Spreading - Despreading

Users ：UE1、UE2、UE3

UE1 spreading ：UE1×c1

UE2 spreading ：UE2×c2

UE3 spreading ：UE3×c3

c1、c2、c3 are orthogonal with each other

Transmitting signal ：

UE1×c1＋ UE2×c2＋ UE3×c3

UE1 uses c1 to despread

(UE1×c1＋ UE2×c2＋UE3×c3)×c1

＝UE1×(c1×c1)＋UE2×(c2×c1)＋UE3×(c3×c1)

＝UE1×1＋UE2×0＋UE3×0

＝UE1

UE2 uses c2 to despread, UE3 uses c3 to despread，

in this way, they can get their own signal