel estimation module to update the channel estimation parameter.

Communication apparatus

A receiving circuit for a digital television is provided. The receiving circuit of the digital television, adapted to process a digital television signal to generate transmission data, includes: a front-end circuit, configured to process the digital television signal to generate an interleaved signal; a setting unit, configured to provide a setting value associated with a digital video standard of the digital television signal; a frequency de-interleaving and time de-interleaving circuit, configured to select a frequency de-interleaving scheme and a time de-interleaving scheme corresponding to different digital video standards according to the setting value, and to process the interleaved signal to generate a de-interleaved signal; a quadrature amplitude modulation (QAM) demapping circuit, configured to demap the de-interleaved signal to generate a demapped signal; and a decoder, configured to decode the demapped signal to generate the transmission data.

Frequency deinterleaving and time deinterleaving circuit, method thereof and receiving circuit of digital television

A device for eliminating a channel effect is provided. A time-domain channel estimating unit generates a channel estimation result according to a first reference signal. A fast Fourier transform (FFT) unit performs FFT on the channel estimation result to generate a plurality of channel frequency responses corresponding to a plurality of frequency indices. An adjusting unit receives a plurality of input signals, and determines whether to adjust the input signal of each of the frequency indices according to the amplitude of the channel frequency response of each of the frequency indices to generate a set of adjusted signals. An inverse fast Fourier transform (IFFT) unit performs IFFT on a set of output signals associated with the set of adjusted signals to generate a feedback signal. The time-domain channel estimating unit further generates another channel estimation result according to a second reference signal and the feedback signal.

Device and method for eliminating channel effect

An error correction apparatus for a digital signal received by a signal reception terminal includes two error correction modules. The first error correction module performs first error correction on an input signal to generate an intermediate signal satisfying a termination condition. The second error correction module receives and selectively performs second error correction on the intermediate signal to generate a corrected signal. The termination condition is associated with a maximum error correction capability of the second error correction.

Error correction apparatus and associated method

A signal processing apparatus for receiving a spectral line of an original signal includes a starting point determining module, a searching module and a symbol rate determining module. The starting point determining module finds a maximum energy in the spectral line and determines at least one search starting point according to the maximum energy. From the at least one search starting point, the searching module searches along the spectral line towards a region with a lower energy for at least one minimum energy satisfying a predetermined condition. The symbol rate determining module determines a symbol rate of the original signal according to the at least one minimum energy.

Signal processing method and associated apparatus

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 signal processing apparatus includes an initial detecting module, a mixer, a symbol rate detecting module, a judging module and a correcting module. The initial detecting module determines an initial carrier frequency offset of an input signal according to a spectrum of the input signal. The mixer adjusts the input signal according to the initial carrier frequency offset to generate a frequency-compensated signal. The symbol rate detecting module determines a symbol rate of the input signal. The judging module judges whether the initial carrier frequency offset is correct according to the frequency-compensated signal. When a judgment result of the judging module is negative, the correcting module determines a corrected carrier frequency offset according to the symbol rate and the spectrum.

Signal processing apparatus and associated method

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.

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Zhubei, Taiwan

Yi-Ying Liao