US5365545A
Expired / Lapsed
US
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MODEM-channel bank converter
Assignee: Motorola Solutions Inc
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Filing: 1992-04-24
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Granted: 1994-11-15
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Expires: 2012-04-24
Abstract
Abstract A converter (200) includes a transmit circuit that converts modem transmit samples at 9,600 samples/second into samples that may be transmitted by a T1 channel bank at 8,000 samples/second. The converter also includes a receive circuit that converts T1 channel bank receive samples at 8,000 samples/second into samples that may be received by a modem at 9,600 samples/second.
Inventors
- 👤 Steven R. Blackwell
- 👤 Michael D. Fanning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:29
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/05
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
262 words
A modem-channel bank converter having a transmit circuit comprising a transmit interpolator and a control unit, the transmit interpolator having a transmit interpolator input, a transmit interpolator output, the transmit interpolator further having a predetermined number (M) of selectable finite impulse response filters controlled by the control unit, the transmit circuit having a transmit circuit input coupled to the transmit interpolator input, the transmit circuit further having a transmit circuit output coupled to the transmit interpolator output, the control unit receiving a modem clock signal of frequency=f modem , a channel bank transmit framing signal of frequency 32 f channel bank, and a master clock signal of frequency=f master , the transmit circuit arranged for forming a channel bank transmit sample on a modem transmit sample and a selected tap value (j) in accordance with a predetermined method, the predetermined method comprising the following steps: (a) upon receiving the modem clock signal, applying the modem transmit sample to the transmit interpolator input, and determining a first master clock reading; (b) upon receiving the channel bank transmit framing signal, determining a second master clock reading; (c) computing a master clock reading transmit difference (D t ) based on the second master clock reading minus the first master clock reading; (d) determining j based on D t ; and, (e) providing the channel bank transmit sample based on the transmit interpolator output, where j is directly proportional to D t , and where: j=the selected tap value, D t =the master clock reading difference; and, M=the predetermined number of selectable finite impulse responses filters.
Claim 2
Dependent Claim
262 words
A modem-channel bank converter having a transmit circuit comprising a transmit interpolator and a control unit, the transmit interpolator having a transmit interpolator input, a transmit interpolator output, the transmit interpolator further having a predetermined number (M) of selectable finite impulse response filters controlled by the control unit, the transmit circuit having a transmit circuit input coupled to the transmit interpolator input, the transmit circuit further having a transmit circuit output coupled to the transmit interpolator output, the control unit receiving a modem clock signal of frequency=f modem , a channel bank transmit framing signal of frequency 32 f channel bank, and a master clock signal of frequency=f master , the transmit circuit arranged for forming a channel bank transmit sample on a modem transmit sample and a selected tap value (j) in accordance with a predetermined method, the predetermined method comprising the following steps: (a) upon receiving the modem clock signal, applying the modem transmit sample to the transmit interpolator input, and determining a first master clock reading; (b) upon receiving the channel bank transmit framing signal, determining a second master clock reading; (c) computing a master clock reading transmit difference (D t ) based on the second master clock reading minus the first master clock reading; (d) determining j based on D t ; and, (e) providing the channel bank transmit sample based on the transmit interpolator output, where j is directly proportional to D t , and where: j=the selected tap value, D t =the master clock reading difference; and, M=the predetermined number of selectable finite impulse responses filters.
Claim 3
Dependent Claim
13 words
The modem-channel bank converter of claim 1, where j is based on: ##EQU3##
Claim 4
Dependent Claim
16 words
The modem-channel bank converter of claim 2, where f master =M×f modem and j=D t .
Claim 5
Dependent Claim
16 words
The modem-channel bank converter of claim 3, where the transmit interpolator is a Newton's Method interpolator.
Claim 6
Dependent Claim
27 words
The modem-channel bank converter of claim 4, further having a linear-to-pulse code modulation converter coupled in series between the transmit interpolator output and the transmit circuit output.
Claim 7
Dependent Claim
18 words
The modem-channel bank converter of claim 5, where M=70, f modem =9,600 Hz, and f master =672,000 Hz.
