Broadband packet wireless access based on VSF-OFCDM and MC/DS-CDMA

This paper proposes broadband packet wireless access employing Variable Spreading Factor-Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM) with two-dimensional spreading that prioritizes time domain spreading in the forward link and Multi-carrier/DS-CDMA (MC/DSCDMA) in the reverse link for the system beyond IMT-2000. Based on the wireless access scheme, we propose major radio air interfaces in the physical layer to achieve our target maximum throughput beyond 100 Mbps and 20 Mbps in the forward and reverse links, respectively. Furthermore, we present key technologies such as the adaptive radio link parameter control coupled with link adaptation, pilot channel assisted coherent detection in both links, adaptive antenna array beam forming transmitter and receiver, cell search, and channel coding. Finally, simulation results elucidate that VSF-OFCDM using the proposed radio link parameters achieves a throughput above 100 Mbps at the average received signal energy per symbol-tobackground noise power spectrum density ratio (Es/N0) of approximately 13 dB (101.5-MHz bandwidth, without antenna diversity reception, 12-path Rayleigh fading channel). Furthermore, MC/DS-CDMA realizes a throughput above 20 Mbps at the average received Es/N0 of approximately 8 dB (40-MHz bandwidth, with antenna diversity reception, 6-path Rayleigh fading channel).