Abstract: Echo canceling method comprising the steps: a) receiving a first signal and a second signal, said second signal comprising an echo of the first signal, b) generating an echo replica signal by filtering the first signal with a finite impulse response filter, said finite impulse filter using a filter coefficient vector for generating the echo replica signal, generating an echo cancelled signal by subtracting the echo replica signal from the second signal, d) determining a measure of interference within the second signal, e) determining a step vector depending on said measure of interference, wherein increasing the measure of interference continuously reduces a size of the step vector, and f) updating the filter coefficient vector by the step vector.

Abstract: The present invention relates to a method and apparatus for detecting voice activity in a communication signal, wherein filter means are provided for estimating or suppressing an offset component of the level of the communication signal. A filter parameter is controlled based on the output of the filter means. Furthermore, the estimation or suppression of the offset component is limited in response to the output of the filter means. The filter means may be based on a non-linear adaptive notch level filter or a noise floor tracking filter. Thereby, the tracking behavior of noise floor estimation to sudden rises in noise floor can be improved and the voice activity detection can work efficiently over a wide dynamic range.

Abstract: Echo canceling method comprising the steps: a) receiving a first signal and a second signal, said second signal comprising an echo of the first signal, b) generating an echo replica signal by filtering the first signal with a finite impulse response filter, said finite impulse filter using a filter coefficient vector for generating the echo replica signal, generating an echo cancelled signal by subtracting the echo replica signal from the second signal, d) determining a measure of interference within the second signal, e) determining a step vector depending on said measure of interference, wherein increasing the measure of interference continuously reduces a size of the step vector, and f) updating the filter coefficient vector by the step vector.

Abstract: The present invention relates to a method and apparatus for detecting voice activity in a communication signal, wherein filter means are provided for estimating or suppressing an offset component of the level of the communication signal. A filter parameter is controlled based on the output of the filter means. Furthermore, the estimation or suppression of the offset component is limited in response to the output of the filter means. The filter means may be based on a non-linear adaptive notch level filter or a noise floor tracking filter. Thereby, the tracking behavior of noise floor estimation to sudden rises in noise floor can be improved and the voice activity detection can work efficiently over a wide dynamic range.

Abstract: C2-C8-olefins are oligomerized in a process in which a stream of an olefin-containing hydrocarbon mixture is passed over a heterogeneous, nickel-containing oligomerization catalyst in n successive adiabatically operated reaction zones, where n?2, and the hydrocarbon mixture experiences a temperature increase 66 Treact in each reaction zone and the hydrocarbon mixture enters the first reaction zone at a temperature Tin and before entering each further reaction zone is cooled to a temperature which in each case may be up to 20° C. above or below Tin, and the relative catalyst volumes of the individual reaction zones are such that the difference in ?Treact between any two reaction zones is not more than 20° C.

Abstract: In a process for oligomerizing C6-olefins by reactin of a C6-olefin-containing reaction mixture over a nickel-containing fixed-bed catalyst, the reaction over the fixed-bed catalyst is run at a conversion to oligomerized C6-olefins of not more than 30% by weight, based on the reaction mixture.

Abstract: A process for isolating isobutene from a hydrocarbon mixture by a) combining the C4-hydrocarbon mixture with a primary C3- or C4-alkanol; b) reacting the isobutene in the C4-hydrocarbon mixture with the primary C3- or C4-alkanol in the presence of a heterogeneous catalyst to give the corresponding tertiary ether of isobutene, c) separating the resultant reaction mixture into the relatively low-boiling, unetherified C4-hydrocarbons and the relatively higher-boiling tertiary ether of isobutene with the aid of a distillation column, where the C4-hydrocarbons are taken off at the top, and the tertiary ether of isobutene obtained at the bottom is transferred into a reactor, d) cleaving this ether into isobutene and the corresponding primary C3- or C4-alkanol, e) distilling this mixture from d) in a further distillation column, and taking off the isobutene as the top product, which comprises carrying out step a) in a zone (4C) containing reactive internals and containing the catalyst for carrying out step b)

Abstract: A digital transmission system, such as a mobile radio system, having a transmitter for transmitting codewords which are derived from a digital signal, and a receiver for receiving codewords, the receiver including a decoder with a prediction filter which is excited by an input signal to produce an estimated digital signal. To improve reconstruction of the digital signal in the event of disturbances, the decoder includes a first switching circuit for switching off the input signal of the prediction filter when a disturbed codeword is received, and a second switching circuit for switching substitute values formed from previous values of the estimated digital signal instead of the estimated digital signal when the input signal is switched off.

Abstract: Optically active compounds of the formula I ##STR1## where R is C.sub.1 -C.sub.12 -alkyl or -perfluoroalkyl in which one or two non-adjacent CH.sub.2 or CF.sub.2 groups can also be replaced by --O-- and/or --CO-- and/or --CO--O-- and/or --CH.dbd.CH-- and/or --CH-halogen- and/or --CHCN-- and/or --O--CO--CH-halogen- and/or --O--CO--CHCN--, or is C.sub.1 -C.sub.12 -alkyl which can have a terminal chemically reactive group and in which a CH.sub.2 group can be replaced by --O--,A.sup.1 and A.sup.2 are each, independently of one another, 1,4-phenylene which is unsubstituted or substituted by one or two F and/or Cl and/or Br atoms and/or CH.sub.3 groups and/or CN groups and in which one or two CH groups can also be replaced by N, 1,4-cyclohexylene in which one or two non-adjacent CH.sub.2 groups can also be replaced by --O-- and/or --S--, 1,4-piperidinediyl, 1,4-bicyclo[2.2.2]octylene, 2,6-naphthalenediyl, decahydro-2,6-naphthalenediyl or 1,2,3,4-tetrahydro-2,6-naphthalenediyl,A.sup.

