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US4977607A
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Method of generating an RF signal modulated by a message signal and distorted by a predetermined fading profile for testing RF receivers, and apparatus for carrying out the method including a fading simulator
Assignee: Rohde and Schwarz GmbH and Co KG
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Filing: 1989-11-30
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Granted: 1990-12-11
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Expires: 2009-11-30
Abstract
Abstract For generating an RF signal modulated by a message and distorted by a predetermined fading profile for testing RF receivers, a sequence of digital phase and amplitude values which corresponds to the message modulation is arithmetically processed by a predetermined fading profile and stored in memory, and an RF carrier is amplitude and phase modulated by the stored values to produce a testing signal for the RF receivers.
Inventors
- 👤 Thomas Maucksch
- 👤 Gottfried Holzmann
- 👤 Frank Korber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:24
CPC Classifications
H; H04; H04B; H04B17/00; H04B17/30; H04B17/391; H04B17/3912
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
73 words
In a method of generating an RF signal modulated by a message signal and distorted by a predetermined fading profile for testing RF receivers, the improvement comprising the steps of: arithmetically processing a sequence of digital phase and amplitude values corresponding to a message signal by a predetermined fading profile; storing the processed sequence; and amplitude and phase modulating and RF carrier with the stored sequence of fading profile-processed phase and amplitude values.
Claim 2
Dependent Claim
73 words
In a method of generating an RF signal modulated by a message signal and distorted by a predetermined fading profile for testing RF receivers, the improvement comprising the steps of: arithmetically processing a sequence of digital phase and amplitude values corresponding to a message signal by a predetermined fading profile; storing the processed sequence; and amplitude and phase modulating and RF carrier with the stored sequence of fading profile-processed phase and amplitude values.
Claim 3
Dependent Claim
38 words
The improved method of claim 1, for plural different message signals, and further defined as: generating different profile-processed phased and amplitude values; and separately storing the generated value in memories for selective retrieval for modulating the RF carrier.
Claim 4
Dependent Claim
156 words
In a fading simulator for performing a method of generating an RF signal modulated by a message signal and distorted by a predetermined fading profile for testing RF receivers in which a sequence of digital phase and amplitude values corresponding to a message signal is arithmetically processed by a predetermined fading profile and is stored in memories, and in which an RF carrier is amplitude and phase modulated by the stored values, the improvement comprising: memory means separately storing the fading profile-processed digital phase and amplitude values; digital-to-analog converters connected to said memories; a digital modulator connected to said digital-to-analog converters; an RF carrier generator for generating a carrier including the frequency of a desired testing RF signal connected to said digital modulator; and means for operating said memories to cause said digital modulator to modulate said carrier with said stored phase and amplitude values to produce a testing signal for connection to an RF receiver.
Claim 5
Dependent Claim
156 words
In a fading simulator for performing a method of generating an RF signal modulated by a message signal and distorted by a predetermined fading profile for testing RF receivers in which a sequence of digital phase and amplitude values corresponding to a message signal is arithmetically processed by a predetermined fading profile and is stored in memories, and in which an RF carrier is amplitude and phase modulated by the stored values, the improvement comprising: memory means separately storing the fading profile-processed digital phase and amplitude values; digital-to-analog converters connected to said memories; a digital modulator connected to said digital-to-analog converters; an RF carrier generator for generating a carrier including the frequency of a desired testing RF signal connected to said digital modulator; and means for operating said memories to cause said digital modulator to modulate said carrier with said stored phase and amplitude values to produce a testing signal for connection to an RF receiver.
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) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-10 | 2002-06-11 | 2002-12-11 | $7700.00 | Window Closed / Lapsed |