Abstract: Methods, systems, and devices for wireless communications are described for reducing overhead associated with a cyclic prefix (CP) by supporting dynamic determination of a CP length. For example, a user equipment (UE) may establish a wireless connection with a base station by receiving initial communications according to a numerology and a first CP configuration associated with a first CP length. The UE may determine a second CP length after establishing the wireless connection and may transmit an indication to the base station, indicating the second CP length. The base station may receive the indication and may transmit downlink signals according to a second CP configuration associated with the second CP length. The initial communications and the downlink signals may be associated with a same numerology or subcarrier spacing.

Abstract: Methods related to wireless communication systems and the transmission of code blocks on such systems are provided. A wireless communication device interleaves a plurality of code block segments in time and frequency. The segments are interleaved by mapping a first code block segment of the plurality of code block segments to a first resource located at a first time and a first frequency, wherein the first code block segment is associated with a first code block, and mapping a second code block segment of the plurality of code block segments to a second resource based on at least one of the first time or the first frequency of the first resource and a code block proximity parameter, wherein the second code block segment is associated with a second code block different from the first code block. The device then transmits the plurality of interleaved code block segments. Other features are also claimed and described.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may transmit, to each user equipment (UE) of a set of UEs, a different respective set of one or more training parameters for a digital pre-distortion procedure. Some or all of the UEs may determine one or more respective training values based on the one or more training parameters, where the training values from the UEs support the base station computing a set of non-linearity coefficients for the digital pre-distortion procedure. The base station thus may receive training parameters from some or all of the UEs and determine the set of non-linearity coefficients based thereon. The base station use the non-linearity coefficients to perform the digital pre-distortion procedure for one or more downlink transmissions, to one or more UEs of the group of UEs used for training, or to one or more other UEs.

Abstract: Certain aspects of the present disclosure provide techniques for over-the-air digital pre-distortion (DPD) kernel function selection. A method that may be performed by a user equipment (UE) includes transmitting capability information to a base station (BS), indicating a capability of the UE for performing digital pre-distortion (DPD) training, receiving, based on the capability information, a request from the BS to perform the DPD training, performing, based on the received request, the DPD training, wherein performing the DPD training includes: receiving one or more reference signals (RSs) and selecting, based on the one or more RSs, an ordered set of kernel functions. Additionally, the method may include transmitting feedback information to the BS indicating the ordered set of kernel functions.

Abstract: Methods, systems, and devices for wireless communications are described. A wireless communications system may support inter-band inter-cell interference coordination (ICIC) measurement and capability reporting. For example, a user equipment (UE) may transmit, to a base station, a capability message indicating its ability to use low power signal processing in the absence of inter-band interference and its ability to report values associated with inter-band interference measurement. In addition, the UE may transmit, to the base station, a measurement report indicating values associated with inter-band interference and in response, the base station may update communications with the UE to avoid inter-band interference or the base station may coordinate with other base stations to avoid inter-band interference.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, a phase tracking reference signal. The phase tracking reference signal is transmitted using a single carrier waveform and encoded within a time domain. Accordingly, the UE may decode, from the base station, a message, based at least in part on the phase tracking reference signal. Numerous other aspects are provided.

Abstract: Techniques for wireless communications are described. A demodulation reference signal generated using user information and a noncoherent modulation technique may be communicated between wireless devices. A data sequence may be extracted from the demodulation reference signal based on demodulating the demodulation reference signal using the noncoherent modulation technique and decoding the demodulation reference signal. The data sequence may be used to reconstruct a version of the demodulation reference signal used to descramble a received version of the demodulation reference signal. The descrambled demodulation reference signal may be used to estimate a data channel between a transmitting device and a receiving device.

Abstract: Methods, systems, and devices for wireless communications are described for estimating one or more environmental factors at a first user equipment (UE). The one or more environmental factors may be based on estimates of a Doppler spread and a power delay profile (PDP) taken over a set of subsets of a time period, based on multiple signals received from a second UE or a base station over the time period. The first UE may estimate the Doppler spread and PDP for a channel over each of the set of subsets of the time period, and may combine the Doppler spread over the set of subsets and combine the PDP over the set of subsets. The first UE may use the combined Doppler spread and the combined PDP to determine one or more communication parameters for the channel.

Abstract: Methods, systems, and devices for wireless communication are described. A communication device, such as a user equipment (UE) may receive control signaling (e.g., a downlink control information (DCI), a radio resource control (RRC) message, a medium access control-control element (MAC-CE)) including an indication of a set of constellation points for a set of constellation distortion points. The set of constellation distortion points may be of a constellation distribution associated with a modulation scheme (e.g., a quadrature amplitude modulation (QAM), an amplitude and phase-shift keying (APSK)). The UE may perform a digital post distortion operation based on the set of constellation points for the set of constellation distortion points of the constellation distribution, and decode the wireless communication based on performing of the digital post distortion operation.

Abstract: Disclosed are techniques related to wireless communication system in which multi-level encoded modulation (MLCM) is applied to non-coherent communication. In the proposed techniques, a small fraction of differential phase rotations or bits participating in differential symbol coding are protected with strong codes while other complementary differential phase rotations or bits are protected with weaker codes. Compared to conventional non-coherent communication techniques in which a uniform protection is applied to any fraction of differential phase rotation or any bit of a differential symbol, the proposed MLCM approach enables more spectrally efficient scheme.