Abstract: Optically active compounds of the formula I ##STR1## where R is C.sub.1 -C.sub.12 -alkyl or -perfluoroalkyl in which one or two non-adjacent CH.sub.2 or CF.sub.2 groups can also be replaced by --O-- and/or --CO-- and/or --CO--O-- and/or --CH.dbd.CH-- and/or --CH-halogen-- and/or --CHCN-- and/or --0--CO--CH-halogen-- and/or --O--CO--CHCN--, or is C.sub.1 -C.sub.12 -alkyl which can have a terminal chemically reactive group and in which a CH.sub.2 group can be replaced by --O--,A.sup.1 and A.sup.2 are each, independently of one another, 1,4-phenylene which is unsubstituted or substituted by one or two F and/or Cl and/or Br atoms and/or CH.sub.3 groups and/or CN groups and in which one or two CH groups can also be replaced by N, 1,4-cyclohexylene in which one or two non-adjacent CH.sub.2 groups can also be replaced by --O-- and/or --S--, 1,4-piperidinediyl, 1,4-bicyclo[2.2.2]octylene, 2,6-naphthalenediyl, decahydro-2,6-naphthalenediyl or 1,2,3,4-tetrahydro-2,6-naphthalenediyl,A.sup.

Abstract: Novel laser-optical recording elements which can be repeatedly erased and recorded on contain recording layers (a) which exhibit enantiotropic, ferroelectric smectic liquid crystalline (S.sub.c*) behavior, so that they can be switched back and forth between two thermodynamically stable, optically distinguishable ferroelectric smectic liquid crystalline S.sub.c* order states on exposure to a laser beam of sufficient luminous power, by applying an external electric field. The recording layers (a) themselves consist mainly or exclusively of novel polymers P having chiral mesogenic side groups.

Abstract: Azolylethane derivatives of the formula I ##STR1## where A and R.sup.1 are each alkyl, phenyl, biphenyl, naphthyl, benzyl, cycloalkyl, alkoxy, alkylthio, phenoxy, benzyloxy, phenylthio, methoxycarbonylethyl or hetaryl, these radicals being substituted or unsubstituted,D is halogen, alkoxy, alkylthio, phenylthio or phenoxy, these radicals being substituted or unsubstituted,X is CH or N,plant-tolerated acid addition salts and metal complex compounds thereof, and fungicides containing these compounds.

Abstract: Novel laser-optical recording elements which can be repeatedly erased and recorded on contain recording layers (a) which exhibit enantiotropic, ferroelectric smectic liquid crystalline (S.sub.C*) behavior, so that they can be switched back and forth between two thermodynamically stable, optically distinguishable ferroelectric smectic liquid crystlaline S.sub.C* order states on exposure to a laser beam of sufficient luminous power, by applying an external electric field. The recording layers (a) themselves consist mainly or exclusively of novel polymers P having chiral mesogenic side groups.

Abstract: Novel laser-optical recording elements which can be repeatedly erased and recorded on contain recording layers (a) which exhibit enantiotropic, ferroelectric smectic liquid crystalline (S.sub.c*) behavior, so that they can be switched back and forth between two thermodynamically stable, optically distinguishable ferroelectric smectic liquid crystalline S.sub.C* order states on exposure to a laser beam of sufficient luminous power, by applying an external electric field. The recording layers (a) themselves consist mainly or exclusively of novel polymers P having chiral mesogenic side groups.

Abstract: The novel compounds of the general formula I ##STR1## where X is straight-chain or branched alkanediyl having from 1 to 20 carbon atoms orX is straight-chain or branched alkanediyl having from 2 to 20 carbon atoms, whose carbon chain is interrupted by --O--, --S-- and/or --NR--,R is hydrogen, straight-chain or branched alkyl having from 1 to 6 carbon atoms or cycloalkyl, andY is a non-centrosymmetric radical containing an easily polarized conjugated .pi.-electron system and at least one terminal electron-acceptor group,having nonlinear optical properties, are highly suitable as nonlinear optical materials for nonlinear optical arrangements and for the preparation of polymers having nonlinear optical properties. In particular, they can be used to prepare organopolysiloxanes having nonlinear optical properties and containing side groups of the general formula Ia ##STR2## in which the variables are as defined above.

Abstract: An echo canceller is described comprising an adaptive filter (15). The adaptation rate of the adaptive filter (15) is controlled by means of a control unit (29) determining the appropriate control signal in response to its input signals (x(k), u(f), e(k)). If the described echo canceller is inserted, for example, in the subscriber set of a telephone network, the adaptation process is to be effected only when the far-end subscriber is talking and the near-end subscriber is silent. If such a decision is automatically made with the associated signals (x(k), u(k)), an erroneous decision may at least temporarily considerably degrade the quality of the telephone communication. For this reason, the adaptation rate of the adaptive filter (15) is provided to be controlled in a gradual manner by means of the control unit (29) in response to suitably chosen mean values of its three input signals (x(k), u(k), e(k)), when the far-end subscriber is talking.