In the absence of using {HEAD ~ the present invention} amplitude degradation can create {TAIL ~ unacceptable DF errors} 
In the absence of using { HEAD ~ the present invention } amplitude degradation can create { TAIL ~ unacceptable DF errors }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL