Method and apparatus for detecting random access and multiuser using multiple sequence spreading

An apparatus for detecting real-time random access and multi-user using multiple sequence spreading, the apparatus comprising:

• a radio frequency (RF) unit transmitting and receiving a wireless signal;
• and
• a processor operatively coupled with the RF unit,
• wherein the processor selects one spreading sequence set from a plurality of spreading sequence sets randomly without a separate resource allocation and/or spreading sequence allocation,
• applies each of the plurality of spreading sequences included in the one spreading sequence set to each of a plurality of symbols included in a group, and
• transmits each of the plurality of symbols spread based on each of the plurality of spreading sequences,
• wherein the base station receives the plurality of spread symbols, and
• the plurality of spread symbols received from the base station is expressed by Equation below,
• yi=A⊙xi+ωi [Equation]
• here, yi represents the plurality of spread symbols received from the base station, A represents a channel matrix, xi represents the plurality of spread symbols, ωi represents a noise vector, and ⊙ is an operation of (a+b)⊙(c+d)=ac+bd,
• the channel matrix is determined based on a spreading matrix based on each of the plurality of spreading sequences below,
• S
• (
• n
• )
• =
• (
• s
• 1
• (
• n
• )
• 0
• …
• 0
• 0
• s
• 2
• (
• n
• )
• …
• 0
• ⋮
• ⋮
• ⋱
• ⋮
• 0
• 0
• …
• s
• v
• (
• n
• )
• )
• here, sl(n) represents the l-th spreading sequence included in the n-th spreading sequence set and s1(n)≠s2(n)≠ . . . ≠sl(n)≠ . . . ≠sv(n),
• the group is generated by grouping a plurality of symbols included in a data symbol sequence into v unit symbols, and
• one spreading sequence set of a plurality of spreading sequence sets to be applied by a unit of the group is determined.