Systems and methods are provided for reducing peak-to-average power ratio (“PAPR”) in an orthogonal frequency division multiplexing (“OFDM”) signal having reference tones by introducing modified pilot tones to cancel peaks in OFDM symbols in the OFDM signal array. The modified pilot tones are added to the original OFDM signal, which in turn conditions the OFDM symbols of the signal to effectively reduce the PAPR. Such systems and methods provide PAPR reduction for OFDM signals generated by an OFDM Signal Processor through the addition of tone reservation PAPR reduction methods, which use reserved tones such as pilot tones to improve PAPR. Such methods offer an advantage of improving the PAPR without introducing distortion to the signal.

The present application discloses a method for transmitting an uplink relay signal by a relay terminal in a wireless communication system. Specifically, the method comprises the steps of: superposition encoding relay data and side link data according to a predetermined power ratio so as to generate the uplink relay signal; and transmitting the uplink relay signal and a superposition encoding-specific reference signal sequence corresponding to the power ratio to a base station and a target terminal.

The application provides a short training sequence design method and apparatus. The method includes: determining a short training sequence, where the short training sequence may be obtained based on an existing sequence, and the short training sequence with comparatively good performance may be obtained through simulation calculation, for example, by adjusting a parameter, and sending a short training field on a target channel, where the short training field is obtained by performing inverse fast Fourier transformation IFFT on the short training sequence, and a bandwidth of the target channel is greater than 160 MHz.

Some demonstrative embodiments include apparatuses, devices, systems and methods of communicating a PPDU including a training field. For example, an Enhanced Directional Multi-Gigabit (DMG) (EDMG) wireless communication station may be configured to determine one or more Orthogonal Frequency Division Multiplexing (OFDM) Training (TRN) sequences in a frequency domain based on a count of one or more 2.16 Gigahertz (GHz) channels in a channel bandwidth for transmission of an EDMG PPDU including a TRN field; generate one or more OFDM TRN waveforms in a time domain based on the one or more OFDM TRN sequences, respectively, and based on an OFDM TRN mapping matrix, which is based on a count of the one or more transmit chains; and transmit an OFDM mode transmission of the EDMG PPDU over the channel bandwidth, the OFDM mode transmission comprising transmission of the TRN field based on the one or more OFDM TRN waveforms.

Aspects of the present application provide methods and devices for a phase tracking reference (PT-RS) scheme for use by a single carrier Offset QAM (SC-OQAM) transmitter and receiver to estimate, and correct, phase errors that occur over the communication link between the SC-OQAM transmitter and receiver. Phase errors can occur due to, for example, phase noise or carrier frequency offset (CFO). A PT-RS that includes PT-RS symbols can be used to track phase error. As a result of SC-OQAM waveform generation, real-valued PT-RS symbols may incur imaginary valued interference and imaginary-valued PT-RS symbols may incur real-valued interference. In order to effectively use the PT-RS to estimate and compensate for the phase noise, the interference must be appropriately considered.

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 a time-domain sequence x(i), an output sequence s(k). The output sequence s(k) is an inverse Fourier transform of a frequency-domain sequence S(j), and S(j) represents a dot-multiplication of a frequency-domain sequence Y(j) corresponding to the time-domain sequence x(i) and a frequency-domain sequence Z(j) corresponding to a three-coefficient function associated with $\frac{\sqrt{2}}{2},$
1, and $\frac{\sqrt{2}}{2}.$
The method also includes generating a waveform using the output sequence s(k), where i is from 0 to I−1, j is from 0 to J−1, k is from 0 to K−1, and I<J<=K.

An apparatus of user equipment (UE) includes processing circuitry coupled to a memory, where to configure the UE for DMRS processing in an NR network, the processing circuitry is to generate a plurality of binary sequences of length L, the binary sequences being arranged according to a signal quality metric. A set of CGSs is generated using the binary sequences, based on minimizing cross-correlation between subsets of binary sequences of different lengths selected from the plurality of binary sequences. A CGS is selected from the set of CGSs as a DMRS, based on uplink PRB resource allocation. The DMRS is encoded for transmission, where the encoding includes BPSK modulation and discrete Fourier transformation (DFT) spreading of the DMRS.

This disclosure provides methods, devices, and systems for a wireless communication device to perform signal phase rotation. In some implementations, the wireless communication device may determine a number of phase rotation parameters to be applied to a number of tones of a transmission signal. In some aspects, each of the phase rotation parameters indicates a phase rotation to be applied to each of the tones according to a carrier index range for each of the tones and a bandwidth mode for the transmission signal. In some implementations, the wireless communication device may apply the phase rotation parameters to respective ones of the tones according to the specified phase rotations and the carrier index ranges, and transmit the transmission signal from the wireless communication device according to the applied phase rotation parameters.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may determine a UE. The apparatus may generate a reference signal using a base sequence obtained from a table, the table including a plurality of base sequences that each have a peak-to-average-power ratio (PAPR) metric below a threshold. Then, the apparatus transmits the reference signal to a base station. The reference signal may be multiplexed with a data transmission.

Because the number of transmitted layers can vary dynamically, the number of transmitted demodulation reference signals (DM-RS) can also vary. However, because the network node can know the number of ports, transmitted layers, or the rank, the network node can utilize the number as part of the scheduling information via a downlink or an uplink control channel. Therefore, the DMRS sequence generation can modified such that it depends on the number of ports, transmitted layers, or the rank, thereby generating a different random sequence for different ports.