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.

Abstract: A method for synchronizing a multi-mode base station using one clock, when the systems to be synchronized are a GSM-type telecommunications system, for instance a GSM or EDGE system, and a WCDMA-type telecommunications system. In the method, the clock of the WCDMA-type system or a multiple thereof is selected as the system clock of the multi-mode base station, the system clock of the GSM-type system is implemented using multiples of the frequency of the selected clock, and the frame structure of the GSM-type system is synchronized at intervals of thirteen frames or a multiple of thirteen frames.

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.

Abstract: Solutions for receiving and transmitting variable transmission bandwidth signal are provided. A receiver comprises square-root raised cosine filter bank, each filter of the filter bank configured to filter a subband, and an adder configured to add up the output signals of one or more filters of the filter bank to obtain a sum signal, the sum of the subbands of the one or more filters being equal to the transmission bandwidth of the received signal. A transmitter comprises a transmission filter, the roll-off factor of the transmission filter being selected on the basis of the bandwidth of the signal to be transmitted.

Abstract: The invention relates to a method of estimating a noise and interference covariance matrix and to a receiver. The method comprises: estimating an initial noise and interference covariance matrix on the basis of a received signal; reducing the impact of the background noise of the receiver from the initial noise and interference covariance matrix for obtaining a residual matrix; accepting the obtained residual matrix when the residual matrix is at least approximately positive semidefinite; modifying the obtained residual matrix such that the positive semidefinity of the residual matrix is achieved when the residual matrix is not at least approximately positive semidefinite; and adding the impact of background noise back to the residual matrix for estimating a final noise and interference covariance matrix.

Abstract: The invention relates to uplink communication in a GSM/EDGE telecommunication system. In the method according to the invention, at least one wide-band carrier wave in the group of carrier waves is generated in the mobile station by applying linear modulation at a second modulation symbol rate, the second modulation symbol rate being a multiple of the first modulation symbol rate, while preserving the predefined carrier spacing and allowing the at least one wide-band carrier wave to overlap with at least one adjacent carrier wave.

Abstract: A transmitter clips a transmission signal before transmission in order to reduce the strength of at least one peak of the transmission signal exceeding a predetermined threshold. The transmitter includes a clipper having a minimizer, a filter and an adder. The minimizer minimizes of a cost function with respect to an optimization signal, the cost function having weighted terms as a function of the optimization signal. The terms relate to an effective modulation distortion and an effective overshoot exceeding the predetermined threshold. The filter forms a clipping signal by filtering the optimization signal formed as a result of the minimization according to the spectrum emission mask requirements of the radio system. The adder subtracts the clipping signal from the transmission signal.

Abstract: The invention relates to a data transmission system between two transceivers, including: dividing the symbols to be transmitted into blocks, the number of which is divisible by the number of transmitting antennas; transmitting one block using each antenna; receiving the blocks using one or more antennas; checking whether the blocks were received successfully; and, if the reception of the blocks failed, storing the received blocks in memory; retransmitting the same blocks in a predetermined format; receiving the retransmitted blocks and combining them with the blocks in memory, the predetermined format being selected in the method so that the blocks transmitted first and the retransmitted blocks form space-time block coding.

Abstract: A system and method for estimating Doppler shift compensation in a mobile communication system is described. A channel impulse response determination circuit determines a channel impulse response for the channel on which the signal is received. A reference vector is generated using a set of known symbols and the channel impulse response, and an error vector is then generated by comparing the reference vector with received samples of the signal. In addition, the noise variance of the incoming signal can be determined. Then, a Doppler correction factor is estimated having a real part representing amplitude correction and an imaginary part representing phase correction.

Abstract: A method for carrying out channel equalization in a radio receiver wherein an impulse response is estimated, noise power is determined by estimating a co-variance matrix of the noise contained in a received signal before prefiltering, and tap coefficients of prefilters and an equalizer are calculated. The method comprises determining the noise power after prefiltering by estimating a noise covariance matrix, after which input signals of the channel equalizer are weighted by weighting coefficients obtained from the noise covariance estimation.

Abstract: A method, a computer program and a system for allocating radio resources are provided for a TDMA cellular telecommunications system which applies spatial diversity and cell-specific radio frequency bands. The system for allocating the radio resources includes a frequency allocating network element for allocating radio frequency bands to at least two radio cells located within a reuse distance from each other, at least one overlap region being formed between the radio frequency bands, the at least one overlap region being reserved for a simultaneous use in the same transmission direction of the at least two radio cells. The invention provides a frequency reuse capability for radio cells located within a reuse distance from each other.

