Patents by Inventor Olli Piirainen

Olli Piirainen 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: 7561643
    Abstract: A method of simultaneously determining a DC offset and a channel impulse response from a received signal in a mobile communication system. The received signal Y comprising a set of training sequence bits that have been modulated prior to transmission. The modulated signals experience a certain phase shift and are rotated by a certain angle. The received signal may also comprise a DC offset component ADC that needs to be removed. By manipulation of the received signal samples with the knowledge of the original training sequence TRS and method of modulation used, it is possible to simultaneously estimate the communication channel's impulse response H and the DC offset ADC by finding the Least Square solution to a linear equation, such that the energy of the noise term introduced into the communication channel may be kept to a minimum.
    Type: Grant
    Filed: October 27, 1999
    Date of Patent: July 14, 2009
    Assignee: Nokia Corporation
    Inventor: Olli Piirainen
  • Patent number: 7561648
    Abstract: There is disclosed a technique for generating an improved estimate of the frequency error in a received signal, and more particularly the application of such a technique in the equalization circuitry of a wireless network element.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: July 14, 2009
    Assignee: Nokia Siemens Networks Oy
    Inventor: Olli Piirainen
  • Patent number: 7546105
    Abstract: The invention relates to interference cancellation in a receiver in a radio system. The receiver receives at least two input data signals, and extracts an interference estimate signal specific to each input data signal. An interference estimate signal covariance matrix is calculated, and autoregressive parameters and covariance parameters are estimated from the covariance matrix. Interference is canceled from the at least two input data signals by finite impulse response filters using the estimated parameters as filter coefficients in the finite impulse response filters.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: June 9, 2009
    Assignee: Nokia Corporation
    Inventor: Olli Piirainen
  • Patent number: 7542734
    Abstract: The invention provides a data transmission solution in a telecommunication system. According to the invention, a data transmission scheme is selected for a first transceiver unit, which comprises a plurality of transmit antennas, on the basis of the quality of a communication link and transmit antenna correlation information associated with the first transceiver unit, from a list including at least the following data transmission schemes: transmitting different data from each antenna of the first transceiver unit, the data transmitted from one antenna being independent of the data transmitted from another antenna; and transmitting the same data from each antenna of the first transceiver unit and controlling the direction of the transmitted data according to the properties of a radio channel. The selection of the data transmission scheme is carried out during an active communication link between the first and a second transceiver unit.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: June 2, 2009
    Assignee: Nokia Corporation
    Inventor: Olli Piirainen
  • Publication number: 20080240311
    Abstract: A frequency error correction scheme applicable in a receiver of a mobile telecommunication system is presented. The present frequency error correction scheme is carried out in a time domain after an equalization process. The present frequency error correction scheme may be applied to a base station receiving signals transmitted according to a single-carrier frequency division multiple access communication scheme. The separation of different received signals for further processing is carried out in the frequency domain before the equalization and the frequency error correction.
    Type: Application
    Filed: June 4, 2007
    Publication date: October 2, 2008
    Inventors: Olli Piirainen, Markku Vainikka, Juha P. Karjalainen
  • Publication number: 20080212666
    Abstract: An interference rejection algorithm for a radio receiver is presented. According to the present solution a signal comprising a training sequence and a data sequence is received at the radio receiver. A radio channel response may be estimated from the received training sequence, and interference parameters may be estimated from at least one of the received training sequence and the received data sequence, the estimation of the interference parameters comprising smoothing a frequency spectrum of at least one of the estimated channel response and the estimated interference parameters through averaging. Then, frequency domain interference suppression weights are calculated from the estimated channel response and the interference parameters, and weighting of the received data sequence is carried out with the calculated weights.
    Type: Application
    Filed: March 1, 2007
    Publication date: September 4, 2008
    Inventors: Kiran Kuchi, Olli Piirainen, Olav Tirkkonen
  • Publication number: 20080089439
    Abstract: There is provided a method of clipping a transmission signal. The method comprises: providing a residual signal of a complex envelope clipper based on the transmission signal to be clipped; providing a reference signal respective to the residual signal, the reference signal corresponding to an ideal residual signal; forming a clipping signal on the basis of the residual signal and the reference signal; subtracting the clipping signal from the residual signal for removing higher amplitudes of the residual signal; and subtracting the clipping signal from the reference signal for providing a reference signal respective to the clipped residual signal.
