Variable spreading factor codes for non-orthogonal multiple access

Abstract

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.

What is claimed is: 
     
         1 . A method of wireless communications performed by a base station (BS), comprising:
 assigning, 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), wherein the number is at least two and at most N;   receiving 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 subset of short code sequences, and 
 a second uplink data or control signal, different from the first uplink data or control signal, is sent using a second subsequence of one of the assigned subset of short code sequences or using one of the assigned subset of short code sequences; and 
   decoding each uplink data or control signal in the signal based on the assigned subset of the short code sequences and subsequences of the short code sequences in the assigned subset of the short code sequences.