An apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: generate (606) a synchronization signal for transmission over one or more symbols, wherein the number of symbols is dependent on a subcarrier spacing.

A first endpoint generates an acoustic spread spectrum signal including a pilot sequence and a data sequence representing a token synchronized to the pilot sequence, transmits the acoustic spread spectrum signal, and records a transmit time at which the acoustic spread spectrum signal is transmitted. A receive time at which a second endpoint received the acoustic spread spectrum signal transmitted by the first endpoint is received from the second endpoint along with an indication of a second token as recovered from the received acoustic spread spectrum signal by the second endpoint. A separation distance between the first endpoint and the second endpoint is computed based on a time difference between the transmit time and the receive time. The first endpoint is paired with the second endpoint when the token matches the second token and the computed distance is less than a threshold distance.

A method for constructing Polarization Assisted Convolutional (PAC) codes, the method including passing a codeword through a noisy channel to obtain a first bit and a noise value, determining whether the first bit is an information bit or a non-information bit based on the noise value by decoding the codeword to obtain a decoded codeword, selecting at least one of a reward or a penalty for the first bit based on the decoded codeword, the reward being set based on a probability of decoding, and the selecting selects the penalty for the first bit in response to determining the first bit is incorrectly decoded, and iterating the passing, the determining and the selecting according to Q-values for each state among a plurality of states, at least one of the Q-values corresponding to the first bit.

A method for constructing Polarization Assisted Convolutional (PAC) codes, the method including passing a codeword through a noisy channel to obtain a first bit and a noise value, determining whether the first bit is an information bit or a non-information bit based on the noise value by decoding the codeword to obtain a decoded codeword, selecting at least one of a reward or a penalty for the first bit based on the decoded codeword, the reward being set based on a probability of decoding, and the selecting selects the penalty for the first bit in response to determining the first bit is incorrectly decoded, and iterating the passing, the determining and the selecting according to Q-values for each state among a plurality of states, at least one of the Q-values corresponding to the first bit.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit a random access preamble to a base station as part of a two-step random access procedure. The UE may generate the preamble by identifying a discrete Fourier transform (DFT) matrix and generating a set of sequences based on the DFT matrix. Each sequence of the set of sequences may be generated by selecting a column of the DFT matrix and performing deterministic sampling of respective entries from the selected column in accordance with a sampling function. The UE may then select a sequence from the set of sequences based on generating the set of sequence. The UE may transmit the selected sequence to a wireless device (e.g., a base station).

A signal sending and receiving method and apparatus are provided. A first signal is sent, and a sequence of the first signal is generated at least based on a first sequence and a second sequence. There are multiple manners for determining the first sequence and the second sequence. For example, the first sequence is determined at least according to start time domain location information of the first signal and current time domain location information of the first signal, and the second sequence is determined at least according to a cell index corresponding to the first signal.

A signal sending and receiving method and apparatus are provided. A first signal is sent, and a sequence of the first signal is generated at least based on a first sequence and a second sequence. There are multiple manners for determining the first sequence and the second sequence. For example, the first sequence is determined at least according to start time domain location information of the first signal and current time domain location information of the first signal, and the second sequence is determined at least according to a cell index corresponding to the first signal.

A method and apparatus for transmitting and receiving a signal in a wireless communication system, according to an embodiment of the present invention, comprise: iteratively mapping a PUCCH sequence to each of resource blocks (RBs) within an interlace; and transmitting a PUCCH on the interlace, wherein a phase shift (PS) value of the PUCCH sequence may be changed on the basis of an RB index of each of the RBs.

An extensible communication system is described herein. The system includes a first module for receiving a root index value and for generating a constant amplitude zero auto-correlation sequence based on the root value. The system further includes a second module for receiving a seed value and for generating a Pseudo-Noise sequence based on the seed value. The system further includes a third module for modulating the constant amplitude zero auto-correlation sequence by the Pseudo-Noise sequence and for generating a complex sequence. The system further includes a fourth module for translating the complex sequence to a time domain sequence, wherein the fourth module applies a cyclic shift to the time domain sequence to obtain a shifted time domain sequence.

A method and apparatus for transmitting and receiving a signal in a wireless communication system, according to an embodiment of the present invention, comprise: iteratively mapping a PUCCH sequence to each of resource blocks (RBs) within an interlace; and transmitting a PUCCH on the interlace, wherein a phase shift (PS) value of the PUCCH sequence may be changed on the basis of an RB index of each of the RBs.