Short-form pulse-amplitude demodulation references disclosed herein may enable low-cost receivers to demodulate wireless messages while avoiding complex 5G and 6G protocols, thereby enabling a multitude of cost-constrained applications. Despite their small footprint, the short-form pulse-amplitude demodulation references enable the receiver to determine all of the amplitude levels of the modulation scheme, including the effects of noise and interference. Mitigation of noise and interference can therefore be provided by embedding short-form pulse-amplitude demodulation references within longer messages, thereby providing an immediate refresh of the modulation calibrations, enhancing communication reliability, and avoiding costly message faults despite high background interference. Short-form pulse-amplitude demodulation references disclosed herein can be used as a default standard demodulation reference in 5G and 6G wireless messages.

[Object] To realize IQ imbalance correction in a more preferable aspect. [Solution] An information processing device including: a calculation unit configured to calculate an error between predetermined reference coordinates on an IQ plane and a signal point of a received predetermined reference signal on a basis of a reception result of the reference signal on which phase modulation or quadrature amplitude modulation is implemented and mapping information of the reference signal; and a generation unit configured to generate correction data for correcting a deviation of a signal point of a received signal on a basis of a calculation result of the error.

Techniques are presented for receiving Quadrature Amplitude Modulated (QAM) symbols from a transmitter via a transmission path. In one example, a demodulator is configured to down-convert an incoming Radio Frequency (RF) signal to a baseband signal and convert the baseband signal to digital samples, and output the digital samples. A demapper is configured to receive the digital samples output from the demodulator and output data encoded in QAM symbols. The demapper is further configured to: determine from a constellation of QAM symbols a subset of QAM symbols that a digital sample from the demodulator may represent; apply an offset to each QAM symbol in the subset of QAM symbols of the constellation to result in a subset of offset QAM symbols; determine which QAM symbol in the subset of offset QAM symbols the digital sample most likely represents; and output data representing a determined QAM symbol.

A wireless transceiver having an in-phase quadrature-phase (IQ) calibration function includes a transmitter, a receiver, a signal generator, and a switch circuit. The switch circuit includes a first and a second switch circuits. The first switch circuit is turned on in a receiver-end calibration process, and outputs a predetermined signal from the signal generator to the transmitter. The second switch circuit is turned on in the receiver calibration process and outputs a derivative signal of the predetermined signal from the transmitter to the receiver to let the receiver performs a receiver-end IQ calibration accordingly. The first switch circuit is turned off and the second switch circuit is turned on in a transmitter-end calibration process; the second switch circuit outputs a radio-frequency signal from the transmitter to the receiver to let the receiver generates a calibration reference accordingly; and the transmitter performs a transmitter-end IQ calibration according to the calibration reference.

A method of suppressing unwanted signal portions in an IQ signal generated by an IQ signal generator system includes generating, by a baseband circuit, a multi-tone baseband IQ signal, modulating, by a IQ modulator circuit, the baseband IQ signal, thereby obtaining a modulated IQ signal, determining, by an analysis circuit, a level function describing a signal level of the modulated IQ signal over time and/or over a phase of the multi-tone signal, determining, by the analysis circuit, at least one error quantity based on the level function, wherein the at least one error quantity is indicative of at least one error in the IQ signal generator system, and controlling, by a control circuit, the baseband circuit and/or the IQ modulator circuit in dependence of the at least one error quantity determined, thereby correcting the at least one error in the IQ signal generator system.

A method of pre-compensating for transmitter in-phase (I) and quadrature (Q) mismatch (IQMM) may include sending a signal through an up-converter of a transmit path to provide an up-converted signal, determining the up-converted signal, determining one or more IQMM parameters for the transmit path based on the determined up-converted signal, and determining one or more pre-compensation parameters for the transmit path based on the one or more IQMM parameters for the transmit path. In some embodiments, the up-converted signal may be determined through a receive feedback path. In some embodiments, the up-converted signal may be determined through an envelope detector.

Example operations may include determining a first noise estimate of noise that propagates along a receive path of a device. The operations may further include determining a second noise estimate of the noise and determining a cross-relationship estimate with respect to the noise. In addition, the operations may include adjusting one or more correction filters configured to correct for imbalances between a first branch and a second branch of the receive path. The adjusting may be based on the first noise estimate, the second noise estimate, and the cross-relationship estimate.

A method of pre-compensating for transmitter in-phase (I) and quadrature (Q) mismatch (IQMM) may include sending a signal through an up-converter of a transmit path to provide an up-converted signal, determining the up-converted signal, determining one or more IQMM parameters for the transmit path based on the determined up-converted signal, and determining one or more pre-compensation parameters for the transmit path based on the one or more IQMM parameters for the transmit path. In some embodiments, the up-converted signal may be determined through a receive feedback path. In some embodiments, the up-converted signal may be determined through an envelope detector.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive pilot signaling associated with inphase and quadrature (IQ) mismatch estimation for a set of antennas of a base station. The UE may measure pilot signals for each of the set of antennas based on a pilot signal pattern of the pilot signaling, and calculate an estimation of an IQ mismatch for each antenna of the set of antennas of the base station based on measuring the pilot signals. The base station may receive, from the UE, a report including an indication of the estimation of the IQ mismatch for each antenna of the set of antennas of the base station based on the pilot signals.

To more efficiently compensate for modulation imbalance, a mobile device modulates and demodulates a calibration tone and generates digital data representing modulation imbalance effects on the calibration tone. Using digital data enables modulation imbalance effects to be quickly estimated using digital signal processing techniques, increasing the number of estimates of modulation imbalance effects calculated. The modulation imbalance estimates are used to refine one or more compensation parameters which are applied to transmitted and/or received signals to compensate for errors caused by modulation.