摘要:
For processing samples of a signal received via a channel represented by an impulse response of W−1 coefficients, the method comprises: determining the W roots of the Z-transform of the channel impulse response; producing an intermediate signal by equalizing the received signal by a zero-forcing method or the like based on an impulse response whose Z-transform is a Z−1 polynomial of degree W-p having as roots those of the W roots which are furthest from the unit circle of the complex plane; and then obtaining estimations of the transmitted signal symbols by applying a Viterbi-type equalization method or the like based on an impulse response whose Z-transform is a Z−1 polynomial of degree p having as roots those of the W roots which are nearest to the unit circle.
摘要:
A method is provided for processing a signal emanating from a multi-path transmission medium. A number L of echoes of the signal received are detected, with L being greater than the number N of fingers of a “Rake” receiver, and there are selected N echoes from among the L echoes that are detected. At least some of the L echoes that are detected are echoes temporally correlated according to a determined correlation criterion. The selection step includes determining, as a function of the initial complex amplitudes associated with at least the temporally correlated echoes, weighted individual energies corresponding respectively to temporally decorrelated virtual echoes, and selecting from among the L echoes of N echoes as a function of a determined power criterion using at least the weighted individual energies.
摘要:
First estimations of the fading coefficients of a multi-path transmission channel are carried out in the sense of maximum likelihood. Sets of Wiener filter coefficients are stored according to predetermined speeds of movement of the mobile terminal and predetermined power levels of the signal. The real speed of the mobile terminal is estimated and the power of the signal for each path is measured. From this, a set of Wiener filter coefficients is derived with which the first estimations are filtered to obtain the final estimation of the fading coefficients.
摘要:
A method for estimating the impulse response of an information transmission channel includes evaluating a useful number of coefficients of an impulse response of the information transmission channel as a function of actual characteristics of the information transmission channel. This evaluation is carried out, for example, by using a time domain spreading parameter of the channel.
摘要:
A method is provided for processing a signal emanating from a multi-path transmission medium. Echoes of the signal that is received are detected, and a rejection processing is performed. The rejection processing includes estimating the cross-correlation between temporally neighboring echoes, and if this cross-correlation satisfies a test, rejecting the one of the two neighboring echoes that exhibits the lower energy. Also provided is a rake receiver that can perform such a method.
摘要:
A method is provided for processing a signal emanating from a multi-path transmission medium. A number L of echoes of the signal received are detected, with L being greater than the number N of fingers of a “Rake” receiver, and there are selected N echoes from among the L echoes that are detected. At least some of the L echoes that are detected are echoes temporally correlated according to a determined correlation criterion. The selection step includes determining, as a function of the initial complex amplitudes associated with at least the temporally correlated echoes, weighted individual energies corresponding respectively to temporally decorrelated virtual echoes, and selecting from among the L echoes of N echoes as a function of a determined power criterion using at least the weighted individual energies.
摘要:
A method is provided for processing a signal emanating from a multi-path transmission medium. Echoes of the signal that is received are detected, and a rejection processing is performed. The rejection processing includes estimating the cross-correlation between temporally neighboring echoes, and if this cross-correlation satisfies a test, rejecting the one of the two neighboring echoes that exhibits the lower energy. Also provided is a rake receiver that can perform such a method.
摘要:
A process for estimating a speed of movement of a mobile terminal operating in a wireless communication system and communicating with a base station via a transmission channel includes estimating fading of the transmission channel, and performing an autocorrelation on the fading for providing a first autocorrelation result. Reference autocorrelation results are calculated for predetermined values of speed of movement of the mobile terminal, with the calculating being based upon a known autocorrelation function performed on the fading. The process further includes comparing the first autocorrelation result to the various reference autocorrelation results, and estimating the speed of movement of the mobile terminal based upon the comparison.
摘要:
A device includes a receiver including an estimation block for estimating the impulse response of the transmission channel and a transformation block. The transformation block may include a preprocessing block for determining a phase minimum transformed impulse response corresponding to a transformed channel based upon the estimated impulse response of the transmission channel, and a filter for filtering the signal received. This makes it possible to retain equality between the autocorrelation of the signal received and the autocorrelation of the filtered signal. Further, the receiver may include an equalizer for applying an equalization processing operation to the filtered signal while taking account of the transformed impulse response.