A digital radio-over-fiber downlink system based on envelope delta-sigma modulation for multi-band/mode operation

A digital radio-over-fiber (DRoF) downlink system using envelope delta-sigma modulation (EDSM) for multimode/band applications is presented. Analyses and simulations reveal that the EDSM scheme increases tolerance to jitter introduced by optical components. This has been verified and demonstrated with a DRoF link using CMOS EDSM IC. As a result of the improvement, this system successfully meets major 3GPP LTE bands from 760 MHz to 2.6 GHz as well as IEEE 802.11g WLAN standard requirement.