In {TAIL ~ the method}, {HEAD ~ a mixed signal} is provided by mixing the tone signal with a reference signal alternating at a frequency fm between values related to sin fr and cos fr, where fr is a frequency substantially equal to fd and where fm is substantially greater than fr 
In
In { TAIL ~ the method } , { HEAD ~ a mixed signal } is provided by mixing the tone signal with a reference signal alternating at a frequency fm between values related to sin fr and cos fr , where fr is a frequency substantially equal to fd and where fm is substantially greater than fr
REL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH