Broadband wireless access based on VSF‐OFCDM and VSCRF‐CDMA and its experiments

Abstract

AbstractThis paper presents broadband packet wireless access schemes based on variable spreading factor (VSF)‐orthogonal frequency and code division multiplexing (OFCDM) in the downlink and variable spreading and chip repetition factors (VSCRF)‐CDMA in the uplink for the systems beyond IMT‐2000. In our design concept for wireless access in both links, radio parameters such as the spreading factor (SF) are optimally controlled so that the system capacity is maximized according to the cell configuration, channel load and radio channel conditions, based on the tradeoff between efficient suppression of other‐cell interference and the capacity increase in the target cell by exploiting orthogonality in the time and frequency domains. We demonstrate that the peak throughput of greater than 100 Mbps and 20 Mbps is achieved by the implemented base station and mobile station transceivers using the 100‐MHz and 40‐MHz bandwidths in the downlink and uplink respectively. Moreover, the simulation results show the possibility of the peak throughput of approximately 1 Gbps for short‐range area applications using the 100‐MHz bandwidth OFCDM downlink by applying four‐branch multiple input multiple output (MIMO) multiplexing with 16 QAM data modulation and punctured turbo coding. Copyright © 2004 AEI