Abstract A system is disclosed for improved detection of signals in the presence of noise and interference. It employs a distributionfree criteria to indicate either the presence or absence of signal. A source of known noise data is connected to means for converting the known noise data to digital form. A separate means for converting signal analog input data similarly converts this data to digital form. An appropriate means is provided for successively comparing the digital quantity of each increment of determinable sequence of the input data with the digital quantity of each increment of a like sequence of the known noise data. This latter means is responsive to the quantitative difference detected for each incremental comparison for producing a signal which is commensurate with the determined difference. The difference signals thus produced for each compared sequence are summed and the sum of the difference signals are compared with a signal of predetermined quantitative significance which produces an output indicative of the presence of signal in the analog input data when the summed difference signals exceed the signal of predetermined quantitative significance and produces an output indicative of the absence of signal in the analog input data when the signal of predetermined quantitative significance exceeds the summed difference signals.
A system for detecting signals in the presence of noise comprising: a source of sequential analog input data; a source of known noise data; means for separately converting said sequential analog input data and said known noise data to digital form; means for successively comparing the digital quantity of each increment of a determinable sequence of said input data with the digital quantity of each increment of a like sequence of known noise data, said means being responsive to the quantitative difference of each such incremental comparison for producing a signal commensurate with said difference; means connected to receive and sum the difference signals of each compared sequence; and means for comparing the said sum of said difference signals with a signal of predetermined quantitative significance, said means being operative to produce an output indicative of the presence of signal in said analog input data when said summed difference signals exceed said signal of predetermined quantitative significance, and to produce an output indicative of the absence of signal in said analog input data when said signal of predetermined quantitative significance exceeds said summed difference signals.
Claim 2
Independent Claim
185 words
A system for detecting signals in the presence of noise comprising: a source of sequential analog input data; a source of known noise data; means for separately converting said sequential analog input data and said known noise data to digital form; means for successively comparing the digital quantity of each increment of a determinable sequence of said input data with the digital quantity of each increment of a like sequence of known noise data, said means being responsive to the quantitative difference of each such incremental comparison for producing a signal commensurate with said difference; means connected to receive and sum the difference signals of each compared sequence; and means for comparing the said sum of said difference signals with a signal of predetermined quantitative significance, said means being operative to produce an output indicative of the presence of signal in said analog input data when said summed difference signals exceed said signal of predetermined quantitative significance, and to produce an output indicative of the absence of signal in said analog input data when said signal of predetermined quantitative significance exceeds said summed difference signals.
Claim 3
Dependent Claim
34 words
A system for detecting signals as claimed in claim 1 wherein said means for separately converting said sequential analog input data and said known noise data to digital form comprises a time-shared analog-to-digital converter.
Claim 4
Dependent Claim
70 words
A system for detecting signals as claimed in claim 1 wherein said means for successively comparing the digital quantity of each increment of a determinable sequence of said input data with the digital quantity of each increment of a like sequence of known noise data is responsive to the excess difference of said digital data input relative to each digital noise data increment for producing a digital signal commensurate therewith.
Claim 5
Dependent Claim
42 words
A system for detecting signals as claimed in claim 1 including means for selecting said signal of predetermined quantitative significance in accordance with a maximum acceptable false alarm rate of said indications of the presence of signals in said analog input data.
Claim 6
Dependent Claim
48 words
A system for detecting signals as claimed in claim 1 wherein said means for comparing said summed difference signals further includes means for producing an output indicative of the presence of signal in analog input data when the known noise data is stochastically smaller than said input data.
Claim 7
Dependent Claim
61 words
A system for detecting signals as claimed in claim 5 wherein said means for comparing the sum of said difference signals further includes means for producing an output indicative of the presence of signal in analog input data when the known data is stochastically smaller than said input data by a margin selected in accordance with a determinable probability of error.