Abstract: Disclosed are short-form demodulation reference signals configured to indicate certain modulation levels of a modulation scheme, from which a receiver can measure phase noise and amplitude noise in 5G/6G. A key feature of short-form demodulation references is resource efficiency. Examples include a demodulation reference occupying just one resource element, while providing the information needed to determine all of the modulation states of the modulation scheme, as well as the current noise factors. In one embodiment, the short-form demodulation reference may include two component signals with orthogonal phase, both being amplitude modulated by the transmitter according to a maximum amplitude level. The receiver can determine the phase noise from a ratio of the two received signal amplitudes, and the amplitude noise from the magnitude of the received waveform, thereby mitigating both amplitude noise and phase noise.

Abstract: A new user seeking a base station to join must first implement a grueling series of complex steps, which may be especially challenging for the majority of devices expected in next-generation 5G and 6G systems. If the user has a real emergency, such as an imminent traffic collision, then the time wasted in locating (“discovering”) a nearby base station and finally logging on may make the difference between life and death. Disclosed herein are procedures for new users to transmit a “hailing” message on an allocated frequency that multiple base stations continuously monitor. The base stations can then reply at a standard amplitude, so that the new user can determine which base station is closer (or provides the best signal reception) according to the received amplitude. In addition, the reply messages can include a characteristic frequency of the replying base station, such as its entry frequency.

Abstract: A faulted message element in 5G or 6G can often be identified according to its modulation parameters, including a large deviation of the branch amplitudes from the predetermined amplitude levels of the modulation scheme, and/or the SNR of the branch amplitudes, and/or an amplitude variation of the raw signal or the branches during the message element, and/or an inconsistency between the modulation state as determined by the amplitude and phase of the raw waveform versus the amplitudes of the orthogonal branch signals, among other measures of modulation quality. An AI model may be necessary to correlate the various quality measures, and optionally to determine the correct demodulation of faulted message elements. Costly, time-consuming retransmissions may be avoided by determining the correct demodulation of each message element at the receiver, thereby improving throughput and reliability with fewer delays.

Abstract: Messages are transmitted in closely-spaced subcarriers in 5G and 6G, configured so that each subcarrier signal is orthogonal to the adjacent subcarrier signals. However, many effects can penetrate that orthogonality—distortion, interference, frequency variations, amplitude variations, crosstalk, etc.—collectively termed energy spill-over. To combat this problem, a receiver can determine the total energy spill-over into adjacent subcarriers by measuring a residual signal in a subcarrier with no transmission, adjacent to another subcarrier with a known transmission. The receiver can measure the amplitude, phase, temporal or spectral properties, and so forth of the residual signal. The receiver can then correct the message during signal processing, by calculating a function of the residual signal and subtracting it from each digitized subcarrier signal of a message.

Abstract: In addition to the normal modulation states of 5G and 6G (BPSK, QPSK, 16QAM, etc.), the modulation scheme may include one or more zero-power states in which an amplitude is transmitted with very low or zero power. The receiver can detect the zero-power state and treat that state as an additional modulation state of the modulation scheme, thereby increasing the information content of each message element due to the additional number of modulation states available for encoding. Alternatively, the zero-power state or states may be used for special options, such as indicating a beginning or an ending of the message. Zero-power states may also be used to separate the message from an associated demodulation reference or to separate sequential messages. Substantial power may be saved since the zero-power states require very little (or no) transmitter power.

Abstract: The transmission power level is an important parameter in 5G/6G networking because it affects the failure rate if too low, background interference if too high, and battery life of user devices if retransmissions are required, among many other aspects of communications. Disclosed is an AI (artificial intelligence) model to recommend a transmission power level, based on inputs including: current network parameters such as the current throughput or message failure rate or average delay per message; parameters of the planned parameters such as the length and priority of the planned message; and environmental parameters such as the current noise or background interference level. In addition, the AI model adjusts for the distance between the transmitter and receiver, plus any known obscurations, among other inputs. The AI model then provides a recommended power setting for each message, adjusted to provide reliable reception but without wasting excess power.

Abstract: In current practice, faulted messages are typically discarded and a retransmission is requested. Forward error-correction codes (FEC) in 5G and 6G are bulky, resource-expensive, and often unable to resolve the problem. Disclosed are systems and methods for determining which specific message elements are faulted, so that just the faulted portion can be retransmitted, instead of the entire message. For example, the amplitudes of the I and Q branches, of each message element, can be compared to the calibrated amplitude levels of the modulation scheme. Any message element with a large amplitude deviation is suspect. Other factors, such as the SNR, can also be considered in evaluating the validity of each message element. Usually, all of the faulted message elements occupy just a portion of the message. Compact formats are disclosed specifying which portion of the message is to be retransmitted, thereby saving time, power, and background generation.

