Patents by Inventor Philippe Sehier

Philippe Sehier has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20040196806
    Abstract: A device is dedicated to controlling access to wireless communications local area networks (WLAN-i) having a local coverage area included in a main coverage area of a main communications network (RP) equipped with mobile communications device positioning means (8). The device comprises management means (20) connected to the positioning means (8) and adapted i) to compare the positions of at least some of the mobile devices (9) to those of the local areas, in order to select the primary identifiers of the mobile devices substantially positioned in said local areas, and ii) to send a messaging server (10) of the main network (RP) instructions including the primary identifier of each mobile device (9) selected, in order for it to send them a message telling their users that they can connect to the local area network (WLAN-i) in whose local area they are placed.
    Type: Application
    Filed: January 5, 2004
    Publication date: October 7, 2004
    Inventors: Siegried Loeffler, Philippe Laine, Philippe Sehier
  • Patent number: 6690935
    Abstract: The invention concerns a method of transmitting non-dated digital data between a transmitter and a receiver in which the data can take at least two different paths between the transmitter and the receiver and handover from one path to another occurs during transmission. In the transmitter, packets intended for the second path are transmitted only after the last packet intended for the first path has been transmitted and in the transmitter and in the receiver packets on the first or second path are delayed in order for packets on the second path to arrive after packets on the first path. It is therefore not necessary to transmit signaling to differentiate the two paths at the receiver, which can include a single demodulator.
    Type: Grant
    Filed: December 10, 1999
    Date of Patent: February 10, 2004
    Assignee: Alcatel
    Inventors: Guillaume Calot, Xavier Denis, Jean Farineau, Bertrand Duros, Jacques Bousquet, Philippe Sehier, Tarif Zein Al-Abedeen, Yves Peligry
  • Publication number: 20030066015
    Abstract: The invention concerns a method and a device for transmitting digital data. The device comprises means (12) for verifying the spectral efficacy of the transmission. The method consists in assigning to the digital data an error correcting code whereof the encoding rate is modifiable in accordance with the desired spectral efficacy. Preferably, the difference between successive encoding rate values is, at least for certain values, not more than 1/10. For example, a parity bit code and/or a repetitive code is used.
    Type: Application
    Filed: August 23, 2002
    Publication date: April 3, 2003
    Inventor: Philippe Sehier
  • Patent number: 6487221
    Abstract: The invention relates to apparatus for filtering, decimating and transposing into baseband, the apparatus being of the entirely digital type, and serving both to extract and transpose into baseband one of the channels, referred to as the “channel of interest”, of a frequency multiplex of channels, and also to reduce the oversampling factor of said channel of interest, each channel being associated with a distinct carrier. The said apparatus comprising at least two stages in cascade (401 to 40L), each stage comprising filter means (42) and decimation means (43), said filter means being placed upstream from said decimation means and enabling a portion of the spectrum to be purged at locations where the decimation means produce aliasing.
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: November 26, 2002
    Assignee: Alcatel
    Inventors: Cyril Bertrand, Philippe Sehier
  • Publication number: 20020031140
    Abstract: Method and system for enhancing channel capacity in a Point-to Multipoint radio communications system that includes terminals stations (12) of different kinds, such as residential terminals and business terminals, with different link budget requirements i.e. different signal-to-noise ratio. The method is characterized by the selective use of different channel coding codes such as forward error correction (FEC) codes, in the different concurrent channels, depending on a pre-defined category of an addressed subscriber. The multiplexing method used may be CDMA (Code Division Multiple Access) and TDMA (Time Division Multiple Access). Each terminal station (12) is in turn equipped only with an appropriate decoder, depending on its kind, e.g. residential or business.
    Type: Application
    Filed: September 13, 2001
    Publication date: March 14, 2002
    Applicant: ALCATEL
    Inventors: Philippe Sehier, Emmanuel Lemois, Thierry Quignon
  • Patent number: 5933467
    Abstract: A device for receiving a source digital signal transmitted at one or more source symbol frequencies F.sub.s samples a received analog signal transposed into the baseband and delivers an entirely demodulated sample signal. The sampling frequency F.sub.e complies with the generalized sampling condition. A single filter module filtering the sampled signal comprises a digital filter controlled by a filter coefficient vector. The filter coefficients are determined according to a determination criterion allowing for the ratio of the sampling frequency F.sub.e to the source frequency F.sub.s, to interpolate the sampled signal, and for an analysis of the transmission path, in order to limit interference introduced by the path.
