EP0163482A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Equalizer for frequency independent and dependent transmission loss components with a pilot used for the frequency independent component
Assignee: NEC Corp
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Filing: 1985-05-22
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Granted: —
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Expires: 2005-05-22
Abstract
Abstract In addition to an information signal subjected to a frequency dependent and a frequency independent loss component and delivered to an automatic equalizer through a transmission path which is typically subscriber's communication path between a subscriber's terminal equipment and an exchange, and equalizer input signal comprises a pilot signal subjected to the frequency independent loss component alone. The equalizer comprises a first equalizer (26, 27, 36) responsive to a pilot signal component derived from the pilot signal for compensating for the frequency independent loss component. A second equalizer (31, 32, 37) compensates for the frequency dependent loss component in response to an information signal component derived from the information signal. The first and the second equalizers are cooperative in various manners in equalizing the input signal into an equalizer output signal. The pilot and the information signal components are extracted either directly or indirectly from the input signal. The output signal is fed back to a frequency dependent component detector (31) either directly or indirectly.
Inventors
- 👤 Toshio Suzuki
- 👤 Satoshi Hiraide
- 👤 Takashi Shinozuka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 07:47
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/10
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
238 words
In an automatic equalizer responsive to an equalizer input signal supplied through a transmission path with said input signal subjected to a transmission loss for producing an equalizer output signal, said transmission loss being classified into a first and a second loss component having substantially no frequency dependency and a frequency dependency, respectively, said automatic equalizer comprising a first and a second equalizer for separately compensating for said first and said second loss components, respectively, said first and said second equalizers being cooperative in producing said equalizer output signal with said first and said second loss components compensated for, the improvement such that: said input signal is made to comprise a pilot signal in addition to an information signal, said information and said pilot signals being susceptible to both said first and said second loss components and to said first loss component alone, respectively; and that: said first equalizer comprises: first loss component detecting means responsive to a pilot signal component derived from said pilot signal and having said no frequency dependency for detecting said first loss component to produce a control signal; and first loss component compensating means responsive to said control signal for compensating for said first loss componentr " said second equalizer being responsive to an information signal component derived from said information signal and having (Claim 1 continued) both said no frequency dependency and said frequency dependency for compensating for said second loss component.
Claim 2
Dependent Claim
58 words
An automatic equalizer as claimed in Claim 1, wherein said first loss component detecting means comprises a pilot signal extractor responsive to said input signal for extracting said pilot signal as said pilot signal component, and a first loss component detector responsive to said pilot signal component for detecting said first loss component to produce said control signal.
Claim 3
Dependent Claim
89 words
An automatic equalizer as claimed in Claim 2, wherein: said second equalizer comprises an information signal extractor responsive to said input signal for extracting said information signal as said information signal component; said first loss component compensating means being responsive to said information signal component and said control signal for compensating for said first loss component to produce an intermediate output signal; said second equalizer further comprising an equalizer part responsive to said intermediate output signal for compensating for said second loss component to produce said equalizer output signal.
Claim 4
Dependent Claim
101 words
An automatic equalizer as claimed in Claim 2, wherein: said first loss component compensating means is responsive to said input and said control signals for compensating for said first loss component to produce an intermediate output signal which comprises a processed information signal having said first loss component compensated for; (Claim 4 continued) said second equalizer comprising an information signal extractor responsive to said intermediate output signal for extracting said processed information signal as said information signal component, and an equalizer part responsive to said information signal component for compensating for said second loss component to produce said equalizer output signal.
Claim 5
Dependent Claim
165 words
An automatic equalizer as claimed in Claim 2, wherein: said first loss component compensating means is responsive to said input and said control signals for compensating for said first loss component to produce an intermediate output signal which comprises a processed information signal having said first loss component compensated for; said second equalizer comprising a variable gain amplifier responsive to said intermediate output signal for producing an amplifier output signal which comprises a further processed information signal, an information signal extractor responsive to said amplifier output signal for extracting said further processed information signal as said information signal component, a second loss component detector responsive to said information signal component for detecting said second loss component to produce a gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make said further processed information signal have said second loss component eventually compersated for, said information signal extractor thereby producing said information signal component as said equalizer output signal.
