A new chip-level differential detection system for DS-CDMA

In this paper we mathematically prove that if the original spreading Pseudo-Noise (PN) code is an m-sequence or a Gold-sequence, then the chip-by-chip differential decoding (CBCDD) sequence of the original PN code is a cyclic shift version of the original PN sequence. By utilizing this property, we design a new chip-level differential detection system for DS-CDMA, which does not require any chip-level differential encoding in the transmitter. We demonstrate simplicity of implementation and robust operation in the presence of carrier frequency shift.