    Type: Grant
    Filed: March 1, 1996
    Date of Patent: August 3, 1999
    Assignee: Alcatel N.V.
    Inventors: Philippe Sehier, Cyril Bertrand
  • Patent number: 5929703
    Abstract: A method of modeling the AM--AM and AM-PM characteristics of an amplifier includes the step of transmitting a reference signal to the amplifier. The response of the amplifier to the reference signal is digitized to produce two sets of AM--AM and AM-PM reference samples, respectively. Two series of polynomials respectively representative of the AM--AM and the AM-PM characteristics are determined from the samples. The determination of each polynomial allows for the second derivative of the polynomial and for the distances between the samples and points on the curve defined by the polynomial.
    Type: Grant
    Filed: August 6, 1997
    Date of Patent: July 27, 1999
    Assignee: Alcatel Telspace
    Inventors: Philippe Sehier, Rossano Marchesani
  • Patent number: 5822384
    Abstract: A search method for acquisition of time synchronization between a spreading sequence of a receiver and a spreading sequence of a transmitter, the receiver receiving a spread signal and demodulating the signal using the spreading sequence of the receiver includes a test step consisting in measuring the energy of the demodulated signal by integrating the demodulated signal during a time interval Tobs.sub.i and comparing that energy with a threshold value to determine if the threshold value is exceeded, for a given hypothesis as to the time shift between the spreading sequences, and modifying the time shift hypothesis if the threshold value is not exceeded and incrementing the value of a counter. Steps a and b are repeated until the value of the counter reaches a predetermined value. When the predetermined value is reached, the time interval Tobs.sub.i is replaced with a time interval Tobs.sub.i+1, with Tobs.sub.i+1 =m.Tobs.sub.i and m>1, and the process resumes at step a replacing Tobs.sub.i with Tobs.sub.
    Type: Grant
    Filed: June 16, 1995
    Date of Patent: October 13, 1998
    Assignee: Alcatel Telspace
    Inventors: Bertrand Thebault, Philippe Sehier
  • Patent number: 5732114
    Abstract: In a method of detecting reference symbols in a digital data stream constituted by successive frames, each frame contains R reference symbols and I information symbols, and the R reference symbols are uniformly spaced apart in the digital data stream. The received signal is sampled with a period T.sub.e =T.sub.s /N.sub.e, where N.sub.e is an integer not less than 2, and T.sub.s is the symbol time. A cross-correlation is calculated, with each calculated cross-correlation supplying a magnitude I.sub.n equal to: ##EQU1## where x.sub.n+dNe represents the sample received at instant n+dN.sub.e, S*.sub.d,k represents the complex conjugate of the reference symbol of index d, k .epsilon. {0, . . . , R-1} and represents frame index, r=R/q, where q is an integer not less than 1. The cross-correlations are summed over M frames so as to form energy levels J.sub.M,d equal to: ##EQU2## where m is the frame index, M is the number of sums performed, and d .epsilon. {0, . . . , N.sub.e (R+1)-1}.
    Type: Grant
    Filed: November 2, 1995
    Date of Patent: March 24, 1998
    Assignee: Alcatel Telspace
    Inventors: Bertrand Thebault, Philippe Sehier
  • Patent number: 5546423
    Abstract: A spread spectrum digital transmission system using low-frequency pseudorandom encoding of desired information, and a spectrum spreading and compression method used in such a system. In a transmitter in the system, each block of a digital signal to be transmitted is combined with a sample obtained from a low-frequency pseudorandom generator. The resulting various combinations are converted into orthogonal or quasi-orthogonal sequences which are modulated and transmitted to a receiver. The receiver demodulates the signal received and combines each sequence with a sample identical to that used for the low-frequency coding at the transmitter to recover the various blocks of the transmitted signal. Hence, low frequency spectrum spreading of a signal to be transmitted is achieved.