Claim 6
Dependent Claim
170 words
An automatic equalizer as claimed in Claim 2, wherein: said first loss component compensating means is responsive (Claim 6 continued) to said input and said control signals for compensating for said first loss component to produce an intermediate output signal which comprises a processed information signal having said first loss component compensated for; said second equalizer comprising a variable gain amplifier responsive to said intermediate output signal for producing an amplifier output signal which comprises a further processed information signal, an information signal extractor responsive to said amplifier output signal for extracting said further processed information signal as said information signal component, a second loss component detector responsive to said information signal component for detecting said second loss component to produce a gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make said further processed infromat i on signal have said second loss component eventually compensated for, said variable gain amplifier thereby producing said amplifier output signal as said equalizer output signal.
Claim 7
Dependent Claim
113 words
An automatic equalizer as claimed in Claim 1, wherein: said first loss component compensating means is responsive to said input and said control signals for compensating for said first loss component to produce an intermediate output signal comprising a processed information signal and a processed pilot signal which have said first loss component compensated for; said first loss component detecting means comprising a pilot signal extractor responsive to said intermediate output signal for extracting said processed pilot signal as said pilot signal component, and a first loss component detector responsive (Claim 7 continued) to said pilot signal component for detecting said first loss component to produce an output signal as said control signal.
Claim 8
Dependent Claim
57 words
An automatic equalizer as claimed in Claim 7, wherein said second equalizer comprises an information signal extractor responsive to said intermediate output signal for extracting said processed information signal as said information signal component, and an equalizer part responsive to said information signal component for compensating for said second loss component to produce said equalizer output signal.
Claim 9
Dependent Claim
124 words
An automatic equalizer as claimed in Claim 7, wherein said second equalizer comprises a variable gain amplifier responsive to said intermediate output signal for producing an amplifier output signal which comprises a further processed information signal, an information signal extractor responsive to said amplifier output signal for extracting said further processed information signal as said information signal component, a second loss component detector responsive to said information signal component for detecting said second loss component to produce a gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make said further processed information signal have said second loss component eventually compensated for, said information signal extractor thereby producing said information signal component as said equalizer output signal.
Claim 10
Dependent Claim
127 words
An automatic equalizer as claimed in Claim 7, wherein said second equalizer comprises a variable gain amplifier responsive to said intermediate output signal for producing an amplifier output signal which comprises a further processed information (Claim 10 continued) signal, an information signal extractor responsive to said amplifier output signal for extracting said further processed information signal as said information signal component, a second loss component detector responsive to said information signal component for detecting said second loss component to produce a gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make said further processed information signal have said second loss component eventually compensated for, said variable gain amplifier thereby producing said amplifier output signal as said equalizer output signal.
Claim 11
Dependent Claim
224 words
An automatic equalizer as claimed in Claim 1, wherein: said second equalizer comprises a variable gain amplifier responsive to said input signal for producing an amplifier output signal which comprises a processed information signal and a processed pilot signal; said first loss component detecting means comprising a pilot signal extractor responsive to said amplifier output signal for extracting said processed pilot signal as said pilot signal component, and a first loss component detector responsive to said pilot si G nal component for detecting said first loss component to produce said control signal; said second equalizer further comprising an information signal extractor responsive to said amplifier output signal for extracting said processed information signal as said information signal component; (Claim 11 continued) said first loss component compensating means being responsive to said information signal component and said control signal for compensating for said first loss component to produce a local output signal; said second equalizer still further comprising a second loss component detector responsive to said local output signal for detecting said second loss component to produce a gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make said processed information signal have said second loss component eventually compensated for; said first loss component compensating means thereby producing said local output signal as said equalizer output signal.
