Title :
All-Optical Demultiplexing of WLAN and Cellular CDMA Radio Signals
Author :
Kosek, Hatice ; He, Yifeng ; Gu, Xijia ; Fernando, Xavier N.
Author_Institution :
Ryerson Univ., Toronto
fDate :
6/1/2007 12:00:00 AM
Abstract :
Subcarrier multiplexed transmission of multimedia radio signals over fiber is often done to deliver broadband services cost effectively. These signals need to be demultiplexed, preferably in the optical domain, to avoid loss and noise due to optical-to-electrical conversion. However, it is challenging to optically isolate signals at subgigahertz range due to the need for very narrow optical bandpass filters with high selectivity and low insertion loss and distortion. We developed such a novel subpicometer all-optical bandpass filter by creating a resonance cavity using two closely matched fiber Bragg gratings. This filter has a bandwidth of 120 MHz at -3 dB, 360 MHz at -10 dB, and 1.5 GHz at -20 dB. Experimental results show that this filter optically separates two RF signals spaced as close as 50 MHz without significant distortion. This paper analytically and experimentally investigates the scenario when this filter was used with 2.4-GHz (wireless local area network) and 900-MHz (cellular wireless) radio signals. The bit-error rate of the underlying baseband data is related to the linearity and isolation of the filter.
Keywords :
Bragg gratings; band-pass filters; cellular radio; code division multiple access; error statistics; multimedia communication; optical fibre filters; radio-over-fibre; subcarrier multiplexing; wireless LAN; WLAN; all-optical demultiplexing; bit-error rate; broadband services; cellular CDMA radio signals; distortion; fiber Bragg gratings; frequency 1.5 GHz; frequency 120 MHz; frequency 2.4 GHz; frequency 360 MHz; frequency 50 MHz; frequency 900 MHz; insertion loss; multimedia radio signal-over-fiber; narrow optical bandpass filters; optical-to-electrical conversion; optically isolated signals; resonance cavity; subcarrier multiplexed transmission; subpicometer all-optical bandpass filter; wireless local area network; Band pass filters; Costs; Demultiplexing; Multiaccess communication; Optical distortion; Optical fiber filters; Optical filters; Optical losses; Optical noise; Wireless LAN; All-optical demultiplexing; fiber Bragg grating (FBG); fiber-wireless system; multimedia over fiber; radio over fiber (ROF); subcarrier multiplexing (SCM); subpicometer bandpass filter;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2007.896767