    Type: Application
    Filed: August 28, 2007
    Publication date: April 17, 2008
    Inventor: Olli Piirainen
  • Publication number: 20080064337
    Abstract: A method, mobile device, network device, system, and software are devised for soft value scaling with a single antenna interference cancellation (SAIC) receiver, or with an interference rejection combining (IRC) receiver, in an unsynchronized network. A signal is received having interference that is caused by a non-synchronized network. A desired power level of that signal is calculated. Then the desired power is compared to a total power of the signal, in order to identify a portion of a received burst having substantial interference. Then that portion of the received burst is weighted, to reduce its importance during decoding.
    Type: Application
    Filed: August 31, 2007
    Publication date: March 13, 2008
    Inventors: Mikko Saily, Olli Piirainen, Kari Niemela, Jari Hulkkonen
  • Patent number: 7340004
    Abstract: A method for limiting a signal in a radio transmitter comprises giving a signal a limiting threshold, taking at least two samples from the signal for obtaining sample values, adding one or more sample values between the obtained first and at least one subsequent sample values, searching for sample values exceeding the limiting threshold, and if at least one sample value exceeding the limiting threshold is found determining limiting coefficients for a predetermined number of sample values by means of the at least one sample value exceeding the limiting threshold, and limiting the signal by one or more determined coefficients.
    Type: Grant
    Filed: October 23, 2002
    Date of Patent: March 4, 2008
    Assignee: Nokia Corporation
    Inventors: Tapio Vuopala, Olli Piirainen
  • Patent number: 7339918
    Abstract: A method for improving the quality of data transmission in cellular radio systems utilizes time division multiple access, in which the strength of a signal received at a base station is measured and a decoder for soft decision-making is employed. The method includes measuring the strength of the signal the base station receives in at least two consecutive time slots and determining a weighting coefficient by comparing the signal strengths and reducing, using the determined weighting coefficient in a soft bit decision-making, the significance of at least one symbol at the beginning of the burst the base station receives in a time slot if the difference between the measured signal strengths is considerable.
    Type: Grant
    Filed: February 25, 2002
    Date of Patent: March 4, 2008
    Assignee: Nokia Corporation
    Inventor: Olli Piirainen
  • Publication number: 20080037411
    Abstract: The specification and drawings present a new method, system, apparatus and software product for variable filtering of a mobile station (MS) for supporting uplink communications using available capabilities of a network element in wireless communication systems (e.g., evolved GERAN). The MS may have at least two different pulse shaping filter capabilities providing at least two different bandwidths: one narrower being suitable for legacy transceivers and another wider and thus optimal for variable symbol rate from performance point of view.
    Type: Application
    Filed: August 27, 2007
    Publication date: February 14, 2008
    Inventors: Kari Niemela, Olli Piirainen, Mikko Saily, Jari Hulkkonen
  • Publication number: 20080014877
    Abstract: The specification and drawings present a new method, system, apparatus and software product for carrier frequency shifting in mobile communication systems, e.g., for eliminating or reducing interference, e.g., for a communication between a mobile station and a network element. The communication between the mobile station and the network element may be performed within a GSM/EDGE radio access network. A signal (e.g., a DSR or MDSR carrier) and at least one further signal (e.g., a speech carrier) are identified, wherein bandwidths of the signal and of the at least one further signal overlap. Then, a frequency shift for said signal may be determined according to a predetermined criterion and a carrier frequency of the signal may be shifted by the determined frequency shift, e.g., for eliminating or reducing the interference.
    Type: Application
    Filed: March 22, 2007
    Publication date: January 17, 2008
    Inventors: Jari Hulkkonen, Kari Niemela, Olli Piirainen, Mikko Saily
  • Patent number: 7317767
    Abstract: A method of simultaneously determining a DC offset and a channel impulse response from a received signal in a mobile communication system. The received signal comprising a set of training sequence bits that have been modulated prior to transmission. The modulated signals experience a certain phase shift and are rotated by a certain angle. The received signal may also comprise a DC offset component that needs to be removed By manipulation of the received signal samples with the knowledge of the original training sequence and method of modulation used, it is possible to simultaneously estimate the communication channel's impulse response and the DC offset by finding the Least Squares solution to a linear equation, such that the energy of the noise term introduced into the communication channel may be kept to a minimum. An improved technique utilising a priori information is also described.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: January 8, 2008
    Assignee: Nokia Corporation
    Inventors: Aki Happonen, Olli Piirainen
  • Publication number: 20080003965
    Abstract: An indicator of a strength of a signal comprising a training sequence portion received in a radio propagation environment is provided. Samples are taken from the training sequence portion, an energy value of the samples over an estimated channel impulse response is computed and the indicator of the strength of the signal is estimated from the energy value.
