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EP0279080A2
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EP
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Radio data transmission system
Assignee: Mitsubishi Electric Corp
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Filing: 1987-12-31
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Granted: —
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Expires: 2007-12-31
Abstract
Abstract A radio data transmission system wherein signals received via a plurality of diversity antennas are switched at a cycle of subtime slot so that, when the reception level of at least one antenna is sufficiently high to receive the required signal in the relevant time slot, the digital signal in that time slot can be detected properly even if the reception level of any other antenna is not sufficiently high. Accordingly, the code error rate can be minimized by constituting the system in such a manner that the correlation of variations in the reception levels of the diversity antennas becomes extremely low.
Inventors
- 👤 Nobuhiro C/O Mitsubishi Denki K.K. Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 09:58
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0802; H04B7/0822; H04L; H04L1/00; H04L1/02; H04L1/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
170 words
A radio data transmission system comprising: a) a plurality n (integer greater than 1) of receiving antennas mutually having a low correlation of reception; b) an antenna switching circuit for switching input signals from said antennas at a cycle of l/n time slot: c) a receiving circuit for amplifying and demodulating a plurality n of output signals of said antenna switching circuit, and then converting said output signals into baseband signals; d) a delay detection circuit for differentially detecting the output signals of said receiving circuit through a delay circuit having a delay time equivalent to one time slot, and detecting the digital data transmitted by said baseband signals: and e) a timing signal generator circuit for extracting the data of one time slot from the output signal of said delay detection circuit, and controlling the switching action of said antenna switching circuit with l/n duration of one time slot, wherein the data is detected from the signals introduced through said plurality n of antennas during every l/n time slot.
Claim 2
Dependent Claim
170 words
A radio data transmission system comprising: a) a plurality n (integer greater than 1) of receiving antennas mutually having a low correlation of reception; b) an antenna switching circuit for switching input signals from said antennas at a cycle of l/n time slot: c) a receiving circuit for amplifying and demodulating a plurality n of output signals of said antenna switching circuit, and then converting said output signals into baseband signals; d) a delay detection circuit for differentially detecting the output signals of said receiving circuit through a delay circuit having a delay time equivalent to one time slot, and detecting the digital data transmitted by said baseband signals: and e) a timing signal generator circuit for extracting the data of one time slot from the output signal of said delay detection circuit, and controlling the switching action of said antenna switching circuit with l/n duration of one time slot, wherein the data is detected from the signals introduced through said plurality n of antennas during every l/n time slot.
Claim 3
Dependent Claim
140 words
The system as defined in claim 1, wherein said receiving circuit comprises: an amplifier for amplifying in common the signals obtained from said plurality of antennas by the switching action; a first switch for switching the output of said amplifier synchronously with said antenna switching circuit and introducing the output signal of the first antenna to a first terminal while introducing the output signal of the second antenna to a second terminal; a first narrow band filter for filtering the signal fed to said first terminal; a second narrow band filter for filtering the signal fed to said second terminal; a second switch for switching the outputs of said first and second narrow band filters and supplying said outputs alternately from one terminal; and a demodulator for demodulating the output of said second switch and thereby demodulating the baseband signal.
Claim 4
Dependent Claim
36 words
The system as defined in claim 2, wherein the switchover timing of said second switch is delayed from that of said first switch correspondingly to the delay time of said first and second narrow band filters.
References Cited (Backward Citations)
No citation records indexed.
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