Claim 12
Dependent Claim
225 words
An automatic equalizer as claimed in Claim 1, wherein: said second equalizer comprises a variable gain amplifier responsive to said input signal for producing an amplifier output signal which comprises a processed information signal and a processed pilot signal; said first loss component detecting means comprising a pilot signal extractor responsive to said amplifier output signal for extracting said processed pilot signal as said pilot signal component, and a first loss component ddector responsive to said pilot signal component for detecting said first loss component to produce said control signal; said first loss component compensating means being responsive to said amplifier output signal and said control signal for compensating for said first loss component to produce a local (Claim 12 continued) output signal which comprises a further processed information signal; said second equalizer further comprising an information signal extractor responsive to said local output signal for extracting said further processed information signal as said information signal component, a second loss component detector responsive to said information signal component for detecting said second loss component to produce a,gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make the processed information signal of..said amplifier output signal have said second loss component eventually compensated for, said information signal extractor thereby producing said information signal component as said equalizer output signal.
Claim 13
Dependent Claim
228 words
An automatic equalizer as claimed in Claim 1, wherein: said second equalizer comprises a variable gain amplifier responsive to said input signal for producing an amplifier output signal which comprises a processed information signal and a processed pilot signal; said first loss component detecting means comprising a pilot signal extractor responsive to said amplifier output signal for extracting said processed pilot signal as said pilot signal component, and a first loss component detector responsive to said pilot signal component for detecting said first loss component to produce said control signal; said first loss component compensating means being responsive to-said amplifier output signal and said control signal (Claim 13 continued) for compensating for said first loss component to produce a local output signal which comprises a further processed information signal; said second equalizer further comprising an information signal extractor responsive to said local output signal for extracting said further processed information signal as said information signal component, a second loss component detector responsive to said information signal component for detecting said second loss component to produce a gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make the processed information signal of said amplifier output signal have said second loss component eventually compensated for; said first loss component compensating means thereby producing said local output signal as said equalizer output signal.
Claim 14
Dependent Claim
238 words
An automatic equalizer as claimed in Claim 1, wherein: said second equalizer comprises a variable gain amplifier responsive to said input signal for producing an amplifier output signal which comprises a processed information signal and a processed pilot signal; said first loss component compensating means being responsive to said amplifier output signal and said control signal for compensating for said first loss component to produce a local output signal which comprises a further processed information signal and a further processed pilot signal; (Claim 14 continued) said first loss component detecting means comprising a pilot signal extractor responsive to said amplifier output signal for extracting said further processed pilot signal as said pilot signal component, and a first loss component detector responsive to said pilot signal component for detecting said first loss component to produce an output signal as said control signal; said second equalizer further comprising an information signal extractor responsive to said local output signal for extracting said further processed information signal as said information signal component, a second loss component detector responsive to said information signal component for detecting said second loss component to produce a gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make the processed information signal of said amplifier output signal have said second loss component eventually compensated for, said information signal extractor thereby producing said information signal component as said equalizer output signal.
Claim 15
Dependent Claim
240 words
An automatic equalizer as claimed in Claim 1, wherein: said second equalizer comprises a variable gain amplifier responsive to said input signal for producing an amplifier output signal which comprises a processed information signal and a processed pilot signal; said first loss component compensating means being responsive to said amplifier output signal and said control signal for compensating for said first loss component to produce a local (Claim 15 continued) output signal which comprises a further processed information signal and a further processed pilot signal; said first loss component detecting means comprising a pilot signal extractor responsive to said amplifier output signal for extracting said further processed pilot signal as said pilot signal component, and a first loss component detector responsive to said pilot signal component for detecting said first loss component to produce an output signal as said control signal; said second equalizer further comprising an information signal extractor responsive to said local output signal for extracting said further processed information signal as said information signal component, a second loss component detector responsive to said information signal component for detecting said second loss component to produce a gain control signal, and means for supplying said gain control signal to said variable gain amplifier to make the processed information signal of said amplifier output signal have said second loss component eventually compensated for; said first loss component compensating means thereby producing said local output signal as said equalizer output signal.
References Cited (Backward Citations)
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