A second pair of analog signals representing the difference and sum of the pairs of analog signals is generated and presented to {HEAD ~ a signal processing circuit} in combination with {TAIL ~ the first pair} of phase quadrature signals 
A second pair of analog signals representing the difference and sum of the pairs of analog signals is generated and presented to { HEAD ~ a signal processing circuit } in combination with { TAIL ~ the first pair } of phase quadrature signals
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH