Dispersion effects in millimeter-wave fiber-radio systems employing direct-sequence code division multiple access

We investigate the impact of fiber chromatic dispersion on the performance of an externally modulated millimeter-wave fiber-radio system incorporating a broadband radio direct-sequence code division multiple access (DS-CDMA) scheme. In particular, we investigate the effect of dispersion on DS-CDMA s ignals with regard to CDMA code rate, center frequency, and modulator chirp . We show that the spreading of the signal spectrum using DS-CDMA can resul t in significant reductions in data amplitude variations normally experienc ed in externally modulated millimeter-wave fiber-radio systems. We also dem onstrate the successful transmission of a 10-Mb/s data channel over a 39-GH z fiber-radio link employing DS-CDMA and consisting of 25 km of standard op tical fiber and a 1-m radio link. (C) 1999 Academic Press.