A novel receiver in parallel combinatory spread spectrum communication systems with soft-PIC for E-education

This paper presents a novel Soft Parallel Interference Cancellation (Soft-PIC) receiver in parallel combinatory spread spectrum (PC/SS). In the PC/SS system, multip1e pseudo-noise (PN) sequences are simultaneously transmitted out of a pre-assigned spreading sequence set. It is necessary for PC/SS to employ the Soft-PIC receiver in frequency selective fading channel as for saving hardware. In the proposed scheme, each correlator of the Soft-PIC receiver scheme cancels the interference from other PN sequences to determine the appearances of the correlative PN sequences or not by taking into account reliability information about the detected interference signals. Compared with conventional Maximum receiver scheme of PC/SS, the Soft-PIC receiver can reconstruct the interference signals more accurately and eliminate MAI of other transmitted PN sequences. The simulation results show that this novel Soft-PIC receiver scheme can achieve preferable system performance without increasing receiver complexity.