Reliable communications is a central goal of 5G and 6G. However, due to signal fading at high frequencies and interference due to crowding, message faults continue to be a problem. Disclosed are methods for base station and user devices to adjust the modulation scheme according to the types of faults received, including amplitude faults (incorrectly demodulated amplitude levels) and phase faults (incorrectly demodulated phase levels), among others. The base station can select a more suitable modulation scheme based on the types of faults observed by user devices, such as modulation schemes with more or fewer amplitude levels and phase levels. In some versions, the number of amplitude levels is different from the number of phase levels, to combat specific fault problems.

Disclosed is a receiver for enhancing estimation of a channel of a received signal. The receiver is being configured to (i) process at least one of (a) power control commands to obtain a pattern of processed power control commands or (b) phase estimation to obtain a pattern of processed phase estimation; (ii) match the pattern of at least one of (a) processed power control commands, or (b) processed phase estimation to a pattern corresponding to one or more channels; (iii) determine a type of channel of the one or more channels based on the matched pattern of at least one of (a) said processed power control commands, or (b) said processed phase estimation, (iv) determine filtering parameters based on a type of channel that is determined and (v) enhance estimation of the channel based on the filtering parameters associated with the type of channel that is determined.

A demodulation device includes a phase rotation module, a phase adjustment module, a phase comparison module, and a reference signal generation module. The phase rotation module rotates phases of an I-Phase signal and a Q-Phase signal in a received signal of a multilevel PSK signal using a reference signal. The phase adjustment module adjusts the phases of the phase rotated I-Phase signal and the phase rotated Q-Phase signal output from the phase rotation module by multiplying the phases of the I-Phase signal and the Q-Phase signal with an integer value to generate a phase adjusted I-Phase signal and a phase adjusted Q-Phase signal. The phase comparison module compares the phase of the phase adjusted I-Phase signal with the phase of the phase adjusted Q-Phase signal to generate a phase comparison result. Also, the reference signal generation module generates a reference signal using the phase comparison result.

An electronic device includes a feedback oscillator configured to output a first oscillation signal and a second oscillation signal, the second oscillation signal having a defined phase difference from the first oscillation signal, the feedback oscillator including a phase shifter configured to receive the first oscillation signal and output the second oscillation signal, an up-conversion mixer configured to output a first loopback signal obtained by mixing the first oscillation signal with a reference tone signal, and output a second loopback signal obtained by mixing the second oscillation signal with the reference tone signal, and a receiver configured to generate a first reference IQ signal from the first loopback signal, generate a second reference IQ signal from the second loopback signal, and compare an actual phase difference between the first reference IQ signal and the second reference IQ signal with the defined phase difference.

Access to FR2 (high frequency bands) is essential for anticipated high-demand networking in 5G-Advanced and 6G systems. Unfortunately, phase noise is an unavoidable barrier, greatly limiting message reliability. Therefore, a low-cost solution is provided in which the transmitter (either base station or user device) transmits a special phase-tracking reference signal consisting of zero amplitude in one branch, and a predetermined non-zero amplitude in the other branch. For example, in QAM, the I-branch may be powered according to the maximum branch amplitude of the modulation scheme, and the Q-branch may have zero amplitude as transmitted. The receiver, on the other hand, generally measures a non-zero amplitude in the received Q branch due to phase noise, which rotates the I and Q branches into each other. The receiver can then determine the phase rotation angle precisely by measuring the non-zero amplitude in the Q branch, negating phase noise at negligible cost.

A method for wireless communication is described. The method includes receiving a signal that is pattern-mapped and Gaussian frequency-shift keying (GFSK) modulated. The method also includes performing a joint demapping and demodulation of the received signal based on a stored accumulated phase. The method may further include updating the stored accumulated phase based on the joint demapping and demodulation.

In some aspects of the systems, methods, and devices described herein, one or more asymmetric modulation constellations may be utilized. For example, a modulation constellation utilized to modulate data symbols may be asymmetric. In some approaches, an asymmetric modulation constellation may be generated by introducing a phase shift (e.g., cyclic shift, phase rotation) to one or more constellation points of a modulation constellation. An asymmetric modulation constellation may allow detecting phase shifts without ambiguity. For example, a user equipment (UE) may perform channel estimation or phase noise estimation aided by data symbols that are modulated with an asymmetric modulation constellation. In some examples, a UE may receive a message from a network entity indicating a configuration of an asymmetric modulation constellation. The UE may demodulate data symbols of a data signal based on a channel characterization estimate that is associated with the configuration of the asymmetric modulation constellation.

In some aspects of the systems, methods, and devices described herein, one or more asymmetric modulation constellations may be utilized. For example, a modulation constellation utilized to modulate data symbols may be asymmetric. In some approaches, an asymmetric modulation constellation may be generated by introducing a phase shift (e.g., cyclic shift, phase rotation) to one or more constellation points of a modulation constellation. An asymmetric modulation constellation may allow detecting phase shifts without ambiguity. For example, a user equipment (UE) may perform channel estimation or phase noise estimation aided by data symbols that are modulated with an asymmetric modulation constellation. In some examples, a UE may receive a message from a network entity indicating a configuration of an asymmetric modulation constellation. The UE may demodulate data symbols of a data signal based on a channel characterization estimate that is associated with the configuration of the asymmetric modulation constellation.

A method includes: determining a plurality of first subcarrier data items on a plurality of first subcarriers of a first frequency subband; performing first phase rotation on each first subcarrier data item based on a mixing frequency and a first reference frequency corresponding to the first frequency subband; determining a to-be-transmitted signal based on a plurality of first subcarrier data items obtained through first phase rotation; and sending the to-be-transmitted signal. In this way, phase rotation can be performed based on at least the first reference frequency, so that modulation can be correctly implemented without a need to know a mixing frequency of a receiving end. In addition, there is no need to notify the receiving end of the used mixing frequency, and the receiving end can correctly demodulate a received signal even if the receiving end does not know the mixing frequency.