Correlation receiver with squaring networks - has networks between subtractors inputs and mixers mixing input with pseudo-random sequences

摘要

The correlation receiver has two networks (N) between the outputs of the second and third mixers and the two inputs of the subtraction circuit. The two mixers are supplied with the input signal, and the output of the subtraction circuit forms the output of the correlation network (KN). Each network (N) contains a squaring device in series with a low pass filter at its input. The two pseudo-random sequences generated for mixing with the input signal have a mutual time displacement that is less than their clock period whilst the receiver is synchronised. The advantage lies in sharpening phase discrimination.