An eNB may determine a root for a sequence to be included in a signal to a UE. The eNB may generate a generalized Chu sequence based on the root and scramble the generalized Chu sequence using a pseudorandom sequence that is common to a plurality of eNBs. The eNB may transmit the scrambled generalized Chu sequence to indicate the beginning of a downlink transmission. The UE may receive this scrambled generalized Chu sequence and determine if a beginning of a downlink transmission from a serving eNB based on the received generalized Chu sequence and an expected generalized Chu sequence.

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.

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 signal generator 10 generates an OOK (on-off keying) modulation signal by mapping a CAZAC (constant amplitude zero auto-correlation) sequence to N subcarriers (N being an integer that is greater than or equal to 2) arranged at a determined interval among M subcarriers (M being an integer that is greater than or equal to 3) that are adjacent in the frequency domain, carrying out inverse fast Fourier transform (IFFT) processing on the mapped CAZAC sequence, and carrying out Manchester coding on a time domain signal generated by the IFFT processing. A radio transmitter 107 transmits the OOK modulation signal.

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 network access node and a client device for generating and using cubic phase polynomial sequences (s.sub.i, s.sub.j) of length L with a third order coefficient value a.sub.3 belonging to the subset of sequences () are described. The network access node transmits a control message to the client device, wherein the control message indicates the cyclical shift value N.sub.CS and the third order coefficient value a.sub.3. The client device receives the control message and determines a cubic polynomial phase sequence (s.sub.i) belonging to the subset of sequences () based on the cyclical shift value N.sub.CS and the third order coefficient value a.sub.3. The client device thereafter transmits the determined cubic polynomial phase sequence (s.sub.i) as a random access preamble to the network access node.

A method is provided to generate and control transmission of reference symbols in a synchronization subframe, wherein a reference symbol includes reference values mapped to a block of K subcarriers. The method includes generating data corresponding to a basic subsequence of K−R1−R2 reference values, where R1 and R2 are integers such that 1≤R1+R2<K, and mapping the data corresponding to the basic subsequence to an original range of K−R1−R2 contiguous subcarriers in the block such that there is a first set of R1 unmapped subcarriers above the original range of subcarriers and a second set of R2 unmapped subcarriers below the original range of subcarriers. Data corresponding to last R1 values in the basic subsequence is mapped to the first set of unmapped subcarriers. Data corresponding to first R2 values in the basic subsequence is mapped to the second set of unmapped subcarriers.

Embodiments of this application disclose a user pairing method and a related device. The method includes: first, determining a first generation parameter of a first base sequence of a first user and a second generation parameter of a second base sequence of a second user, and the second base sequence is used to generate a second uplink reference signal of the second user; then, determining multiplexing evaluation information based on the first generation parameter and the second generation parameter, where the multiplexing evaluation information may include correlation strength between sequences and interference leakage width; afterwards, determining, based on the multiplexing evaluation information, whether the first user and the second user are successfully paired. Finally, when the first user and the second user are successfully paired, it is determined that the first user and the second user multiplex a same communication resource for communication.

Methods, systems, and devices related to applying a spreading code to reference signals are described. In one exemplary aspect, a method for wireless communication includes receiving a message indicating a set of control options available to the mobile device for data transmissions. The method includes selecting a spreading code sequence from a number of spreading code sequences, wherein the spreading code sequence corresponds to a control option in the set of control options, wherein the number of spreading code sequences is greater than a length of each of the spreading code sequence, and wherein the spreading code sequences are generated using a method when the length of each of the spreading code sequences is greater than or equal to a value. The method also includes generating a plurality of reference signal symbols using the spreading code sequence, and transmitting the plurality of reference signal symbols.