    Type: Grant
    Filed: June 8, 1994
    Date of Patent: August 13, 1996
    Assignee: Alcatel Telspace
    Inventors: Philippe Sehier, Dominique Deprey
  • Patent number: 5285482
    Abstract: A timing recovery device for receiver installations using oversampling and adaptive equalization in association with differentially coherent demodulation, applicable in particular to receivers operating in diversity mode, derives a transition coding signal from the output signal of the adaptive equalizer. Channel estimator circuits receive this coding signal and digital signals supplied by oversampling devices on the diversity channels. The timing error is calculated from signals supplied by the estimators. The error calculation circuit controls an oscillator which generates a clock signal corresponding to the recovered symbol timing rate.
    Type: Grant
    Filed: December 9, 1992
    Date of Patent: February 8, 1994
    Assignee: Alcatel Telspace
    Inventors: Philippe Sehier, Veronique Truelle
  • Patent number: 5278867
    Abstract: A receiver system processes signals transmitted via a multipath dispersive transmission medium. It includes a device for digitizing the received signals to supply corresponding digital signals. An adaptive digital equalizer responsive to the digital signals supplies information symbols. A symbol-clock signal controls the digitizer and the equalizer. A timing signal recovery device responsive to the digital signals and to the information symbols derives a phase control signal for controlling the phase of the symbol-clock signal.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: January 11, 1994
    Assignee: Alcatel Telspace
    Inventors: Philippe Sehier, Alain Gressier
  • Patent number: 5170410
    Abstract: A digital signal receiver comprises receiver and demodulator means producing from the received signal a succession of complex elements. It produces sequences of successive complex elements consisting of conjugate elements of homologous elements used at the transmitting end. The sequences so used at the receiving end are synchronized to the homologous sequences used at the transmitting end. The complex elements obtained at the output of the demodulator are multiplied by a corresponding sequence of successive complex elements so produced and synchronized. The resultant complex elements appearing during the duration of an information symbol are summed over said duration to produce an estimate of the original information symbols used at the transmitting end. The complex elements obtained at the output of the demodulator are analyzed to identify a marking introduced at the transmitting end.
    Type: Grant
    Filed: June 26, 1991
    Date of Patent: December 8, 1992
    Assignee: Alcatel Transmission par Faisceaux Hertziens
    Inventors: Alain Gressier, Philippe Sehier
  • Patent number: 5027371
    Abstract: A self-adaptive equalizer circuit for a receive using differential demodulation, and in particular for a receiver using a plurality of paths in diversity (1, 2). For each diversity path (1, 2) there is a self-adaptive filter (18, 19) placed before the differential demodulation. The coefficients (CO to Cn) of the filter are updated at each instant KT, where T is the symbol rate period, using the formula:Ci(k)=Ci(k-1)-.mu.. y(k-1). x(k-1)* . e(k)where .mu. is a real number much less than 1, e.g. equal to 0.001, where Ci(k) is the value given to the coefficient (Ci) at instant kT; Ci(k-1) is the value taken by the same coefficient Ci at the instant (k-1)T; y(K-1) is the output signal from the self-adaptive filter, the symbol being sampled at the symbol rate of period T; x(k-i)* is the complex conjugate value of the sample x(k-i) present in the filter at said instant kT and relating to the coefficient Ci; and e(k) is the above-mentioned error at the instant kT.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: June 25, 1991
    Assignee: Alcatel Transmission par Faisceaux Hertziens
    Inventors: Philippe Sehier, Ghassan K. Kaleh
  • Patent number: 4949357
    Abstract: A synchronizing circuit for offset quaternary phase shift keying, comprises: a four-phase demodulator 10; a processing module (11, 12); and a phase error calculating circuit (15) followed by a phase correcting circuit (16) which delivers a phase error correction signal. The invention is applicable to telecommunications by microwave beams.
    Type: Grant
    Filed: March 14, 1989
    Date of Patent: August 14, 1990
    Assignee: Alcatel N.V.
    Inventor: Philippe Sehier