Patents by Inventor Johan Sköld

Johan Sköld 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).

  • Patent number: 6456627
    Abstract: A method of communicating control information in systems that support multiple modulation schemes for communicating voice or data and control information. To provide backward compatibility dedicated control channels use the modulation scheme used in current systems, for example GMSK modulation scheme. Traffic channels and associated control channels use linear modulation schemes that have the same symbol rate. The modulation scheme of the associated control channel uses a reduced signal set of the modulation scheme used for traffic channels. Also, an in-band signalling procedure is used to indicate to a receiving station the modulation type, channel coding and speech coding used for a transmitted burst.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: September 24, 2002
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Carl Magnus Frodigh, Mikael H{umlaut over (oo)}k, Frank Müller, Peter Schramm, Johan Sköld
  • Patent number: 6125148
    Abstract: A method of demodulating voice or data and control information in systems that support multiple modulation schemes modulates voice or data using a first linear modulation scheme, such as 16QAM modulation scheme, and modulates control information using a second linear modulation scheme, for example, QPSK modulation scheme, that has the same symbol rate as that of the first modulation scheme. The first linear modulation scheme has a higher modulation level than the second linear modulation scheme. Information modulated using the second linear modulation scheme, which uses a reduced signal set of the first linear modulation scheme, are demodulated using the same demodulator that is used for demodulating information modulated using the first linear modulation scheme. Also, in-band signalling information within a traffic channel, such as stealing flags, are modulated using the second modulation scheme.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: September 26, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Carl Magnus Frodigh, Mikael Hook, Frank Muller, Peter Schramm, Johan Skold
  • Patent number: 6084862
    Abstract: Time dispersion of a signal that has been received from a channel is measured by utilizing metrics to determine the energy inside an equalizer window and outside of the equalizer window. In one embodiment, the estimate of the energy outside the window is a difference between residual interference estimates. In another embodiment, the estimate of the energy outside the window is a difference between residual impulse response power estimates.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: July 4, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Peter Bjork, Linus Ericsson, Johan Skold
  • Patent number: 5933768
    Abstract: Apparatus, and an associated method, for estimating an interfering-signal component portion of a receive signal received at a receiver. The training sequence associated with the interfering-signal component portion is determined, even without prior knowledge of the training sequence associated with such interfering-signal component portion. Once the training sequence of the interfering-signal component portion is determined, the receive signal is selectively, jointly-detected utilizing a joint detector, the interfering-signal component portion of the receive signal is better able thereby to be canceled or otherwise suppressed.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: August 3, 1999
    Assignee: Telefonaktiebolaget L/M Ericsson
    Inventors: Johan Skold, Mikael Hook, Nils Edvardsson
  • Patent number: 5909469
    Abstract: A communication system supports multiple modulation schemes having differing symbol rates. The system supports two modulation schemes that have the same symbol rate and at least one modulation scheme that does not have the same symbol rate. For as long as communication can be carried out using the modulation schemes with the same symbol rate, the system avoids using the modulation scheme with different symbol rate, even if communication can be carried out using this scheme.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: June 1, 1999
    Assignee: Telefonaktoebolaget LM Ericsson
    Inventors: Carl Magnus Frodigh, Mikael Hook, Frank Muller, Peter Schramm, Johan Skold
  • Patent number: 5903610
    Abstract: In a receiver of a digital radio communication system, a combined channel estimate is formed by averaging a long channel estimate with a short channel estimate.
    Type: Grant
    Filed: April 29, 1997
    Date of Patent: May 11, 1999
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Johan Skold, Linus Ericsson, Per-Olof Eriksson
  • Patent number: 5657348
    Abstract: A method in connection with digital mobile radio communication systems for forming, in a receiver, a quality measure SQ of the signal vector received in a signal burst comprises forming a first estimate E.sub.s of the energy of the useful signal of the signal vector, forming a second estimate E.sub.n of the energy of the remaining signal components of the signal vector, and forming the quality measure SQ of the signal vector in accordance with the formula SQ=K.sub.1 E.sub.s /(K.sub.2 +E.sub.n), where K.sub.1 and K.sub.2 are predetermined constants.
    Type: Grant
    Filed: January 2, 1996
    Date of Patent: August 12, 1997
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Leif Linus Ericsson, Andras Antal Toth, Johan Skold
  • Patent number: 5581548
    Abstract: According to method and apparatus for communication in a cellular TDMA mobile radio communication system with channel hopping, base and mobile stations transmit radio signal bursts in time slots of a plurality of radio channels in accordance with channel hopping schemes. All of the schemes used by a base and mobile stations in a cell are free from coincidence on any radio channel with any other of the schemes used for transmission within the same cell. A scheme used by a mobile station in one cell occasionally coincides on a radio channel with a scheme used by a mobile station in another cell. The major part of every channel shifting scheme used by a mobile station in a cell is free from coincidence on any radio channel with the major part of any channel hopping scheme used by a mobile station in another cell.
    Type: Grant
    Filed: December 19, 1994
    Date of Patent: December 3, 1996
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Jon K. Ugland, Perols B. O. Gudmundson, Johan Skold
  • Patent number: 5481572
    Abstract: Signals in synchronizing sequences and data sequences are transmitted over a fading channel to a sequence estimation receiver. The signals are received by a plurality of mutually separated antennas and sampled to produce received antenna signals (S.sub.in,r (k)). Using the received antenna signals, part transmission channel estimates (h.sub.est,r) are formed for each antenna. These part channel estimates are used to form precomputed metric values (f.sub.a,r ((.DELTA.T.sub.ij),g.sub.a (.DELTA.T.sub.ij)). For the sequence estimation algorithm, branch metric values (m(.DELTA.T.sub.ij,k)) are formed by combining the precomputed metric values with the received antenna signals for state transitions (.DELTA.T.sub.ij). For one state transition there is formed a metric value such as the sum of a metric value (M(T.sub.j,k-1)) for an old state (T.sub.j) at a preceeding sampling time point (k-1) with a branch metric value (m(.DELTA.T.sub.ij,k)).
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: January 2, 1996
    Assignee: Ericsson Inc.
    Inventors: Johan Skold, Per-Olof Eriksson
  • Patent number: 5373507
    Abstract: A method of synchronizing a received signal frame in a TDMA radio system with a locally generated (TR) training sequence and of determining a channel estimate based on the comparison the received signal frame and the locally generated training sequence. A center of energy value is calculated for a first vector having M correlation values. A second vector having N consecutive correlation values distributed around the center of energy is chosen to form the channel estimate. The center of energy in the second vector can be chosen as synchronizing position.
    Type: Grant
    Filed: January 12, 1993
    Date of Patent: December 13, 1994
    Assignee: Telefonaktiebolaget L M Ericsson
    Inventor: Johan Skold