Claim 8
Dependent Claim
262 words
A modem-channel bank converter having a receive circuit comprising a receive interpolator and a control unit, the receive interpolator having a receive interpolator input, a receive interpolator output, the receive interpolator further having a predetermined number (N) of selectable finite impulse response filters controlled by the control unit, the receive circuit having a receive circuit input coupled to the receive interpolator input, the receive circuit further having a receive circuit output coupled to the receive interpolator output, the control unit receiving a modem clock signal of frequency=f modem , a channel bank receive framing signal of frequency=f channel bank, and a master clock signal of frequency=f master , the receive circuit arranged for forming a modem receive sample based on a channel bank receive sample and a selected tap value (k) in accordance with a predetermined method, the predetermined method comprising the following steps: (a) upon receiving the channel bank receive framing signal, applying the channel bank receive sample to the receive interpolator input, and determining a first master clock reading; (b) upon receiving a modem sample clock signal, determining a second master clock reading; (c) computing a master clock reading receive difference (D r ) based on the second master clock reading minus the first master clock reading; (d) determining k based on D r ; and, (e) providing the modem receive sample based on the receive interpolator output, where k is directly proportional to D r , and where: k=the selected tap value, D r =the master clock reading difference; and, N=the predetermined number of selectable finite impulse response filters.
Claim 9
Dependent Claim
262 words
A modem-channel bank converter having a receive circuit comprising a receive interpolator and a control unit, the receive interpolator having a receive interpolator input, a receive interpolator output, the receive interpolator further having a predetermined number (N) of selectable finite impulse response filters controlled by the control unit, the receive circuit having a receive circuit input coupled to the receive interpolator input, the receive circuit further having a receive circuit output coupled to the receive interpolator output, the control unit receiving a modem clock signal of frequency=f modem , a channel bank receive framing signal of frequency=f channel bank, and a master clock signal of frequency=f master , the receive circuit arranged for forming a modem receive sample based on a channel bank receive sample and a selected tap value (k) in accordance with a predetermined method, the predetermined method comprising the following steps: (a) upon receiving the channel bank receive framing signal, applying the channel bank receive sample to the receive interpolator input, and determining a first master clock reading; (b) upon receiving a modem sample clock signal, determining a second master clock reading; (c) computing a master clock reading receive difference (D r ) based on the second master clock reading minus the first master clock reading; (d) determining k based on D r ; and, (e) providing the modem receive sample based on the receive interpolator output, where k is directly proportional to D r , and where: k=the selected tap value, D r =the master clock reading difference; and, N=the predetermined number of selectable finite impulse response filters.
Claim 10
Dependent Claim
13 words
The modem-channel bank converter of claim 7, where k is based on: ##EQU4##
Claim 11
Dependent Claim
17 words
The modem-channel bank converter of claim 8, where f master =N×f channel bank and k=D r .
Claim 12
Dependent Claim
16 words
The modem-channel bank converter of claim 9, where the receive interpolator is a Newton's Method interpolator.
Claim 13
Dependent Claim
27 words
The modem-channel bank converter of claim 10, further having a pulse code modulation-to-linear converter coupled in series between the receive circuit input and the receive interpolator input.
Claim 14
Dependent Claim
19 words
The modem-channel bank converter of claim 11, where N=84, f channel bank =8,000 Hz, and f master =672,000 Hz.
Claim 15
Dependent Claim
253 words
In a modem-channel bank converter having a transmit circuit comprising a transmit interpolator and a control unit, the transmit interpolator having a transmit interpolator input, a transmit interpolator output, the transmit interpolator further having a predetermined number (M) of selectable finite impulse response filters controlled by the control unit, the transmit circuit having a transmit circuit input coupled to the transmit interpolator input, the transmit circuit further having a transmit circuit output coupled to the transmit interpolator output, the control unit receiving a modem clock signal of frequency=f modem , a channel bank transmit framing signal of frequency=f channel bank, and a master clock signal of frequency=f master , a method for forming a channel bank transmit sample based on a modem transmit sample and a selected tap value (j), the method comprising the following steps: (a) upon receiving the modem clock signal, applying the modem transmit sample to the transmit interpolator input, and determining a first master clock reading; (b) upon receiving the channel bank transmit framing signal, determining a second master clock reading; (c) computing a master clock reading transmit difference (D t ) based on the second master clock reading minus the first master clock reading; (d) determining j based on D t ; and, (e) providing the channel bank transmit sample based on the transmit interpolator output, where j is directly, proportional to D t , and where: j=the selected tap value, D t =the master clock reading difference; and, M=the predetermined number of selectable finite impulse response filters,
Claim 16
Dependent Claim
253 words
In a modem-channel bank converter having a transmit circuit comprising a transmit interpolator and a control unit, the transmit interpolator having a transmit interpolator input, a transmit interpolator output, the transmit interpolator further having a predetermined number (M) of selectable finite impulse response filters controlled by the control unit, the transmit circuit having a transmit circuit input coupled to the transmit interpolator input, the transmit circuit further having a transmit circuit output coupled to the transmit interpolator output, the control unit receiving a modem clock signal of frequency=f modem , a channel bank transmit framing signal of frequency=f channel bank, and a master clock signal of frequency=f master , a method for forming a channel bank transmit sample based on a modem transmit sample and a selected tap value (j), the method comprising the following steps: (a) upon receiving the modem clock signal, applying the modem transmit sample to the transmit interpolator input, and determining a first master clock reading; (b) upon receiving the channel bank transmit framing signal, determining a second master clock reading; (c) computing a master clock reading transmit difference (D t ) based on the second master clock reading minus the first master clock reading; (d) determining j based on D t ; and, (e) providing the channel bank transmit sample based on the transmit interpolator output, where j is directly, proportional to D t , and where: j=the selected tap value, D t =the master clock reading difference; and, M=the predetermined number of selectable finite impulse response filters,
Claim 17
Dependent Claim
11 words
The method of claim 13, where j is based on: ##EQU5##
Claim 18
Dependent Claim
15 words
The method of claim 14, where f master =M×f modem and j =D t .
