Apparatus and method for equalizing a signal independent of the impact of doppler frequency
AssigneeLucent Technologies Inc.
InventorMarkus Rupp
Life of this patent
Estimating the term…
Abstract
A method and apparatus for equalizing a signal to accurately deconvolute the channel includes deriving a functional relationship between Doppler frequency and variance between the instantaneous energy of the received signal and the mean energy of the received signal. Theoretical values of Doppler frequency for a range of values of variance are mapped based on the derived functional relationship. The variance of a received signal is determined and the corresponding Doppler frequency estimate selected from the map. Optimal equalization learning parameters are then selected based on the corresponding Doppler frequency estimate so that the received signal may be deconvoluted independent of the impact of Doppler frequency.
Claims27
A method of equalizing a signal comprising the steps of:
- a) determining mean energy of the signal;
- b) determining a variance between instantaneous energy of the signal and the mean energy of the signal determined in said step a);
- c) generating an estimate of Doppler frequency of the signal based on the variance determined in said step b);
- d) selecting an optimum equalization learning parameter for the signal in accordance with the estimate of Doppler frequency generated in said step c);
- and
- e) equalizing the signal using the optimum equalization learning parameter selected in said step d).
A signal processing apparatus for equalizing a signal comprising:
- first determination means for determining mean energy of the signal;
- second determination means for determining a variance between instantaneous energy of the signal and the mean energy of the signal determined by said first determination means;
- generation means for generating an estimate of Doppler frequency of the signal based on the variance determined by said second determination means;
- selection means for selecting an optimum equalization learning parameter for the signal in accordance with the estimate of Doppler frequency generated by said generating means;
- and
- equalization means for equalizing the signal using the optimum equalization learning parameter selected by said selection means.
A signal processing apparatus for equalizing a signal comprising:
- a controller that determines mean energy of the signal, determines a variance between instantaneous energy of the signal and the mean energy of the signal and provides an estimate of Doppler frequency of the signal based on the variance;
- a memory that stores respective optimum equalization learning parameters for Doppler frequencies;
- and
- an equalizer that equalizes the signal using an optimum equalization learning parameter, said controller selects the optimum equalization learning parameter for the signal from said memory based on the estimate of Doppler frequency.
An article of manufacture taking the form of a computer-readable medium for equalizing a signal, the article of manufacture comprising:
- a first determination source code segment for causing a computer to determine mean energy of the signal;
- a second determination source code segment for causing the computer to determine a variance between instantaneous energy of the signal and the mean energy of the signal;
- a generation source code segment for causing the computer to generate an estimate of Doppler frequency of the signal based on the variance;
- a selection source code segment for causing the computer to select an optimum equalization learning parameter for the signal in accordance with the estimate of Doppler frequency;
- and
- an equalization source code segment for causing the computer to equalize the signal using the optimum equalization learning parameter selected for the signal.
Dependencies are inferred from the claim text.