Nokia Networks Oy

Nokia Corporation

Mikko Huttunen

A method for defining correction parameters used in transmitter linearization executed by a predistortion method and a transmitter comprising: sampling means () for sampling the signal (OUT) coming out of the transmitter, a predistorter () for predistorting the signal to be sent (I_IN, Q_IN) to compensate the nonlinearity of the transmitter, the transmitter also comprising: categorization means () for categorizing into predefined classes signal samples (FB) taken from the signal (OUT) coming out of the transmitter, comparison means () for comparing the signal samples (FB) with the corresponding ideal signal values (REF), and definition means (), responsive to said comparison means (), for defining amplitude and preferably phase correction parameters for each class in question, whereby the predistorter is arranged to use said correction parameters when predistorting the signal being transmitted.

Transmitter linearization

A method for selecting a modulation detector in a receiver and a receiver which includes a first and a second modulation detector, mechanisms for determining at least one cross-correlation value between the stored training sequence and at least one training sequence of the received signal, and mechanisms for selecting the detector used for the detection of a signal to be received in response to the determined at least one cross-correlation value.

Method for selecting modulation detection in receiver, and receiver

A method and equipment for detecting an interfering signal in a time division multiple access radio receiver, in which case, samples are taken from a received signal in symbol sequences over a time division multiple access timeslot, a signal path corresponding to the time division multiple access timeslot, or a portion thereof, is generated by a modulation detector, an error estimate representing the erroneousness of the signal path generated is determined, the error estimate is compared with a predetermined threshold value, and the reception of the interfering signal is recognized if the error estimate is greater than the predetermined threshold value.

Detection of interfering signal in radio receiver

A method for estimating a frequency error in a communication system, in particular in a mobile communication system involving successively sampling sample sets from a signal to be received at given points corresponding to symbol sequence points of the receiver, and frequency error estimates corresponding to each point are determined based on the sample sets at the given points and variance of the frequency error estimates of every given point is calculated. The frequency error estimate of the signal to be received is selected based on the frequency error estimates of the given point whose variance is least.

Method for frequency error estimation

A self-optimizing channel equalization and detection method and a channel equalizer/detector ( ) implementing the method, the method comprising receiving a signal (RFI), taking samples of the signal within each symbol period over a timeslot, calculating reference constellation points within each symbol period on the basis of a channel estimate, updating the channel estimate within each symbol period on the basis of an error between each sample point and the reference constellation point, the error having been processed by one or more adaptivity parameters, and defining, for bit detection, the signal path having the best error metrics in the timeslot on the basis of the error metrics calculated from the sample points on the basis of the channel estimate. One or more adaptivity parameters used in channel estimate update are updated by timeslots in a direction which tends to decrease the error metrics of the best defined signal path within a single-timeslot or multiple-timeslot observation period when being compared with the error metrics of a corresponding path in a previous timeslot.

Self-optimizing channel equalization and detection

A modulation detection method and apparatus, comprising taking a sample from a received signal, determining reference constellation points, calculating path-specific error metrics from a sample point to the reference constellation points, and applying the path-specific error metrics corresponding to the reference constellation points to a modulation detector. Out of the reference constellation points the constellation points, preferably two of them, having the smallest error metrics are selected, and only the error metrics corresponding thereto are applied to the modulation detector.

Growing community of inventors

Espoo, Finland

Mikko Huttunen