Abstract: Methods, systems, and devices for wireless communications are described. Generally, to improve throughput via more intentional tone reservation, a receiving device (e.g., a user equipment (UE)), may identify one or more tones that have poor signal quality. The receiving device may transmit an indication of the one or more tones having poor signal quality to a transmitting device. The transmitting device may reserve one or more of the identified tones for use in a tone reservation scheme, such as to carry peak-to-average power ratio (PAPR) reduction signals, and may transmit data signals over tones that have higher signal quality.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may transmit an indication of a capability of the UE to communicate one or more of uplink transmissions or downlink transmissions having amplitude-modulated phase tracking reference signals on at least a first layer of a multilayered communication link that includes the first layer and a second layer; and communicate an uplink transmission or a downlink transmission based at least in part on the indication. Numerous other aspects are provided.

Abstract: This disclosure provides methods, devices and systems for reducing PAPR in wireless communications. Some implementations more specifically relate to suppressing the amplitudes of a data signal that exceed a threshold amplitude level. In some implementations, a transmitting device may detect one or more peaks associated with a data signal to be transmitted to a receiving device. A peak may be any sample of a data signal having an amplitude that exceeds a threshold amplitude level. The transmitting device generates peak suppression information indicating the amplitude, a phase and a position of each of the samples associated with the detected peaks. The transmitting device adjusts the data signal by reducing the amplitudes associated with the detected peaks and transmits the adjusted data signal, with the peak suppression information, to the receiving device. In some implementations, the transmitting device may compress the peak suppression information to reduce the overhead of the transmission.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may transmit a request, for an uplink transmission or a downlink transmission, for amplitude modulated phase tracking reference signals; and communicate the uplink transmission or the downlink transmission based at least in part on the request. Numerous other aspects are provided.

Abstract: A phase tracking reference signal (PTRS) may be enhanced to carry data encoded with a relative low modulation and coding scheme (MCS). A receive device may receiving a data channel, the data channel including a transport block encoded using a first MCS. The receiving device may receiving a PTRS interleaved with the data channel. The PTRS is encoded with the second MCS that is lower than the first MCS. The receiving device may decode the PTRS to determine PTRS data. The receiving device may track phase noise using the PTRS data as a transmitted sequence of the PTRS. The receiving device may decode the transport block for the data channel based on the first MCS and the tracked phase noise.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitting device such as a base station and a user equipment (UE), may segment a set of bits within a transport block into a first subset of bits including modulation bits and a second subset of bits including index modulation bits. The transmitting device may map the first subset of bits to a first set of subcarriers, the second subset of bits to a second set of subcarriers, and an additional set of bits to a third set of subcarriers. The transmitting device may generate a signal according to a boosting factor based on mapping the first subset of bits, the second subset of bits, and the additional set of bits, and transmit the generated signal to a receiving device.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitting device may encode a set of bits to transmit to a receiving device based on a repetition factor. The transmitting device may map, based on the repetition factor, the set of encoded bits to a subset of subcarriers such as adjacent subcarriers of a set of subcarriers. The transmitting device may generate a signal including the set of encoded bits based on the mapping, and transmit the generated signal to the receiving device. The receiving device may receive a modulated signal from the transmitting device, and identify, based on a repetition factor, a subset of subcarriers including adjacent subcarriers of a set of subcarriers associated with the modulated signal. The receiving device may average the subset of subcarriers including the adjacent subcarriers, and demodulate the modulated signal in accordance with the averaged subset of subcarriers including the adjacent subcarriers.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitting device may encode a set of data bits on a set of subcarriers based on a boosting factor, and map the set of encoded data bits to a resource block including a first subset of subcarriers corresponding to the set of encoded data bits and a second subset of subcarriers corresponding to a set of null bits. The transmitting device may generate and transmit a signal including the set of encoded data bits. A receiving device may receive a modulated signal on a set of subcarriers, and de-map the modulated signal to a first subset of subcarriers and a second subset of subcarriers based on a boosting factor. The receiving device may decode the first subset of subcarriers to a first set of data bits and the second subset of subcarriers to a second set of data bits.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may transmit a request, for an uplink transmission or a downlink transmission, for tone reservation on one or more subchannels allocated for phase tracking reference signals (PT-RSs); and transmit the uplink transmission or receiving the downlink transmission based at least in part on the request. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitting device may encode a set of bits to transmit to a receiving device based on a repetition factor. The transmitting device may map, based on the repetition factor, the set of encoded bits to a subset of subcarriers such as adjacent subcarriers of a set of subcarriers. The transmitting device may generate a signal including the set of encoded bits based on the mapping, and transmit the generated signal to the receiving device. The receiving device may receive a modulated signal from the transmitting device, and identify, based on a repetition factor, a subset of subcarriers including adjacent subcarriers of a set of subcarriers associated with the modulated signal. The receiving device may average the subset of subcarriers including the adjacent subcarriers, and demodulate the modulated signal in accordance with the averaged subset of subcarriers including the adjacent subcarriers.