Patents by Inventor Jan E. Uddenfeldt
Jan E. Uddenfeldt 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).
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Patent number: 5257401Abstract: The invention relates to a method in a mobile radio system having both digital and analog radio channels. An object of the invention is that a connection established on a digital radio channel often shall be possible to maintain even when the time dispersion on available digital radio channels exceeds the designed maximum time dispersion of equalizers in receiving stations. According the invention equalizers in the receivers of the system may be designed for a smaller maximum time dispersion than the total time dispersion the whole system shall be capable to handle. Instead handoff is made to an other channel when the time dispersion of a used digital channel tends to become too big. When an other digital radio channel with low time dispersion is available handoff is preferably done to this channel. Alternatively or in the absence of such a digital radio channel handoff is performed to an analog radio channel.Type: GrantFiled: April 11, 1990Date of Patent: October 26, 1993Assignee: Telefonaktiebolaget L M EricssonInventors: Jan E. .ANG.ke S. Dahlin, Jan E. Uddenfeldt
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Patent number: 5212803Abstract: A method in a mobile radio station to select one of a number of dedicated control channels (DCCH1-21) which are transmitted from a number of base stations (B1-B21) in a mobile radio system. In the mobile station there is an equalizer to compensate for the multipath propagation characteristics of the radio medium between the mobile station and a certain base station. This equalizer is power consuming and should not be used if not necessary. According to the method an investigation is carried out in the mobile station whether or not the equalizer can be disconnected during the initialization of a call from the mobile to a base station. The signal quality of the dedicated channel (DCCH1) which has the greatest signal strength is measured without the equalizer. If the signal quality is not acceptable, a new detection is made with the use of the equalizer.Type: GrantFiled: September 6, 1990Date of Patent: May 18, 1993Assignee: Telefonaktiebolaget L M EricssonInventors: Jan E. Uddenfeldt, Alex K. Raith
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Patent number: 5088108Abstract: The invention relates to a cellular digital mobile radio system including base stations (B.sub.m, B.sub.n) and mobile stations (MS.sub.1, MS.sub.2) with transmitters and receivers. The invention also relates to a method of transmitting message information digitally between mobile and base stations in such a system. In accordance with the invention, at least two base station transmitters (B.sub.ma, B.sub.mb, B.sub.na, B.sub.nb) at a given transmitting distance from each other are assigned to each of certain cells (C.sub.m, C.sub.n) within a restricted geographical area. The base station transmitters which are assigned to the same cell transmit digitally modulated radio signals within the same frequency range at least partially simultaneously to the mobile stations of the cell. The radio signals from different base station transmitters associated with the same cell are digitally modulated with the same message information to the mobile stations in the cell.Type: GrantFiled: September 6, 1990Date of Patent: February 11, 1992Assignee: Telefonaktiebolaget L M EricssonInventors: Jan E. Uddenfeldt, Alex K. Raith
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Patent number: 4972506Abstract: Method of transmitting data information in a mobile, cellular, radio communication system operating according to the TDMA principle. Within certain large cells (C2) in the system the number of calls in progress is less than the number of slots (CH1, CH2 . . . ) in each frame, where these slots have been allotted to the mobiles (M1) within the cell. The unoccupied slots thus occuring are utilised in accordance with the method such that the bit frequency (f) of the data information is reduced to a new value (f.sub.r) in response to the number of unoccupied time slots. The transmission range between mobile and base station is thus increased.Type: GrantFiled: February 17, 1989Date of Patent: November 20, 1990Assignee: Telefonaktiebolaget L M EricsssonInventor: Jan E. Uddenfeldt
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Patent number: RE37685Abstract: The invention relates to a method in mobile radio systems in which the responsibility for transmitting message information to a mobile station (MS1, MS2) is handed over from at least a first base station transmitter (Bma, Bmb) to at least a second base station transmitter (Bna, Bnb). In accordance with the invention, the same radio channel is used, if possible, before and after the handover for transmitting message information to the mobile station. If the same radio channel can be utilized, the handover takes place without the mobile station being informed beforehand of the handover by a special signal or order or the like. In digital mobile radio systems with digital transmission of message information by digital modulation of the radio signals, the transmission is preferably started from a second base station transmitter before the transmission is terminated from a first base station transmitter.Type: GrantFiled: January 11, 1999Date of Patent: April 30, 2002Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Jan E. Uddenfeldt, Alex K. Raith
