Abstract:
The invention relates to a method for estimating an impulse response, and a receiver whose received signal is formed of bursts comprising a training sequence and the receiver comprising analog-to-digital converter for sampling the received signal and signal processor for measuring a DC offset in the samples. To simplify the receiver structure, the receiver comprises a calculating device for calculating the impulse response by correlating the samples taken with the training sequence before removing the DC offset, and the signal processor for removing the DC offset effect from the calculated impulse response.
Abstract:
The invention relates to a data transmission method and a radio system implementing method. A transmitter has at least two modulation methods by which it can modulate a signal. One or more demodulators (106) of the receiver demodulates the received signal in a manner which corresponds to each modulation method used. The modulation method used for the signal is inferred in a reference block (110) from the impulse response estimate. The signal according to the inferred modulation method is detected in a detector (114).
Abstract:
An apparatus includes a radio frequency receiver and a timing adjustment unit that contains at least two channel impulse response estimators. The at least two channel impulse response estimators include an on-time estimator and at least one of an early estimator and a late estimator. The apparatus also includes a calculation unit that is configurable to obtain a channel estimate for each measured channel impulse response and to average obtained channel estimates over a plurality of received signal events to determine a timing adjustment in accordance with residual signal power.
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.
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.
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.
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:
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:
The invention relates to a method and arrangement for connecting a processor to an ASIC. In the arrangement, the processor generates control signals employed when the processor reads data from and writes data to the ASIC. The arrangement comprises means (10) for receiving control signals from the processor and generating read and write signals on the basis of the received signals. The means (10) are implemented by an asynchronous state machine that changes its state on the basis of the received signals. The means (10) change their state without a synchronizing clock signal.
Abstract:
The invention relates to a reception method and a receiver. Mechanisms are used for generating, at each level, numbers relating to a bit 1 and a bit 2 and representing a probability of a transition metric of survivor paths. Mechanisms are used for separately summing the numbers relating to the bit 1 and the bit 0 of more than one state and representing the probability of the transition metric. Mechanisms are used for generating logarithms of the sums and means for generating a difference of the logic numbers relating to the bit 1 and the bit 0 representing the probability of the transition metric, whereby a received bit can be determined without a correct path tracing phase.