Abstract: With rapid increases in the number and spatial density of wireless messages as 5G and 6G are rolled out, it is essential that improved methods for fault-tolerant demodulation and error mitigation be developed. Disclosed herein are methods for receiving a message concatenated with a demodulation reference, determining the predetermined modulation levels of a modulation scheme, and demodulating the message by measuring the amplitude mad/or phase modulation values of each message element. The measured modulation values are then compared with the predetermined modulation levels of the modulation scheme to demodulate the message. Importantly, the message can be demodulated by determining an amplitude and phase of the raw signal for each message element, or by separating the raw signal into two orthogonal “branches” and determining the amplitudes of the two branches. By demodulating the message both ways, message faults may be identified and mitigated, according to some embodiments.

Abstract: Billions of low-cost autonomous sensors and actuators are expected to join 5G and 6G networks. Most of them will use DRX (discontinuous reception) to save power. However, if an incoming message arrives while the device is in sleep-mode, a complex process is required for the device to obtain its message. Instead, a fast, lean polling method is provided, in which the base station can inform the user devices periodically of their messages on hold, using an encoded matrix of bits, one bit per user device in the network. When a user device wakes up and receives the matrix, it can determine, according to its bit position, whether it has messages waiting. If so, the user device can then transmit a very brief signal in an allocated reply region, at a specific location corresponding to its bit position in the matrix, thereby requesting the message or messages on hold.

Abstract: A receiver can determine that a received message is corrupt according to an associated error-detection code in 5G/6G. The receiver can then calculate the modulation quality of each message element of the message by comparing a modulation value of the message element with a set of predetermined modulation levels, wherein a larger deviation from the closest predetermined modulation level corresponds to a lower modulation quality. Noise and interference usually generate random changes in the modulation as-received, and this generally results in a larger deviation relative to the predetermined modulation levels and hence a lower modulation quality. The receiver can count the number of faulted message elements with modulation quality below a threshold, and if the number of faults is less than some limit, the receiver can attempt to recover the message by altering the worst-quality message elements, testing each version for consistency.

Abstract: In a message modulated according to orthogonal amplitude-modulated component signals in 5G or 6G, the receiver can attempt to recover a corrupted message by evaluating the modulation quality of each component signal in each message element. The modulation quality of each component signal may be determined according to a distance between the amplitude of the component signal and the closest amplitude level of the modulation scheme, as determined by a prior demodulation reference. The modulation quality may also be determined by the SNR and amplitude stability of the component signal. Upon detecting a corrupted message, the receiver can identify the faulted message elements according to modulation quality, and if the faulted message elements are clustered in a portion of the message (as is common), the receiver can request that just the faulted portion be retransmitted, saving time and bandwidth.

Abstract: When two different messages are transmitted at the same time in 5G or 6G, the message is “collided”. The resulting interference causes a message fault, necessitating a costly retransmission. Disclosed is a modulation scheme in which the modulation states are configured so that a message element can be collided by an intruder message, yet the receiver can still recover the original message element. In other cases, depending on the colliding states, the receiver can narrow the possible values of each faulted message element to just two or three possibilities, thereby greatly reducing the amount of time required for testing each combination against an error-detection code. Especially under high-noise conditions, the collision-proof modulation scheme may enable enhanced throughput by identifying and mitigating the faulted message element, and may thereby avoid unnecessary retransmissions.

Abstract: Phase noise is a limiting factor in high-frequency 5G and 6G communications. Disclosed is a multiplexed amplitude-phase modulation scheme that can provide extremely wide phase noise margins at high frequencies. The transmitter can transmit a wave modulated in amplitude and phase, configured to provide a wide separation of phase states. The receiver, on the other hand, demodulates the message using quadrature amplitude modulation QAM, since that is generally more economical and technically preferred for signal processing. The demodulated message, however, still retains the large phase margins. As a further benefit, the examples illustrate non-square and asymmetric modulation schemes, which can extend the noise margins even further. By modulating with amplitude and phase, but demodulating with orthogonal branch signals, wireless networks can expand into high-frequency bandwidths while retaining high reliability and high throughput, as required for wireless applications of tomorrow.

Abstract: A base station of a 5G/6G network can include its location coordinates in the SSB system information message which is broadcast on a standard frequency periodically. A mobile user device can receive the SSB and thereby determine the base station location. Thereafter, the user device can measure its own location, speed, and direction of travel, and thereby calculate a Doppler frequency correction before transmitting a message to the base station, thus causing the base station to receive the message at the expected standard frequency. In addition, the user device can calculate, based on the location of the base station relative to the direction of travel of the mobile user device, a particular frequency at which downlink messages from the base station will be received. In addition, the user device can pre-emptively adjust its transmission frequency when changing speed or direction, thereby avoiding wasteful frequency-correction messages from the base station.

