Group-Based Linear Parallel Interference Cancellation for DS-CDMA Systems

The increase in the demand for voice and data wireless services creates a need for a more efficient use of the available bandwidth. Current and future generations cellular systems based on DS-CDMA are known to be interference- limited. Several approaches exist to mitigate the multiple access interference including multiuser detection (MUD). Group-based techniques have been proposed to reduce the complexity of the MUD and have been shown to provide a performance-complexity tradeoff between match filtering and full MUD. In this work, we propose to reduce the inter-group interference (IGI), a limiting factor in group-based systems, using linear parallel interference cancellation (PIC). The complete equivalent matrix filter is derived and conditions for its convergence are discussed. The numerical results show that the proposed technique is effective against IGI, at a reduced computational cost.