Abstract: The present invention proposes a method for estimating a signal variance of a received signal (y) transmitted via a transmission channel, said method comprising the steps of: estimating the energy (RSSI) of the received signal (y), estimating the energy (Emax) of channel impulse response (h) taps, and estimating said signal variance (VAR) of said received signal by subtracting said estimated energy of channel impulse response taps (Emax) from said estimated energy (RSSI) of said received signal, such that said signal variance is obtained as VAR=RSSI?Emax. The present invention also proposes a correspondingly adapted device.

Abstract: A method for limiting a signal in a radio transmitter comprises giving (302) a signal a limiting threshold, taking (304) at least two samples from the signal for obtaining sample values, adding (306) one or more sample values between the obtained first and at least one subsequent sample values, searching (308) for sample values exceeding the limiting threshold, and if at least one sample value exceeding the limiting threshold is found determining (310) limiting coefficients or reducing coefficients for a predetermined number of sample values by means of the at least one sample value exceeding the limiting threshold, and limiting (312) the signal by one or more determined coefficients.

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 equalisation circuitry of a wireless network element.

Abstract: A method of reducing the peak-to-mean ratio of a multi-carrier signal includes the steps of: generating a residual signal from the multicarrier signal, the residual signal representing the difference between the multicarrier signal and a hard-clipped multicarrier signal. The method also includes the steps of applying a least squares function to the residual signal for each carrier of the multi-carrier signal, thereby generating a minimized residual signal for each carrier and combining the minimized residual signals and the multicarrier signal.

Abstract: The present invention proposes a device (1) for processing received signals transmitted via a transmission channel (4), said device comprising obtaining means (2a) adapted to obtain an estimated response function (h+e) of said transmission channel (4), based on said received signals (y); deriving means (2b) adapted to derive and estimated variance (&dgr;2) of said received signals (y); and modifying means (2c) adapted to modify said estimated response function (h+e) by applying said estimated variance (&dgr;2) to said estimated response function (h+e), thereby obtaining a modified impulse response (h). The present invention also proposes a corresponding method.

Abstract: The present invention proposes a device for processing received signals (y) having been transmitted via a transmission channel (1), comprising: estimation means (2, 2a) adapted to obtain an estimated impulse response function (hk) of said channel (1) based on said received signals (y) which are received at a first time; derivation means (3; 3a-3f) adapted to derive history information (wink) based on at least one previously estimated impulse response function, calculation means (4; 4a, 4b) adapted to calculate modifying information (mwink) on the basis of said history information (wink), and modification means (5) adapted to modify said estimated impulse response function (hk) of said channel (1) obtained on the basis of said received signals (y), by applying said modifying information (mwink) to said estimated impulse response function (hk) of said channel obtained on the basis of said received signals (y), and adapted to output a modified impulse response function (hmk).

Abstract: The invention relates to a multiplexing method and a transceiver used in a TDMA radio system. The transceiver sets up a connection to another transceiver by transmitting modulated signals in time slots. The transceiver comprises coding means for channel-coding a signal that consists of bits and that is formed into a communication signal, and interleaving means for interleaving the bits of the channel-coded Signal into blocks of a predetermined size. The transceiver also comprises multiplexing means that receive blocks from the interleaving means and that multiplex the interleaved blocks of at least two channel-coded signals together. The transceiver further comprises modulation means for modulating the blocks multiplexed by the multiplexing means with at least four-level modulation before the modulated signal blocks are transmitted as a communication signal in a time slot, so that the transmission speed of the communication signal and the number of the connections to be established can be increased.

Abstract: A method for synchronizing a multi-mode base station using one clock, when the systems to be synchronized are a GSM-type telecommunications system, for instance a GSM or EDGE system, and a WCDMA-type telecommunications system. In the method, the clock of the WCDMA-type system or a multiple thereof is selected as the system clock of the multi-mode base station, the system clock of the GSM-type system is implemented using multiples of the frequency of the selected clock, and the frame structure of the GSM-type system is synchronized at intervals of thirteen frames or a multiple of thirteen frames.

Abstract: The invention relates to a method for determining connection quality, and a receiver in a radio system, the receiver comprising means for decoding a received signal by the Viterbi method by means of a trellis diagram comprising a group of state points, and means for calculating state transition values for the two possible transitions in each point of the diagram. To determine advantageously the quality of the connection between a transmitter and the receiver, the inventive receiver comprises means for calculating, in each column of the trellis diagram, the maximum values for both the transitions of the points in the column, for determining the absolute value of the difference of the calculated maximum values, and means for estimating connection quality by utilizing said absolute value.