System architecture for implementing multiuser detector within an ad-hoc network

The near-far problem for direct-sequence spread-spectrum (DS-SS) can be alleviated by the use of low-complexity multiuser receiver implementations, such as successive interference cancellation (SIC) and parallel interference cancellation (PIC) receivers. Ironically, multiuser detection (MUD) has received more research attention for its potential application to 3rd generation commercial cellular systems which employ tight power control than for its application to ad-hoc military networks that might benefit from the near-far resistance of MUD techniques. Some previous research has demonstrated the feasibility of simple MUD techniques for improving the performance and capacity of ad-hoc peer-to-peer packet radio networks (Howlader and Woerner 1998, 1999). This paper presents an architecture for DS-SS packet radio networks exploiting MUD. Issues to be considered include: the performance of fixed complexity PIC and SIC receivers in peer-to-peer environments with AWGN and fading channels, the formulation of signal amplitude estimation for the MUD, and packet acquisition using receiver-oriented spreading codes.