EP0689312A2
Expired / Lapsed
EP
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Soft decision signal outputting receiver
Assignee: NEC Corp
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Filing: 1995-06-20
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Granted: —
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Expires: 2015-06-20
Abstract
Abstract The invention provides a soft decision signal outputting receiver which can simply produce correct reliability information even if the receive condition varies while employing a simple reliability information production method. A demodulator (11) demodulates a burst signal to obtain a hard decision signal. A reliability information production circuit (40) receives demodulation process information from the demodulator (11) and produces reliability information regarding the hard decision signal. The reliability information production circuit (40) receives signal quality information which reflects a receive condition for each burst or each plurality of symbol times, and changes, based on the signal quality information, the production method or elements such as threshold levels to be used in the production method for each burst or each plurality of symbol times. A soft decision signal production circuit (12) produces a soft decision signal from the hard decision signal and the reliability information.
Inventors
- 👤 Akihisa Ushirokawa
- 👤 Akira Hioki
- 👤 Kazuhiro Okanoue
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 05:48
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/004; H04L1/0045; H04L1/0047; H03; H03M; H03M13/00; H03M13/37; H03M13/3723; H03M13/39; H03M13/41; H03M13/45; H03M13/65; H03M13/6577; H03M13/6591; H04L1/0054; H04L1/0056; H04L1/0071
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
73 words
A soft decision signal outputting receiver, characterized in that it comprises: a demodulator (11) for modulating a burst signal and outputting a hard decision signal; a reliability information production circuit (13) for producing reliability information regarding the hard decision signal from signal quality information for each plurality of symbol times; and a soft decision signal production circuit (12) for producing a soft decision signal from the hard decision signal and the reliability information.
Claim 2
Dependent Claim
114 words
A soft decision signal outputting receiver, characterized in that it comprises: a demodulator (11) for modulating a burst signal and outputting a hard decision signal; a reliability information production circuit (40) for receiving demodulation process information from said demodulator (11) and producing reliability information regarding the hard decision signal; a soft decision signal production circuit (12) for producing a soft decision signal from the hard decision signal and the reliability information; and changing means (41 l to 41 K , 42; 43 l to 43 K , 44, 45) for changing the production method for reliability information for each plurality of symbol times based on signal quality information for the plurality of symbol times.
Claim 3
Dependent Claim
51 words
A soft decision signal outputting receiver as set forth in claim 2, characterized in that said changing means (41 l to 41 K , 42) has a plurality of production methods for reliability information prepared in advance and selectively uses one of the production methods for each plurality of symbol times.
Claim 4
Dependent Claim
88 words
A soft decision signal outputting receiver as set forth in claim 2, characterized in that said changing means (43 l to 43 K , 44, 45) has a plurality of sets of threshold levels prepared in advance and selects one of the sets of threshold levels to be used for each plurality of symbol times based on signal quality information, and said reliability information production circuit (40) compares the demodulation process information from said demodulator (11) with the thus selected set of threshold levels to obtain reliability information.
Claim 5
Dependent Claim
103 words
A soft decision signal outputting receiver, characterized in that it comprises: a demodulator (11) for modulating a burst signal and outputting a hard decision signal; a reliability information production circuit (50) for receiving demodulation process information from said demodulator (11) and producing reliability information regarding the hard decision signal; a reliability information correction circuit (51) for correcting the reliability information based on signal quality information for each plurality of symbol times to obtain a corrected reliability information value; and a soft decision signal production circuit (12) for producing a soft decision signal from the hard decision signal and the corrected reliability information value.
Claim 6
Dependent Claim
110 words
A soft decision signal outputting receiver, characterized in that it comprises: a demodulator (11) for modulating a burst signal and outputting a hard decision signal; a reliability information production circuit (13) for receiving demodulation process information from said demodulator (11) and producing reliability information regarding the hard decision signal; a soft decision signal production circuit (12) for producing a tentative soft decision signal from the hard decision signal and the reliability information; and a soft decision signal correction circuit (52) for correcting the tentative soft decision signal based on signal quality information for each plurality of symbol times and outputting the corrected soft decision signal as a soft decision signal.
Claim 7
Dependent Claim
33 words
A soft decision signal outputting receiver as set forth in any one of the preceding claims, characterized in that the plurality of symbol times are equal to a time of one burst length.
Claim 8
Dependent Claim
41 words
A soft decision signal outputting receiver as set forth in claim 2, 5 or 6, characterized in that said reliability information production circuit (40; 50) compares the demodulation process information with a predetermined plurality of threshold levels to obtain reliability information.
Claim 9
Dependent Claim
26 words
A soft decision signal outputting receiver as set forth in claim 1, 2, 5 or 6, characterized in that said demodulator (11) performs maximum-likelihood sequence estimation.
Claim 10
Dependent Claim
44 words
A soft decision signal outputting receiver as set forth in claim 2, 5 or 6, characterized in that said demodulator (11) performs maximum-likelihood sequence estimation and produces demodulation process information based on an error signal of a channel estimator used for maximum-likelihood sequence estimation.
Claim 11
Dependent Claim
43 words
A soft decision signal outputting receiver as set forth in claim 2, 5 or 6, characterized in that said demodulator (11) performs maximum-likelihood sequence estimation and produces demodulation process information based on a difference in path metric between states in maximum-likelihood sequence estimation.
Claim 12
Dependent Claim
75 words
A soft decision signal outputting receiver as set forth in claim 1, 2, 5 or 6, characterized in that the signal quality information for each plurality of symbol times includes, solely or in combination, an average value or a minimum value of a received signal strength indicator within the plurality of symbol times or an average value for the plurality of symbol times of a variation amount of a received signal strength indicator between symbols.
Claim 13
Dependent Claim
83 words
A soft decision signal outputting receiver as set forth in claim 1, 2, 5 or 6, characterized in that the plurality of symbol times is set equal to a time of one burst length, and the signal quality information for each burst time includes, solely or in combination, an average value or a minimum value of a received signal strength indicator within the burst or an average value within the burst of a variation amount of a received signal strength indicator between symbols.
Claim 14
Dependent Claim
88 words
A soft decision signal outputting receiver as set forth in claim 1, 2, 5 or 6, characterized in that the plurality of symbol times is set equal to a time of one burst length, and the signal quality information for each burst time includes, solely or in combination, a number of errors upon demodulation of a known signal portion within the burst, a mean square value of an error signal of said demodulator (11), or an unequalizable interference amount obtained from a known signal portion within the burst.
References Cited (Backward Citations)
JPH02288512A
Cited
JPH03284021A
Cited
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