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Patent number: RE37754Abstract: The invention relates to a cellular digital mobile radio system including base stations (Bm, Bn) and mobile stations (MS1, MS2) with transmitters and receivers. The invention also relates to a method of transmitting message information digitally between mobile and base stations in such a system. In accordance with the invention, at least two base station transmitters (Bma, Bmb, Pna, Bnb) at a given transmitting distance from each other are assigned to each of certain cells (Cm, Cn) within a restricted geographical area. The base station transmitters which are assigned to the same cell transmit digitally modulated radio signals within the same frequency range at least partially simultaneously to the mobile stations of the cell. The radio signals from different base station transmitters associated with the same cell are digitally modulated with the same message information to the mobile stations in the cell.Type: GrantFiled: December 21, 1998Date of Patent: June 18, 2002Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Jan E. Uddenfeldt, Alex K. Raith
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Patent number: RE37787Abstract: The invention relates to a method in mobile radio systems in which the responsibility for transmitting message information to a mobile station is handed over from a first base station transmitter to a second base station transmitter. In this method, the same radio channel is used, if possible, before and after the handover for transmitting message information to the mobile station. If the same radio channel can be utilized, the handover takes place without the mobile station being informed beforehand of the handover by a special signal or order or the like. In digital mobile ratio systems with digital transmission of message information by digital modulation of the radio signals, the transmission is preferably started from a second base station transmitter before the transmission is terminated from a first base station transmitter. During a certain transmission time substantially the same message information is transmitted to the mobile station from both the first and second base station transmitters.Type: GrantFiled: January 21, 1999Date of Patent: July 9, 2002Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Jan E. Uddenfeldt, Alex K. Raith
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Patent number: RE36017Abstract: The invention relates to a cellular digital mobile radio system including base stations (B.sub.m, B.sub.n) and mobile stations (MS.sub.1, MS.sub.2) with transmitters and receivers. The invention also relates to a method of transmitting message information digitally between mobile and base stations in such a system. In accordance with the invention, at least two base station transmitters (B.sub.ma, B.sub.mb, B.sub.na, B.sub.nb) at a given transmitting distance from each other are assigned to each of certain cells (C.sub.m, C.sub.n) within a restricted geographical area. The base station transmitters which are assigned to the same cell transmit digitally modulated radio signals within the same frequency range at least partially simultaneously to the mobile stations of the cell. The radio signals from different base station transmitters associated with the same cell are digitally modulated with the same message information to the mobile stations in the cell.Type: GrantFiled: October 15, 1993Date of Patent: December 29, 1998Assignee: Telefonaktiebolaget LM EricssonInventors: Jan E. Uddenfeldt, Alex K. Raith
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Patent number: RE36079Abstract: The invention relates to a method in mobile radio systems in which the responsibility for transmitting message information to a mobile station is handed over from a first base station transmitter to a second base station transmitter. In this method, the same radio channel is used, if possible, before and after the handover for transmitting message information to the mobile station. If the same radio channel can be utilized, the handover takes place without the mobile station being informed beforehand of the handover by a special signal or order or the like. In digital mobile ratio systems with digital transmission of message information by digital modulation of the radio signals, the transmission is preferably started from a second base station transmitter before the transmission is terminated from a first base station transmitter. During a certain transmission time substantially the same message information is transmitted to the mobile station from both the first and second base station transmitters.Type: GrantFiled: September 26, 1997Date of Patent: February 2, 1999Assignee: Telefonaktiebolaget LM EricssonInventors: Jan E. Uddenfeldt, Alex K. Raith