US5377229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-modulation scheme compatible radio
Assignee: Motorola Solutions Inc
•
Filing: 1990-12-19
•
Granted: 1994-12-27
•
Expires: 2010-12-19
Abstract
Abstract A transceiver compatible with both wide channel constant envelope 4 level FSK FM modulation and narrow channel π/4 differential QPSK linear modulation allows compatible interaction between modified constant envelope and non-constant envelope transmitters. All Nyquist filtering occurs in the transmitters, and none in the receiver.
Inventors
- 👤 Alan L. Wilson
- 👤 Mark C. Cudak
- 👤 Bradley M. Hiben
- 👤 Eric F. Ziolko
- 👤 Steven C. Jasper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:40
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/0008
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
98 words
A radio transceiver capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, the transceiver comprising: A) a transmitter including a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate; and B) a receiver including means for amplifying a received signal and means for recovering digital information signals from the received signal; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter.
Claim 2
Dependent Claim
98 words
A radio transceiver capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, the transceiver comprising: A) a transmitter including a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate; and B) a receiver including means for amplifying a received signal and means for recovering digital information signals from the received signal; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter.
Claim 3
Dependent Claim
151 words
A radio transceiver capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, the transceiver comprising: A) a transmitter, comprising at least a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate, and means for modulating a carrier frequency with a digital information signal, and transmitting at least one of: i) a constant envelope signal; and ii) a non-constant envelope signal; and B) a receiver including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: i) a constant envelope signal; and ii) a non-constant envelope signal; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter.
Claim 4
Dependent Claim
151 words
A radio transceiver capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, the transceiver comprising: A) a transmitter, comprising at least a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate, and means for modulating a carrier frequency with a digital information signal, and transmitting at least one of: i) a constant envelope signal; and ii) a non-constant envelope signal; and B) a receiver including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: i) a constant envelope signal; and ii) a non-constant envelope signal; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter.
Claim 5
Dependent Claim
183 words
A radio transceiver capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, the transceiver comprising: A) a transmitter, comprising at least a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate, and means for modulating a carrier frequency with a digital information signal, and transmitting at least one of: i) a constant envelope signal occupying a first spectral bandwidth; and ii) a non-constant envelope signal occupying a second spectral bandwidth, which second spectral bandwidth is different from the first spectral bandwidth; and B) a receiver including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: i) a constant envelope signal occupying the first spectral bandwidth; and ii) a non-constant envelope signal occupying the second spectral band width; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter.
Claim 6
Dependent Claim
183 words
A radio transceiver capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, the transceiver comprising: A) a transmitter, comprising at least a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate, and means for modulating a carrier frequency with a digital information signal, and transmitting at least one of: i) a constant envelope signal occupying a first spectral bandwidth; and ii) a non-constant envelope signal occupying a second spectral bandwidth, which second spectral bandwidth is different from the first spectral bandwidth; and B) a receiver including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: i) a constant envelope signal occupying the first spectral bandwidth; and ii) a non-constant envelope signal occupying the second spectral band width; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter.
Claim 7
Dependent Claim
190 words
A radio transceiver capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, the transceiver comprising: A) a transmitter, comprising: i) a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate; ii) differential encoder means coupled to the filter for filtering an input information signal to cause selective rotation of a phase value of a modulated signal by a predetermined amount; and iii) frequency modulator means operably coupled to the differential encoder means for outputting the modulated signal; and B) a receiver including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: i) a constant envelope signal occupying a first spectral bandwidth; and ii) a non-constant envelope signal occupying a second spectral bandwidth, wherein the first spectral bandwidth is different from the second spectral bandwidth; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter.
Claim 8
Dependent Claim
190 words
A radio transceiver capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, the transceiver comprising: A) a transmitter, comprising: i) a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate; ii) differential encoder means coupled to the filter for filtering an input information signal to cause selective rotation of a phase value of a modulated signal by a predetermined amount; and iii) frequency modulator means operably coupled to the differential encoder means for outputting the modulated signal; and B) a receiver including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: i) a constant envelope signal occupying a first spectral bandwidth; and ii) a non-constant envelope signal occupying a second spectral bandwidth, wherein the first spectral bandwidth is different from the second spectral bandwidth; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter.
Claim 9
Dependent Claim
352 words
A radio communication system, comprising: A) a first plurality of transceivers capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, each transceiver comprising: i) a transmitter, comprising at least a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate, and means for modulating a carrier frequency with a digital information signal, and transmitting a constant envelope signal occupying a first spectral bandwidth; ii) receiver means including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: a) a constant envelope signal occupying the first spectral bandwidth; and b) a non-constant envelope signal occupying a second spectral bandwidth, which second spectral bandwidth is different than the first spectral bandwidth; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter; and B) a second plurality of transceivers capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, each transceiver comprising: i) a transmitter, comprising at least a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate, and means for modulating a carrier frequency with a digital information signal, and transmitting a non-constant envelope signal occupying the second spectral bandwidth; and ii) receiver means including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: a) a constant envelope signal occupying the first spectral bandwidth; and b) a non-constant envelope signal occupying the second spectral bandwidth; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter; such that transceivers from the first plurality of transceivers can compatibly communicate with transceivers from the second plurality of transceivers.
Claim 10
Dependent Claim
352 words
A radio communication system, comprising: A) a first plurality of transceivers capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, each transceiver comprising: i) a transmitter, comprising at least a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate, and means for modulating a carrier frequency with a digital information signal, and transmitting a constant envelope signal occupying a first spectral bandwidth; ii) receiver means including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: a) a constant envelope signal occupying the first spectral bandwidth; and b) a non-constant envelope signal occupying a second spectral bandwidth, which second spectral bandwidth is different than the first spectral bandwidth; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter; and B) a second plurality of transceivers capable of transmitting and receiving quantized digital information signals having two or more levels and a predetermined symbol rate, each transceiver comprising: i) a transmitter, comprising at least a filter that satisfies Nyquist's criterion for minimizing intersymbol interference, the filter having a bandwidth in Hertz of approximately one half the symbol rate, and means for modulating a carrier frequency with a digital information signal, and transmitting a non-constant envelope signal occupying the second spectral bandwidth; and ii) receiver means including means for amplifying a received signal and means for recovering digital information signals from the received signal, wherein the receiver is capable of receiving and properly demodulating both: a) a constant envelope signal occupying the first spectral bandwidth; and b) a non-constant envelope signal occupying the second spectral bandwidth; wherein, instead of distributing filtering intended to minimize intersymbol interference between the transmitter and the receiver, all such filtering occurs at the transmitter; such that transceivers from the first plurality of transceivers can compatibly communicate with transceivers from the second plurality of transceivers.
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) | 1997-12-26 | 1998-06-27 | 1998-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-26 | 2002-06-27 | 2002-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-26 | 2006-06-27 | 2006-12-27 | $7700.00 | Window Closed / Lapsed |