    Type: Application
    Filed: March 20, 2007
    Publication date: January 3, 2008
    Inventors: Mikko Saily, Olli Piirainen, Kari Niemela, Jari Hulkkonen
  • Publication number: 20070286300
    Abstract: The specification and drawings present a new method, system, apparatus and software product for using a new modified dual symbol rate (MDSR) in an uplink direction in mobile communication systems. The communication between the mobile station and the network element may be performed within evolved GSM/EDGE radio access networks. The MDSR can be for example one and a half times a symbol rate of an uplink speech service, e.g., the current GSM/EDGE symbol rate (13/48 MHz) in the mobile communication system, thus the MDSR may be substantially 13/32 MHz or about 405 kHz. The uplink signal with the MDSR may be modulated, e.g., using a quadrature amplitude modulation (QAM), e.g., 16-QAM with 16 states and/or a quadrature phase-shift keying (QPSK, or ?/4-QPSK) modulation.
    Type: Application
    Filed: March 29, 2007
    Publication date: December 13, 2007
    Inventors: Olli Piirainen, Kari Niemela, Jari Hulkkonen, Mikko Saily
  • Publication number: 20070287444
    Abstract: A method and corresponding equipment for use by a mobile station and/or a radio access network, for altering one or more characteristics of transmissions of the mobile station to a base transceiver station of the radio access network in respect to power and/or modulation and/or coding of the transmissions, based on monitoring broadcast transmissions from other base transceiver stations of the radio access network and determining an estimate of the likelihood of transmissions by the mobile station interfering with communication between the other base transceiver stations and the mobile stations in communication with those other base transceiver stations.
    Type: Application
    Filed: March 22, 2007
    Publication date: December 13, 2007
    Inventors: Jari Hulkkonen, Olli Piirainen, Kari Niemela, Mikko Saily
  • Patent number: 7260162
    Abstract: A method and apparatus for improving the quality of a signal which has been detrimentally affected by inter-symbol interference due to time dispersion. The invention includes selecting one of at least two algorithms of equalization and after the selection, and processing the signal by performing steps according to the selected algorithm.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: August 21, 2007
    Assignee: Nokia Corporation
    Inventor: Olli Piirainen
  • Publication number: 20070173271
    Abstract: A network element, a terminal and a method of allocating a radio channel to a connection between a terminal and a base station in a telecommunication system are provided. The number and properties of potential interferers in a plurality of available radio channels are determined, and channel allocation is performed on the basis of the determination.
    Type: Application
    Filed: December 21, 2006
    Publication date: July 26, 2007
    Inventors: Jari Hulkkonen, Olli Piirainen
  • Publication number: 20070161361
    Abstract: An interference suppression scheme is provided for a radio receiver. According to the provided interference suppression scheme, the bandwidth of a received pilot signal and a data signal is divided into a plurality of frequency sub-bands. The pilot signal and the data signal have been transmitted according to single carrier data transmission technology. Interference parameters are calculated for each frequency sub-band separately. Interference suppression may be carried out jointly or separately for each frequency sub-band. After the interference suppression, the frequency sub-bands are combined. A filter bank may be used for dividing the total frequency band into sub-bands.
    Type: Application
    Filed: February 21, 2006
    Publication date: July 12, 2007
    Inventors: Petri Vaisanen, Olli Piirainen, Markku Vainikka
  • Publication number: 20070161376
    Abstract: The specification and drawings present a new method, system, apparatus and software product for a timeslot (TSL) reuse typically combined with a frequency reuse for a service based interference control in communication systems. TSL reuse method can be applied to a service with a wider spectrum or a higher symbol rate than for a normal channel bandwidth of a communication system to provide the way for controlling interference. The TSL reuse method can enable interference control for synchronized and unsynchronized networks in uplink (UL) or downlink (DL).
    Type: Application
    Filed: January 10, 2007
    Publication date: July 12, 2007
    Inventors: Jarri Hulkkonen, Olli Piirainen, Kari Niemela, Mikko Saily