Channel Partitioning (CDMA)
CDMA (Code Division Multiple Access)
unique “code” assigned to each user; ie, code set partitioning
used mostly in wireless broadcast channels (cellular, satellite,etc)
all users share same frequency, but each user has own “chipping” sequence (ie, code) to encode data
encoded signal = (original data) X (chipping sequence)
decoding: inner-product of encoded signal and chipping sequence
allows multiple users to “coexist” and transmit simultaneously with minimal interference (if codes are “orthogonal”)