Abstract: The invention provides a method for testing a transmission medium used in a full-duplex communication system comprising an endpoint that comprises a transmitting end (TX) and a receiving end (RX); the method comprises the steps of: first, transmitting a transmitted signal which comprises a test signal sequence with a high auto-correlation characteristic; then, receiving a received signal, and performing a correlation operation on the test signal and the received signal; finally, according to the result of the correlation operation, determining the impedance matching condition of the transmission medium.

Abstract: The invention provides a method for testing a transmission medium used in a full-duplex communication system comprising an endpoint that comprises a transmitting end (TX) and a receiving end (RX); the method comprises the steps of: first, transmitting a transmitted signal which comprises a test signal sequence with a high auto-correlation characteristic; then, receiving a received signal, and performing a correlation operation on the test signal and the received signal; finally, according to the result of the correlation operation, determining the impedance matching condition of the transmission medium.

Abstract: The apparatus for communication channel estimation device of the present invention includes: a frequency response square computing circuit, to generate a first frequency response corresponding to a first frequency and a second frequency response corresponding to a second frequency according to a input signal, and to square the first and the second frequency response; and an estimating circuit, to estimate a channel length according to the squares of the first frequency and the second frequency response. Wherein the input signal is transmitted in a symbol rate and the first frequency and the second frequency are 1/M and 1/N times of the symbol rate respectively, wherein M and N are in the order of 2.

Abstract: A signal processing device for processing a passband signal to generate an equalized signal includes a passband adaptive equalizer for generating the equalized signal according to the passband signal, including at least one feed-forward equalizer (FFE) and one feedback equalizer (FBE), and a multilevel quantizer coupled with the passband adaptive equalizer for selectively utilizing a single predetermined threshold or a plurality of multiple predetermined thresholds to quantize the equalized signal in order to generate a sliced signal.

Abstract: An initialization method for a network system is disclosed, which uses a channel estimation to predetermine coefficients of an FFE and an FBE. As such, convergence of the FFE, the FBE, a timing recovery, an echo canceller and a NEXT canceller is speeded up. Also, interaction of the cited devices and a divergence caused by the interaction are avoided. Therefore, system performance and stability are increased.

Abstract: A transceiver of a communication system is disclosed. The transceiver is implemented by a demodulation apparatus including a front-end receiver, a noise canceller, a feedforward equalizer (FFE) and a decoding system. The front-end receiver receives a remote signal and converts it into a first signal with a pre-cursor and a post-cursor in digital form. The noise canceller is coupled to the front-end receiver for subtracting a noise signal from the first signal and thus generates a second signal. The FFE is coupled to the noise canceller for eliminating the pre-cursor in the second signal and thus generates a third signal. The decoding system is coupled to the FFE for decoding the third signal and eliminating the post-cursor in the third signal.

Abstract: A transceiver of a communication system is disclosed. The transceiver comprises a front-end receiver for receiving a receiving signal and converting to a first signal with a pre-cursor component and a post-cursor component, a noise canceller coupled to the front-end receiver 10 for generating a second signal through eliminating the noise of the first signal, a Feed-Forward Equalizer (FFE) coupled to the noise canceller for generating a third signal through eliminating the pre-cursor component in the second signal according to a transfer function including a plurality of adjustable constants, wherein the adjustable constants includes a main-tap and the value of the main-tap is predetermined, and a decoding system coupled to the FFE for decoding the third signal and eliminating the post-cursor component in the third signal.

Abstract: The apparatus for communication channel estimation device of the present invention includes: a frequency response square computing circuit, to generate a first frequency response corresponding to a first frequency and a second frequency response corresponding to a second frequency according to a input signal, and to square the first and the second frequency response; and an estimating circuit, to estimate a channel length according to the squares of the first frequency and the second frequency response. Wherein the input signal is transmitted in a symbol rate and the first frequency and the second frequency are 1/M and 1/N times of the symbol rate respectively, wherein M and N are in the order of 2.

Abstract: An equalizer and an equalizing method for equalizing a received signal, where the received signal includes at least one primary interference and a plurality of secondary interferences. The Viterbi equalizer includes a filter module for filtering out the secondary interferences from the received signal to generate a filtered signal, a serial to parallel converter, coupled to the filter module, for generating a plurality of sequences according to the filtered signal, and a Viterbi equalizing module, coupled to the serial to parallel converter, for respectively equalizing the plurality of sequences to generate a plurality of equalized sequences. The architecture of the Viterbi equalizing module is greatly simplified thereby reducing the calculation activity of the Viterbi equalizer as well as maintaining its efficiency.

Abstract: The apparatus for communication channel estimation device of the present invention includes: a frequency response square computing circuit, to generate a first frequency response corresponding to a first frequency and a second frequency response corresponding to a second frequency according to a input signal, and to square the first and the second frequency response; and an estimating circuit, to estimate a channel length according to the squares of the first frequency and the second frequency response. Wherein the input signal is transmitted in a symbol rate and the first frequency and the second frequency are 1/M and 1/N times of the symbol rate respectively, wherein M and N are in the order of 2.

