Decision feedback multipath cancellation for coherent direct sequence spread spectrum wireless networks

We describe a new receiver structure for direct-sequence spread spectrum signals in highly dispersive multipath wireless channels. This structure uses spread-spectrum correlation detection in combination with decision feedback multipath cancellation (DFMC). The multipath discrimination capability of correlation detection is used for suppression of symbol self-interference, and DFMC performs cancellation of intersymbol interference. We demonstrate that a significant performance improvement is possible over that for correlation detection alone. In particular, simulation results show that the joint correlator-DFMC detector does not suffer from error propagation at typical error rates and can approach the performance of the ideal single-path matched filter detector. This technique holds promise for high-rate wireless applications and where bandwidth limitations allow only modest spreading gains.