Methods and apparatus for receiving a user message in a communication network are disclosed. In an exemplary embodiment, a method includes receiving data samples in an uplink transmission from user equipment, performing preamble detection on the data samples, generating a trigger signal that indicates when a preamble is detected, and decoding a user message in response to the trigger signal, wherein the user message follows the detected preamble.

The proposed solution relates to a method and an apparatus in a communication system. The solution includes receiving as an input a frame including of a set of data symbols and reference symbols, each data symbol forming a rectangular symbol constellation of samples, derotating the first symbol of the set on the basis of the reference symbols, and setting phase rotating angle of the first symbol as zero. The solution further includes for each following successive symbol in the set of symbols: performing equalization; reducing the number of samples in the constellation by selecting samples in two or more corners of the constellation by utilizing two or more threshold values; estimating the phase rotating angle of the symbol from the reduced number of samples and derotating the symbol on the basis of the determined phase rotating angle.

A system and method employ an exclusive-OR gate having a first input configured to receive an RF carrier signal having an RF carrier, and a second input configured to receive a square wave signal having a square wave frequency, to output to a signal processing channel under test a binary phase shift keying (BPSK) signal comprising the RF carrier signal modulated by the square wave signal. A digital signal processor is configured to receive from the signal processing channel in-phase (I) and quadrature-phase (Q) data produced by the signal processing channel in response to the BPSK signal, and to process the I and Q data to determine an amplitude response and phase response of the signal processing channel as a function of frequency.

Methods and systems for I/Q mismatch calibration and compensation for wideband communication receivers may comprise receiving a plurality of radio frequency (RF) channels, downconverting the received plurality of received RF channels to baseband frequencies, determining and removing average in-phase (I) and quadrature (Q) gain and phase mismatch of the downconverted channels, determining a phase and amplitude tilt of the downconverted channels with removed average I and Q gain and phase mismatch, and compensating for said phase and amplitude tilt I and Q gain and phase mismatch of the downconverted channels. The determined phase tilt may be compensated utilizing a phase tilt correction filter, which may comprise one or more all-pass filters. The average I and Q gain and phase mismatch may be determined utilizing a blind source separation (BSS) estimation algorithm.

A semiconductor device of an embodiment includes first and second couplers, an encoding circuit, and a demodulating circuit. The encoding circuit executes differential Manchester encoding on digital data based on a clock inputted thereto via the first coupler and outputs an encoded data. The demodulating circuit includes a first sampling circuit which samples the encoded data inputted via the second coupler based on a sampling frequency set to be two times higher than that of the encoded data and which outputs first sample data, a second sampling circuit which samples the encoded data at a timing earlier than that in the first sampling circuit and which outputs second sample data, a determination circuit which determines whether or not the first and the second sample data match each other, and a selection circuit which selects first phase data or second phase data from the first sample data.

A semiconductor device of an embodiment includes first and second couplers, an encoding circuit, and a demodulating circuit. The encoding circuit executes differential Manchester encoding on digital data based on a clock inputted thereto via the first coupler and outputs an encoded data. The demodulating circuit includes a first sampling circuit which samples the encoded data inputted via the second coupler based on a sampling frequency set to be two times higher than that of the encoded data and which outputs first sample data, a second sampling circuit which samples the encoded data at a timing earlier than that in the first sampling circuit and which outputs second sample data, a determination circuit which determines whether or not the first and the second sample data match each other, and a selection circuit which selects first phase data or second phase data from the first sample data.

A method for transmitting a frame is provided by a device in a wireless communication network. The device compensates a carrier frequency using a value of carrier frequency offset (CFO), and transmits a frame with the compensated carrier frequency to a receiver. The value of the CFO is indicated in TXVECTOR. A method for transmitting a frame is provided by a device in a wireless communication network. The device allocates data tones for a last symbol based on a payload size, generates the last symbol having repeated waveforms and transmits a frame including at least one period waveform of the repeated waveforms in the last symbol.

The present disclosure relates to an encoded signal demodulation method, apparatus, and device. Some embodiments of the present disclosure are beneficial to improving demodulation performance.

A semiconductor device of an embodiment includes first and second couplers, an encoding circuit, and a demodulating circuit. The encoding circuit executes differential Manchester encoding on digital data based on a clock inputted thereto via the first coupler and outputs an encoded data. The demodulating circuit includes a first sampling circuit which samples the encoded data inputted via the second coupler based on a sampling frequency set to be two times higher than that of the encoded data and which outputs first sample data, a second sampling circuit which samples the encoded data at a timing earlier than that in the first sampling circuit and which outputs second sample data, a determination circuit which determines whether or not the first and the second sample data match each other, and a selection circuit which selects first phase data or second phase data from the first sample data.

A power transmitter (101) provides power transfer to a power receiver (105) using a wireless inductive power transfer signal. The power transmitter (101) comprises an inductor (103) generating the power transfer signal when a voltage drive signal is applied. A measurement unit (311) performs measurements of a current or voltage of the inductor (103). The measurements are performed with a time offset relative to a reference signal synchronized to the voltage drive signal. An adaptor (313) can vary the time offset to determine an optimum measurement timing offset resulting in a maximum demodulation depth which reflects a difference measure for measurements for different modulation loads of the power transfer signal. A demodulator (309) then demodulates load modulation of the inductive carrier signal from measurements with the time offset set to the optimum measurement timing offset. In some scenarios, both the timing and duration of measurements may be varied. The approach improves communication reliability.