EP0318665A2
Expired / Lapsed
EP
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Antenna selection control circuit
Assignee: Motorola Solutions Inc
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Filing: 1988-09-29
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Granted: —
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Expires: 2008-09-29
Abstract
Abstract An antenna switch control circuit for use in achieving antenna selection diversity in TDM RF receivers. RSSI for at least one antenna is monitored during time slots containing information not of interest. This information can then be compared with other antenna performance information to allow a selection to be made such that the receiver generally operates with the antenna receiving the strongest signal. In one embodiment, all possible antennas are monitored during a time slot containing information not of interest. In another embodiment, RSSI for the selected antenna can be monitored during the time slot of interest, such that antenna selection can again be varied should the selected antenna diminish in performance.
Inventors
- 👤 Donald L. Linder
- 👤 Steve Howard Goode
- 👤 Henry Ludwig Kazecki
- 👤 Donald William Dennis
- 👤 James Clark Baker
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 14:36
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0802; H04B7/0805; H04B7/0814; H04B7/0808; H04B7/0811
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
132 words
An antenna selection control circuit for use with a TDM RF receiver having a least two antennas for receiving an information signal, which information signal is comprised of time slots of interest and other time slots not of interest, characterized by: A) first means (11, 51) for developing signals related to received signal quality for at least two of said antennas, wherein said signal is developed for at least one of said antennas during a time slot not of interest; B) second means (12, 52) for comparing said developed signals to identify which of said at least two antennas received a signal of higher quality; C) third means (13, 32, 53) responsive to said second means for causing said receiver to use said identified antenna during a subsequent time slot of interest.
Claim 2
Dependent Claim
132 words
An antenna selection control circuit for use with a TDM RF receiver having a least two antennas for receiving an information signal, which information signal is comprised of time slots of interest and other time slots not of interest, characterized by: A) first means (11, 51) for developing signals related to received signal quality for at least two of said antennas, wherein said signal is developed for at least one of said antennas during a time slot not of interest; B) second means (12, 52) for comparing said developed signals to identify which of said at least two antennas received a signal of higher quality; C) third means (13, 32, 53) responsive to said second means for causing said receiver to use said identified antenna during a subsequent time slot of interest.
Claim 3
Dependent Claim
29 words
The antenna selection control circuit of claim 1 wherein said first means develops said signals for at least two of said antennas during a time slot not of interest.
Claim 4
Dependent Claim
17 words
The antenna selection control circuit of claim 1 or 2 wherein said signal quality comprises signal strength.
Claim 5
Dependent Claim
60 words
The antenna selection control circuit of claim 2 wherein said first means includes sample and hold means (14) for sampling, during a first TDM time slot prior to a TDM time slot of interest, a first signal related to received signal quality from a selected one of said antennas and for providing an output signal related to said sampled signal.
Claim 6
Dependent Claim
104 words
The antenna selection control circuit of claim 2 and further including: A) fourth means for comparing, during said next subsequent time slot of interest, a reference signal with a signal related to received signal quality for said used antenna, and for providing a comparison output signal related to said comparison; and B) antenna switch control means for responding to said fourth means output signal by causing said receiver to select a different one of said antennas for receiving said signal when said signal related to received signal quality for said used antenna is less than said reference signal during said time slot of interest.
Claim 7
Dependent Claim
32 words
The antenna selection control circuit of claim 5 wherein said reference signal is related to a mean value of received signal quality for said used antenna during said time slot of interest.
Claim 8
Independent Claim
125 words
A method of selecting an antenna for a TDM RF receiver having at least two antennas for receiving a signal of interest, which signal is comprised of time slots of interest and other time slots not of interest, said method characterized by the steps of: during a time slot not of interest and preceding a time slot of interest: A) sampling and holding a signal related to received signal quality for one of said antennas; B) comparing said sampled and held signal with a second signal related to received signal quality for a second one of said antennas; C) selecting, based upon said comparison, one of said antennas to be used to received said signal of interest in a next occurring time slot of interest.
Claim 9
Independent Claim
125 words
A method of selecting an antenna for a TDM RF receiver having at least two antennas for receiving a signal of interest, which signal is comprised of time slots of interest and other time slots not of interest, said method characterized by the steps of: during a time slot not of interest and preceding a time slot of interest: A) sampling and holding a signal related to received signal quality for one of said antennas; B) comparing said sampled and held signal with a second signal related to received signal quality for a second one of said antennas; C) selecting, based upon said comparison, one of said antennas to be used to received said signal of interest in a next occurring time slot of interest.
Claim 10
Dependent Claim
70 words
The method of claim 7 and including the additional steps of: during a time slot of interest that occurs subsequent to said time slot not of interest: D) monitoring a signal related to received signal quality for said selected antenna; E) comparing said monitored signal with a reference signal; F) in response to said comparison between said monitored signal and said reference signal, deciding whether to select a different antenna.
Claim 11
Dependent Claim
29 words
The method of claim 8 wherein said reference signal is related to a mean value of received signal quality for said selected antenna during said time slot of interest.
Claim 12
Dependent Claim
31 words
The method of claim 9 wherein in step F, a decision is made to select a different antenna when said monitored signal is less than 10 dB below said reference signal.
References Cited (Backward Citations)
No citation records indexed.
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