Generalized Multi - Carrier Cdmafor Mui / Isi -

Relying on symbol blocking and judicious design of user codes, this paper develops a Generalized Multicarrier (GMC) quasi-synchronous CDMA system capable of multiuser interference (MUI) elimination and inter-symbol interference (ISI) suppression, irrespective of the wireless frequency selective channels encountered in the uplink. As the term reveals , GMC-CDMA provides a unifying framework for multicarrier (MC) CDMA systems and as this paper shows, it ooers exibility in full load (maximum number of users allowed by the available bandwidth) and in reduced load settings. A blind channel estimation algorithm is also derived. Analytic evaluation and simulations illustrate that GMC-CDMA outperforms competing MC-CDMA alternatives especially in the presence of uplink multipath channels. 1. INTRODUCTION Mitigation of frequency selective multipath and elimination of multiuser interference have received considerable attention as they constitute the main limiting performance factors in wireless CDMA systems. Multicarrier (MC) CDMA systems have been introduced to mitigate both MUI and ISI caused by frequency selective channel eeects, but they do not guarantee (blind or not) recovery of the transmitted symbols in the uplink without imposing constraints on the unknown multipath channel nulls 1, 6, 9]. In 7, 8] a spread-spectrum multicarrier multiple access scheme was developed and shown to achieve MUI