US5493714A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for automatically controlling a reference frequency in a dual mode receiver
Assignee: Motorola Solutions Inc
•
Filing: 1995-06-29
•
Granted: 1996-02-20
•
Expires: 2015-06-29
Abstract
Abstract An apparatus and method for automatically controlling a reference frequency (120) in a receiver (104) that receives either analog (116) or digital (136) information signals. The receiver (18) includes a frequency translator (109) for translating a carrier frequency (137) to an intermediate frequency (118) and maintaining the intermediate frequency (118) at a desired value responsive to the reference frequency (120). A first measure of frequency error (211, 212) is detected between the reference frequency (120) and the intermediate frequency (118). A second measure of frequency error (125, 126) is detected between the reference frequency (120) and the intermediate frequency (118). A current signal (213) is produced responsive to the first measure of frequency error (211, 212) when the receiver receives the analog information signal (116) and responsive to the second measure of frequency error (125, 126) when receiver receives the digital information signal (136). A frequency control signal (130) is produced responsive to the current signal (213) to automatically control thereby the reference frequency (120) when the receiver (18) receives either analog (116) or digital (136) information signals.
Inventors
- 👤 Stephen V. Cahill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:38
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/0003; H04B1/0007; H03; H03J; H03J7/00; H03J7/02; H03J7/04; H03J7/06; H03J7/065; H04B1/06; H04B1/16; H04B1/26
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
245 words
In a receiver for receiving either an analog information signal or a digital information signal modulated on a carrier signal at a carrier frequency subsequent to transmission thereof by a transmitter, wherein the receiver includes a frequency translator for translating the carrier frequency to an intermediate frequency and maintaining the intermediate frequency at a desired value responsive to a reference frequency, an apparatus for automatically controlling the reference frequency when the receiver receives either the analog information signal or the digital information signal, comprising: a phase detector coupled to receive the reference frequency and the intermediate frequency and operative to detect a first measure of frequency error between the reference frequency and the intermediate frequency; a processor coupled to receive the reference frequency and the intermediate frequency and operative to determine a second measure of frequency error between the reference frequency and the intermediate frequency; a current device coupled to receive the first measure of frequency error when the receiver receives the analog information signal and coupled to receive the second measure of frequency error when receiver receives the digital information signal, and operative to produce a current signal responsive to either the first or the second measure of frequency error; and a capacitive device coupled to receive the current signal and operative to produce a frequency control signal responsive to the current signal to automatically control thereby the reference frequency when the receiver receives either the analog information signal or the digital information signal.
Claim 2
Dependent Claim
245 words
In a receiver for receiving either an analog information signal or a digital information signal modulated on a carrier signal at a carrier frequency subsequent to transmission thereof by a transmitter, wherein the receiver includes a frequency translator for translating the carrier frequency to an intermediate frequency and maintaining the intermediate frequency at a desired value responsive to a reference frequency, an apparatus for automatically controlling the reference frequency when the receiver receives either the analog information signal or the digital information signal, comprising: a phase detector coupled to receive the reference frequency and the intermediate frequency and operative to detect a first measure of frequency error between the reference frequency and the intermediate frequency; a processor coupled to receive the reference frequency and the intermediate frequency and operative to determine a second measure of frequency error between the reference frequency and the intermediate frequency; a current device coupled to receive the first measure of frequency error when the receiver receives the analog information signal and coupled to receive the second measure of frequency error when receiver receives the digital information signal, and operative to produce a current signal responsive to either the first or the second measure of frequency error; and a capacitive device coupled to receive the current signal and operative to produce a frequency control signal responsive to the current signal to automatically control thereby the reference frequency when the receiver receives either the analog information signal or the digital information signal.
Claim 3
Dependent Claim
65 words
An apparatus according to claim 1 further comprising a switch, operatively coupled to the current device, coupled to receive the first measure of frequency error and the second measure of frequency error and operable to alternatively select the first measure of frequency error when the receiver receives the analog information signal and the second measure of frequency error when receiver receives the digital information signal.
