Abstract: The invention relates to a receiver for receiving a signal of a desired user, which signal may arrive at the receiver in different components along several different paths at several different delays. The receiver includes an antenna array, rake branches, and at least one search branch. At least one rake branch includes a plurality of beam formers, a plurality of correlators coupled to the inputs of the beam formers, a demodulator coupled to the outputs of the correlators, a code generator for generating codes required by the correlators, controls means, and calculation means. The calculation means are adapted to calculate and transmit to the control means, on the basis of the outputs of the correlators, information on how the code generator and the beam formers are to be controlled.

Abstract: In a mobile communication system, a method and circuit for symbol estimation is described. According to the method, a soft output decision for a symbol is estimated and is fed back to modify decisions made for a subsequent set of received samples. This has the advantage of conveying not only information about the most likely symbol, but also information about the noise environment.

Abstract: A radio system comprising a base station and a terminal, said base station and terminal being able to serve as a transmitter and the other as a receiver, a signal to be transmitted on a radio channel between the transmitter and the receiver comprising bursts including a training sequence known to the receiver, the receiver comprising means for creating, on the basis of the training sequence a radio channel impulse response comprising taps representing signal strength at different points of time. The receiver further comprising means for calculating the real time of arrival of the burst from the time of occurrence and energy of the taps of the impulse response, means for creating the time difference between the real and expected times of arrival of the burst, and means for calculating the distance between the transmitter and the receiver on the basis of the time difference.

Abstract: In a mobile communication system, a method and circuit for symbol estimation is described. According to the method, a soft output decision for a symbol is estimated and is fed back to modify decisions made for a subsequent set of received samples. This has the advantage of conveying not only information about the most likely symbol, but also information about the noise environment.

Abstract: The present invention relates to a method for allocating RAKE branches and a RAKE receiver. The solution is used in a radio system where a transmitter transmits a signal to a receiver comprising RAKE branches which receive the signal at different polarization levels. The RAKE branches are allocated to receive the signal on the basis of an impulse response, and in which method the impulse responses of the signals received at different polarization levels are weighted by values describing signal quality for optimizing allocation.

Abstract: A method for determining a phase error in a radio-frequency signal received by a receiver, wherein an impulse response of a received signal is calculated, measuring points are chosen from the signal, and samples are taken from the surrounding areas of the measuring points. The samples are filter with a complex adapted filter. A phase error in the samples is measured from the filtering result, and the total phase error in the received signal is calculated on the basis of the measured phase error. In order to be also able to measure large phase errors, the measuring points are chosen on the basis of phase errors measured from signals received earlier, in such a manner that the phase error at the measuring points remains within predetermined limits. The receiver includes a compensator for the phase and frequency errors in the received signal.