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EP0500326A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Digital mobile communication terminal equipment and receiving method therefor

Assignee: NEC Electronics Corp
•
Filing: 1992-02-19
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Granted: —
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Expires: 2012-02-19
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Abstract

Abstract A reference voltage (V ref ) is set to a received signal level corresponding to an anticipated data error rate and compared with outputs of intermediate frequency amplifiers (3-1, 3-2) by comparators (7-1, 7-2). When the outputs of the intermediate frequency amplifiers (3-1, 3-2) are lower than the reference voltage (V ref ), operation of receiving circuits (A12-1, B12-2) is stopped. At inter symbol interference amount calculating sections (6-1, 6-2), inter symbol interference amounts are calculated from auto-correlation parameters of preamble signal bit trains included in received signal data, and selectors (9-1, 9-2) are controlled so that a diversity branch having the least residual inter symbol interference amount or the highest S/N ratio is selected and the received signal data of the selected branch are inputted to an equalizing section (11). When a signal having a high data error rate is received, operation of the corresponding receiving circuit is stopped. Consequently, power consumption is minimized, the data error rate caused by residual inter symbol interferences is minimized and data errors caused by thermal noises and other factors are also improved.

Inventors

  • 👤 Makoto Tsurumaru

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-30 05:33
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0868; H04B7/0874; H04B7/0877; H04B7/0802; H04B7/0817; H04B7/082; Y; Y02; Y02D; Y02D30/00; Y02D30/70

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 118 words
Digital mobile communications terminal equipment having an equalizer for compensating for frequency selective fading included in a received signal, characterized in comprising; an equalizing processing controlling circuit which starts and stops equalizing processing of said equalizer in response to a level of the received signal; and a diversity branch selecting circuit for adaptively selecting one of a plurality of diversity branches of a selection-after-detection diversity receiving circuit including said equalizing processing controlling circuit which selects a diversity branch having the least inter symbol interference when inter symbol interferences exceed the equalizing capacity of said equalizer and selects a diversity branch having the highest S/N ratio when inter symbol interferences do not exceed the equalizing capacity of said equalizer.
Claim 2
Dependent Claim 118 words
Digital mobile communications terminal equipment having an equalizer for compensating for frequency selective fading included in a received signal, characterized in comprising; an equalizing processing controlling circuit which starts and stops equalizing processing of said equalizer in response to a level of the received signal; and a diversity branch selecting circuit for adaptively selecting one of a plurality of diversity branches of a selection-after-detection diversity receiving circuit including said equalizing processing controlling circuit which selects a diversity branch having the least inter symbol interference when inter symbol interferences exceed the equalizing capacity of said equalizer and selects a diversity branch having the highest S/N ratio when inter symbol interferences do not exceed the equalizing capacity of said equalizer.
Claim 3
Dependent Claim 18 words
Digital mobile communications terminal equipment as claimed in claim 1, wherein the number of diversity branches is two.
Claim 4
Dependent Claim 21 words
Digital mobile communications terminal equipment as claimed in claim 1, wherein the number of the diversity branches is three or more.
Claim 5
Dependent Claim 42 words
Digital mobile communications terminal equipment as claimed in any one of claims 1 to 3, further comprising means for stopping operation of receiving circuits of a diversity branch which has received a signal with a level lower than a prescribed reference level.
Claim 6
Dependent Claim 98 words
A receiving method for digital mobile communications terminal equipment having a selection-after-detection diversity receiving circuit and an equalizer for compensating for frequency selective fading included in a received signal, characterized in comprising the steps of selecting one of a plurality of diversity branches having the least residual inter symbol interference when inter symbol interference which is produced be tween received radio waves and delayed waves of such received radio waves exceed the equalizing capacity of said equalizer, and of selecting a diversity branch having highest S/N ratio when such inter symbol interferences do not exceed the equalizing capacity.
Claim 7
Dependent Claim 98 words
A receiving method for digital mobile communications terminal equipment having a selection-after-detection diversity receiving circuit and an equalizer for compensating for frequency selective fading included in a received signal, characterized in comprising the steps of selecting one of a plurality of diversity branches having the least residual inter symbol interference when inter symbol interference which is produced be tween received radio waves and delayed waves of such received radio waves exceed the equalizing capacity of said equalizer, and of selecting a diversity branch having highest S/N ratio when such inter symbol interferences do not exceed the equalizing capacity.
Claim 8
Dependent Claim 55 words
A receiving method for digital mobile communications terminal equipment as claimed in claim 5, further comprising the steps of comparing the level of a received signal with a preset reference level for each diversity branch, and of stopping the receiving operation of each diversity branch whose receiving level is lower than a prescribed reference level.

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