A method in a transmitter comprises transmitting a first data block to a first user, using an index modulation scheme and using SSD for transmitting the first data block. In some embodiments, the index modulation scheme is index-modulated OFDM and the indices comprise subcarrier indices. The method further comprises determining that a retransmission of the first data block to the first user is needed, and rearranging a bit mapping of bits in the first data block to indices used in the index modulation scheme, compared to a bit mapping previously used for transmitting the first data block to the first user using the index modulation scheme. The method further comprises retransmitting the second data block to the first user, where this retransmitting comprises using the index modulation scheme with the rearranged bit mapping and using SSD.

In some implementations, a device may provide content received via a quadrature amplitude modulation channel. The device may receive supplemental content information regarding supplemental content to be provided during a period of time associated with providing the content, wherein the supplemental content information includes a uniform resource locator (URL) identifying a location of the supplemental content and start time information identifying a time when the supplemental content is to be provided. The device may obtain the supplemental content using the URL. The device may transition, from providing the content, to providing the supplemental content based on the start time information. The device may transition, from providing the supplemental content, to providing the content after providing the supplemental content.

Provided are systems and methods for transmitting data over a wireless channel from a data transmitting node to a data receiving node in a communication system. The data transmitting node comprises second-layer processing circuitry for receiving at least one second-layer SDU, to be mapped onto a resource allocated for data transmission, and for generating a second-layer PDU, including the at least one second-layer SDU and at least one second-layer control element, and first-layer processing circuitry for receiving the second-layer PDU generated by the second-layer processing circuitry and for mapping the second-layer PDU onto the resource allocated for data transmission. The data receiving node comprises first-layer processing circuitry for de-mapping at least one second-layer PDU, and second layer processing circuitry for receiving and parsing the second-layer PDU demapped by the first-layer processing circuitry, the second-layer PDU including at least one second-layer SDU, and at least one second-layer control element.

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.

Provided are systems and methods for transmitting data over a wireless channel from a data transmitting node to a data receiving node in a communication system. The data transmitting node comprises second-layer processing circuitry for receiving at least one second-layer SDU, to be mapped onto a resource allocated for data transmission, and for generating a second-layer PDU, including the at least one second-layer SDU and at least one second-layer control element, and first-layer processing circuitry for receiving the second-layer PDU generated by the second-layer processing circuitry and for mapping the second-layer PDU onto the resource allocated for data transmission. The data receiving node comprises first-layer processing circuitry for de-mapping at least one second-layer PDU, and second layer processing circuitry for receiving and parsing the second-layer PDU demapped by the first-layer processing circuitry, the second-layer PDU including at least one second-layer SDU, and at least one second-layer control element.

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.

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.

A transmitter for transmitting payload data and emergency information using data symbols in a single-carrier or multi-carrier broadcast system comprises a modulator configured to modulate one or more transmission symbols with signaling data for use in detecting and recovering the payload data at a receiver and to modulate one or more transmission symbols with the payload data. An emergency information receiver receives emergency information carrying information of an actual emergency. An emergency information embedder embeds emergency information into one or more transmission symbols, wherein the emergency information is embedded within a predetermined time period after its reception by using a resource used for carrying signaling data and/or payload data if no emergency information shall be transmitted. A transmission unit transmits the transmission symbols.

A signal specification identification apparatus includes processing circuitry that estimates the transmission rate of a received signal, performs sampling frequency conversion on the received signal, calculates a probability corresponding to each of a plurality of candidates for a specification of the received signal, selects a candidate using the respective probabilities, and calculates reliability corresponding to a selected candidate, determines whether to output the selected candidate as an identification result or perform the sampling frequency conversion again, based on the reliability, and changes a parameter indicating the ratio of the sampling frequency conversion when it is determined that the sampling frequency conversion is to be performed again. Processing is repeated until the processing circuitry determines that the selected candidate as the identification result is to be output.

A transmitting apparatus is disclosed. The transmitting apparatus includes an encoder to perform channel encoding with respect to bits and generate a codeword, an interleaver to interleave the codeword, and a modulator to map the interleaved codeword onto a non-uniform constellation according to a modulation scheme, and the constellation may include constellation points defined based on various tables according to the modulation scheme.