Aspects of the present disclosure provide techniques for variable spreading factor codes for non-orthogonal multiple access (NOMA). In an exemplary method, a base station assigns, from a first codebook of N short code sequences of length K, a subset of the short code sequences to a number of user equipments (UEs); receives a signal including uplink data or control signals from two or more of the UEs, wherein a first uplink data or control signal is sent using a first subsequence of one of the assigned short code sequences, and a second uplink data or control signal is sent using a second subsequence of one of the assigned short code sequences or using one of the assigned short code sequences; and decodes each uplink data or control signal in the signal based on the assigned short code sequences and subsequences of the assigned the short code sequences.

Aspects of the present disclosure provide techniques for variable spreading factor codes for non-orthogonal multiple access (NOMA). In an exemplary method, a base station assigns, from a first codebook of N short code sequences of length K, a subset of the short code sequences to a number of user equipments (UEs); receives a signal including uplink data or control signals from two or more of the UEs, wherein a first uplink data or control signal is sent using a first subsequence of one of the assigned short code sequences, and a second uplink data or control signal is sent using a second subsequence of one of the assigned short code sequences or using one of the assigned short code sequences; and decodes each uplink data or control signal in the signal based on the assigned short code sequences and subsequences of the assigned the short code sequences.

A communication method performed by a base station in a wireless communication network is disclosed. The base station notifies a terminal of a cyclic shift increment N.sub.CS configuration information indicating an N.sub.CS value. The base station then receives from the terminal a random access preamble related to the N.sub.CS value indicated by the N.sub.CS configuration information. The N.sub.CS value belongs to a set of cyclic shift increments including all of the following cyclic shift increments of 0, 13, 15, 18, 22, 26, 32, 38, 46, 59, 76, 93, 119, 167, 279, 419.

A method of facilitating a user equipment (UE) communicating with a base station (BS) via a cell of a mobile communications system is disclosed. The UE selects a random access preamble (RAP) from a set of RAPs and transmits the RAP to the BS. The BS receives the RAP and estimates a time of arrival of the RAP. A pre-defined set is used in generating the set of RAPs via at least one Zadoff-Chu sequence. The pre-defined set includes all of the following values: 0, 13, 15, 18, 22, 26, 32, 38, 46, 59, 76, 93, 119, 167, 279, 419.

This disclosure describes the generation and implementation of Golay sequences and Golay Sequence Sets (GSSs) for channel estimation in wireless networks. In one embodiment, this disclosure describes an extension of the Golay sequences Ga and Gb defined in various legacy standards to GSSs. In various embodiments, the disclosed GSSs can include a number of Golay complementary pairs (e.g., Ga and Gb). In one embodiment, the disclosed Golay complementary pairs can meet various predetermined design rules and can be used to define enhanced directional multi-gigabit (EDMG) short training field (STF) and/or channel estimation field (CEF) fields for multiple-input and multiple-output (MIMO) transmission.

Systems and methods are provided for transmit signalling to configure a UE with a UE specific root to use in generating a Zhadoff Chu (ZC) sequence for reference signal transmission. With conventional LTE, a cell specific root is used within each cell. There is a need for a more flexible association between roots and UEs that, for example, allows for multiple roots to be associated with a cell. The provided approach may help with maintaining re-use distance as networks become denser. The method provided in this embodiment improves the capabilities of automatic driving and ADAS of electric vehicles. The method can be applied to vehicle networking, such as V2X, LTE-V, V2X, etc.

An uplink reference signal generation unit that generates a reference signal, and a reception unit that receives control information at least including information related to the number of allocation subcarriers and bandwidth extension transmitted from the base station apparatus are included. The uplink reference signal generation unit generates, by generating a Zadoff-Chu sequence based on the number of subcarriers after extension calculated based on the information related to the number of the allocation subcarriers and the bandwidth extension and cyclically extending the generated Zadoff-Chu sequence, a reference signal sequence having a sequence length whose number is equal to the number of the subcarriers after extension.

A parametric generating method for a zero correlation zone sequence set, includes: determining a ZCZ sequence set to be generated; determining a limited symbol set; determining an initial non-periodic orthogonal complementary sequence set; constructing a discrete Fourier transformation matrix by using elements in the limited symbol set; constructing a coefficient matrix based on the number of sequences and the number of iterations in the sequence set; using the columns of the coefficient matrix respectively as the coefficients of each sequence in the ZCZ sequence set, iteratively generating ZCZ sequence sets by using a method of zero filling the tails of weighting coefficients; and traversing the coefficient matrix, and selecting a ZCZ sequence set meeting the criteria or an optimal ZCZ sequence set according to requirements.

A parametric generating method for a zero correlation zone sequence set, includes: determining a ZCZ sequence set to be generated; determining a limited symbol set; determining an initial non-periodic orthogonal complementary sequence set; constructing a discrete Fourier transformation matrix by using elements in the limited symbol set; constructing a coefficient matrix based on the number of sequences and the number of iterations in the sequence set; using the columns of the coefficient matrix respectively as the coefficients of each sequence in the ZCZ sequence set, iteratively generating ZCZ sequence sets by using a method of zero filling the tails of weighting coefficients; and traversing the coefficient matrix, and selecting a ZCZ sequence set meeting the criteria or an optimal ZCZ sequence set according to requirements.

Various embodiments comprise systems, methods, architectures, mechanisms and apparatus for undersea transmission using a Zero-Correlation-Zone (ZCZ) signal with an auto-correlation function having a zero-sidelobe zone, wherein modulated data is mapped to circular time shifts in ZCZ signals for transmission, and wherein periodic cross-correlation function peaks of received ZCZ signals are detected to enable thereby recovery of the circular time shifts in the received ZCZ signals in the time domain.