EP0480507A2
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EP
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Method and apparatus for communication channel identification and signal restoration by sending a test signal used for channel impulse response calculation
Assignee: Koninklijke Philips NV
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Filing: 1991-10-01
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Granted: —
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Expires: 2011-10-01
Abstract
Abstract A test signal is transmitted over a communication channel and the signal is received by a receiver. The temporal evolution of the test signal is represented in a matrix and the inverse of the test signal evolution matrix is stored in the receiver. Samples of the received signal and the test signal evolution matrix inverse are used to compute the channel impulse response, and the values of the channel impulse response set signal restoration filter coefficient values. The received signal is then restored by filtering.
Inventors
- 👤 David Koo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 11:31
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/21; H04N7/00; H04N7/08; H04L; H04L1/00; H04L1/24; H04L1/242; H04L25/00; H04L25/02; H04L25/0202; H04L25/0224; H04L25/0228; H04L25/024; H04L25/0242; H04L25/0244; H04N5/211
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
102 words
A system for communication channel identification, comprising: - a transmitter for transmitting a test signal T over a communication channel to be identified; - a receiver for receiving a signal R which is the test signal T after it has passed through the communication channel; characterized in that the system comprises calculating means for calculating a sequence of channel values where T⁻¹(p, q) is representative for the (p, q)th element of the inverse of the test signal evolution matrix {T(i)} is a sequence of values of the transmitted test signal and {R(i)} is a sequence of values of the received test signal.
Claim 2
Dependent Claim
68 words
A system for communication channel identification according to Claim 1, characterized in that T⁻¹(p, q) is representative for the (p, q)th element of the inverse of a cyclic Toeplitz matrix derived from the text signal evolution matrix; an in that the system comprises means for discarding at least some of those elements form {C(m)} that have errors resulting from the use of the inverse matrix in Toeplitz form.
Claim 3
Dependent Claim
57 words
A system for communication channel identification according to Claim 1 or 2, characterized in that T⁻¹(p,q) is representative for the (p,q)th element of the inverse of a matrix [T*] derived from the test signal evolution matrix defined by a component being uncorrelated to each row of the signal evolution matrix added to the test signal evolution matrix.
Claim 4
Dependent Claim
50 words
A system for communication channel identification according to Claim 3, characterized in that T⁻¹(p, q) is representative for the (p, q)th element of a matrix derived from matrix [T*] by deleting a number of the upper rows of [T*] and an equal number of the right most columns of [T*].
Claim 5
Independent Claim
35 words
A system for communication channel identification according to on of the Claims 1 to 5, characterized in that the communication channel is a video channel, and the test signal T is a video test signal.
Claim 6
Independent Claim
45 words
A system for removing channel-induced distortion from signals, using a system according to one of the claims 1-5 characterized in that the system comprises means for filtering signals transmitted over the channel according to filter coefficients determined from the sequence {C(p)} of calculated channel values.
Claim 7
Dependent Claim
17 words
Receiver suitable for use in a system as defined in one of the Claims 1 to 6.
Claim 8
Dependent Claim
44 words
A receiver according to Claim 7, characterized in that the receiver comprises - means for storing calculated channel impulse response samples for more that one channel; and - said calculating means is effective to calculate channel impulse response samples to permit multi-channel signal restoration.
Claim 9
Independent Claim
87 words
A method of communication channel identification, comprising: - transmitting a test signal T over a communication channel to be identified; - receiving a signal R which is the test signal T after it has passed through the communication channel; and - calculating a sequence of channel values where T⁻¹(p, q) is the (p, q)th element of the inverse of the test signal evolution matrix {T(i)} is a sequence of values of the transmitted test signal and {R(i)} is a sequence of values of the received test signal.
Claim 10
Dependent Claim
80 words
A method of communication channel identification according to Claim 1, further comprising: - writing the matrix [T] in cyclic Toeplitz form and inverting the matrix [T] to form an inverse matrix [T]⁻¹ which is also in Toeplitz form; - calculating the sequence {C(p)} of channel values using the inverse matrix [T]⁻¹ in Toeplitz form; and - discarding at least some of those elements of {C(m)} that have errors resulting from the use of the inverse matrix [T]⁻¹ in Toeplitz form.
References Cited (Backward Citations)
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