{HEAD ~ The invention} relates to {TAIL ~ optical communications systems} and, more particularly, wavelength division multiplexed optical communications systems utilizing complex modulation 
relates to
{ HEAD ~ The invention } relates to { TAIL ~ optical communications systems } and , more particularly , wavelength division multiplexed optical communications systems utilizing complex modulation
HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH