In this disclosure, methods for pre-compensation of the phase shifting error, and apparatuses for the same are disclosed. In one example, a device performs precoding of a digital signal, while acquiring information on an error caused by a phase shifting of the precoding. Then, the device performs phase compensation on the digital signal based on the acquired information. This phase compensated-digital signal is converted to an analog signal, and is transmitted to a receiver.

To reduce a bandwidth required for an optical transmission path (30) in a base station system including an RAU (21) for performing MIMO transmission using a plurality of antenna elements and a BBU (11), in a communication control method of the present invention, the BBU (11) transmits antenna weight coefficient information indicative of antenna weight coefficients of a plurality of antenna elements (205) and a transmission signal, and the RAU (21) multiplies the transmission signal from the BBU (11) by each of the antenna weight coefficients to generate weighted signals of the plurality of antenna elements (205), and transmits the weighted signals from the plurality of antenna elements (205).

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

[00001]$\frac{\sqrt{2}}{2},$

1, and

[00002]$\frac{\sqrt{2}}{2}.$

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.

A communications device for use in a wireless communications system comprising an infrastructure equipment and the communications device is provided. The communications device is configured to transmit an uplink channel to the infrastructure equipment in a plurality of allocated subcarriers. The communications device comprises circuitry for one or more modulation symbol repetition blocks, each configured to receive modulated symbols mapped to one of plurality of modulated symbol sets and to repeat each of the received modulated symbols within each of the plurality of modulated symbol sets, and circuitry for a precoder block configured to carry out a precoder function on the repeated modulation symbols, the precoder function comprising multiplying each of the repeated modulation symbols by an element of a precoder vector to produce precoded symbols.

A signal transmission method and an apparatus are provided, to resolve a problem, in a conventional technology, that transmission performance is poor when a signal is transmitted in a DFT-s-OFDM waveform. A transmitting end maps a plurality of modulation symbols to a plurality of layers, performs discrete Fourier transform (DFT) on a modulation symbol at a part of the layers to obtain a first symbol, and performs discrete Fourier transform DFT and phase offset on a modulation symbol at a remaining part of the layers to obtain a second symbol. Phase offset is performed on a symbol at a part of layers, so that a PAPR can be reduced.

A UE determines a respective set of subcarriers from N subcarriers in each OFDM symbol of M1 consecutive OFDM symbols within a slot. The respective set of subcarriers carries a respective set of SRSs that form transmission combs of a transmission comb size. The respective set of subcarriers in one of the M1 consecutive OFDM symbols do not overlap in frequency domain with the respective set of subcarriers in any other one of the M1 consecutive OFDM symbols. The UE applies the respective set of phase rotations to the respective set of SRSs in each OFDM symbol to obtain a cyclic shift. The UE maps the respective set of SRSs applied with phase rotations to the respective set of subcarriers in each OFDM symbol. The UE transmits the respective sets of SRSs in the M OFDM symbols.

Provided are an information transmission method, a base station, a terminal and a computer-readable storage medium. The information transmission method includes: a base station sending a first message. The first message includes at least one of: at least one set of channel quality threshold values, where each of the at least one set of channel quality threshold values includes at least one channel quality threshold value; or a deviation value relative to the at least one channel quality threshold value. The at least one channel quality threshold value is set according to at least one following type of channel quality: reference signal receiving power, a reference signal receiving quality, a downlink signal to interference plus noise ratio, a downlink signal to noise ratio, an uplink signal to interference plus noise ratio, an uplink signal to noise ratio, a downlink path loss, or an uplink path loss.

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.

A base station for transmitting a synchronization signal from N transmission antennas (N>=2) in orthogonal frequency division multiple access includes a signal sequence generation unit configured to generate a synchronization signal sequence to be used for the synchronization signal in a frequency domain; a subcarrier mapping unit configured to divide a transmission band of the synchronization signal into K frequency blocks (K>=2) and map the synchronization signal sequence into one or more subcarriers in the K frequency blocks; a precoding unit configured to generate N precoding vectors to be multiplied by the synchronization signal sequence in the frequency domain and multiply the synchronization signal sequence to be transmitted from an n-th antenna (1<=n<=N) by at least an n-th precoding vector; and a transmission unit configured to transmit the synchronization signal from the N transmission antennas.

Techniques for peak-to-average power ratio (PAPR) reduction are described. Wireless devices may provide signaling with respect to one or more PAPR shaping resources. For example, a wireless device may provide signaling of PAPR shaping capability information. PAPR shaping capability information may include information regarding one or more PAPR shaping resources the wireless device has a capability to implement. Additionally or alternatively, a wireless device may provide signaling of PAPR shaping information. PAPR shaping information may include information regarding shaping the signal by a wireless device prior to transmission in a communication link by implementing one or more PAPR shaping resources. Other aspects and features are also claimed and described.