US3936749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Matched filter communication systems
Assignee: United States Department of the Army
•
Filing: 1961-06-23
•
Granted: 1976-02-03
•
Expires: 1981-06-23
Abstract
Abstract In a wideband matched filter communication system for transmitting digital information identified by initial sharp pulses from a transmitter thru a communication channel to a receiver, a filter network comprising a multiplicity of filter sections of differing phase-frequency characteristics all in series, the overall characteristic of the entire multiplicity of sections being linear, said sections being distributed between a group at said transmitter and another group at said receiver, the overall characteristics of the sections in each group being non-linear, whereby the various frequency components of the initial sharp pulse are differently delayed in the transmitter group to decrease the amplitude of the pulse signal by spreading its energy over a substantial time period and also differently delayed in the receiver group, but in a complementary manner, to restore the pulse in the receiver at a predetermined time delay due to the operation of the filter.
Inventors
- 👤 Ernst A. Guillemin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:07
CPC Classifications
H; H04; H04K; H04K3/00; H04K3/20; H04K3/25; H04B; H04B7/00; H04B7/005; H04K1/00; H04K3/80; H04K3/82; H04K3/827
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
146 words
In a wideband matched filter communication system or transmitting digital information identified by initial sharp pulses from a transmitter thru a communication channel to a receiver, a filter network comprising a multiplicity of filter sections of differing phase-frequency characteristics all in series, the overall characteristic of the entire multiplicity of sections being linear, said sections being distributed between a group at said transmitter and another group at said receiver, the overall characteristics of the sections in each group being non-linear, whereby the various frequency components of the initial sharp pulse are differently delayed in the transmitter group to decrease the amplitude of the pulse signal by spreading its energy over a substantial time period and also differently delayed in the receiver group, but in a complementary manner, to restore the pulse in the receiver at a predetermined time delay due to the operation of the filter.
Claim 2
Dependent Claim
146 words
In a wideband matched filter communication system or transmitting digital information identified by initial sharp pulses from a transmitter thru a communication channel to a receiver, a filter network comprising a multiplicity of filter sections of differing phase-frequency characteristics all in series, the overall characteristic of the entire multiplicity of sections being linear, said sections being distributed between a group at said transmitter and another group at said receiver, the overall characteristics of the sections in each group being non-linear, whereby the various frequency components of the initial sharp pulse are differently delayed in the transmitter group to decrease the amplitude of the pulse signal by spreading its energy over a substantial time period and also differently delayed in the receiver group, but in a complementary manner, to restore the pulse in the receiver at a predetermined time delay due to the operation of the filter.
Claim 3
Dependent Claim
68 words
A filter network as in claim 1 wherein said entire multiplicity of filter sections are provided at both transmitter and receiver, the additional sections serving as additional series groups for transmission of alternative signal pulses in parallel to said first groups, the receiver output being derived from the difference between the pulses thru the alternative groups, whereby the effect of random noise interference is reduced to a minimum.
Claim 4
Dependent Claim
54 words
A filter network as in claim 1 wherein said entire multiplicity of filter sections are provided at both transmitter and receiver, and synchronized switching means for frequently changing between successive signals the sections used in the groups at transmitter and receiver, whereby the presence and nature of the information being transmitted is effectively obscured.
Claim 5
Dependent Claim
132 words
In a wideband matched filter communication system for transmitting information from a transmitter through a communication channel to a receiver, a filter network comprising a multiplicity of filter sections of differing phase-frequency characteristics all in series, the overall characteristic of the entire multiplicity of sections being linear, said sections being distributed between a group at said transmitter and another group at said receiver, the overall characteristics of the sections in each group being non-linear, whereby the various frequency components of the information are differently delayed in the transmitter group to obscure the presence and nature of the information being transmitted, and also differently delayed in the receiver group, but in a complementary manner, to restore the information in the receiver at a predetermined time delay due to the operation of the filter.
Claim 6
Dependent Claim
132 words
In a wideband matched filter communication system for transmitting information from a transmitter through a communication channel to a receiver, a filter network comprising a multiplicity of filter sections of differing phase-frequency characteristics all in series, the overall characteristic of the entire multiplicity of sections being linear, said sections being distributed between a group at said transmitter and another group at said receiver, the overall characteristics of the sections in each group being non-linear, whereby the various frequency components of the information are differently delayed in the transmitter group to obscure the presence and nature of the information being transmitted, and also differently delayed in the receiver group, but in a complementary manner, to restore the information in the receiver at a predetermined time delay due to the operation of the filter.
Claim 7
Dependent Claim
50 words
A filter network as in claim 4 wherein said entire multiplicity of filter sections are provided at both transmitter and receiver, and synchronized switching means for changing the sections used in the groups at transmitter and receiver, whereby the presence and nature of the information being transmitted is further obscured.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-02 | 1979-08-04 | 1980-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-02 | 1983-08-04 | 1984-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-02 | 1987-08-04 | 1988-02-03 | $7700.00 | Window Closed / Lapsed |