Methods, apparatus, and systems for reducing Peak Average Power Ratio (PAPR) in signal transmissions are described. In one example aspect, a wireless communication method includes determining, for an input sequence, an output sequence corresponding to an output of a convolutional modulation between a plurality of values and an intermediate sequence. The intermediate sequence is generated by inserting a set of coefficients between coefficients of the input sequence. Each non-zero coefficient of the set of coefficients is inserted between a first adjacent coefficient and a second adjacent coefficient. Each non-zero coefficient has a power that is between a first power of the first adjacent coefficient and a second power of the second adjacent coefficient and a phase value between a first phase value of the first adjacent coefficient and a second phase value of the second adjacent coefficient. The method also includes generating a waveform using the output sequence.

Certain aspects of the present disclosure provide techniques for generating and decoding orthogonal frequency division (OFDM) waveforms with peak reduction tones (PRTs) designed to reduce PAPR. By generating PRT tones with a machine learning (e.g., neural network) based encoder and mapping some of the PRT tones to subcarriers used for physical channels or signals, PAPR may be reduced while efficiently using system resources.

Methods, systems, and devices for wireless communication are described. A wireless device, such as a device in a wireless local area network, may use a radio frame structure that includes a high efficiency (HE) signal field and an HE data field for communications, for example, over shared radio frequency spectrum. One or more bits or symbols within the HE signal field may be adjusted to avoid a high peak-to-average power ratio (PAPR). In some cases, the adjustment may be to a signal A (SIG-A) or signal B (SIG-B) field. In some examples, a random bit sequence may be used for padding in a signal field. In other examples, bits may be reversed or scrambled. In yet other examples, bits may be modulated and a phase rotation may be applied to the corresponding signal.

A method and apparatus for artificial neural network precoding for massive MIMO systems are disclosed. In one embodiment, a method includes processing, by an artificial neural network, ANN, precoding engine, at least one input signal by 5 performing a low peak-to-average-power ratio, PAPR, precoding on the at least one input signal; and transmitting, via at least one antenna array having at least one antenna, at least one precoded output signal processed by the ANN precoding engine.

Embodiments of the present disclosure relate to a method and system to generate a waveform in a communication network. The transmitter receives an input data and transmit a generated waveform to another communication system. The input data is spread with a spread code to generate a spread data and rotated using a constellation rotation operation to produce a rotated data. The rotated data is then precoded using precoding filter to produce a precoded data, and transformed into DFT output data using DFT operation. The DFT output data is then mapped with subcarriers to generate the sub-carrier mapped DFT data and modulated using Orthogonal Frequency Division Multiplexing (OFDM) modulation to generate the waveform with low PAPR.

Methods, apparatuses and systems directed to complementary sequence (CS) encoding and encoded CS transmissions are provided. Among the apparatuses is apparatus having a transmitter that may be configured to (i) transmit an encoded CS via a block based, e.g., orthogonal frequency division multiplexing (OFDM), waveform, and/or (ii) generate the encoded CS using a plurality of seed sequences and a plurality of information items, wherein: of the elements of the encoded CS encodes a first set of the plurality of information items; (b) phases of the encoded-CS elements encode a second set of the plurality of information items); and (c) the encoded-CS elements define a number of zeros that encode a third set of the plurality of information items. The encoded-CS elements may define respective numbers of zeros that collectively form the number of zeros that encode the third information-item set.

Certain aspects of the present disclosure generally relate to wireless communications. In some aspects, a wireless device reduces a peak-to-average power ratio (PAPR) of a discrete-time orthogonal frequency division multiplexing (OFDM) transmission by selecting a signal with low PAPR from a set of candidate discrete-time OFDM signals. The wireless device may generate a partial-update discrete-time OFDM signal by performing a sparse transform operation on a base data symbol sequence, and then linearly combine the partial-update discrete-time OFDM signal with a base discrete-time OFDM signal to produce an updated discrete-time OFDM signal, which is added to the set of candidate discrete-time OFDM signals. Numerous other aspects are provided.

Methods, systems, and devices for wireless communications are described. An interfering base station may transmit to a neighboring base station a configuration to measure beam resources for a plurality of PAPR reduction beams. The neighboring base station may forward this measurement configuration to an associated UE. The UE may then take measurements of the interfering base station's PAPR reduction beams in accordance with the configuration and transmit the report to its serving base station. The neighboring base station may then compile a headroom report and transmit the headroom report to the interfering base station. The interfering base station may then adjust its PAPR reduction beams based on the headroom report.

In some embodiments, an apparatus and a system, as well as a method and an article, may operate to transmit and receive data. Transmission may comprise transforming larger values of acquired data into smaller values of transformed data using a transform defined by a seed value selected to reduce digital pulse position modulation transmission time for the acquired data. Additional activities include digital pulse position modulating the transformed data and a checksum associated with the transformed data to provide a propagation signal, and transmitting the propagation signal into drilling fluid or a geological formation. Reception may comprise receiving the propagation signal, demodulating the propagation signal to extract the transformed data and the checksum, and transforming the transformed data into an estimate of the acquired data, using the transform defined by the seed value validated by the checksum. Additional apparatus, systems, and methods are described.

An information transmission apparatus, an information detection apparatus and a transmitter is provided where serial numbers of information transport blocks are determined according to information indicating branch selection, so as to transmit information on the branch selection by using the serial numbers of information transport blocks. Hence, no additional transmission path needs to be provided, and the information on the branch selection may be simply and conveniently transmitted and a probability of wrongly determining the information indicating branch selection may be reduced, thereby efficiently improving performance of the system.