Abstract: In 5G and 6G, a message received with even a single-bit fault generally discarded and a retransmission is requested. However, the faulted message contains a wealth of information that the receiver can use to avoid, or at least mitigate, such faults thereafter. Disclosed is a method for comparing a faulted message with an unfaulted copy, thereby determining which part of the message is faulted, and specifically how it was faulted. For example, the fault may have been an amplitude fault in which a demodulated amplitude differs by one level from the initially modulated amplitude, or it may be a phase fault in which the received phase differs by one phase level, or there may be a displacement by multiple amplitude or phase levels (a non-adjacent fault). Different mitigation strategies are disclosed for each situation, including AI models configured to select a suitable modulation scheme to combat specific faults.

Abstract: A supercomputer, with traffic-modeling software and 5G/6G connectivity, can assist an autonomous vehicle in avoiding, or at least minimizing the expected harm of, an imminent collision. Upon detecting the imminent collision, the autonomous vehicle can transmit a message to an access point, requesting an uncontested direct communication link to the supercomputer, and then transfer sensor data and other traffic data to the supercomputer through the access point. The supercomputer can calculate a multitude of sequences of braking, steering, and accelerating actions of the autonomous vehicle, and can select the sequence that enables the autonomous vehicle to avoid the collision if possible. If all sequences cannot avoid the collision, the supercomputer can select the sequence that results in the least harm (fatalities, injuries, and property damage) in the unavoidable collision.

Abstract: With rapid increases in the number and spatial density of wireless messages as 5G and 6G are rolled out, it is essential that improved methods for fault-tolerant demodulation and error mitigation be developed. Disclosed herein are methods for receiving a message concatenated with a demodulation reference, determining the predetermined modulation levels of a modulation scheme, and demodulating the message by measuring the amplitude mad/or phase modulation values of each message element. The measured modulation values are then compared with the predetermined modulation levels of the modulation scheme to demodulate the message. Importantly, the message can be demodulated by determining an amplitude and phase of the raw signal for each message element, or by separating the raw signal into two orthogonal “branches” and determining the amplitudes of the two branches. By demodulating the message both ways, message faults may be identified and mitigated, according to some embodiments.

Abstract: A faulted 5G/6G message may be recovered by finding the faulted message elements and altering them until the fault is corrected. Disclosed are methods to evaluate the modulation quality of each message element using multiple criteria. The receiver can determine a first quality by measuring the overall (sum-signal) amplitude and phase of each message element, and comparing to the predetermined amplitude and phase levels. The receiver can determine a second quality by separating the overall wave into orthogonal components (branches) and comparing the branch amplitudes to the predetermined levels. The receiver can determine a third quality according to the SNR of the overall signal and the two branch signals. By combining the first, second, and third quality factors, the receiver can identify the most likely faulted message elements. The receiver can then alter the worst message elements in a nested grid search to find the correct message version.

Abstract: To mitigate phase noise and amplitude noise in a 5G or 6G message, the transmitter can include an extremely compact demodulation reference with a predetermined format including a first branch and an orthogonal second branch. The first branch can exhibit the maximum positive amplitude level of the modulation scheme, and the second branch can exhibit either the minimum positive level or the maximum negative level, depending on implementation. The receiver can determine, from the received branch amplitudes, a phase correction and an amplitude correction. Upon receiving a message including noise, the receiver can calculate a sum-signal amplitude and sum-signal phase according to the branch amplitudes of each message element, subtract the amplitude correction and phase correction, derive corrected branch amplitudes, and compare them to the predetermined amplitude levels of the modulation scheme. The receiver can thereby demodulate the message element with the phase noise and amplitude noise largely negated.

Abstract: At high frequencies planned for 5G and 6G, phase noise may be a limiting factor on reliability and throughput. The default modulation scheme is currently QAM. Disclosed is a more versatile demodulation method based on the amplitude and phase of the sum-signal, which is the vector sum of the two branch amplitudes of QAM. The transmitter modulates a message by sum-signal amplitude and phase. The receiver can process the received waveform according to quadrature branches as usual, and determines the branch amplitudes. The receiver then calculates, from the branch amplitudes, the sum-signal amplitude and sum-signal phase for demodulation. The receiver can thereby obtain substantially enhanced phase-noise tolerance and amplitude spacing uniformity at virtually no cost. In addition, methods are disclosed for determining specific message fault types and non-square modulation tables depending on the type of mitigation required.