Abstract: A technique is provided including at least obtaining a noise and interference covariance matrix, performing scaling of the noise and interference covariance matrix, determining a sum of diagonal elements of the scaled noise and interference covariance matrix, performing a first spectral shift by the sum to the scaled noise and interference covariance matrix to obtain a first spectral shifted matrix, performing eigenvalue decomposition to the first spectral shifted matrix to obtain an eigenvalue matrix, performing a second spectral shift by the sum to the eigenvalue matrix, limiting the eigenvalue matrix to a diagonal matrix, and obtaining a new noise and interference covariance matrix adding the scaled noise and interference covariance matrix and eigenvalue pairs that are obtained based, at least partly, on the performed eigenvalue decomposition.

Abstract: A method comprising obtaining a noise and interference covariance matrix, performing scaling of the noise and interference covariance matrix, determining a sum of diagonal elements of the scaled noise and interference covariance matrix, performing a first spectral shift by the sum to the scaled noise and interference covariance matrix to obtain a first spectral shifted matrix, performing eigenvalue decomposition to the first spectral shifted matrix to obtain an eigenvalue matrix, performing a second spectral shift by the sum to the eigenvalue matrix, limiting the eigenvalue matrix to a diagonal matrix, and obtaining a new noise and interference covariance matrix adding the scaled noise and interference covariance matrix and eigenvalue pairs that are obtained based, at least partly, on the performed eigenvalue decomposition.

Abstract: A solution for equalization in a radio receiver is provided. According to the provided solution, equalization with a zero forcing equalization algorithm is improved with frequency domain processing of received information symbols. The frequency spectrum of received information symbols is modified with a calculated frequency domain representation of the radio channel impulse response. Thereafter, the information symbols having the modified frequency spectrum are filtered with a zero forcing filter having the filter coefficients calculated through a zero forcing algorithm.

Abstract: The invention relates to a method for multiple access interference suppression and to a receiver applying the method. A preliminarily detected signal is spreading coded and channel distorted in a MAI estimator (350) for generating an estimate signal (274) corresponding to a received and reception-filtered signal. Pulses (360) corresponding to a signal component of each path of each user are generated from the signal in a pulse generator block (300), and the pulses are combined according to path delays into a pulse sequence (362) in a combiner (310). In a filter (312), the pulse sequence (362) is subjected to waveform filtering, which is the convolution of reception filtering and pulse shaping filtering. Finally, in a summer (220), the estimate signal (274) is subtracted from the received and reception-filtered signal (270) to cancel multiple access interference.

Abstract: A method for code tracking RAKE receiver fingers, the method comprising: taking several successive samples from a received signal, combining sample values measured in different fingers into measurement value sets, comparing the measurement value sets with each other and selecting the measurement value set having the highest value from among the measurement value sets meeting a minimum delay distance condition for the fingers, if any one of the sample values of the selected measurement value set is earlier than an on-time sample value determined on the basis of code phase acquisition, advancing the sampling or code phase of the particular finger, and if any one of the sample values of the selected measurement value set is later than an on-time sample value determined on the basis of code acquisition, delaying the sampling or code phase of the particular finger.

Abstract: The invention relates to a method of processing multipath-propagated components of a signal in a communications system. In the method, a signal transmitted on the radio channel of the communications system is received in a RAKE receiver and an impulse response of the radio channel is formed. In the method, one or more taps having the highest signal energy in the impulse response are located and matched to a short matched filter. A weighting value for the impulse response is calculated on the basis of the one or more taps in the matched filter and a deviation between the weighting value and the center point of the matched filter is compared with a threshold value set for the deviation. The matched filter is moved toward the deviation when the deviation exceeds the threshold value set for the deviation.

Abstract: The invention concerns generally the technology of reducing frequency offset in a radio receiver. Especially the invention concerns receivers where a channel estimator is used for correcting the base band signal. The objects of the invention are achieved by monitoring the phase of the channel estimation output and generating a complex phasor on the basis of successive phase values. The received baseband signal is then multiplied by the generated complex phasor for compensating the frequency offset. The frequency compensation can be made before or after said channel estimation thus producing a feedback compensation or feed forward compensation. The feedback compensation can be implemented by compensating the baseband signal either prior to the despreading or after the despreading.

Abstract: The invention relates to a method and arrangement for establishing a connection between a base station and mobile station. The invention is especially applicable to digital TDMA (Time Division Multiple Access) and CDMA (Code Division Multiple Access) cellular systems which use extended cell operating ranges. An idea of the invention is that when establishing a connection a mobile station transmits access bursts using a preferably extended timing advance different from zero. In one embodiment, different timing advance values are used until a timing advance is found with which the burst falls on a CCCH channel time slot at the base station. The mobile station preferably transmits the first bursts using the normal timing advance, the next bursts using a second timing advance, the corresponding timing advance parameter value being the normal timing advance parameter maximum value+1, and the subsequent bursts using a timing advance of 2×the second timing advance, etc.