Abstract: A link down detector and a link down detecting method for Ethernet are provided. The link down detecting method includes the following steps. Firstly, a received signal is received, and a high-frequency band signal is extracted from the received signal. Consequently, the high-frequency band signal is formed as an extraction signal. Then, a high-frequency band power value of the extraction signal is calculated, and a full band power value of the received signal is calculated. Then, a ratio value of the high-frequency band power value to the full band power value is calculated. In a link up status, if the ratio value is changed dramatically in a specified time, a link down signal is asserted to indicate that a network device connected to the Ethernet is switched to a link down status.

Abstract: The present invention discloses a Trellis-Coded-Modulation (TCM) decoder applied in a receiver, wherein the TCM decoder includes a branch metric unit, a path metric unit, a trace-back length selection circuit and a survival path management circuit. In operations of the TCM decoder, the branch metric unit is configured to receive multiple input codes to generate multiple sets of branch information. The path metric unit is configured to calculate multiple survival paths according to the multiple sets of branch information. The trace-back length selection circuit is configured to select a trace-back length, wherein the trace-back length is determined according to a signal quality of the receiver. The survival path management circuit is configured to return the multiple survival paths for the trace-back length in order to generate an output code.

Abstract: The present invention discloses a Trellis-Coded-Modulation (TCM) decoder applied in a receiver, wherein the TCM decoder includes a branch metric unit, a path metric unit, a trace-back length selection circuit and a survival path management circuit. In operations of the TCM decoder, the branch metric unit is configured to receive multiple input codes to generate multiple sets of branch information. The path metric unit is configured to calculate multiple survival paths according to the multiple sets of branch information. The trace-back length selection circuit is configured to select a trace-back length, wherein the trace-back length is determined according to a signal quality of the receiver. The survival path management circuit is configured to return the multiple survival paths for the trace-back length in order to generate an output code.

Abstract: A Sigma-Delta (?-?) analog-to-digital converter (ADC) and operation method thereof are provided. The ?-? ADC includes a ?-? modulator, a dynamic element matching (DEM) circuit and a control circuit. An input terminal of the ?-? modulator is configured to receive an analog signal. The ?-? modulator is configured to convert the analog signal into a digital signal based on a feedback signal. The DEM circuit is coupled to the ?-? modulator to receive the digital signal. The DEM circuit is configured to perform a DEM algorithm on the digital signal to generate a feedback signal, and provide the feedback signal to the ?-? modulator. The control circuit listens to the digital signal to detect a mute period. The control circuit disables the DEM circuit during the mute period to suspend a progress of the DEM algorithm.

Abstract: A signal receiving method of a receiver includes the following steps. A time-domain received signal is transformed into a frequency-domain received signal, which includes multiple pilot symbols and multiple data symbols. Multiple channel impulse responses corresponding to the pilot symbols are estimated. Multiple inter-carrier interference and inter-block interference (ICIIBI) values corresponding to the pilot symbols are estimated based on the pilot symbols and the corresponding channel impulse responses. Multiple ICIIBI values corresponding to the data symbols are obtained via an interpolation operation according to the ICIIBI values corresponding to the pilot symbols. The estimated corresponding ICIIBI values are cancelled from the data symbols. The interference-cancelled data symbols are demapped to obtain soft-decision or hard-decision bits.

Abstract: A signal receiving method of a receiver includes the following steps. A time-domain received signal is transformed into a frequency-domain received signal, which includes multiple pilot symbols and multiple data symbols. Multiple channel impulse responses corresponding to the pilot symbols are estimated. Multiple inter-carrier interference and inter-block interference (ICIIBI) values corresponding to the pilot symbols are estimated based on the pilot symbols and the corresponding channel impulse responses. Multiple ICIIBI values corresponding to the data symbols are obtained via an interpolation operation according to the ICIIBI values corresponding to the pilot symbols. The estimated corresponding ICIIBI values are cancelled from the data symbols. The interference-cancelled data symbols are demapped to obtain soft-decision or hard-decision bits.