Claim 19
Dependent Claim
14 words
The method of claim 15, where the transmit interpolator is a Newton's Method interpolator.
Claim 20
Dependent Claim
25 words
The method of claim 16, further having a linear-to-pulse code modulation converter coupled in series between the transmit interpolator output and the transmit circuit output.
Claim 21
Dependent Claim
16 words
The method of claim 17, where M=70, f modem =9,600 Hz, and f master =672,000 Hz.
Claim 22
Dependent Claim
253 words
In a modem-channel bank converter having a receive circuit comprising a receive interpolator and a control unit, the receive interpolator having a receive interpolator input, a receive interpolator output, the receive interpolator further having a predetermined number (N) of selectable finite impulse response filters controlled by the control unit, the receive circuit having a receive circuit input coupled to the receive interpolator input, the receive circuit further having a receive circuit output coupled to the receive interpolator output, the control unit receiving a modem clock signal of frequency=f modem , a channel bank receive framing signal of frequency=f channel bank, and a master clock signal of frequency=f master , a method for forming a modem receive sample based on a channel bank receive sample and a selected tap value (k), the method comprising the following steps: (a) upon receiving the channel bank receive framing signal, applying the channel bank receive sample to the receive interpolator input, and determining a first master clock reading; (b) upon receiving the modem sample clock signal, determining a second master clock reading; (c) computing a master clock reading receive difference (D r ) based on the second master clock reading minus the first master clock reading; (d) determining k based on D r ; and, (e) providing the modem receive sample based on the receive interpolator where k is directly proportional to D r , and where: k=the selected tap value, D r =the master clock reading difference; and, N=the predetermined number of selectable finite impulse response filters.
Claim 23
Dependent Claim
253 words
In a modem-channel bank converter having a receive circuit comprising a receive interpolator and a control unit, the receive interpolator having a receive interpolator input, a receive interpolator output, the receive interpolator further having a predetermined number (N) of selectable finite impulse response filters controlled by the control unit, the receive circuit having a receive circuit input coupled to the receive interpolator input, the receive circuit further having a receive circuit output coupled to the receive interpolator output, the control unit receiving a modem clock signal of frequency=f modem , a channel bank receive framing signal of frequency=f channel bank, and a master clock signal of frequency=f master , a method for forming a modem receive sample based on a channel bank receive sample and a selected tap value (k), the method comprising the following steps: (a) upon receiving the channel bank receive framing signal, applying the channel bank receive sample to the receive interpolator input, and determining a first master clock reading; (b) upon receiving the modem sample clock signal, determining a second master clock reading; (c) computing a master clock reading receive difference (D r ) based on the second master clock reading minus the first master clock reading; (d) determining k based on D r ; and, (e) providing the modem receive sample based on the receive interpolator where k is directly proportional to D r , and where: k=the selected tap value, D r =the master clock reading difference; and, N=the predetermined number of selectable finite impulse response filters.
Claim 24
Dependent Claim
11 words
The method of claim 19, where k is based on: ##EQU6##
Claim 25
Dependent Claim
15 words
The method of claim 20, where f master =N×f channel bank and k=D r .
Claim 26
Dependent Claim
14 words
The method of claim 21, where the receive interpolator is a Newton's Method interpolator.
Claim 27
Dependent Claim
25 words
The method of claim 22, further having a pulse code modulation-to-linear converter coupled in series between the receive circuit input and the receive, interpolator input.
Claim 28
Dependent Claim
17 words
The method of claim 23, where N=84, f channel bank =8,000 Hz, and f master =672,000 Hz.
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) | 1997-11-14 | 1998-05-16 | 1998-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-14 | 2002-05-16 | 2002-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-14 | 2006-05-16 | 2006-11-15 | $7700.00 | Window Closed / Lapsed |