Abstract: An apparatus and a method for detecting a motor rotor position are provided. The method for detecting a motor rotor position includes: transmitting test current commands and preset angles to a field oriented control circuit before a motor rotor rotates, to enable the field oriented control circuit to generate feedback currents, determining current peaks of the feedback currents, and comparing the current peaks of the feedback currents, and when determining that a current peak of a feedback current with a largest current peak in the feedback currents is greater than a current peak of another feedback current, outputting, according to a largest current peak current command corresponding to the feedback current with the largest current peak, a preset angle corresponding to the largest current peak current command as an initial angle position of the motor rotor.

Abstract: A receiving device comprises a signal detection unit, a reliability unit coupled to the signal detection unit and a decoding unit coupled to the signal detection unit and the reliability unit. The signal detection unit is for receiving a plurality of compensated symbols on a plurality of subcarriers, to generate a plurality of soft information and a plurality demodulated symbols of the plurality of compensated symbols according to the plurality of compensated symbols. The reliability unit is for generating a plurality of weights of the plurality of soft information according to a plurality of reliability information of the plurality of subcarriers. The decoding unit is for decoding the plurality of demodulated symbols according to the plurality of soft information and the plurality of weights, to generate a plurality of decoded bits.

Abstract: A receiving device comprises a signal detection unit, a reliability unit coupled to the signal detection unit and a decoding unit coupled to the signal detection unit and the reliability unit. The signal detection unit is for receiving a plurality of compensated symbols on a plurality of subcarriers, to generate a plurality of soft information and a plurality demodulated symbols of the plurality of compensated symbols according to the plurality of compensated symbols. The reliability unit is for generating a plurality of weights of the plurality of soft information according to a plurality of reliability information of the plurality of subcarriers. The decoding unit is for decoding the plurality of demodulated symbols according to the plurality of soft information and the plurality of weights, to generate a plurality of decoded bits.

Abstract: A Doppler frequency estimation system includes a basis projector, a polynomial generator and an extreme value determinator. The basis projector receives and projects multiple channel sampling signals to a set of orthogonal bases to thereby generate multiple channel correlation vectors. The polynomial generator is connected to the basis projector in order to produce a target polynomial based on the channel correlation vectors, an estimated channel-envelope-to-noise-plus-interference power-ratio and a channel-envelope power. The extreme value determinator is connected to the polynomial generator in order to determine an extreme value of the polynomial and output a frequency corresponding to the extreme value as an estimated Doppler frequency.

Abstract: A communication method for estimating Doppler spread includes the following steps: transmitting a preamble signal to a receiver from a transmitter of a transmission terminal. The preamble signal is received by the receiver; followed by dividing the received samples in the preamble signal into a plurality of sets of samples. The plurality of sets of samples are introduced into a Doppler spread estimation algorithm to estimate Doppler spread.

Abstract: A Doppler frequency estimation system includes a basis projector, a polynomial generator and an extreme value determinator. The basis projector receives and projects multiple channel sampling signals to a set of orthogonal bases to thereby generate multiple channel correlation vectors. The polynomial generator is connected to the basis projector in order to produce a target polynomial based on the channel correlation vectors, an estimated channel-envelope-to-noise-plus-interference power-ratio and a channel-envelope power. The extreme value determinator is connected to the polynomial generator in order to determine an extreme value of the polynomial and output a frequency corresponding to the extreme value as an estimated Doppler frequency.