Claim 4
Dependent Claim
23 words
An apparatus according to claim 2 wherein the switch is actuated responsive to either the analog information signal or the digital information signal.
Claim 5
Dependent Claim
12 words
An apparatus according to claim 2 wherein the switch comprises a multiplexer.
Claim 6
Dependent Claim
45 words
An apparatus according to claim 1 wherein the first measure of frequency error and the second measure of frequency error each comprises a first signal for adjusting the reference frequency up in frequency and a second signal for adjusting the reference frequency down in frequency.
Claim 7
Dependent Claim
45 words
An apparatus according to claim 1 wherein the frequency control signal responds to the current signal at a first rate in time when the receiver receives the analog information signal and at a second rate in time when the receiver receives the digital information signal.
Claim 8
Dependent Claim
211 words
In a receiver for receiving either an analog information signal or a digital information signal modulated on a carrier signal at a carrier frequency subsequent to transmission thereof by a transmitter, wherein the receiver includes a frequency translator for translating the carrier frequency to an intermediate frequency and maintaining the intermediate frequency at a desired value responsive to a reference frequency, a method for automatically controlling the reference frequency when the receiver receives either the analog information signal or the digital information signal, comprising the steps of: detecting a first measure of frequency error between the reference frequency and the intermediate frequency when the receiver receives the analog information signal; determining a second measure of frequency error between the reference frequency and the intermediate frequency when receiver receives the digital information signal; producing a current signal, wherein the current signal is responsive to the first measure of frequency error when the receiver receives the analog information signal, and wherein the current signal is further responsive to the second measure of frequency error when receiver receives the digital information signal; and producing a frequency control signal responsive to the current signal to automatically control thereby the reference frequency when the receiver receives either the analog information signal or the digital information signal.
Claim 9
Dependent Claim
211 words
In a receiver for receiving either an analog information signal or a digital information signal modulated on a carrier signal at a carrier frequency subsequent to transmission thereof by a transmitter, wherein the receiver includes a frequency translator for translating the carrier frequency to an intermediate frequency and maintaining the intermediate frequency at a desired value responsive to a reference frequency, a method for automatically controlling the reference frequency when the receiver receives either the analog information signal or the digital information signal, comprising the steps of: detecting a first measure of frequency error between the reference frequency and the intermediate frequency when the receiver receives the analog information signal; determining a second measure of frequency error between the reference frequency and the intermediate frequency when receiver receives the digital information signal; producing a current signal, wherein the current signal is responsive to the first measure of frequency error when the receiver receives the analog information signal, and wherein the current signal is further responsive to the second measure of frequency error when receiver receives the digital information signal; and producing a frequency control signal responsive to the current signal to automatically control thereby the reference frequency when the receiver receives either the analog information signal or the digital information signal.
Claim 10
Dependent Claim
41 words
A method according to claim 7 further comprising the step of alternatively selecting the first measure of frequency error when the receiver receives the analog information signal and the second measure of frequency error when receiver receives the digital information signal.
Claim 11
Dependent Claim
26 words
A method according to claim 8 wherein the step of alternatively selecting is determined responsive to either the analog information signal or the digital information signal.
Claim 12
Dependent Claim
46 words
A method according to claim 8 wherein the step of alternatively selecting further comprises the step of multiplexing the first measure of frequency error when the receiver receives the analog information signal and the second measure of frequency error when receiver receives the digital information signal.
Claim 13
Dependent Claim
45 words
A method according to claim 7 wherein the first measure of frequency error and the second measure of frequency error each comprises a first signal for adjusting the reference frequency up in frequency and a second signal for adjusting the reference frequency down in frequency.
Claim 14
Dependent Claim
45 words
A method according to claim 7 wherein the frequency control signal responds to the current signal at a first rate in time when the receiver receives the analog information signal and at a second rate in time when the receiver receives the digital information signal.
