PHY-MAC dialogue with multi-packet reception

Abstract

Cross-layer design has been considered recently as a new approach when designing MAC protocols in systems with diversity such as CDMA. This paper goes one step further in the cross layer design by proposing a PHY-MAC dialogue involving the exchange of parameters such as BER and active users. By means of this PHY-MAC dialogue, system performance can be improved. A two-stage receiver is used at PHY level. The first stage tracks active users while the second stage is a data demodulator. The Modified Dynamic Queue Protocol (MDQP) is proposed as the MAC protocol of our system. When the knowledge of active users is possible, it is demonstrated by simulations that MDQP outperforms DQP.