Interleaving aspects in the case of Signal Space Diversity (SSD) are considered here, in particular when the SSD transmission is expected to be overlapped by a colliding non-orthogonal Ultra Reliable & Low Latency Communication (URLLC). The interleaver's depth when interleaving I and Q components of a rotated modulated symbol is chosen such that a gap of at least an expected maximum size, measured in transmission units, of a possible colliding wireless signal, is generated between a respective In and Qn component of a same symbol n.

Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal over the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a baseband signal after a first mapping and a baseband signal after a second mapping by a precoding weight and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.

Certain aspects of the present disclosure relate to methods and apparatus relating to reference signal design for Pi/2-binary phase shift keying (Pi/2-BPSK) modulation with frequency domain spectral shaping (FDSS). In certain aspects, a method includes generating a set of Gold sequences each having a length and adjusting the length of each of the Gold sequences in the set of Gold sequences. The method also includes applying a phase rotation to each of the Gold sequences in the set of Gold sequences and modulating each of the Gold sequences in the set of Gold sequences by a DFT-s-OFDM with frequency domain spectral shaping (FDSS). The method further includes selecting one or more sequences from the set of modulated Gold sequences based on a parameter and transmitting the one or more sequences to a user equipment (UE) or a base station (BS).

Methods, systems, and devices for wireless communications are described. A transmitting device may identify a set of allocated resource blocks and a number of the allocated resource blocks. The transmitting device may determine a bit sequence length corresponding to the number of allocated resource blocks. The transmitting device may generate a reference signal based on a bit sequence having the bit sequence length and transmit the reference signal within the allocated resource blocks. The transmitting device may modulate the bit sequence using a π/2 binary phase shift keying modulation scheme. The transmitting device may modulate a data bit sequence using the same modulation scheme to generate a modulated data bit sequence, where a peak to average power ratio (PAPR) of tones transporting the modulated data bit sequence satisfies a PAPR threshold and a PAPR of tones transporting the reference signal also satisfies the PAPR threshold.

The present specification relates to a method for transmitting, by a terminal, a demodulation reference signal (DMRS) in a wireless communication system supporting narrow-band (NB)-Internet of things (IOT), the method comprising: generating, for single tone transmission, a reference signal sequence to be used for demodulation; mapping the reference signal sequence to a plurality of symbols; and transmitting, in the plurality of symbols, the demodulation reference signal to a base station by using a single tone, wherein phase rotation is applied to each of the plurality of symbols.

A transmission device that improves data reception quality includes: a weighting synthesizer that generates a first precoded signal and a second precoded signal from a first baseband signal and a second baseband signal, respectively; a phase changer that applies a phase change of i to the second precoded signal; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. satisfies /2 radians<< radians or radians<<3/2 radians. Each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.

A random access preamble sequence generation method and user equipment are provided. The method includes the following: when receiving first notification signaling sent by a base station, determining, by UE, to calculate a cyclic shift value by using a first solution; obtaining a first logical root sequence number, and determining a root sequence based on the first logical root sequence number; and generating a random access preamble sequence based on the root sequence and the cyclic shift value, where the first solution is a solution of calculating the cyclic shift value when a Doppler shift of the UE is less than a first preset value and greater than a second preset value, the first preset value is less than twice of a physical random access channel (PRACH) subcarrier spacing, the second preset value is greater than the PRACH subcarrier spacing.

A method and apparatus for communication, e.g. in an LTE system, that uses two tones with an in-phase pi/2 BPSK modulation with single carrier frequency-division multiple access (SC-FDMA). Pairs of input bits are converted to symbols using pi/2 BPSK, with each one of the pair of bits converted using a same symbol constellation, and successive pairs of bits converted using alternatingly different symbol constellations. The two constellations may be identical after a pi/2 radian rotation. Pairs of symbols corresponding to pairwise converted bits may be treated as the symbols for a pair of tones of a subsequent SC-FDMA, OFDMA, or similar processing operation.

Methods, systems, and devices for multiple access with interference mitigation are described. A wireless communication method is provided to comprise: generating, from information bits, a modulated signal; spreading the modulated signal using a spreading code to provide a spread data signal; processing the spread data signal through a randomization; and transmitting an orthogonal frequency division multiplexing (OFDM) signal based on an output of the processing.

A transmission device that improves data reception quality includes: a weighting synthesizer that generates a first precoded signal and a second precoded signal from a first baseband signal and a second baseband signal, respectively; a phase changer that applies a phase change of i to the second precoded signal; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. satisfies /2 radians<< radians or radians<<3/2 radians. Each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.