Abstract: A P-tap parallel decision-feedback decoder (PDFD) is also disclosed. The PDFD includes a plurality of state shift registers. For each state of a code utilized by an incoming data stream, a survivor metric for a state is shifted into the first shift register for the state. Each first shift register has M cells. A decision device is coupled to the first shift registers for outputting a first survivor metric according to survivor metrics in the first shift registers. A second shift register has N delay cells, and the first survivor metric is shifted into the second shift register.

Abstract: The present invention provides a method and apparatus for correcting symbol timing of a receiver. The receiver receives a signal transmitted by a transmitter based on a symbol period. The method includes: sampling the signal with a sampling period to generate N sampled data in series, wherein the sampling period is half the symbol period; from Kth data of the N sampled data, getting M data to serve as a first data set; performing a timing recovery algorithm upon the first data set to generate a first timing metric; from (Kth+1) data of the N sampled data, getting M data to serve as a second data set; performing the timing recovery algorithm upon the second data set to generate a second timing metric; and correcting the symbol timing according to the first and second timing metrics.

Abstract: A quadrature amplitude modulation trellis coded modulation (QAM-TCM) decoding apparatus and the related method that receives and decodes a QAM signal. The QAM-TCM decoding apparatus includes an in-phase least significant bit (LSB) decoding path, which includes a in-phase Viterbi decoder for executing a decoding procedure on at least one LSB corresponding to an in-phase component of the QAM signal, a quadrature-phase LSB decoding path, which includes a quadrature-phase Viterbi decoder for executing a decoding procedure on at least one LSB corresponding to a quadrature-phase component of the QAM signal, and a most significant bit (MSB) decoding path for executing a decoding procedure on MSB portions corresponding to the in-phase or the quadrature-phase of the QAM signal. In doing so, the apparatus and method reduces the complexity of the decoding calculation.

Abstract: The present invention provides a method and circuit for equalizing and compensating IQ imbalance at the same time. The method includes: down-converting an RF signal to generate a baseband signal, and driving an adaptive equalizer to process the baseband signal for achieving equalization and IQ imbalance compensation simultaneously.

Abstract: A P-tap parallel decision-feedback decoder (PDFD) is also disclosed. The PDFD includes a plurality of state shift registers. For each state of a code utilized by an incoming data stream, a survivor metric for a state is shifted into the first shift register for the state. Each first shift register has M cells. A decision device is coupled to the first shift registers for outputting a first survivor metric according to survivor metrics in the first shift registers. A second shift register has N delay cells, and the first survivor metric is shifted into the second shift register.

Abstract: The invention provides a method for testing a transmission medium used in a full-duplex communication system comprising an endpoint that comprises a transmitting end (TX) and a receiving end (RX); the method comprises the steps of: first, transmitting a transmitted signal which comprises a test signal sequence with a high auto-correlation characteristic; then, receiving a received signal, and performing a correlation operation on the test signal and the received signal; finally, according to the result of the correlation operation, determining the impedance matching condition of the transmission medium.

Abstract: A signal processing device for processing a passband signal to generate an equalized signal includes a passband adaptive equalizer for generating the equalized signal according to the passband signal, including at least one feed-forward equalizer (FFE) and one feedback equalizer (FBE), and a multilevel quantizer coupled with the passband adaptive equalizer for selectively utilizing a single predetermined threshold or a plurality of multiple predetermined thresholds to quantize the equalized signal in order to generate a sliced signal.

Abstract: A transceiver of a communication system is disclosed. The transceiver comprises a front-end receiver for receiving a receiving signal and converting to a first signal with a pre-cursor component and a post-cursor component, a noise canceller coupled to the front-end receiver 10 for generating a second signal through eliminating the noise of the first signal, a Feed-Forward Equalizer (FFE) coupled to the noise canceller for generating a third signal through eliminating the pre-cursor component in the second signal according to a transfer function including a plurality of adjustable constants, wherein the adjustable constants includes a main-tap and the value of the main-tap is predetermined, and a decoding system coupled to the FFE for decoding the third signal and eliminating the post-cursor component in the third signal.

Abstract: A transceiver of a communication system is disclosed. The transceiver is implemented by a demodulation apparatus including a front-end receiver, a noise canceller, a feedforward equalizer (FFE) and a decoding system. The front-end receiver receives a remote signal and converts it into a first signal with a pre-cursor and a post-cursor in digital form. The noise canceller is coupled to the front-end receiver for subtracting a noise signal from the first signal and thus generates a second signal. The FFE is coupled to the noise canceller for eliminating the pre-cursor in the second signal and thus generates a third signal. The decoding system is coupled to the FFE for decoding the third signal and eliminating the post-cursor in the third signal.

Abstract: An initialization method for a network system is disclosed, which uses a channel estimation to predetermine coefficients of an FFE and an FBE. As such, convergence of the FFE, the FBE, a timing recovery, an echo canceller and a NEXT canceller is speeded up. Also, interaction of the cited devices and a divergence caused by the interaction are avoided. Therefore, system performance and stability are increased.