Claim 15
Dependent Claim
224 words
A communication unit comprising: a receiver for receiving either an analog information signal or a digital information signal modulated on a carrier signal at a carrier frequency subsequent to transmission thereof by a transmitter, the receiver including: a frequency translator for translating the carrier frequency to an intermediate frequency and maintaining the intermediate frequency at a desired value responsive to a reference frequency; a phase detector coupled to receive the reference frequency and the intermediate frequency and operative to detect a first measure of frequency error between the reference frequency and the intermediate frequency; a processor coupled to receive the reference frequency and the intermediate frequency and operative to determine a second measure of frequency error between the reference frequency and the intermediate frequency; a current device coupled to receive the first measure of frequency error when the receiver receives the analog information signal and coupled to receive the second measure of frequency error when receiver receives the digital information signal, and operative to produce a current signal responsive to either the first or the second measure of frequency error; and a capacitive device coupled to receive the current signal and operative to produce a frequency control signal responsive to the current signal to automatically control thereby the reference frequency when the receiver receives either the analog information signal or the digital information signal.
Claim 16
Dependent Claim
224 words
A communication unit comprising: a receiver for receiving either an analog information signal or a digital information signal modulated on a carrier signal at a carrier frequency subsequent to transmission thereof by a transmitter, the receiver including: a frequency translator for translating the carrier frequency to an intermediate frequency and maintaining the intermediate frequency at a desired value responsive to a reference frequency; a phase detector coupled to receive the reference frequency and the intermediate frequency and operative to detect a first measure of frequency error between the reference frequency and the intermediate frequency; a processor coupled to receive the reference frequency and the intermediate frequency and operative to determine a second measure of frequency error between the reference frequency and the intermediate frequency; a current device coupled to receive the first measure of frequency error when the receiver receives the analog information signal and coupled to receive the second measure of frequency error when receiver receives the digital information signal, and operative to produce a current signal responsive to either the first or the second measure of frequency error; and a capacitive device coupled to receive the current signal and operative to produce a frequency control signal responsive to the current signal to automatically control thereby the reference frequency when the receiver receives either the analog information signal or the digital information signal.
Claim 17
Independent Claim
193 words
A method of operating a communication unit comprising the step of: receiving either an analog information signal or a digital information signal modulated on a carrier signal at a carrier frequency subsequent to transmission thereof by a transmitter, the step of receiving further including the steps of: translating the carrier frequency to an intermediate frequency and maintaining the intermediate frequency at a desired value responsive to a reference frequency; detecting a first measure of frequency error between the reference frequency and the intermediate frequency when the receiver receives the analog information signal; determining a second measure of frequency error between the reference frequency and the intermediate frequency when receiver receives the digital information signal; producing a current signal, wherein the current signal is responsive to the first measure of frequency error when the receiver receives the analog information signal, and wherein the current signal is further responsive to the second measure of frequency error when receiver receives the digital information signal; and producing a frequency control signal responsive to the current signal to automatically control thereby the reference frequency when the receiver receives either the analog information signal or the digital information signal.
Claim 18
Independent Claim
193 words
A method of operating a communication unit comprising the step of: receiving either an analog information signal or a digital information signal modulated on a carrier signal at a carrier frequency subsequent to transmission thereof by a transmitter, the step of receiving further including the steps of: translating the carrier frequency to an intermediate frequency and maintaining the intermediate frequency at a desired value responsive to a reference frequency; detecting a first measure of frequency error between the reference frequency and the intermediate frequency when the receiver receives the analog information signal; determining a second measure of frequency error between the reference frequency and the intermediate frequency when receiver receives the digital information signal; producing a current signal, wherein the current signal is responsive to the first measure of frequency error when the receiver receives the analog information signal, and wherein the current signal is further responsive to the second measure of frequency error when receiver receives the digital information signal; and producing a frequency control signal responsive to the current signal to automatically control thereby the reference frequency when the receiver receives either the analog information signal or the digital information signal.
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) | 1999-02-19 | 1999-08-21 | 2000-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-02-19 | 2003-08-21 | 2004-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-02-19 | 2007-08-21 | 2008-02-20 | $7700.00 | Window Closed / Lapsed |